Merge remote-tracking branch 'origin/dev' into wip/pointerhandler

Change-Id: Ie2894830470a69827d4ace3d8af9bee971e3fbd4

289 files changed, 6727 insertions, 3721 deletions

diff --git a/.gitmodules b/.gitmodules
index 881629497e..c9561f396d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,4 +1,3 @@
-[submodule "tests/manual/v4/test262"]
-	path = tests/manual/v4/test262
+[submodule "tests/auto/qml/ecmascripttests/test262"]
+	path = tests/auto/qml/ecmascripttests/test262
 	url = ../qtdeclarative-testsuites.git
-	update = none
diff --git a/examples/qml/doc/src/qml-extending.qdoc b/examples/qml/doc/src/qml-extending.qdoc
index b4174426a8..f99aca5457 100644
--- a/examples/qml/doc/src/qml-extending.qdoc
+++ b/examples/qml/doc/src/qml-extending.qdoc
@@ -73,24 +73,24 @@ This example builds on:
 \li \l {Extending QML - Adding Types Example}
 \endlist
 
-Shows how to use \l {QQmlEngine::}{qmlRegisterExtendedType()} to provide an \l {Registering
-Extension Objects}{extension object} to a \l QLineEdit without modifying or
-subclassing.
+Shows how to use \l {QQmlEngine::}{qmlRegisterExtendedType()} to provide an
+\l {Registering Extension Objects}{extension object} to a \l QLineEdit without modifying or
+subclassing it.
+
+Firstly, the LineEditExtension class is registered with the QML system as an extension of QLineEdit:
 
 \snippet referenceexamples/extended/main.cpp 0
 
-The QML engine instantiates a \l QLineEdit
+The QML engine then instantiates a \l QLineEdit:
 
 \snippet referenceexamples/extended/main.cpp 1
 
-and sets a property that oly exists on the extension type.
+In QML, a property is set on the line edit that only exists in the LineEditExtension class:
 
 \snippet referenceexamples/extended/example.qml 0
 
-The QML engine instantiates a \l QLineEdit and sets a property that
-only exists on the extension type. The extension type performs calls on the
-\l QLineEdit that otherwise will not be accessible to the QML engine.
-
+The extension type performs calls on the \l QLineEdit that otherwise will
+not be accessible to the QML engine.
 */
 
 /*!
diff --git a/examples/qml/referenceexamples/properties/birthdayparty.cpp b/examples/qml/referenceexamples/properties/birthdayparty.cpp
index b69b7c8a11..0b426fc00b 100644
--- a/examples/qml/referenceexamples/properties/birthdayparty.cpp
+++ b/examples/qml/referenceexamples/properties/birthdayparty.cpp
@@ -57,9 +57,18 @@ void BirthdayParty::setHost(Person *c)
 
 QQmlListProperty<Person> BirthdayParty::guests()
 {
-    return QQmlListProperty<Person>(this, m_guests);
+    return QQmlListProperty<Person>(this, this,
+             &BirthdayParty::appendGuest,
+             &BirthdayParty::guestCount,
+             &BirthdayParty::guest,
+             &BirthdayParty::clearGuests);
 }
 
+void BirthdayParty::appendGuest(Person* p) {
+    m_guests.append(p);
+}
+
+
 int BirthdayParty::guestCount() const
 {
     return m_guests.count();
@@ -69,5 +78,25 @@ Person *BirthdayParty::guest(int index) const
 {
     return m_guests.at(index);
 }
+
+void BirthdayParty::clearGuests() {
+    return m_guests.clear();
+}
+
 // ![0]
 
+void BirthdayParty::appendGuest(QQmlListProperty<Person>* list, Person* p) {
+    reinterpret_cast< BirthdayParty* >(list->data)->appendGuest(p);
+}
+
+void BirthdayParty::clearGuests(QQmlListProperty<Person>* list) {
+    reinterpret_cast< BirthdayParty* >(list->data)->clearGuests();
+}
+
+Person* BirthdayParty::guest(QQmlListProperty<Person>* list, int i) {
+    return reinterpret_cast< BirthdayParty* >(list->data)->guest(i);
+}
+
+int BirthdayParty::guestCount(QQmlListProperty<Person>* list) {
+    return reinterpret_cast< BirthdayParty* >(list->data)->guestCount();
+}
diff --git a/examples/qml/referenceexamples/properties/birthdayparty.h b/examples/qml/referenceexamples/properties/birthdayparty.h
index d0a2cad285..df55df3e80 100644
--- a/examples/qml/referenceexamples/properties/birthdayparty.h
+++ b/examples/qml/referenceexamples/properties/birthdayparty.h
@@ -41,6 +41,7 @@
 #define BIRTHDAYPARTY_H
 
 #include <QObject>
+#include <QVector>
 #include <QQmlListProperty>
 #include "person.h"
 
@@ -63,12 +64,19 @@ public:
     void setHost(Person *);
 
     QQmlListProperty<Person> guests();
+    void appendGuest(Person*);
     int guestCount() const;
     Person *guest(int) const;
+    void clearGuests();
 
 private:
+    static void appendGuest(QQmlListProperty<Person>*, Person*);
+    static int guestCount(QQmlListProperty<Person>*);
+    static Person* guest(QQmlListProperty<Person>*, int);
+    static void clearGuests(QQmlListProperty<Person>*);
+
     Person *m_host;
-    QList<Person *> m_guests;
+    QVector<Person *> m_guests;
 };
 // ![3]
 
diff --git a/examples/quick/demos/demos.pro b/examples/quick/demos/demos.pro
index 0644b81a22..5a6fd52baf 100644
--- a/examples/quick/demos/demos.pro
+++ b/examples/quick/demos/demos.pro
@@ -7,5 +7,7 @@ SUBDIRS = samegame \
             photosurface \
             stocqt
 
-qtHaveModule(xmlpatterns): SUBDIRS += rssnews photoviewer
-
+qtHaveModule(xmlpatterns) {
+    SUBDIRS += rssnews
+    qtHaveModule(widgets): SUBDIRS += photoviewer
+}
diff --git a/examples/quick/demos/stocqt/content/StockListModel.qml b/examples/quick/demos/stocqt/content/StockListModel.qml
index 9b48124bda..02ece32a49 100644
--- a/examples/quick/demos/stocqt/content/StockListModel.qml
+++ b/examples/quick/demos/stocqt/content/StockListModel.qml
@@ -82,27 +82,28 @@ ListModel {
         xhr.onreadystatechange = function() {
             if (xhr.readyState === XMLHttpRequest.LOADING || xhr.readyState === XMLHttpRequest.DONE) {
                 var records = xhr.responseText.split('\n');
+                var unknown = "n/a";
+                set(index, {"value": unknown, "change": unknown, "changePercentage": unknown});
                 if (records.length > 0 && xhr.status == 200) {
                     var r = records[1].split(',');
                     var today = parseFloat(r[4]);
-                    setProperty(index, "value", today.toFixed(2));
+                    if (!isNaN(today))
+                        setProperty(index, "value", today.toFixed(2));
+                    if (records.length > 2) {
+                        r = records[2].split(',');
+                        var yesterday = parseFloat(r[4]);
+                        var change = today - yesterday;
+                        if (change >= 0.0)
+                            setProperty(index, "change", "+" + change.toFixed(2));
+                        else
+                            setProperty(index, "change", change.toFixed(2));
 
-                    r = records[2].split(',');
-                    var yesterday = parseFloat(r[4]);
-                    var change = today - yesterday;
-                    if (change >= 0.0)
-                        setProperty(index, "change", "+" + change.toFixed(2));
-                    else
-                        setProperty(index, "change", change.toFixed(2));
-
-                    var changePercentage = (change / yesterday) * 100.0;
-                    if (changePercentage >= 0.0)
-                        setProperty(index, "changePercentage", "+" + changePercentage.toFixed(2) + "%");
-                    else
-                        setProperty(index, "changePercentage", changePercentage.toFixed(2) + "%");
-                } else {
-                    var unknown = "n/a";
-                    set(index, {"value": unknown, "change": unknown, "changePercentage": unknown});
+                        var changePercentage = (change / yesterday) * 100.0;
+                        if (changePercentage >= 0.0)
+                            setProperty(index, "changePercentage", "+" + changePercentage.toFixed(2) + "%");
+                        else
+                            setProperty(index, "changePercentage", changePercentage.toFixed(2) + "%");
+                    }
                 }
             }
         }
diff --git a/examples/quick/rendercontrol/window_singlethreaded.cpp b/examples/quick/rendercontrol/window_singlethreaded.cpp
index ef8f2fed43..bd4de9a7cb 100644
--- a/examples/quick/rendercontrol/window_singlethreaded.cpp
+++ b/examples/quick/rendercontrol/window_singlethreaded.cpp
@@ -82,6 +82,10 @@ WindowSingleThreaded::WindowSingleThreaded()
 {
     setSurfaceType(QSurface::OpenGLSurface);
 
+    // The rendercontrol does not necessarily need an FBO. Demonstrate this
+    // when requested.
+    m_onscreen = QCoreApplication::arguments().contains(QStringLiteral("--onscreen"));
+
     QSurfaceFormat format;
     // Qt Quick may need a depth and stencil buffer. Always make sure these are available.
     format.setDepthBufferSize(16);
@@ -164,8 +168,14 @@ void WindowSingleThreaded::createFbo()
     // The scene graph has been initialized. It is now time to create an FBO and associate
     // it with the QQuickWindow.
     m_dpr = devicePixelRatio();
-    m_fbo = new QOpenGLFramebufferObject(size() * m_dpr, QOpenGLFramebufferObject::CombinedDepthStencil);
-    m_quickWindow->setRenderTarget(m_fbo);
+    if (!m_onscreen) {
+        m_fbo = new QOpenGLFramebufferObject(size() * m_dpr, QOpenGLFramebufferObject::CombinedDepthStencil);
+        m_quickWindow->setRenderTarget(m_fbo);
+    } else {
+        // Special case: No FBO. Render directly to the window's default framebuffer.
+        m_onscreenSize = size() * m_dpr;
+        m_quickWindow->setRenderTarget(0, m_onscreenSize);
+    }
 }
 
 void WindowSingleThreaded::destroyFbo()
@@ -176,7 +186,10 @@ void WindowSingleThreaded::destroyFbo()
 
 void WindowSingleThreaded::render()
 {
-    if (!m_context->makeCurrent(m_offscreenSurface))
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    if (!m_context->makeCurrent(surface))
         return;
 
     // Polish, synchronize and render the next frame (into our fbo).  In this example
@@ -195,7 +208,10 @@ void WindowSingleThreaded::render()
     m_quickReady = true;
 
     // Get something onto the screen.
-    m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+    if (!m_onscreen)
+        m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+    else
+        m_context->swapBuffers(this);
 }
 
 void WindowSingleThreaded::requestUpdate()
@@ -237,7 +253,10 @@ void WindowSingleThreaded::run()
     updateSizes();
 
     // Initialize the render control and our OpenGL resources.
-    m_context->makeCurrent(m_offscreenSurface);
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    m_context->makeCurrent(surface);
     m_renderControl->initialize(m_context);
     m_quickInitialized = true;
 }
@@ -266,7 +285,8 @@ void WindowSingleThreaded::exposeEvent(QExposeEvent *)
 {
     if (isExposed()) {
         if (!m_quickInitialized) {
-            m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+            if (!m_onscreen)
+                m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
             startQuick(QStringLiteral("qrc:/rendercontrol/demo.qml"));
         }
     }
@@ -274,7 +294,10 @@ void WindowSingleThreaded::exposeEvent(QExposeEvent *)
 
 void WindowSingleThreaded::resizeFbo()
 {
-    if (m_rootItem && m_context->makeCurrent(m_offscreenSurface)) {
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    if (m_rootItem && m_context->makeCurrent(surface)) {
         delete m_fbo;
         createFbo();
         m_context->doneCurrent();
@@ -287,8 +310,13 @@ void WindowSingleThreaded::resizeEvent(QResizeEvent *)
 {
     // If this is a resize after the scene is up and running, recreate the fbo and the
     // Quick item and scene.
-    if (m_fbo && m_fbo->size() != size() * devicePixelRatio())
-        resizeFbo();
+    if (!m_onscreen) {
+        if (m_fbo && m_fbo->size() != size() * devicePixelRatio())
+            resizeFbo();
+    } else {
+        if (m_onscreenSize != size() * devicePixelRatio())
+            resizeFbo();
+    }
 }
 
 void WindowSingleThreaded::handleScreenChange()
diff --git a/examples/quick/rendercontrol/window_singlethreaded.h b/examples/quick/rendercontrol/window_singlethreaded.h
index 534d6b9bc3..4736f036ad 100644
--- a/examples/quick/rendercontrol/window_singlethreaded.h
+++ b/examples/quick/rendercontrol/window_singlethreaded.h
@@ -97,6 +97,8 @@ private:
     QTimer m_updateTimer;
     CubeRenderer *m_cubeRenderer;
     qreal m_dpr;
+    bool m_onscreen;
+    QSize m_onscreenSize;
 };
 
 #endif
diff --git a/src/3rdparty/masm/assembler/MacroAssembler.h b/src/3rdparty/masm/assembler/MacroAssembler.h
index 7d9f156c8c..f37861eb66 100644
--- a/src/3rdparty/masm/assembler/MacroAssembler.h
+++ b/src/3rdparty/masm/assembler/MacroAssembler.h
@@ -94,6 +94,7 @@ public:
     using DataLabelCompact = typename MacroAssemblerBase::DataLabelCompact;
     using Jump = typename MacroAssemblerBase::Jump;
     using PatchableJump = typename MacroAssemblerBase::PatchableJump;
+    using MacroAssemblerBase::PointerSize;
 
     using MacroAssemblerBase::pop;
     using MacroAssemblerBase::jump;
@@ -200,19 +201,19 @@ public:
     // described in terms of other macro assembly methods.
     void pop()
     {
-        addPtr(TrustedImm32(sizeof(void*)), MacroAssemblerBase::stackPointerRegister);
+        addPtr(TrustedImm32(PointerSize), MacroAssemblerBase::stackPointerRegister);
     }
     
     void peek(RegisterID dest, int index = 0)
     {
-        loadPtr(Address(MacroAssemblerBase::stackPointerRegister, (index * sizeof(void*))), dest);
+        loadPtr(Address(MacroAssemblerBase::stackPointerRegister, (index * PointerSize)), dest);
     }
 
     Address addressForPoke(int index)
     {
-        return Address(MacroAssemblerBase::stackPointerRegister, (index * sizeof(void*)));
+        return Address(MacroAssemblerBase::stackPointerRegister, (index * PointerSize));
     }
-    
+
     void poke(RegisterID src, int index = 0)
     {
         storePtr(src, addressForPoke(index));
@@ -223,10 +224,12 @@ public:
         store32(value, addressForPoke(index));
     }
 
+#if !defined(V4_BOOTSTRAP)
     void poke(TrustedImmPtr imm, int index = 0)
     {
         storePtr(imm, addressForPoke(index));
     }
+#endif
 
 #if (CPU(X86_64) || CPU(ARM64)) && !defined(V4_BOOTSTRAP)
     void peek64(RegisterID dest, int index = 0)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerARM64.h b/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
index a11637f7ca..11f1672e15 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
@@ -127,6 +127,8 @@ private:
     static const ptrdiff_t REPATCH_OFFSET_CALL_TO_POINTER = -16;
     
 public:
+    static const int PointerSize = 8;
+
     MacroAssemblerARM64()
         : m_dataMemoryTempRegister(this, dataTempRegister)
         , m_cachedMemoryTempRegister(this, memoryTempRegister)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h b/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
index 806f2e13b6..fe8170d098 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
@@ -46,6 +46,8 @@ protected: // the YarrJIT needs know about addressTempRegister in order to push
     inline ARMRegisters::FPSingleRegisterID fpTempRegisterAsSingle() { return ARMRegisters::asSingle(fpTempRegister); }
 
 public:
+    static const int PointerSize = 4;
+
     MacroAssemblerARMv7()
         : m_makeJumpPatchable(false)
     {
@@ -1242,7 +1244,7 @@ public:
     void pop(RegisterID dest)
     {
         // store postindexed with writeback
-        m_assembler.ldr(dest, ARMRegisters::sp, sizeof(void*), false, true);
+        m_assembler.ldr(dest, ARMRegisters::sp, 4 /*sizeof(void*)*/, false, true);
     }
 
     void push(RegisterID src)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h b/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
index 68584527fc..f2ad6a4470 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
@@ -37,6 +37,7 @@ namespace JSC {
 class MacroAssemblerMIPS : public AbstractMacroAssembler<MIPSAssembler> {
 public:
     typedef MIPSRegisters::FPRegisterID FPRegisterID;
+    static const int PointerSize = 4;
 
     MacroAssemblerMIPS()
         : m_fixedWidth(false)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerX86.h b/src/3rdparty/masm/assembler/MacroAssemblerX86.h
index 742a4b48f7..280cf427fc 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerX86.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerX86.h
@@ -35,6 +35,7 @@ namespace JSC {
 class MacroAssemblerX86 : public MacroAssemblerX86Common {
 public:
     static const Scale ScalePtr = TimesFour;
+    static const int PointerSize = 4;
 
     using MacroAssemblerX86Common::add32;
     using MacroAssemblerX86Common::and32;
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h b/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
index 3566702413..c7c6aae637 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
@@ -37,6 +37,7 @@ namespace JSC {
 class MacroAssemblerX86_64 : public MacroAssemblerX86Common {
 public:
     static const Scale ScalePtr = TimesEight;
+    static const int PointerSize = 8;
 
     using MacroAssemblerX86Common::add32;
     using MacroAssemblerX86Common::and32;
@@ -327,14 +328,61 @@ public:
         m_assembler.xorq_ir(imm.m_value, srcDest);
     }
 
+    void lshift64(TrustedImm32 imm, RegisterID dest)
+    {
+        m_assembler.shlq_i8r(imm.m_value, dest);
+    }
+
+    void lshift64(RegisterID src, RegisterID dest)
+    {
+        if (src == X86Registers::ecx)
+            m_assembler.shlq_CLr(dest);
+        else {
+            ASSERT(src != dest);
+
+            // Can only shift by ecx, so we do some swapping if we see anything else.
+            swap(src, X86Registers::ecx);
+            m_assembler.shlq_CLr(dest == X86Registers::ecx ? src : dest);
+            swap(src, X86Registers::ecx);
+        }
+    }
+
+    void rshift64(TrustedImm32 imm, RegisterID dest)
+    {
+        m_assembler.sarq_i8r(imm.m_value, dest);
+    }
+
+    void rshift64(RegisterID src, RegisterID dest)
+    {
+        if (src == X86Registers::ecx)
+            m_assembler.sarq_CLr(dest);
+        else {
+            ASSERT(src != dest);
+
+            // Can only shift by ecx, so we do some swapping if we see anything else.
+            swap(src, X86Registers::ecx);
+            m_assembler.sarq_CLr(dest == X86Registers::ecx ? src : dest);
+            swap(src, X86Registers::ecx);
+        }
+    }
+
     void urshift64(TrustedImm32 imm, RegisterID dest)
     {
         m_assembler.shrq_i8r(imm.m_value, dest);
     }
 
-    void lshift64(TrustedImm32 imm, RegisterID dest)
+    void urshift64(RegisterID src, RegisterID dest)
     {
-        m_assembler.shlq_i8r(imm.m_value, dest);
+        if (src == X86Registers::ecx)
+            m_assembler.shrq_CLr(dest);
+        else {
+            ASSERT(src != dest);
+
+            // Can only shift by ecx, so we do some swapping if we see anything else.
+            swap(src, X86Registers::ecx);
+            m_assembler.shrq_CLr(dest == X86Registers::ecx ? src : dest);
+            swap(src, X86Registers::ecx);
+        }
     }
 
     void load64(ImplicitAddress address, RegisterID dest)
diff --git a/src/3rdparty/masm/assembler/X86Assembler.h b/src/3rdparty/masm/assembler/X86Assembler.h
index 24462ef38f..b71cf290f8 100644
--- a/src/3rdparty/masm/assembler/X86Assembler.h
+++ b/src/3rdparty/masm/assembler/X86Assembler.h
@@ -253,6 +253,7 @@ public:
     {
     }
 
+#if defined(V4_BOOTSTRAP)
     template <typename LabelType>
     class Jump {
         template<class TemplateAssemblerType>
@@ -291,6 +292,7 @@ public:
     private:
         AssemblerLabel m_label;
     };
+#endif
 
     // Stack operations:
 
@@ -723,6 +725,21 @@ public:
         }
     }
 
+    void sarq_CLr(RegisterID dst)
+    {
+        m_formatter.oneByteOp64(OP_GROUP2_EvCL, GROUP2_OP_SAR, dst);
+    }
+
+    void sarq_i8r(int imm, RegisterID dst)
+    {
+        if (imm == 1)
+            m_formatter.oneByteOp64(OP_GROUP2_Ev1, GROUP2_OP_SAR, dst);
+        else {
+            m_formatter.oneByteOp64(OP_GROUP2_EvIb, GROUP2_OP_SAR, dst);
+            m_formatter.immediate8(imm);
+        }
+    }
+
     void shrq_i8r(int imm, RegisterID dst)
     {
         // ### doesn't work when removing the "0 &&"
@@ -734,6 +751,11 @@ public:
         }
     }
 
+    void shrq_CLr(RegisterID dst)
+    {
+        m_formatter.oneByteOp64(OP_GROUP2_EvCL, GROUP2_OP_SHR, dst);
+    }
+
     void shlq_i8r(int imm, RegisterID dst)
     {
         // ### doesn't work when removing the "0 &&"
@@ -745,7 +767,10 @@ public:
         }
     }
 
-
+    void shlq_CLr(RegisterID dst)
+    {
+        m_formatter.oneByteOp64(OP_GROUP2_EvCL, GROUP2_OP_SHL, dst);
+    }
 #endif
 
     void sarl_i8r(int imm, RegisterID dst)
@@ -793,23 +818,6 @@ public:
         m_formatter.oneByteOp(OP_GROUP2_EvCL, GROUP2_OP_SHL, dst);
     }
 
-#if CPU(X86_64)
-    void sarq_CLr(RegisterID dst)
-    {
-        m_formatter.oneByteOp64(OP_GROUP2_EvCL, GROUP2_OP_SAR, dst);
-    }
-
-    void sarq_i8r(int imm, RegisterID dst)
-    {
-        if (imm == 1)
-            m_formatter.oneByteOp64(OP_GROUP2_Ev1, GROUP2_OP_SAR, dst);
-        else {
-            m_formatter.oneByteOp64(OP_GROUP2_EvIb, GROUP2_OP_SAR, dst);
-            m_formatter.immediate8(imm);
-        }
-    }
-#endif
-
     void imull_rr(RegisterID src, RegisterID dst)
     {
         m_formatter.twoByteOp(OP2_IMUL_GvEv, dst, src);
diff --git a/src/3rdparty/masm/masm-defs.pri b/src/3rdparty/masm/masm-defs.pri
index fa0d3d3c55..c0c5f3d114 100644
--- a/src/3rdparty/masm/masm-defs.pri
+++ b/src/3rdparty/masm/masm-defs.pri
@@ -40,3 +40,10 @@ INCLUDEPATH += $$PWD/disassembler/udis86
 INCLUDEPATH += $$_OUT_PWD
 
 CONFIG(release, debug|release): DEFINES += NDEBUG
+
+!intel_icc:!clang:gcc {
+    greaterThan(QT_GCC_MAJOR_VERSION, 6) { # GCC 7
+        QMAKE_CXXFLAGS_WARN_ON += -Wno-expansion-to-defined
+        QMAKE_CXXFLAGS += -Wno-expansion-to-defined
+    }
+}
diff --git a/src/3rdparty/masm/wtf/Assertions.h b/src/3rdparty/masm/wtf/Assertions.h
index 6263e50ed9..af65f5325c 100644
--- a/src/3rdparty/masm/wtf/Assertions.h
+++ b/src/3rdparty/masm/wtf/Assertions.h
@@ -233,7 +233,7 @@ WTF_EXPORT_PRIVATE void WTFInstallReportBacktraceOnCrashHook();
 #define ASSERT_NOT_REACHED() ((void)0)
 #define NO_RETURN_DUE_TO_ASSERT
 
-#if COMPILER(INTEL) && !OS(WINDOWS) || COMPILER(RVCT)
+#if COMPILER(RVCT)
 template<typename T>
 inline void assertUnused(T& x) { (void)x; }
 #define ASSERT_UNUSED(variable, assertion) (assertUnused(variable))
diff --git a/src/imports/builtins/builtins.qmltypes b/src/imports/builtins/builtins.qmltypes
index 88e3ac6634..ac95a8837b 100644
--- a/src/imports/builtins/builtins.qmltypes
+++ b/src/imports/builtins/builtins.qmltypes
@@ -150,6 +150,25 @@ Module {
             }
         }
         Enum {
+            name: "TextFlag"
+            values: {
+                "TextSingleLine": 256,
+                "TextDontClip": 512,
+                "TextExpandTabs": 1024,
+                "TextShowMnemonic": 2048,
+                "TextWordWrap": 4096,
+                "TextWrapAnywhere": 8192,
+                "TextDontPrint": 16384,
+                "TextIncludeTrailingSpaces": 134217728,
+                "TextHideMnemonic": 32768,
+                "TextJustificationForced": 65536,
+                "TextForceLeftToRight": 131072,
+                "TextForceRightToLeft": 262144,
+                "TextLongestVariant": 524288,
+                "TextBypassShaping": 1048576
+            }
+        }
+        Enum {
             name: "TextElideMode"
             values: {
                 "ElideLeft": 0,
@@ -440,7 +459,8 @@ Module {
                 "AA_SynthesizeMouseForUnhandledTabletEvents": 24,
                 "AA_CompressHighFrequencyEvents": 25,
                 "AA_DontCheckOpenGLContextThreadAffinity": 26,
-                "AA_AttributeCount": 27
+                "AA_DisableShaderDiskCache": 27,
+                "AA_AttributeCount": 28
             }
         }
         Enum {
@@ -1096,7 +1116,8 @@ Module {
                 "SystemLocaleLongDate": 5,
                 "DefaultLocaleShortDate": 6,
                 "DefaultLocaleLongDate": 7,
-                "RFC2822Date": 8
+                "RFC2822Date": 8,
+                "ISODateWithMs": 9
             }
         }
         Enum {
@@ -1607,6 +1628,13 @@ Module {
                 "MouseEventFlagMask": 255
             }
         }
+        Enum {
+            name: "ChecksumType"
+            values: {
+                "ChecksumIso3309": 0,
+                "ChecksumItuV41": 1
+            }
+        }
     }
     Component { name: "QEasingCurve"; prototype: "QQmlEasingValueType" }
 }
diff --git a/src/imports/imports.pro b/src/imports/imports.pro
index 544993c073..71c05c4b89 100644
--- a/src/imports/imports.pro
+++ b/src/imports/imports.pro
@@ -6,9 +6,9 @@ SUBDIRS += \
     builtins \
     qtqml \
     folderlistmodel \
-    localstorage \
     models
 
+qtHaveModule(sql): SUBDIRS += localstorage
 qtConfig(settings): SUBDIRS += settings
 qtConfig(statemachine): SUBDIRS += statemachine
 
@@ -18,10 +18,10 @@ qtHaveModule(quick) {
         layouts \
         qtquick2 \
         window \
-        sharedimage \
         testlib
 
-    qtConfig(quick-sprite):qtConfig(opengl(es1|es2)?): \
+    qtConfig(systemsemaphore): SUBDIRS += sharedimage
+    qtConfig(quick-particles): \
         SUBDIRS += particles
 }
 
diff --git a/src/imports/localstorage/plugin.cpp b/src/imports/localstorage/plugin.cpp
index 8679750842..40682dd6a8 100644
--- a/src/imports/localstorage/plugin.cpp
+++ b/src/imports/localstorage/plugin.cpp
@@ -770,6 +770,8 @@ void QQuickLocalStorage::openDatabaseSync(QQmlV4Function *args)
     }
 
     args->setReturnValue(db.asReturnedValue());
+#else
+    Q_UNUSED(args)
 #endif // settings
 }
 
diff --git a/src/imports/particles/plugins.qmltypes b/src/imports/particles/plugins.qmltypes
index 5c4bd01980..6c7c98cc71 100644
--- a/src/imports/particles/plugins.qmltypes
+++ b/src/imports/particles/plugins.qmltypes
@@ -275,11 +275,11 @@ Module {
             Parameter { name: "arg"; type: "double" }
         }
         Method {
-            name: "setAcceleration"
+            name: "setMagnitude"
             Parameter { name: "arg"; type: "double" }
         }
         Method {
-            name: "setMagnitude"
+            name: "setAcceleration"
             Parameter { name: "arg"; type: "double" }
         }
         Method {
@@ -552,7 +552,7 @@ Module {
             Parameter { name: "arg"; type: "bool" }
         }
         Method {
-            name: "setmirrored"
+            name: "setMirrored"
             Parameter { name: "arg"; type: "bool" }
         }
     }
diff --git a/src/imports/qtquick2/plugins.qmltypes b/src/imports/qtquick2/plugins.qmltypes
index 441cd743aa..a9534b5ccc 100644
--- a/src/imports/qtquick2/plugins.qmltypes
+++ b/src/imports/qtquick2/plugins.qmltypes
@@ -4,7 +4,7 @@ import QtQuick.tooling 1.2
 // It is used for QML tooling purposes only.
 //
 // This file was auto-generated by:
-// 'qmlplugindump -nonrelocatable -noforceqtquick QtQuick 2.8'
+// 'qmlplugindump -nonrelocatable -noforceqtquick QtQuick 2.9'
 
 Module {
     dependencies: []
@@ -440,6 +440,13 @@ Module {
         }
     }
     Component {
+        name: "QPointingDeviceUniqueId"
+        exports: ["QtQuick/PointingDeviceUniqueId 2.9"]
+        isCreatable: false
+        exportMetaObjectRevisions: [0]
+        Property { name: "numericId"; type: "qlonglong"; isReadonly: true }
+    }
+    Component {
         name: "QQmlApplication"
         prototype: "QObject"
         Property { name: "arguments"; type: "QStringList"; isReadonly: true }
@@ -1159,6 +1166,8 @@ Module {
         Property { name: "supportsMultipleWindows"; type: "bool"; isReadonly: true }
         Property { name: "state"; type: "Qt::ApplicationState"; isReadonly: true }
         Property { name: "font"; type: "QFont"; isReadonly: true }
+        Property { name: "displayName"; type: "string" }
+        Property { name: "screens"; type: "QQuickScreenInfo"; isList: true; isReadonly: true }
         Signal {
             name: "stateChanged"
             Parameter { name: "state"; type: "Qt::ApplicationState" }
@@ -1168,9 +1177,13 @@ Module {
         name: "QQuickBasePositioner"
         defaultProperty: "data"
         prototype: "QQuickImplicitSizeItem"
-        exports: ["QtQuick/Positioner 2.0", "QtQuick/Positioner 2.6"]
+        exports: [
+            "QtQuick/Positioner 2.0",
+            "QtQuick/Positioner 2.6",
+            "QtQuick/Positioner 2.9"
+        ]
         isCreatable: false
-        exportMetaObjectRevisions: [0, 6]
+        exportMetaObjectRevisions: [0, 6, 9]
         attachedType: "QQuickPositionerAttached"
         Property { name: "spacing"; type: "double" }
         Property { name: "populate"; type: "QQuickTransition"; isPointer: true }
@@ -1186,6 +1199,8 @@ Module {
         Signal { name: "leftPaddingChanged"; revision: 6 }
         Signal { name: "rightPaddingChanged"; revision: 6 }
         Signal { name: "bottomPaddingChanged"; revision: 6 }
+        Signal { name: "positioningComplete"; revision: 9 }
+        Method { name: "forceLayout"; revision: 9 }
     }
     Component {
         name: "QQuickBehavior"
@@ -1502,8 +1517,8 @@ Module {
         name: "QQuickFlickable"
         defaultProperty: "flickableData"
         prototype: "QQuickItem"
-        exports: ["QtQuick/Flickable 2.0"]
-        exportMetaObjectRevisions: [0]
+        exports: ["QtQuick/Flickable 2.0", "QtQuick/Flickable 2.9"]
+        exportMetaObjectRevisions: [0, 9]
         Enum {
             name: "BoundsBehavior"
             values: {
@@ -1563,6 +1578,8 @@ Module {
             isPointer: true
         }
         Property { name: "pixelAligned"; type: "bool" }
+        Property { name: "horizontalOvershoot"; revision: 9; type: "double"; isReadonly: true }
+        Property { name: "verticalOvershoot"; revision: 9; type: "double"; isReadonly: true }
         Property { name: "flickableData"; type: "QObject"; isList: true; isReadonly: true }
         Property { name: "flickableChildren"; type: "QQuickItem"; isList: true; isReadonly: true }
         Signal { name: "isAtBoundaryChanged" }
@@ -1572,6 +1589,8 @@ Module {
         Signal { name: "flickEnded" }
         Signal { name: "dragStarted" }
         Signal { name: "dragEnded" }
+        Signal { name: "horizontalOvershootChanged"; revision: 9 }
+        Signal { name: "verticalOvershootChanged"; revision: 9 }
         Method {
             name: "resizeContent"
             Parameter { name: "w"; type: "double" }
@@ -2084,8 +2103,13 @@ Module {
         name: "QQuickItem"
         defaultProperty: "data"
         prototype: "QObject"
-        exports: ["QtQuick/Item 2.0", "QtQuick/Item 2.1", "QtQuick/Item 2.4"]
-        exportMetaObjectRevisions: [0, 1, 2]
+        exports: [
+            "QtQuick/Item 2.0",
+            "QtQuick/Item 2.1",
+            "QtQuick/Item 2.4",
+            "QtQuick/Item 2.7"
+        ]
+        exportMetaObjectRevisions: [0, 1, 2, 7]
         Enum {
             name: "TransformOrigin"
             values: {
@@ -2210,23 +2234,21 @@ Module {
             Parameter { name: "point"; type: "QPointF" }
         }
         Method {
-            name: "mapToGlobal"
-            revision: 7
-            type: "QPointF"
-            Parameter { name: "point"; type: "QPointF" }
+            name: "mapFromItem"
+            Parameter { type: "QQmlV4Function"; isPointer: true }
         }
         Method {
-            name: "mapFromGlobal"
-            revision: 7
-            type: "QPointF"
-            Parameter { name: "point"; type: "QPointF" }
+            name: "mapToItem"
+            Parameter { type: "QQmlV4Function"; isPointer: true }
         }
         Method {
-            name: "mapFromItem"
+            name: "mapFromGlobal"
+            revision: 7
             Parameter { type: "QQmlV4Function"; isPointer: true }
         }
         Method {
-            name: "mapToItem"
+            name: "mapToGlobal"
+            revision: 7
             Parameter { type: "QQmlV4Function"; isPointer: true }
         }
         Method { name: "forceActiveFocus" }
@@ -2259,6 +2281,11 @@ Module {
             type: "bool"
             Parameter { name: "fileName"; type: "string" }
         }
+        Method {
+            name: "saveToFile"
+            type: "bool"
+            Parameter { name: "fileName"; type: "string" }
+        }
     }
     Component {
         name: "QQuickItemLayer"
@@ -2318,9 +2345,13 @@ Module {
         name: "QQuickItemView"
         defaultProperty: "flickableData"
         prototype: "QQuickFlickable"
-        exports: ["QtQuick/ItemView 2.1", "QtQuick/ItemView 2.3"]
+        exports: [
+            "QtQuick/ItemView 2.1",
+            "QtQuick/ItemView 2.3",
+            "QtQuick/ItemView 2.7"
+        ]
         isCreatable: false
-        exportMetaObjectRevisions: [1, 2]
+        exportMetaObjectRevisions: [1, 2, 7]
         Enum {
             name: "LayoutDirection"
             values: {
@@ -2495,6 +2526,10 @@ Module {
             Parameter { name: "event"; type: "QQuickKeyEvent"; isPointer: true }
         }
         Signal {
+            name: "shortcutOverride"
+            Parameter { name: "event"; type: "QQuickKeyEvent"; isPointer: true }
+        }
+        Signal {
             name: "digit0Pressed"
             Parameter { name: "event"; type: "QQuickKeyEvent"; isPointer: true }
         }
@@ -2757,9 +2792,10 @@ Module {
         exports: [
             "QtQuick/MouseArea 2.0",
             "QtQuick/MouseArea 2.4",
-            "QtQuick/MouseArea 2.5"
+            "QtQuick/MouseArea 2.5",
+            "QtQuick/MouseArea 2.9"
         ]
-        exportMetaObjectRevisions: [0, 1, 2]
+        exportMetaObjectRevisions: [0, 1, 2, 9]
         Property { name: "mouseX"; type: "double"; isReadonly: true }
         Property { name: "mouseY"; type: "double"; isReadonly: true }
         Property { name: "containsMouse"; type: "bool"; isReadonly: true }
@@ -2774,6 +2810,7 @@ Module {
         Property { name: "propagateComposedEvents"; type: "bool" }
         Property { name: "cursorShape"; type: "Qt::CursorShape" }
         Property { name: "containsPress"; revision: 1; type: "bool"; isReadonly: true }
+        Property { name: "pressAndHoldInterval"; revision: 9; type: "int" }
         Signal { name: "hoveredChanged" }
         Signal { name: "scrollGestureEnabledChanged"; revision: 2 }
         Signal {
@@ -2816,6 +2853,7 @@ Module {
         Signal { name: "exited" }
         Signal { name: "canceled" }
         Signal { name: "containsPressChanged"; revision: 1 }
+        Signal { name: "pressAndHoldIntervalChanged"; revision: 9 }
     }
     Component {
         name: "QQuickMultiPointTouchArea"
@@ -3600,14 +3638,20 @@ Module {
     Component {
         name: "QQuickShortcut"
         prototype: "QObject"
-        exports: ["QtQuick/Shortcut 2.5", "QtQuick/Shortcut 2.6"]
-        exportMetaObjectRevisions: [0, 1]
+        exports: [
+            "QtQuick/Shortcut 2.5",
+            "QtQuick/Shortcut 2.6",
+            "QtQuick/Shortcut 2.9"
+        ]
+        exportMetaObjectRevisions: [0, 1, 9]
         Property { name: "sequence"; type: "QVariant" }
+        Property { name: "sequences"; revision: 9; type: "QVariantList" }
         Property { name: "nativeText"; revision: 1; type: "string"; isReadonly: true }
         Property { name: "portableText"; revision: 1; type: "string"; isReadonly: true }
         Property { name: "enabled"; type: "bool" }
         Property { name: "autoRepeat"; type: "bool" }
         Property { name: "context"; type: "Qt::ShortcutContext" }
+        Signal { name: "sequencesChanged"; revision: 9 }
         Signal { name: "activated" }
         Signal { name: "activatedAmbiguously" }
     }
@@ -3926,9 +3970,10 @@ Module {
             "QtQuick/Text 2.0",
             "QtQuick/Text 2.2",
             "QtQuick/Text 2.3",
-            "QtQuick/Text 2.6"
+            "QtQuick/Text 2.6",
+            "QtQuick/Text 2.9"
         ]
-        exportMetaObjectRevisions: [0, 2, 3, 6]
+        exportMetaObjectRevisions: [0, 2, 3, 6, 9]
         Enum {
             name: "HAlignment"
             values: {
@@ -4038,6 +4083,7 @@ Module {
         Property { name: "leftPadding"; revision: 6; type: "double" }
         Property { name: "rightPadding"; revision: 6; type: "double" }
         Property { name: "bottomPadding"; revision: 6; type: "double" }
+        Property { name: "fontInfo"; revision: 9; type: "QJSValue"; isReadonly: true }
         Signal {
             name: "textChanged"
             Parameter { name: "text"; type: "string" }
@@ -4093,7 +4139,9 @@ Module {
         Signal { name: "leftPaddingChanged"; revision: 6 }
         Signal { name: "rightPaddingChanged"; revision: 6 }
         Signal { name: "bottomPaddingChanged"; revision: 6 }
+        Signal { name: "fontInfoChanged"; revision: 9 }
         Method { name: "doLayout" }
+        Method { name: "forceLayout"; revision: 9 }
         Method {
             name: "linkAt"
             revision: 3
@@ -4390,9 +4438,10 @@ Module {
             "QtQuick/TextInput 2.2",
             "QtQuick/TextInput 2.4",
             "QtQuick/TextInput 2.6",
-            "QtQuick/TextInput 2.7"
+            "QtQuick/TextInput 2.7",
+            "QtQuick/TextInput 2.9"
         ]
-        exportMetaObjectRevisions: [0, 2, 3, 6, 7]
+        exportMetaObjectRevisions: [0, 2, 3, 6, 7, 9]
         Enum {
             name: "EchoMode"
             values: {
@@ -4497,6 +4546,7 @@ Module {
         Property { name: "bottomPadding"; revision: 6; type: "double" }
         Signal { name: "accepted" }
         Signal { name: "editingFinished"; revision: 2 }
+        Signal { name: "textEdited"; revision: 9 }
         Signal {
             name: "fontChanged"
             Parameter { name: "font"; type: "QFont" }
@@ -4657,13 +4707,16 @@ Module {
     Component {
         name: "QQuickTouchPoint"
         prototype: "QObject"
-        exports: ["QtQuick/TouchPoint 2.0"]
-        exportMetaObjectRevisions: [0]
+        exports: ["QtQuick/TouchPoint 2.0", "QtQuick/TouchPoint 2.9"]
+        exportMetaObjectRevisions: [0, 0]
         Property { name: "pointId"; type: "int"; isReadonly: true }
+        Property { name: "uniqueId"; revision: 9; type: "QPointingDeviceUniqueId"; isReadonly: true }
         Property { name: "pressed"; type: "bool"; isReadonly: true }
         Property { name: "x"; type: "double"; isReadonly: true }
         Property { name: "y"; type: "double"; isReadonly: true }
+        Property { name: "ellipseDiameters"; revision: 9; type: "QSizeF"; isReadonly: true }
         Property { name: "pressure"; type: "double"; isReadonly: true }
+        Property { name: "rotation"; revision: 9; type: "double"; isReadonly: true }
         Property { name: "velocity"; type: "QVector2D"; isReadonly: true }
         Property { name: "area"; type: "QRectF"; isReadonly: true }
         Property { name: "startX"; type: "double"; isReadonly: true }
@@ -4672,6 +4725,9 @@ Module {
         Property { name: "previousY"; type: "double"; isReadonly: true }
         Property { name: "sceneX"; type: "double"; isReadonly: true }
         Property { name: "sceneY"; type: "double"; isReadonly: true }
+        Signal { name: "uniqueIdChanged"; revision: 9 }
+        Signal { name: "ellipseDiametersChanged"; revision: 9 }
+        Signal { name: "rotationChanged"; revision: 9 }
     }
     Component { name: "QQuickTransform"; prototype: "QObject" }
     Component {
diff --git a/src/imports/testlib/TestCase.qml b/src/imports/testlib/TestCase.qml
index 18c70e1169..8c1744a2b2 100644
--- a/src/imports/testlib/TestCase.qml
+++ b/src/imports/testlib/TestCase.qml
@@ -38,6 +38,7 @@
 ****************************************************************************/
 
 import QtQuick 2.0
+import QtQuick.Window 2.0 // used for qtest_verifyItem
 import QtTest 1.1
 import "testlogger.js" as TestLogger
 import Qt.test.qtestroot 1.0
@@ -443,6 +444,9 @@ Item {
         or \c{QVERIFY2(condition, message)} in C++.
     */
     function verify(cond, msg) {
+        if (arguments.length > 2)
+            qtest_fail("More than two arguments given to verify(). Did you mean tryVerify() or tryCompare()?", 1)
+
         if (msg === undefined)
             msg = "";
         if (!qtest_results.verify(cond, msg, util.callerFile(), util.callerLine()))
@@ -1085,8 +1089,8 @@ Item {
     function waitForRendering(item, timeout) {
         if (timeout === undefined)
             timeout = 5000
-        if (!item)
-            qtest_fail("No item given to waitForRendering", 1)
+        if (!qtest_verifyItem(item, "waitForRendering"))
+            return
         return qtest_results.waitForRendering(item, timeout)
     }
 
@@ -1198,8 +1202,8 @@ Item {
         \sa mouseRelease(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseMove(), mouseDrag(), mouseWheel()
     */
     function mousePress(item, x, y, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mousePress", 1)
+        if (!qtest_verifyItem(item, "mousePress"))
+            return
 
         if (button === undefined)
             button = Qt.LeftButton
@@ -1232,8 +1236,8 @@ Item {
         \sa mousePress(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseMove(), mouseDrag(), mouseWheel()
     */
     function mouseRelease(item, x, y, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseRelease", 1)
+        if (!qtest_verifyItem(item, "mouseRelease"))
+            return
 
         if (button === undefined)
             button = Qt.LeftButton
@@ -1268,8 +1272,8 @@ Item {
         \sa mousePress(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseMove(), mouseRelease(), mouseWheel()
     */
     function mouseDrag(item, x, y, dx, dy, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseDrag", 1)
+        if (!qtest_verifyItem(item, "mouseDrag"))
+            return
 
         if (item.x === undefined || item.y === undefined)
             return
@@ -1319,8 +1323,8 @@ Item {
         \sa mousePress(), mouseRelease(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseMove(), mouseDrag(), mouseWheel()
     */
     function mouseClick(item, x, y, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseClick", 1)
+        if (!qtest_verifyItem(item, "mouseClick"))
+            return
 
         if (button === undefined)
             button = Qt.LeftButton
@@ -1353,8 +1357,8 @@ Item {
         \sa mouseDoubleClickSequence(), mousePress(), mouseRelease(), mouseClick(), mouseMove(), mouseDrag(), mouseWheel()
     */
     function mouseDoubleClick(item, x, y, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseDoubleClick", 1)
+        if (!qtest_verifyItem(item, "mouseDoubleClick"))
+            return
 
         if (button === undefined)
             button = Qt.LeftButton
@@ -1394,8 +1398,8 @@ Item {
         \sa mouseDoubleClick(), mousePress(), mouseRelease(), mouseClick(), mouseMove(), mouseDrag(), mouseWheel()
     */
     function mouseDoubleClickSequence(item, x, y, button, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseDoubleClickSequence", 1)
+        if (!qtest_verifyItem(item, "mouseDoubleClickSequence"))
+            return
 
         if (button === undefined)
             button = Qt.LeftButton
@@ -1426,8 +1430,8 @@ Item {
         \sa mousePress(), mouseRelease(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseDrag(), mouseWheel()
     */
     function mouseMove(item, x, y, delay, buttons) {
-        if (!item)
-            qtest_fail("No item given to mouseMove", 1)
+        if (!qtest_verifyItem(item, "mouseMove"))
+            return
 
         if (delay == undefined)
             delay = -1
@@ -1454,8 +1458,8 @@ Item {
         \sa mousePress(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence(), mouseMove(), mouseRelease(), mouseDrag(), QWheelEvent::angleDelta()
     */
     function mouseWheel(item, x, y, xDelta, yDelta, buttons, modifiers, delay) {
-        if (!item)
-            qtest_fail("No item given to mouseWheel", 1)
+        if (!qtest_verifyItem(item, "mouseWheel"))
+            return
 
         if (delay == undefined)
             delay = -1
@@ -1515,8 +1519,8 @@ Item {
     */
 
     function touchEvent(item) {
-        if (!item)
-            qtest_fail("No item given to touchEvent", 1)
+        if (!qtest_verifyItem(item, "touchEvent"))
+            return
 
         return {
             _defaultItem: item,
@@ -1625,6 +1629,23 @@ Item {
     function cleanup() {}
 
     /*! \internal */
+    function qtest_verifyItem(item, method) {
+        try {
+            if (!(item instanceof Item) &&
+                !(item instanceof Window)) {
+                // it's a QObject, but not a type
+                qtest_fail("TypeError: %1 requires an Item or Window type".arg(method), 2);
+                return false;
+            }
+        } catch (e) { // it's not a QObject
+            qtest_fail("TypeError: %1 requires an Item or Window type".arg(method), 3);
+            return false;
+        }
+
+        return true;
+    }
+
+    /*! \internal */
     function qtest_runInternal(prop, arg) {
         try {
             qtest_testCaseResult = testCase[prop](arg)
diff --git a/src/imports/testlib/plugins.qmltypes b/src/imports/testlib/plugins.qmltypes
index 563778e55e..5d7ca51adc 100644
--- a/src/imports/testlib/plugins.qmltypes
+++ b/src/imports/testlib/plugins.qmltypes
@@ -4,11 +4,45 @@ import QtQuick.tooling 1.2
 // It is used for QML tooling purposes only.
 //
 // This file was auto-generated by:
-// 'qmlplugindump -nonrelocatable -noforceqtquick QtTest 1.1'
+// 'qmlplugindump -nonrelocatable -noforceqtquick QtTest 1.2'
 
 Module {
     dependencies: ["QtQuick 2.0"]
     Component {
+        name: "QQuickTouchEventSequence"
+        prototype: "QObject"
+        Method {
+            name: "press"
+            type: "QObject*"
+            Parameter { name: "touchId"; type: "int" }
+            Parameter { name: "item"; type: "QObject"; isPointer: true }
+            Parameter { name: "x"; type: "double" }
+            Parameter { name: "y"; type: "double" }
+        }
+        Method {
+            name: "move"
+            type: "QObject*"
+            Parameter { name: "touchId"; type: "int" }
+            Parameter { name: "item"; type: "QObject"; isPointer: true }
+            Parameter { name: "x"; type: "double" }
+            Parameter { name: "y"; type: "double" }
+        }
+        Method {
+            name: "release"
+            type: "QObject*"
+            Parameter { name: "touchId"; type: "int" }
+            Parameter { name: "item"; type: "QObject"; isPointer: true }
+            Parameter { name: "x"; type: "double" }
+            Parameter { name: "y"; type: "double" }
+        }
+        Method {
+            name: "stationary"
+            type: "QObject*"
+            Parameter { name: "touchId"; type: "int" }
+        }
+        Method { name: "commit"; type: "QObject*" }
+    }
+    Component {
         name: "QuickTestEvent"
         prototype: "QObject"
         exports: ["QtTest/TestEvent 1.0"]
@@ -127,6 +161,12 @@ Module {
             Parameter { name: "yDelta"; type: "int" }
             Parameter { name: "delay"; type: "int" }
         }
+        Method {
+            name: "touchEvent"
+            type: "QQuickTouchEventSequence*"
+            Parameter { name: "item"; type: "QObject"; isPointer: true }
+        }
+        Method { name: "touchEvent"; type: "QQuickTouchEventSequence*" }
     }
     Component {
         name: "QuickTestResult"
diff --git a/src/imports/window/plugins.qmltypes b/src/imports/window/plugins.qmltypes
index a79bd8c332..cea2a910a7 100644
--- a/src/imports/window/plugins.qmltypes
+++ b/src/imports/window/plugins.qmltypes
@@ -4,7 +4,7 @@ import QtQuick.tooling 1.2
 // It is used for QML tooling purposes only.
 //
 // This file was auto-generated by:
-// 'qmlplugindump -nonrelocatable QtQuick.Window 2.2'
+// 'qmlplugindump -nonrelocatable QtQuick.Window 2.3'
 
 Module {
     dependencies: ["QtQuick 2.8"]
@@ -24,14 +24,28 @@ Module {
     Component {
         name: "QQuickScreen"
         prototype: "QObject"
-        exports: ["QtQuick.Window/Screen 2.0"]
+        exports: ["QtQuick.Window/Screen 2.0", "QtQuick.Window/Screen 2.3"]
         isCreatable: false
-        exportMetaObjectRevisions: [0]
+        exportMetaObjectRevisions: [0, 1]
         attachedType: "QQuickScreenAttached"
     }
     Component {
         name: "QQuickScreenAttached"
+        prototype: "QQuickScreenInfo"
+        Property { name: "orientationUpdateMask"; type: "Qt::ScreenOrientations" }
+        Method {
+            name: "angleBetween"
+            type: "int"
+            Parameter { name: "a"; type: "int" }
+            Parameter { name: "b"; type: "int" }
+        }
+    }
+    Component {
+        name: "QQuickScreenInfo"
         prototype: "QObject"
+        exports: ["QtQuick.Window/ScreenInfo 2.3"]
+        isCreatable: false
+        exportMetaObjectRevisions: [2]
         Property { name: "name"; type: "string"; isReadonly: true }
         Property { name: "width"; type: "int"; isReadonly: true }
         Property { name: "height"; type: "int"; isReadonly: true }
@@ -42,25 +56,18 @@ Module {
         Property { name: "devicePixelRatio"; type: "double"; isReadonly: true }
         Property { name: "primaryOrientation"; type: "Qt::ScreenOrientation"; isReadonly: true }
         Property { name: "orientation"; type: "Qt::ScreenOrientation"; isReadonly: true }
-        Property { name: "orientationUpdateMask"; type: "Qt::ScreenOrientations" }
+        Property { name: "virtualX"; revision: 1; type: "int"; isReadonly: true }
+        Property { name: "virtualY"; revision: 1; type: "int"; isReadonly: true }
         Signal { name: "desktopGeometryChanged" }
-        Method {
-            name: "angleBetween"
-            type: "int"
-            Parameter { name: "a"; type: "int" }
-            Parameter { name: "b"; type: "int" }
-        }
+        Signal { name: "virtualXChanged"; revision: 1 }
+        Signal { name: "virtualYChanged"; revision: 1 }
     }
     Component {
         name: "QQuickWindow"
         defaultProperty: "data"
         prototype: "QWindow"
-        exports: [
-            "QtQuick.Window/Window 2.0",
-            "QtQuick.Window/Window 2.1",
-            "QtQuick.Window/Window 2.2"
-        ]
-        exportMetaObjectRevisions: [0, 1, 2]
+        exports: ["QtQuick.Window/Window 2.0"]
+        exportMetaObjectRevisions: [0]
         Enum {
             name: "SceneGraphError"
             values: {
@@ -125,11 +132,16 @@ Module {
         name: "QQuickWindowQmlImpl"
         defaultProperty: "data"
         prototype: "QQuickWindow"
-        exports: ["QtQuick.Window/Window 2.1", "QtQuick.Window/Window 2.2"]
-        exportMetaObjectRevisions: [0, 1]
+        exports: [
+            "QtQuick.Window/Window 2.1",
+            "QtQuick.Window/Window 2.2",
+            "QtQuick.Window/Window 2.3"
+        ]
+        exportMetaObjectRevisions: [0, 1, 2]
         attachedType: "QQuickWindowAttached"
         Property { name: "visible"; type: "bool" }
         Property { name: "visibility"; type: "Visibility" }
+        Property { name: "screen"; revision: 2; type: "QObject"; isPointer: true }
         Signal {
             name: "visibleChanged"
             Parameter { name: "arg"; type: "bool" }
@@ -138,6 +150,7 @@ Module {
             name: "visibilityChanged"
             Parameter { name: "visibility"; type: "QWindow::Visibility" }
         }
+        Signal { name: "screenChanged"; revision: 2 }
     }
     Component {
         name: "QWindow"
@@ -153,6 +166,13 @@ Module {
                 "FullScreen": 5
             }
         }
+        Enum {
+            name: "AncestorMode"
+            values: {
+                "ExcludeTransients": 0,
+                "IncludeTransients": 1
+            }
+        }
         Property { name: "title"; type: "string" }
         Property { name: "modality"; type: "Qt::WindowModality" }
         Property { name: "flags"; type: "Qt::WindowFlags" }
diff --git a/src/particles/particles.pri b/src/particles/particles.pri
index af71634ec6..576d826903 100644
--- a/src/particles/particles.pri
+++ b/src/particles/particles.pri
@@ -1,6 +1,5 @@
 HEADERS += \
     $$PWD/qquickangledirection_p.h \
-    $$PWD/qquickcustomparticle_p.h \
     $$PWD/qquickcustomaffector_p.h \
     $$PWD/qquickellipseextruder_p.h \
     $$PWD/qquicktrailemitter_p.h \
@@ -33,7 +32,6 @@ HEADERS += \
 
 SOURCES += \
     $$PWD/qquickangledirection.cpp \
-    $$PWD/qquickcustomparticle.cpp \
     $$PWD/qquickcustomaffector.cpp \
     $$PWD/qquickellipseextruder.cpp \
     $$PWD/qquicktrailemitter.cpp \
@@ -63,6 +61,14 @@ SOURCES += \
     $$PWD/qquickparticlegroup.cpp \
     $$PWD/qquickgroupgoal.cpp
 
+qtConfig(quick-shadereffect) {
+HEADERS += \
+    $$PWD/qquickcustomparticle_p.h
+
+SOURCES += \
+    $$PWD/qquickcustomparticle.cpp
+}
+
 OTHER_FILES += \
     $$PWD/shaders/customparticletemplate.vert \
     $$PWD/shaders/customparticle.vert \
diff --git a/src/particles/qquickparticlesmodule.cpp b/src/particles/qquickparticlesmodule.cpp
index accdb668de..03f47a3961 100644
--- a/src/particles/qquickparticlesmodule.cpp
+++ b/src/particles/qquickparticlesmodule.cpp
@@ -37,8 +37,12 @@
 **
 ****************************************************************************/
 
+#include <private/qtquickglobal_p.h>
+
 #include "qquickangledirection_p.h"
+#if QT_CONFIG(quick_shadereffect)
 #include "qquickcustomparticle_p.h"
+#endif
 #include "qquickellipseextruder_p.h"
 #include "qquicktrailemitter_p.h"
 #include "qquickfriction_p.h"
@@ -84,7 +88,9 @@ void QQuickParticlesModule::defineModule()
     qmlRegisterType<QQuickParticleGroup>(uri, 2, 0, "ParticleGroup");
 
     qmlRegisterType<QQuickImageParticle>(uri, 2, 0, "ImageParticle");
+#if QT_CONFIG(quick_shadereffect)
     qmlRegisterType<QQuickCustomParticle>(uri, 2, 0, "CustomParticle");
+#endif
     qmlRegisterType<QQuickItemParticle>(uri, 2, 0, "ItemParticle");
 
     qmlRegisterType<QQuickParticleEmitter>(uri, 2, 0, "Emitter");
diff --git a/src/particles/qquickparticlesystem.cpp b/src/particles/qquickparticlesystem.cpp
index 99e278238b..6f134f08df 100644
--- a/src/particles/qquickparticlesystem.cpp
+++ b/src/particles/qquickparticlesystem.cpp
@@ -668,8 +668,11 @@ void QQuickParticleSystem::setPaused(bool arg) {
         if (m_animation && m_animation->state() != QAbstractAnimation::Stopped)
             m_paused ? m_animation->pause() : m_animation->resume();
         if (!m_paused) {
-            foreach (QQuickParticlePainter *p, m_painters)
-                p->update();
+            foreach (QQuickParticlePainter *p, m_painters) {
+                if (p) {
+                    p->update();
+                }
+            }
         }
         emit pausedChanged(arg);
     }
@@ -873,8 +876,11 @@ void QQuickParticleSystem::emittersChanged()
     if (particleCount > bySysIdx.size())//New datum requests haven't updated it
         bySysIdx.resize(particleCount);
 
-    foreach (QQuickParticleAffector *a, m_affectors)//Groups may have changed
-        a->m_updateIntSet = true;
+    foreach (QQuickParticleAffector *a, m_affectors) {//Groups may have changed
+        if (a) {
+            a->m_updateIntSet = true;
+        }
+    }
 
     foreach (QQuickParticlePainter *p, m_painters)
         loadPainter(p);
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
index 151e44c4d4..3fb0522cd1 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
@@ -409,18 +409,7 @@ QQmlEngineDebugServiceImpl::objectData(QObject *object)
     rv.objectId = QQmlDebugService::idForObject(object);
     rv.contextId = QQmlDebugService::idForObject(qmlContext(object));
     rv.parentId = QQmlDebugService::idForObject(object->parent());
-    QQmlType *type = QQmlMetaType::qmlType(object->metaObject());
-    if (type) {
-        QString typeName = type->qmlTypeName();
-        int lastSlash = typeName.lastIndexOf(QLatin1Char('/'));
-        rv.objectType = lastSlash < 0 ? typeName : typeName.mid(lastSlash+1);
-    } else {
-        rv.objectType = QString::fromUtf8(object->metaObject()->className());
-        int marker = rv.objectType.indexOf(QLatin1String("_QMLTYPE_"));
-        if (marker != -1)
-            rv.objectType = rv.objectType.left(marker);
-    }
-
+    rv.objectType = QQmlMetaType::prettyTypeName(object);
     return rv;
 }
 
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
index a4bad5618b..430ba4f255 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.cpp
@@ -55,11 +55,11 @@
 
 QT_BEGIN_NAMESPACE
 
-QV4::CallContext *QV4DataCollector::findContext(int frame)
+QV4::SimpleCallContext *QV4DataCollector::findContext(int frame)
 {
     QV4::ExecutionContext *ctx = engine()->currentContext;
     while (ctx) {
-        QV4::CallContext *cCtxt = ctx->asCallContext();
+        QV4::SimpleCallContext *cCtxt = ctx->asSimpleCallContext();
         if (cCtxt && cCtxt->d()->v4Function) {
             if (frame < 1)
                 return cCtxt;
@@ -71,7 +71,7 @@ QV4::CallContext *QV4DataCollector::findContext(int frame)
     return 0;
 }
 
-QV4::Heap::CallContext *QV4DataCollector::findScope(QV4::ExecutionContext *ctxt, int scope)
+QV4::Heap::SimpleCallContext *QV4DataCollector::findScope(QV4::ExecutionContext *ctxt, int scope)
 {
     if (!ctxt)
         return 0;
@@ -81,7 +81,7 @@ QV4::Heap::CallContext *QV4DataCollector::findScope(QV4::ExecutionContext *ctxt,
     for (; scope > 0 && ctx; --scope)
         ctx = ctx->d()->outer;
 
-    return (ctx && ctx->d()) ? ctx->asCallContext()->d() : 0;
+    return (ctx && ctx->d()) ? ctx->asSimpleCallContext()->d() : 0;
 }
 
 QVector<QV4::Heap::ExecutionContext::ContextType> QV4DataCollector::getScopeTypes(int frame)
@@ -89,13 +89,13 @@ QVector<QV4::Heap::ExecutionContext::ContextType> QV4DataCollector::getScopeType
     QVector<QV4::Heap::ExecutionContext::ContextType> types;
 
     QV4::Scope scope(engine());
-    QV4::CallContext *sctxt = findContext(frame);
+    QV4::SimpleCallContext *sctxt = findContext(frame);
     if (!sctxt || sctxt->d()->type < QV4::Heap::ExecutionContext::Type_QmlContext)
         return types;
 
     QV4::ScopedContext it(scope, sctxt);
     for (; it; it = it->d()->outer)
-        types.append(it->d()->type);
+        types.append(QV4::Heap::ExecutionContext::ContextType(it->d()->type));
 
     return types;
 }
@@ -118,15 +118,18 @@ int QV4DataCollector::encodeScopeType(QV4::Heap::ExecutionContext::ContextType s
     }
 }
 
-QV4DataCollector::QV4DataCollector(QV4::ExecutionEngine *engine) : m_engine(engine)
+QV4DataCollector::QV4DataCollector(QV4::ExecutionEngine *engine)
+    : m_engine(engine), m_namesAsObjects(true), m_redundantRefs(true)
 {
     m_values.set(engine, engine->newArrayObject());
 }
 
+// TODO: Directly call addRef() once we don't need to support redundantRefs anymore
 QV4DataCollector::Ref QV4DataCollector::collect(const QV4::ScopedValue &value)
 {
     Ref ref = addRef(value);
-    m_collectedRefs.append(ref);
+    if (m_redundantRefs)
+        m_collectedRefs.append(ref);
     return ref;
 }
 
@@ -184,30 +187,48 @@ const QV4::Object *collectProperty(const QV4::ScopedValue &value, QV4::Execution
     case QV4::Value::Integer_Type:
         dict.insert(valueKey, value->integerValue());
         return 0;
-    default: // double
-        dict.insert(valueKey, value->doubleValue());
+    default: {// double
+        const double val = value->doubleValue();
+        if (qIsFinite(val))
+            dict.insert(valueKey, val);
+        else if (qIsNaN(val))
+            dict.insert(valueKey, QStringLiteral("NaN"));
+        else if (val < 0)
+            dict.insert(valueKey, QStringLiteral("-Infinity"));
+        else
+            dict.insert(valueKey, QStringLiteral("Infinity"));
         return 0;
     }
+    }
 }
 
-QJsonObject QV4DataCollector::lookupRef(Ref ref)
+QJsonObject QV4DataCollector::lookupRef(Ref ref, bool deep)
 {
     QJsonObject dict;
-    if (lookupSpecialRef(ref, &dict))
-        return dict;
+
+    if (m_namesAsObjects) {
+        if (lookupSpecialRef(ref, &dict))
+            return dict;
+    }
+
+    if (m_redundantRefs)
+        deep = true;
 
     dict.insert(QStringLiteral("handle"), qint64(ref));
     QV4::Scope scope(engine());
     QV4::ScopedValue value(scope, getValue(ref));
 
-    if (const QV4::Object *o = collectProperty(value, engine(), dict))
-        dict.insert(QStringLiteral("properties"), collectProperties(o));
+    const QV4::Object *object = collectProperty(value, engine(), dict);
+    if (deep && object)
+        dict.insert(QStringLiteral("properties"), collectProperties(object));
 
     return dict;
 }
 
+// TODO: Drop this method once we don't need to support namesAsObjects anymore
 QV4DataCollector::Ref QV4DataCollector::addFunctionRef(const QString &functionName)
 {
+    Q_ASSERT(m_namesAsObjects);
     Ref ref = addRef(QV4::Primitive::emptyValue(), false);
 
     QJsonObject dict;
@@ -220,8 +241,10 @@ QV4DataCollector::Ref QV4DataCollector::addFunctionRef(const QString &functionNa
     return ref;
 }
 
+// TODO: Drop this method once we don't need to support namesAsObjects anymore
 QV4DataCollector::Ref QV4DataCollector::addScriptRef(const QString &scriptName)
 {
+    Q_ASSERT(m_namesAsObjects);
     Ref ref = addRef(QV4::Primitive::emptyValue(), false);
 
     QJsonObject dict;
@@ -250,6 +273,7 @@ bool QV4DataCollector::collectScope(QJsonObject *dict, int frameNr, int scopeNr)
     if (!ctxt)
         return false;
 
+    Refs collectedRefs;
     QV4::ScopedValue v(scope);
     int nFormals = ctxt->formalCount();
     for (unsigned i = 0, ei = nFormals; i != ei; ++i) {
@@ -258,7 +282,7 @@ bool QV4DataCollector::collectScope(QJsonObject *dict, int frameNr, int scopeNr)
             qName = name->string;
         names.append(qName);
         v = ctxt->argument(i);
-        collect(v);
+        collectedRefs.append(collect(v));
     }
 
     for (unsigned i = 0, ei = ctxt->variableCount(); i != ei; ++i) {
@@ -267,21 +291,26 @@ bool QV4DataCollector::collectScope(QJsonObject *dict, int frameNr, int scopeNr)
             qName = name->string;
         names.append(qName);
         v = ctxt->d()->locals[i];
-        collect(v);
+        collectedRefs.append(collect(v));
     }
 
     QV4::ScopedObject scopeObject(scope, engine()->newObject());
 
-    Q_ASSERT(names.size() == m_collectedRefs.size());
+    Q_ASSERT(names.size() == collectedRefs.size());
     QV4::ScopedString propName(scope);
-    for (int i = 0, ei = m_collectedRefs.size(); i != ei; ++i) {
+    for (int i = 0, ei = collectedRefs.size(); i != ei; ++i) {
         propName = engine()->newString(names.at(i));
-        scopeObject->put(propName, QV4::Value::fromReturnedValue(getValue(m_collectedRefs.at(i))));
+        scopeObject->put(propName, QV4::Value::fromReturnedValue(getValue(collectedRefs.at(i))));
     }
 
     Ref scopeObjectRef = addRef(scopeObject);
-    dict->insert(QStringLiteral("ref"), qint64(scopeObjectRef));
-    m_collectedRefs.append(scopeObjectRef);
+    if (m_redundantRefs) {
+        dict->insert(QStringLiteral("ref"), qint64(scopeObjectRef));
+        m_collectedRefs.append(scopeObjectRef);
+    } else {
+        *dict = lookupRef(scopeObjectRef, true);
+    }
+
     return true;
 }
 
@@ -293,15 +322,16 @@ QJsonObject toRef(QV4DataCollector::Ref ref) {
 
 QJsonObject QV4DataCollector::buildFrame(const QV4::StackFrame &stackFrame, int frameNr)
 {
-    QV4DataCollector::Ref ref;
-
     QJsonObject frame;
     frame[QLatin1String("index")] = frameNr;
     frame[QLatin1String("debuggerFrame")] = false;
-    ref = addFunctionRef(stackFrame.function);
-    frame[QLatin1String("func")] = toRef(ref);
-    ref = addScriptRef(stackFrame.source);
-    frame[QLatin1String("script")] = toRef(ref);
+    if (m_namesAsObjects) {
+        frame[QLatin1String("func")] = toRef(addFunctionRef(stackFrame.function));
+        frame[QLatin1String("script")] = toRef(addScriptRef(stackFrame.source));
+    } else {
+        frame[QLatin1String("func")] = stackFrame.function;
+        frame[QLatin1String("script")] = stackFrame.source;
+    }
     frame[QLatin1String("line")] = stackFrame.line - 1;
     if (stackFrame.column >= 0)
         frame[QLatin1String("column")] = stackFrame.column;
@@ -310,7 +340,7 @@ QJsonObject QV4DataCollector::buildFrame(const QV4::StackFrame &stackFrame, int
     QV4::Scope scope(engine());
     QV4::ScopedContext ctxt(scope, findContext(frameNr));
     while (ctxt) {
-        if (QV4::CallContext *cCtxt = ctxt->asCallContext()) {
+        if (QV4::SimpleCallContext *cCtxt = ctxt->asSimpleCallContext()) {
             if (cCtxt->d()->activation)
                 break;
         }
@@ -318,7 +348,7 @@ QJsonObject QV4DataCollector::buildFrame(const QV4::StackFrame &stackFrame, int
     }
 
     if (ctxt) {
-        QV4::ScopedValue o(scope, ctxt->asCallContext()->d()->activation);
+        QV4::ScopedValue o(scope, ctxt->asSimpleCallContext()->d()->activation);
         frame[QLatin1String("receiver")] = toRef(collect(o));
     }
 
@@ -340,15 +370,17 @@ QJsonObject QV4DataCollector::buildFrame(const QV4::StackFrame &stackFrame, int
     return frame;
 }
 
+// TODO: Drop this method once we don't need to support redundantRefs anymore
 QJsonArray QV4DataCollector::flushCollectedRefs()
 {
+    Q_ASSERT(m_redundantRefs);
     QJsonArray refs;
     std::sort(m_collectedRefs.begin(), m_collectedRefs.end());
     for (int i = 0, ei = m_collectedRefs.size(); i != ei; ++i) {
         QV4DataCollector::Ref ref = m_collectedRefs.at(i);
         if (i > 0 && ref == m_collectedRefs.at(i - 1))
             continue;
-        refs.append(lookupRef(ref));
+        refs.append(lookupRef(ref, true));
     }
 
     m_collectedRefs.clear();
@@ -360,14 +392,16 @@ void QV4DataCollector::clear()
     m_values.set(engine(), engine()->newArrayObject());
     m_collectedRefs.clear();
     m_specialRefs.clear();
+    m_namesAsObjects = true;
+    m_redundantRefs = true;
 }
 
 QV4DataCollector::Ref QV4DataCollector::addRef(QV4::Value value, bool deduplicate)
 {
     class ExceptionStateSaver
     {
-        quint32 *hasExceptionLoc;
-        quint32 hadException;
+        quint8 *hasExceptionLoc;
+        quint8 hadException;
 
     public:
         ExceptionStateSaver(QV4::ExecutionEngine *engine)
@@ -403,8 +437,10 @@ QV4::ReturnedValue QV4DataCollector::getValue(Ref ref)
     return array->getIndexed(ref, Q_NULLPTR);
 }
 
+// TODO: Drop this method once we don't need to support namesAsObjects anymore
 bool QV4DataCollector::lookupSpecialRef(Ref ref, QJsonObject *dict)
 {
+    Q_ASSERT(m_namesAsObjects);
     SpecialRefs::const_iterator it = m_specialRefs.constFind(ref);
     if (it == m_specialRefs.cend())
         return false;
@@ -442,7 +478,8 @@ QJsonObject QV4DataCollector::collectAsJson(const QString &name, const QV4::Scop
     if (value->isManaged() && !value->isString()) {
         Ref ref = addRef(value);
         dict.insert(QStringLiteral("ref"), qint64(ref));
-        m_collectedRefs.append(ref);
+        if (m_redundantRefs)
+            m_collectedRefs.append(ref);
     }
 
     collectProperty(value, engine(), dict);
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
index fd6356f22e..de12e8d527 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4datacollector.h
@@ -58,42 +58,50 @@ public:
     typedef uint Ref;
     typedef QVector<uint> Refs;
 
-    static QV4::Heap::CallContext *findScope(QV4::ExecutionContext *ctxt, int scope);
+    static QV4::Heap::SimpleCallContext *findScope(QV4::ExecutionContext *ctxt, int scope);
     static int encodeScopeType(QV4::Heap::ExecutionContext::ContextType scopeType);
 
     QVector<QV4::Heap::ExecutionContext::ContextType> getScopeTypes(int frame);
-    QV4::CallContext *findContext(int frame);
+    QV4::SimpleCallContext *findContext(int frame);
 
     QV4DataCollector(QV4::ExecutionEngine *engine);
 
-    Ref collect(const QV4::ScopedValue &value);
-    Ref addFunctionRef(const QString &functionName);
-    Ref addScriptRef(const QString &scriptName);
+    Ref collect(const QV4::ScopedValue &value);      // only for redundantRefs
+    Ref addFunctionRef(const QString &functionName); // only for namesAsObjects
+    Ref addScriptRef(const QString &scriptName);     // only for namesAsObjects
+
+    void setNamesAsObjects(bool namesAsObjects) { m_namesAsObjects = namesAsObjects; }
+    bool namesAsObjects() const { return m_namesAsObjects; }
+
+    void setRedundantRefs(bool redundantRefs) { m_redundantRefs = redundantRefs; }
+    bool redundantRefs() const { return m_redundantRefs; }
 
     bool isValidRef(Ref ref) const;
-    QJsonObject lookupRef(Ref ref);
+    QJsonObject lookupRef(Ref ref, bool deep);
 
     bool collectScope(QJsonObject *dict, int frameNr, int scopeNr);
     QJsonObject buildFrame(const QV4::StackFrame &stackFrame, int frameNr);
 
     QV4::ExecutionEngine *engine() const { return m_engine; }
-    QJsonArray flushCollectedRefs();
+    QJsonArray flushCollectedRefs(); // only for redundantRefs
     void clear();
 
 private:
     Ref addRef(QV4::Value value, bool deduplicate = true);
     QV4::ReturnedValue getValue(Ref ref);
-    bool lookupSpecialRef(Ref ref, QJsonObject *dict);
+    bool lookupSpecialRef(Ref ref, QJsonObject *dict); // only for namesAsObjects
 
     QJsonArray collectProperties(const QV4::Object *object);
     QJsonObject collectAsJson(const QString &name, const QV4::ScopedValue &value);
     void collectArgumentsInContext();
 
     QV4::ExecutionEngine *m_engine;
-    Refs m_collectedRefs;
+    Refs m_collectedRefs;                        // only for redundantRefs
     QV4::PersistentValue m_values;
-    typedef QHash<Ref, QJsonObject> SpecialRefs;
-    SpecialRefs m_specialRefs;
+    typedef QHash<Ref, QJsonObject> SpecialRefs; // only for namesAsObjects
+    SpecialRefs m_specialRefs;                   // only for namesAsObjects
+    bool m_namesAsObjects;
+    bool m_redundantRefs;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugger.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4debugger.cpp
index 5cc2043cb1..75cbc9eba1 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugger.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugger.cpp
@@ -230,7 +230,12 @@ void QV4Debugger::leavingFunction(const QV4::ReturnedValue &retVal)
     QMutexLocker locker(&m_lock);
 
     if (m_stepping != NotStepping && m_currentContext.asManaged()->d() == m_engine->current) {
-        m_currentContext.set(m_engine, *m_engine->parentContext(m_engine->currentContext));
+        if (QV4::ExecutionContext *parentContext
+                = m_engine->parentContext(m_engine->currentContext)) {
+            m_currentContext.set(m_engine, *parentContext);
+        } else {
+            m_currentContext.clear();
+        }
         m_stepping = StepOver;
         m_returnedValue.set(m_engine, retVal);
     }
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
index d5fadad50a..107ec60943 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
@@ -151,7 +151,7 @@ void BacktraceJob::run()
         result.insert(QStringLiteral("toFrame"), fromFrame + frameArray.size());
         result.insert(QStringLiteral("frames"), frameArray);
     }
-    collectedRefs = collector->flushCollectedRefs();
+    flushRedundantRefs();
 }
 
 FrameJob::FrameJob(QV4DataCollector *collector, int frameNr) :
@@ -166,7 +166,7 @@ void FrameJob::run()
         success = false;
     } else {
         result = collector->buildFrame(frames[frameNr], frameNr);
-        collectedRefs = collector->flushCollectedRefs();
+        flushRedundantRefs();
         success = true;
     }
 }
@@ -196,7 +196,7 @@ void ScopeJob::run()
     result[QLatin1String("index")] = scopeNr;
     result[QLatin1String("frameIndex")] = frameNr;
     result[QLatin1String("object")] = object;
-    collectedRefs = collector->flushCollectedRefs();
+    flushRedundantRefs();
 }
 
 bool ScopeJob::wasSuccessful() const
@@ -226,9 +226,9 @@ void ValueLookupJob::run()
             exception = QString::fromLatin1("Invalid Ref: %1").arg(ref);
             break;
         }
-        result[QString::number(ref)] = collector->lookupRef(ref);
+        result[QString::number(ref)] = collector->lookupRef(ref, true);
     }
-    collectedRefs = collector->flushCollectedRefs();
+    flushRedundantRefs();
     if (scopeObject)
         engine->popContext();
 }
@@ -249,8 +249,9 @@ void ExpressionEvalJob::handleResult(QV4::ScopedValue &value)
 {
     if (hasExeption())
         exception = value->toQStringNoThrow();
-    result = collector->lookupRef(collector->collect(value));
-    collectedRefs = collector->flushCollectedRefs();
+    result = collector->lookupRef(collector->collect(value), true);
+    if (collector->redundantRefs())
+        collectedRefs = collector->flushCollectedRefs();
 }
 
 const QString &ExpressionEvalJob::exceptionMessage() const
@@ -263,8 +264,10 @@ const QJsonObject &ExpressionEvalJob::returnValue() const
     return result;
 }
 
+// TODO: Drop this method once we don't need to support redundantRefs anymore
 const QJsonArray &ExpressionEvalJob::refs() const
 {
+    Q_ASSERT(collector->redundantRefs());
     return collectedRefs;
 }
 
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.h b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.h
index 00d3e6206a..eca8710e15 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.h
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.h
@@ -78,11 +78,24 @@ class CollectJob : public QV4DebugJob
 protected:
     QV4DataCollector *collector;
     QJsonObject result;
-    QJsonArray collectedRefs;
+    QJsonArray collectedRefs; // only for redundantRefs
+
+    void flushRedundantRefs()
+    {
+        if (collector->redundantRefs())
+            collectedRefs = collector->flushCollectedRefs();
+    }
+
 public:
     CollectJob(QV4DataCollector *collector) : collector(collector) {}
     const QJsonObject &returnValue() const { return result; }
-    const QJsonArray &refs() const { return collectedRefs; }
+
+    // TODO: Drop this method once we don't need to support redundantRefs anymore
+    const QJsonArray &refs() const
+    {
+        Q_ASSERT(collector->redundantRefs());
+        return collectedRefs;
+    }
 };
 
 class BacktraceJob: public CollectJob
@@ -133,7 +146,7 @@ class ExpressionEvalJob: public JavaScriptJob
     QV4DataCollector *collector;
     QString exception;
     QJsonObject result;
-    QJsonArray collectedRefs;
+    QJsonArray collectedRefs; // only for redundantRefs
 
 public:
     ExpressionEvalJob(QV4::ExecutionEngine *engine, int frameNr, int context,
@@ -141,7 +154,7 @@ public:
     void handleResult(QV4::ScopedValue &value) override;
     const QString &exceptionMessage() const;
     const QJsonObject &returnValue() const;
-    const QJsonArray &refs() const;
+    const QJsonArray &refs() const; // only for redundantRefs
 };
 
 class GatherSourcesJob: public QV4DebugJob
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.cpp
index 1d2cc092dc..68cdb57a44 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.cpp
@@ -121,8 +121,18 @@ protected:
         response.insert(QStringLiteral("running"), debugService->debuggerAgent.isRunning());
     }
 
+    QV4DataCollector *saneCollector(QV4Debugger *debugger)
+    {
+        QV4DataCollector *collector = debugger->collector();
+        collector->setNamesAsObjects(debugService->clientRequiresNamesAsObjects());
+        collector->setRedundantRefs(debugService->clientRequiresRedundantRefs());
+        return collector;
+    }
+
+    // TODO: drop this method once we don't need to support redundantRefs anymore.
     void addRefs(const QJsonArray &refs)
     {
+        Q_ASSERT(debugService->clientRequiresRedundantRefs());
         response.insert(QStringLiteral("refs"), refs);
     }
 
@@ -286,7 +296,7 @@ public:
             return;
         }
 
-        BacktraceJob job(debugger->collector(), fromFrame, toFrame);
+        BacktraceJob job(saneCollector(debugger), fromFrame, toFrame);
         debugger->runInEngine(&job);
 
         // response:
@@ -295,7 +305,8 @@ public:
         addSuccess(true);
         addRunning();
         addBody(job.returnValue());
-        addRefs(job.refs());
+        if (debugService->clientRequiresRedundantRefs())
+            addRefs(job.refs());
     }
 };
 
@@ -322,7 +333,7 @@ public:
             return;
         }
 
-        FrameJob job(debugger->collector(), frameNr);
+        FrameJob job(saneCollector(debugger), frameNr);
         debugger->runInEngine(&job);
         if (!job.wasSuccessful()) {
             createErrorResponse(QStringLiteral("frame retrieval failed"));
@@ -337,7 +348,8 @@ public:
         addSuccess(true);
         addRunning();
         addBody(job.returnValue());
-        addRefs(job.refs());
+        if (debugService->clientRequiresRedundantRefs())
+            addRefs(job.refs());
     }
 };
 
@@ -369,7 +381,7 @@ public:
             return;
         }
 
-        ScopeJob job(debugger->collector(), frameNr, scopeNr);
+        ScopeJob job(saneCollector(debugger), frameNr, scopeNr);
         debugger->runInEngine(&job);
         if (!job.wasSuccessful()) {
             createErrorResponse(QStringLiteral("scope retrieval failed"));
@@ -382,7 +394,8 @@ public:
         addSuccess(true);
         addRunning();
         addBody(job.returnValue());
-        addRefs(job.refs());
+        if (debugService->clientRequiresRedundantRefs())
+            addRefs(job.refs());
     }
 };
 
@@ -410,7 +423,7 @@ public:
             debugger = debuggers.first();
         }
 
-        ValueLookupJob job(handles, debugger->collector());
+        ValueLookupJob job(handles, saneCollector(debugger));
         debugger->runInEngine(&job);
         if (!job.exceptionMessage().isEmpty()) {
             createErrorResponse(job.exceptionMessage());
@@ -421,7 +434,8 @@ public:
             addSuccess(true);
             addRunning();
             addBody(job.returnValue());
-            addRefs(job.refs());
+            if (debugService->clientRequiresRedundantRefs())
+                addRefs(job.refs());
         }
     }
 };
@@ -630,7 +644,7 @@ public:
         }
 
         ExpressionEvalJob job(debugger->engine(), frame, context, expression,
-                              debugger->collector());
+                              saneCollector(debugger));
         debugger->runInEngine(&job);
         if (job.hasExeption()) {
             createErrorResponse(job.exceptionMessage());
@@ -640,7 +654,8 @@ public:
             addSuccess(true);
             addRunning();
             addBody(job.returnValue());
-            addRefs(job.refs());
+            if (debugService->clientRequiresRedundantRefs())
+                addRefs(job.refs());
         }
     }
 };
@@ -662,7 +677,7 @@ V8CommandHandler *QV4DebugServiceImpl::v8CommandHandler(const QString &command)
 
 QV4DebugServiceImpl::QV4DebugServiceImpl(QObject *parent) :
     QQmlConfigurableDebugService<QV4DebugService>(1, parent),
-    debuggerAgent(this), theSelectedFrame(0),
+    debuggerAgent(this), theSelectedFrame(0), redundantRefs(true), namesAsObjects(true),
     unknownV8CommandHandler(new UnknownV8CommandHandler)
 {
     addHandler(new V8VersionRequest);
@@ -766,6 +781,14 @@ void QV4DebugServiceImpl::messageReceived(const QByteArray &message)
         TRACE_PROTOCOL(qDebug() << "... type:" << type);
 
         if (type == V4_CONNECT) {
+            QJsonObject parameters = QJsonDocument::fromJson(payload).object();
+            namesAsObjects = true;
+            redundantRefs = true;
+            if (parameters.contains("namesAsObjects"))
+                namesAsObjects = parameters.value("namesAsObjects").toBool();
+            if (parameters.contains("redundantRefs"))
+                redundantRefs = parameters.value("redundantRefs").toBool();
+
             emit messageToClient(name(), packMessage(type));
             stopWaiting();
         } else if (type == V4_PAUSE) {
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.h b/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.h
index 69e32189b8..bb13890ae4 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.h
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugservice.h
@@ -86,6 +86,9 @@ public:
     int selectedFrame() const;
     void selectFrame(int frameNr);
 
+    bool clientRequiresRedundantRefs() const { return redundantRefs; }
+    bool clientRequiresNamesAsObjects() const { return namesAsObjects; }
+
     QV4DebuggerAgent debuggerAgent;
 
 protected:
@@ -105,6 +108,9 @@ private:
     static int sequence;
     int theSelectedFrame;
 
+    bool redundantRefs;
+    bool namesAsObjects;
+
     void addHandler(V8CommandHandler* handler);
     QHash<QString, V8CommandHandler*> handlers;
     QScopedPointer<UnknownV8CommandHandler> unknownV8CommandHandler;
diff --git a/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp b/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
index 7f842419e7..6cb1ab4051 100644
--- a/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
@@ -481,17 +481,20 @@ void NativeDebugger::handleVariables(QJsonObject *response, const QJsonObject &a
     QJsonArray output;
     QV4::Scope scope(engine);
 
-    if (QV4::CallContext *callContext = executionContext->asCallContext()) {
+    if (QV4::SimpleCallContext *callContext = executionContext->asSimpleCallContext()) {
         QV4::Value thisObject = callContext->thisObject();
         collector.collect(&output, QString(), QStringLiteral("this"), thisObject);
         QV4::Identifier *const *variables = callContext->variables();
         QV4::Identifier *const *formals = callContext->formals();
-        for (unsigned i = 0, ei = callContext->variableCount(); i != ei; ++i) {
-            QString qName;
-            if (QV4::Identifier *name = variables[i])
-                qName = name->string;
-            QV4::Value val = callContext->d()->locals[i];
-            collector.collect(&output, QString(), qName, val);
+        if (callContext->d()->type == QV4::Heap::ExecutionContext::Type_CallContext) {
+            QV4::CallContext *ctx = static_cast<QV4::CallContext *>(callContext);
+            for (unsigned i = 0, ei = ctx->variableCount(); i != ei; ++i) {
+                QString qName;
+                if (QV4::Identifier *name = variables[i])
+                    qName = name->string;
+                QV4::Value val = ctx->d()->locals[i];
+                collector.collect(&output, QString(), qName, val);
+            }
         }
         for (unsigned i = 0, ei = callContext->formalCount(); i != ei; ++i) {
             QString qName;
diff --git a/src/plugins/scenegraph/openvg/openvg.pro b/src/plugins/scenegraph/openvg/openvg.pro
index 6d5b190b37..43c2636343 100644
--- a/src/plugins/scenegraph/openvg/openvg.pro
+++ b/src/plugins/scenegraph/openvg/openvg.pro
@@ -31,7 +31,6 @@ HEADERS += \
     qsgopenvghelpers.h \
     qsgopenvgfontglyphcache.h \
     qsgopenvgpainternode.h \
-    qsgopenvgspritenode.h \
     qsgopenvgrenderable.h \
     qopenvgoffscreensurface.h
 
@@ -52,6 +51,10 @@ SOURCES += \
     qsgopenvghelpers.cpp \
     qsgopenvgfontglyphcache.cpp \
     qsgopenvgpainternode.cpp \
-    qsgopenvgspritenode.cpp \
     qsgopenvgrenderable.cpp \
     qopenvgoffscreensurface.cpp
+
+qtConfig(quick-sprite) {
+    HEADERS += qsgopenvgspritenode.h
+    SOURCES += qsgopenvgspritenode.cpp
+}
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgcontext.cpp b/src/plugins/scenegraph/openvg/qsgopenvgcontext.cpp
index 41fce7c7fc..76ebb7c4ee 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgcontext.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvgcontext.cpp
@@ -45,7 +45,9 @@
 #include "qsgopenvgglyphnode_p.h"
 #include "qsgopenvgfontglyphcache.h"
 #include "qsgopenvgpainternode.h"
+#if QT_CONFIG(quick_sprite)
 #include "qsgopenvgspritenode.h"
+#endif
 
 #include "qopenvgcontext_p.h"
 
@@ -171,11 +173,12 @@ int QSGOpenVGRenderContext::maxTextureSize() const
     return qMin(width, height);
 }
 
-
+#if QT_CONFIG(quick_sprite)
 QSGSpriteNode *QSGOpenVGContext::createSpriteNode()
 {
     return new QSGOpenVGSpriteNode();
 }
+#endif
 
 QSGRendererInterface *QSGOpenVGContext::rendererInterface(QSGRenderContext *renderContext)
 {
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgcontext_p.h b/src/plugins/scenegraph/openvg/qsgopenvgcontext_p.h
index fa9939a253..31a1e8643f 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgcontext_p.h
+++ b/src/plugins/scenegraph/openvg/qsgopenvgcontext_p.h
@@ -95,7 +95,9 @@ public:
     QSurfaceFormat defaultSurfaceFormat() const override;
     QSGInternalRectangleNode *createInternalRectangleNode() override;
     QSGInternalImageNode *createInternalImageNode() override;
+#if QT_CONFIG(quick_sprite)
     QSGSpriteNode *createSpriteNode() override;
+#endif
     QSGRendererInterface *rendererInterface(QSGRenderContext *renderContext) override;
 };
 
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.cpp b/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.cpp
index dd630c776f..df47e920af 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.cpp
@@ -94,7 +94,7 @@ void QSGOpenVGFontGlyphCache::populate(const QVector<quint32> &glyphs)
         referencedGlyphs.insert(glyphIndex);
 
 
-        if (!m_cachedGlyphs.contains(glyphIndex)) {
+        if (!m_glyphReferences.contains(glyphIndex)) {
             newGlyphs.insert(glyphIndex);
         }
     }
@@ -119,17 +119,9 @@ void QSGOpenVGFontGlyphCache::requestGlyphs(const QSet<quint32> &glyphs)
 {
     VGfloat origin[2];
     VGfloat escapement[2];
-    QRectF metrics;
     QRawFont rawFont = m_referenceFont;
 
-    // Before adding any new glyphs, remove any unused glyphs
-    for (auto glyph : qAsConst(m_unusedGlyphs)) {
-        vgClearGlyph(m_font, glyph);
-    }
-
     for (auto glyph : glyphs) {
-         m_cachedGlyphs.insert(glyph);
-
         // Calculate the path for the glyph and cache it.
         QPainterPath path = rawFont.pathForGlyph(glyph);
         VGPath vgPath;
@@ -151,12 +143,23 @@ void QSGOpenVGFontGlyphCache::requestGlyphs(const QSet<quint32> &glyphs)
 
 void QSGOpenVGFontGlyphCache::referenceGlyphs(const QSet<quint32> &glyphs)
 {
-    m_unusedGlyphs -= glyphs;
+    for (auto glyph : glyphs) {
+        if (m_glyphReferences.contains(glyph))
+            m_glyphReferences[glyph] += 1;
+        else
+            m_glyphReferences.insert(glyph, 1);
+    }
 }
 
 void QSGOpenVGFontGlyphCache::releaseGlyphs(const QSet<quint32> &glyphs)
 {
-    m_unusedGlyphs += glyphs;
+    for (auto glyph : glyphs) {
+        int references = m_glyphReferences[glyph] -= 1;
+        if (references == 0) {
+            vgClearGlyph(m_font, glyph);
+            m_glyphReferences.remove(glyph);
+        }
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.h b/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.h
index a88d28b0fe..107ec0c892 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.h
+++ b/src/plugins/scenegraph/openvg/qsgopenvgfontglyphcache.h
@@ -87,8 +87,7 @@ private:
     int m_glyphCount;
 
     VGFont m_font;
-    QSet<quint32> m_cachedGlyphs;
-    QSet<quint32> m_unusedGlyphs;
+    QHash<quint32, int> m_glyphReferences;
 };
 
 
diff --git a/src/plugins/scenegraph/openvg/qsgopenvglayer.h b/src/plugins/scenegraph/openvg/qsgopenvglayer.h
index 2af0bfb40f..8deedc3347 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvglayer.h
+++ b/src/plugins/scenegraph/openvg/qsgopenvglayer.h
@@ -83,6 +83,7 @@ public:
     void setDevicePixelRatio(qreal ratio) override;
     void setMirrorHorizontal(bool mirror) override;
     void setMirrorVertical(bool mirror) override;
+    void setSamples(int) override { }
 
 public slots:
     void markDirtyTexture() override;
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.cpp b/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.cpp
index 8aa179f705..41606c653a 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.cpp
@@ -43,7 +43,9 @@
 #include "qsgopenvgpublicnodes.h"
 #include "qsgopenvgglyphnode_p.h"
 #include "qsgopenvgpainternode.h"
+#if QT_CONFIG(quick_sprite)
 #include "qsgopenvgspritenode.h"
+#endif
 #include "qsgopenvgrenderable.h"
 
 #include "qopenvgcontext_p.h"
@@ -209,6 +211,7 @@ void QSGOpenVGNodeVisitor::endVisit(QSGRootNode *)
 {
 }
 
+#if QT_CONFIG(quick_sprite)
 bool QSGOpenVGNodeVisitor::visit(QSGSpriteNode *node)
 {
     renderRenderableNode(static_cast<QSGOpenVGSpriteNode*>(node));
@@ -218,6 +221,7 @@ bool QSGOpenVGNodeVisitor::visit(QSGSpriteNode *node)
 void QSGOpenVGNodeVisitor::endVisit(QSGSpriteNode *)
 {
 }
+#endif
 
 bool QSGOpenVGNodeVisitor::visit(QSGRenderNode *)
 {
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.h b/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.h
index 4805d63024..c6461ca67d 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.h
+++ b/src/plugins/scenegraph/openvg/qsgopenvgnodevisitor.h
@@ -73,8 +73,10 @@ public:
     void endVisit(QSGGlyphNode *) override;
     bool visit(QSGRootNode *) override;
     void endVisit(QSGRootNode *) override;
+#if QT_CONFIG(quick_sprite)
     bool visit(QSGSpriteNode *) override;
     void endVisit(QSGSpriteNode *) override;
+#endif
     bool visit(QSGRenderNode *) override;
     void endVisit(QSGRenderNode *) override;
 
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgspritenode.h b/src/plugins/scenegraph/openvg/qsgopenvgspritenode.h
index 3ade2ef8ad..d47b389a0b 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgspritenode.h
+++ b/src/plugins/scenegraph/openvg/qsgopenvgspritenode.h
@@ -43,6 +43,8 @@
 #include <private/qsgadaptationlayer_p.h>
 #include "qsgopenvgrenderable.h"
 
+QT_REQUIRE_CONFIG(quick_sprite);
+
 QT_BEGIN_NAMESPACE
 class QSGOpenVGTexture;
 class QSGOpenVGSpriteNode : public QSGSpriteNode, public QSGOpenVGRenderable
diff --git a/src/qml/compiler/compiler.pri b/src/qml/compiler/compiler.pri
index fa66d3a6e3..871f28f2d0 100644
--- a/src/qml/compiler/compiler.pri
+++ b/src/qml/compiler/compiler.pri
@@ -10,7 +10,8 @@ HEADERS += \
     $$PWD/qv4isel_util_p.h \
     $$PWD/qv4ssa_p.h \
     $$PWD/qqmlirbuilder_p.h \
-    $$PWD/qqmltypecompiler_p.h
+    $$PWD/qqmltypecompiler_p.h \
+    $$PWD/qv4jssimplifier_p.h
 
 SOURCES += \
     $$PWD/qv4compileddata.cpp \
@@ -19,7 +20,8 @@ SOURCES += \
     $$PWD/qv4isel_p.cpp \
     $$PWD/qv4jsir.cpp \
     $$PWD/qv4ssa.cpp \
-    $$PWD/qqmlirbuilder.cpp
+    $$PWD/qqmlirbuilder.cpp \
+    $$PWD/qv4jssimplifier.cpp
 
 !qmldevtools_build {
 
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 030f485504..218f5675dc 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -1361,7 +1361,7 @@ bool IRBuilder::isRedundantNullInitializerForPropertyDeclaration(Property *prope
     return QQmlJS::AST::cast<QQmlJS::AST::NullExpression *>(expr);
 }
 
-QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, QQmlEngine *engine, const QV4::CompiledData::ResolvedTypeReferenceMap &dependentTypes)
+QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
 {
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = output.javaScriptCompilationUnit;
     QV4::CompiledData::Unit *jsUnit = compilationUnit->createUnitData(&output);
@@ -1404,17 +1404,16 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, QQmlEngine
     qmlUnit->stringTableSize = output.jsGenerator.stringTable.stringCount();
 
 #ifndef V4_BOOTSTRAP
-    if (!dependentTypes.isEmpty()) {
+    if (dependencyHasher) {
         QCryptographicHash hash(QCryptographicHash::Md5);
-        if (dependentTypes.addToHash(&hash, engine)) {
+        if (dependencyHasher(&hash)) {
             QByteArray checksum = hash.result();
             Q_ASSERT(checksum.size() == sizeof(qmlUnit->dependencyMD5Checksum));
             memcpy(qmlUnit->dependencyMD5Checksum, checksum.constData(), sizeof(qmlUnit->dependencyMD5Checksum));
         }
     }
 #else
-    Q_UNUSED(dependentTypes);
-    Q_UNUSED(engine);
+    Q_UNUSED(dependencyHasher);
 #endif
 
     // write imports
@@ -2116,7 +2115,8 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
 
     object->indexOfDefaultPropertyOrAlias = serializedObject->indexOfDefaultPropertyOrAlias;
     object->defaultPropertyIsAlias = serializedObject->defaultPropertyIsAlias;
-
+    object->flags = serializedObject->flags;
+    object->id = serializedObject->id;
     object->location = serializedObject->location;
     object->locationOfIdProperty = serializedObject->locationOfIdProperty;
 
@@ -2175,6 +2175,15 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
         object->properties->append(p);
     }
 
+    {
+        const QV4::CompiledData::Alias *serializedAlias = serializedObject->aliasTable();
+        for (uint i = 0; i < serializedObject->nAliases; ++i, ++serializedAlias) {
+            QmlIR::Alias *a = pool->New<QmlIR::Alias>();
+            *static_cast<QV4::CompiledData::Alias*>(a) = *serializedAlias;
+            object->aliases->append(a);
+        }
+    }
+
     QQmlJS::Engine *jsParserEngine = &output->jsParserEngine;
 
     const QV4::CompiledData::LEUInt32 *functionIdx = serializedObject->functionOffsetTable();
@@ -2205,6 +2214,11 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
         const QString name = unit->stringAt(compiledFunction->nameIndex);
         f->functionDeclaration = new(pool) QQmlJS::AST::FunctionDeclaration(jsParserEngine->newStringRef(name), paramList, /*body*/0);
 
+        f->formals.allocate(pool, int(compiledFunction->nFormals));
+        formalNameIdx = compiledFunction->formalsTable();
+        for (uint i = 0; i < compiledFunction->nFormals; ++i, ++formalNameIdx)
+            f->formals[i] = *formalNameIdx;
+
         object->functions->append(f);
     }
 
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index b579a963a1..64bf111d9a 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -548,7 +548,7 @@ public:
 
 struct Q_QML_PRIVATE_EXPORT QmlUnitGenerator
 {
-    QV4::CompiledData::Unit *generate(Document &output, QQmlEngine *engine, const QV4::CompiledData::ResolvedTypeReferenceMap &dependentTypes);
+    QV4::CompiledData::Unit *generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher = QV4::CompiledData::DependentTypesHasher());
 
 private:
     typedef bool (Binding::*BindingFilter)() const;
diff --git a/src/qml/compiler/qqmltypecompiler.cpp b/src/qml/compiler/qqmltypecompiler.cpp
index 109eb86c2e..d1d22be0ac 100644
--- a/src/qml/compiler/qqmltypecompiler.cpp
+++ b/src/qml/compiler/qqmltypecompiler.cpp
@@ -47,6 +47,7 @@
 #include <private/qv4ssa_p.h>
 
 #include "qqmlpropertycachecreator_p.h"
+#include "qv4jssimplifier_p.h"
 
 #define COMPILE_EXCEPTION(token, desc) \
     { \
@@ -58,10 +59,11 @@ QT_BEGIN_NAMESPACE
 
 QQmlTypeCompiler::QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData,
                                    QmlIR::Document *parsedQML, const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
-                                   const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache)
+                                   const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
     : resolvedTypes(resolvedTypeCache)
     , engine(engine)
     , typeData(typeData)
+    , dependencyHasher(dependencyHasher)
     , typeNameCache(typeNameCache)
     , document(parsedQML)
 {
@@ -143,7 +145,7 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
         if (!jsCodeGen.generateCodeForComponents())
             return nullptr;
 
-        QQmlJavaScriptBindingExpressionSimplificationPass pass(this);
+        QQmlJavaScriptBindingExpressionSimplificationPass pass(document->objects, &document->jsModule, &document->jsGenerator);
         pass.reduceTranslationBindings();
 
         QV4::ExecutionEngine *v4 = engine->v4engine();
@@ -156,7 +158,7 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
     // Generate QML compiled type data structures
 
     QmlIR::QmlUnitGenerator qmlGenerator;
-    QV4::CompiledData::Unit *qmlUnit = qmlGenerator.generate(*document, QQmlEnginePrivate::get(engine), resolvedTypes);
+    QV4::CompiledData::Unit *qmlUnit = qmlGenerator.generate(*document, dependencyHasher);
 
     Q_ASSERT(document->javaScriptCompilationUnit);
     // The js unit owns the data and will free the qml unit.
@@ -1428,344 +1430,4 @@ void QQmlDefaultPropertyMerger::mergeDefaultProperties(int objectIndex)
     }
 }
 
-QQmlJavaScriptBindingExpressionSimplificationPass::QQmlJavaScriptBindingExpressionSimplificationPass(QQmlTypeCompiler *typeCompiler)
-    : QQmlCompilePass(typeCompiler)
-    , qmlObjects(*typeCompiler->qmlObjects())
-    , jsModule(typeCompiler->jsIRModule())
-{
-
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings()
-{
-    for (int i = 0; i < qmlObjects.count(); ++i)
-        reduceTranslationBindings(i);
-    if (!irFunctionsToRemove.isEmpty()) {
-        QQmlIRFunctionCleanser cleanser(compiler, irFunctionsToRemove);
-        cleanser.clean();
-    }
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings(int objectIndex)
-{
-    const QmlIR::Object *obj = qmlObjects.at(objectIndex);
-
-    for (QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
-        if (binding->type != QV4::CompiledData::Binding::Type_Script)
-            continue;
-
-        const int irFunctionIndex = obj->runtimeFunctionIndices.at(binding->value.compiledScriptIndex);
-        QV4::IR::Function *irFunction = jsModule->functions.at(irFunctionIndex);
-        if (simplifyBinding(irFunction, binding)) {
-            irFunctionsToRemove.append(irFunctionIndex);
-            jsModule->functions[irFunctionIndex] = 0;
-            delete irFunction;
-        }
-    }
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitMove(QV4::IR::Move *move)
-{
-    QV4::IR::Temp *target = move->target->asTemp();
-    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
-        discard();
-        return;
-    }
-
-    if (QV4::IR::Call *call = move->source->asCall()) {
-        if (QV4::IR::Name *n = call->base->asName()) {
-            if (n->builtin == QV4::IR::Name::builtin_invalid) {
-                visitFunctionCall(n->id, call->args, target);
-                return;
-            }
-        }
-        discard();
-        return;
-    }
-
-    if (QV4::IR::Name *n = move->source->asName()) {
-        if (n->builtin == QV4::IR::Name::builtin_qml_context
-            || n->builtin == QV4::IR::Name::builtin_qml_imported_scripts_object) {
-            // these are free of side-effects
-            return;
-        }
-        discard();
-        return;
-    }
-
-    if (!move->source->asTemp() && !move->source->asString() && !move->source->asConst()) {
-        discard();
-        return;
-    }
-
-    _temps[target->index] = move->source;
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target)
-{
-    // more than one function call?
-    if (_nameOfFunctionCalled) {
-        discard();
-        return;
-    }
-
-    _nameOfFunctionCalled = name;
-
-    _functionParameters.clear();
-    while (args) {
-        int slot;
-        if (QV4::IR::Temp *param = args->expr->asTemp()) {
-            if (param->kind != QV4::IR::Temp::VirtualRegister) {
-                discard();
-                return;
-            }
-            slot = param->index;
-            _functionParameters.append(slot);
-        } else if (QV4::IR::Const *param = args->expr->asConst()) {
-            slot = --_synthesizedConsts;
-            Q_ASSERT(!_temps.contains(slot));
-            _temps[slot] = param;
-            _functionParameters.append(slot);
-        }
-        args = args->next;
-    }
-
-    _functionCallReturnValue = target->index;
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitRet(QV4::IR::Ret *ret)
-{
-    // nothing initialized earlier?
-    if (_returnValueOfBindingExpression != -1) {
-        discard();
-        return;
-    }
-    QV4::IR::Temp *target = ret->expr->asTemp();
-    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
-        discard();
-        return;
-    }
-    _returnValueOfBindingExpression = target->index;
-}
-
-bool QQmlJavaScriptBindingExpressionSimplificationPass::simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding)
-{
-    _canSimplify = true;
-    _nameOfFunctionCalled = 0;
-    _functionParameters.clear();
-    _functionCallReturnValue = -1;
-    _temps.clear();
-    _returnValueOfBindingExpression = -1;
-    _synthesizedConsts = 0;
-
-    // It would seem unlikely that function with some many basic blocks (after optimization)
-    // consists merely of a qsTr call or a constant value return ;-)
-    if (function->basicBlockCount() > 10)
-        return false;
-
-    for (QV4::IR::BasicBlock *bb : function->basicBlocks()) {
-        for (QV4::IR::Stmt *s : bb->statements()) {
-            visit(s);
-            if (!_canSimplify)
-                return false;
-        }
-    }
-
-    if (_returnValueOfBindingExpression == -1)
-        return false;
-
-    if (_nameOfFunctionCalled) {
-        if (_functionCallReturnValue != _returnValueOfBindingExpression)
-            return false;
-        return detectTranslationCallAndConvertBinding(binding);
-    }
-
-    return false;
-}
-
-bool QQmlJavaScriptBindingExpressionSimplificationPass::detectTranslationCallAndConvertBinding(QmlIR::Binding *binding)
-{
-    if (*_nameOfFunctionCalled == QLatin1String("qsTr")) {
-        QString translation;
-        QV4::CompiledData::TranslationData translationData;
-        translationData.number = -1;
-        translationData.commentIndex = 0; // empty string
-
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        translation = *stringParam->value;
-
-        ++param;
-        if (param != end) {
-            stringParam = _temps[*param]->asString();
-            if (!stringParam)
-                return false;
-            translationData.commentIndex = compiler->registerString(*stringParam->value);
-            ++param;
-
-            if (param != end) {
-                QV4::IR::Const *constParam = _temps[*param]->asConst();
-                if (!constParam || constParam->type != QV4::IR::SInt32Type)
-                    return false;
-
-                translationData.number = int(constParam->value);
-                ++param;
-            }
-        }
-
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_Translation;
-        binding->stringIndex = compiler->registerString(translation);
-        binding->value.translationData = translationData;
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("qsTrId")) {
-        QString id;
-        QV4::CompiledData::TranslationData translationData;
-        translationData.number = -1;
-        translationData.commentIndex = 0; // empty string, but unused
-
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        id = *stringParam->value;
-
-        ++param;
-        if (param != end) {
-            QV4::IR::Const *constParam = _temps[*param]->asConst();
-            if (!constParam || constParam->type != QV4::IR::SInt32Type)
-                return false;
-
-            translationData.number = int(constParam->value);
-            ++param;
-        }
-
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_TranslationById;
-        binding->stringIndex = compiler->registerString(id);
-        binding->value.translationData = translationData;
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TR_NOOP") || *_nameOfFunctionCalled == QLatin1String("QT_TRID_NOOP")) {
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        ++param;
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_String;
-        binding->stringIndex = compiler->registerString(*stringParam->value);
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TRANSLATE_NOOP")) {
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        ++param;
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        ++param;
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_String;
-        binding->stringIndex = compiler->registerString(*stringParam->value);
-        return true;
-    }
-    return false;
-}
-
-QQmlIRFunctionCleanser::QQmlIRFunctionCleanser(QQmlTypeCompiler *typeCompiler, const QVector<int> &functionsToRemove)
-    : QQmlCompilePass(typeCompiler)
-    , module(typeCompiler->jsIRModule())
-    , functionsToRemove(functionsToRemove)
-{
-}
-
-void QQmlIRFunctionCleanser::clean()
-{
-    QVector<QV4::IR::Function*> newFunctions;
-    newFunctions.reserve(module->functions.count() - functionsToRemove.count());
-
-    newFunctionIndices.resize(module->functions.count());
-
-    for (int i = 0; i < module->functions.count(); ++i) {
-        QV4::IR::Function *f = module->functions.at(i);
-        Q_ASSERT(f || functionsToRemove.contains(i));
-        if (f) {
-            newFunctionIndices[i] = newFunctions.count();
-            newFunctions << f;
-        }
-    }
-
-    module->functions = newFunctions;
-
-    for (QV4::IR::Function *function : qAsConst(module->functions)) {
-        for (QV4::IR::BasicBlock *block : function->basicBlocks()) {
-            for (QV4::IR::Stmt *s : block->statements()) {
-                visit(s);
-            }
-        }
-    }
-
-    for (QmlIR::Object *obj : qAsConst(*compiler->qmlObjects())) {
-        for (int i = 0; i < obj->runtimeFunctionIndices.count; ++i)
-            obj->runtimeFunctionIndices[i] = newFunctionIndices[obj->runtimeFunctionIndices.at(i)];
-    }
-}
-
-void QQmlIRFunctionCleanser::visit(QV4::IR::Stmt *s)
-{
-
-    switch (s->stmtKind) {
-    case QV4::IR::Stmt::PhiStmt:
-        // nothing to do
-        break;
-    default:
-        STMT_VISIT_ALL_KINDS(s);
-        break;
-    }
-}
-
-void QQmlIRFunctionCleanser::visit(QV4::IR::Expr *e)
-{
-    switch (e->exprKind) {
-    case QV4::IR::Expr::ClosureExpr: {
-        auto closure = e->asClosure();
-        closure->value = newFunctionIndices.at(closure->value);
-    } break;
-    default:
-        EXPR_VISIT_ALL_KINDS(e);
-        break;
-    }
-}
-
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/qqmltypecompiler_p.h b/src/qml/compiler/qqmltypecompiler_p.h
index 2b59e7e42f..79fc073d8b 100644
--- a/src/qml/compiler/qqmltypecompiler_p.h
+++ b/src/qml/compiler/qqmltypecompiler_p.h
@@ -89,7 +89,8 @@ struct QQmlTypeCompiler
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlTypeCompiler)
 public:
-    QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData, QmlIR::Document *document, const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache);
+    QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData, QmlIR::Document *document, const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache,
+                     const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
 
     // --- interface used by QQmlPropertyCacheCreator
     typedef QmlIR::Object CompiledObject;
@@ -139,6 +140,7 @@ private:
     QList<QQmlError> errors;
     QQmlEnginePrivate *engine;
     QQmlTypeData *typeData;
+    const QV4::CompiledData::DependentTypesHasher &dependencyHasher;
     QQmlRefPointer<QQmlTypeNameCache> typeNameCache;
     QmlIR::Document *document;
     // index is string index of type name (use obj->inheritedTypeNameIndex)
@@ -343,86 +345,6 @@ private:
     const QQmlPropertyCacheVector * const propertyCaches;
 };
 
-class QQmlJavaScriptBindingExpressionSimplificationPass : public QQmlCompilePass
-{
-public:
-    QQmlJavaScriptBindingExpressionSimplificationPass(QQmlTypeCompiler *typeCompiler);
-
-    void reduceTranslationBindings();
-
-private:
-    void reduceTranslationBindings(int objectIndex);
-
-    void visit(QV4::IR::Stmt *s)
-    {
-        switch (s->stmtKind) {
-        case QV4::IR::Stmt::MoveStmt:
-            visitMove(s->asMove());
-            break;
-        case QV4::IR::Stmt::RetStmt:
-            visitRet(s->asRet());
-            break;
-        case QV4::IR::Stmt::CJumpStmt:
-            discard();
-            break;
-        case QV4::IR::Stmt::ExpStmt:
-            discard();
-            break;
-        case QV4::IR::Stmt::JumpStmt:
-            break;
-        case QV4::IR::Stmt::PhiStmt:
-            break;
-        }
-    }
-
-    void visitMove(QV4::IR::Move *move);
-    void visitRet(QV4::IR::Ret *ret);
-
-    void visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target);
-
-    void discard() { _canSimplify = false; }
-
-    bool simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding);
-    bool detectTranslationCallAndConvertBinding(QmlIR::Binding *binding);
-
-    const QVector<QmlIR::Object*> &qmlObjects;
-    QV4::IR::Module *jsModule;
-
-    bool _canSimplify;
-    const QString *_nameOfFunctionCalled;
-    QVector<int> _functionParameters;
-    int _functionCallReturnValue;
-
-    QHash<int, QV4::IR::Expr*> _temps;
-    int _returnValueOfBindingExpression;
-    int _synthesizedConsts;
-
-    QVector<int> irFunctionsToRemove;
-};
-
-class QQmlIRFunctionCleanser : public QQmlCompilePass
-{
-public:
-    QQmlIRFunctionCleanser(QQmlTypeCompiler *typeCompiler, const QVector<int> &functionsToRemove);
-
-    void clean();
-
-private:
-    virtual void visitMove(QV4::IR::Move *s) {
-        visit(s->source);
-        visit(s->target);
-    }
-
-    void visit(QV4::IR::Stmt *s);
-    void visit(QV4::IR::Expr *e);
-
-private:
-    QV4::IR::Module *module;
-    const QVector<int> &functionsToRemove;
-
-    QVector<int> newFunctionIndices;
-};
-
 QT_END_NAMESPACE
 
 #endif // QQMLTYPECOMPILER_P_H
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 0afc97e4bf..693a4230ba 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -92,6 +92,27 @@ static bool cjumpCanHandle(IR::AluOp op)
     }
 }
 
+static inline void setJumpOutLocation(IR::Stmt *s, const Statement *body,
+                                      const SourceLocation &fallback)
+{
+    switch (body->kind) {
+    // Statements where we might never execute the last line.
+    // Use the fallback.
+    case Statement::Kind_ConditionalExpression:
+    case Statement::Kind_ForEachStatement:
+    case Statement::Kind_ForStatement:
+    case Statement::Kind_IfStatement:
+    case Statement::Kind_LocalForEachStatement:
+    case Statement::Kind_LocalForStatement:
+    case Statement::Kind_WhileStatement:
+        setLocation(s, fallback);
+        break;
+    default:
+        setLocation(s, body->lastSourceLocation());
+        break;
+    }
+}
+
 Codegen::ScanFunctions::ScanFunctions(Codegen *cg, const QString &sourceCode, CompilationMode defaultProgramMode)
     : _cg(cg)
     , _sourceCode(sourceCode)
@@ -1497,7 +1518,7 @@ IR::Expr *Codegen::identifier(const QString &name, int line, int col)
     IR::Function *f = _function;
 
     while (f && e->parent) {
-        if (f->insideWithOrCatch || (f->isNamedExpression && f->name == name))
+        if (f->insideWithOrCatch || (f->isNamedExpression && QStringRef(f->name) == name))
             return _block->NAME(name, line, col);
 
         int index = e->findMember(name);
@@ -1508,7 +1529,7 @@ IR::Expr *Codegen::identifier(const QString &name, int line, int col)
                 al->isArgumentsOrEval = true;
             return al;
         }
-        const int argIdx = f->indexOfArgument(&name);
+        const int argIdx = f->indexOfArgument(QStringRef(&name));
         if (argIdx != -1)
             return _block->ARG(argIdx, scope);
 
@@ -2269,7 +2290,7 @@ bool Codegen::visit(DoWhileStatement *ast)
 
     _block = loopbody;
     statement(ast->statement);
-    _block->JUMP(loopcond);
+    setJumpOutLocation(_block->JUMP(loopcond), ast->statement, ast->semicolonToken);
 
     _block = loopcond;
     condition(ast->expression, loopbody, loopend);
@@ -2334,7 +2355,7 @@ bool Codegen::visit(ForEachStatement *ast)
         return false;
     move(*init, _block->TEMP(temp));
     statement(ast->statement);
-    _block->JUMP(foreachin);
+    setJumpOutLocation(_block->JUMP(foreachin), ast->statement, ast->forToken);
 
     _block = foreachin;
 
@@ -2373,7 +2394,7 @@ bool Codegen::visit(ForStatement *ast)
 
     _block = forbody;
     statement(ast->statement);
-    _block->JUMP(forstep);
+    setJumpOutLocation(_block->JUMP(forstep), ast->statement, ast->forToken);
 
     _block = forstep;
     statement(ast->expression);
@@ -2399,12 +2420,12 @@ bool Codegen::visit(IfStatement *ast)
 
     _block = iftrue;
     statement(ast->ok);
-    _block->JUMP(endif);
+    setJumpOutLocation(_block->JUMP(endif), ast->ok, ast->ifToken);
 
     if (ast->ko) {
         _block = iffalse;
         statement(ast->ko);
-        _block->JUMP(endif);
+        setJumpOutLocation(_block->JUMP(endif), ast->ko, ast->elseToken);
     }
 
     _block = endif;
@@ -2473,7 +2494,7 @@ bool Codegen::visit(LocalForEachStatement *ast)
     int temp = _block->newTemp();
     move(identifier(ast->declaration->name.toString()), _block->TEMP(temp));
     statement(ast->statement);
-    _block->JUMP(foreachin);
+    setJumpOutLocation(_block->JUMP(foreachin), ast->statement, ast->forToken);
 
     _block = foreachin;
 
@@ -2512,7 +2533,7 @@ bool Codegen::visit(LocalForStatement *ast)
 
     _block = forbody;
     statement(ast->statement);
-    _block->JUMP(forstep);
+    setJumpOutLocation(_block->JUMP(forstep), ast->statement, ast->forToken);
 
     _block = forstep;
     statement(ast->expression);
@@ -2813,7 +2834,7 @@ bool Codegen::visit(WhileStatement *ast)
 
     _block = whilebody;
     statement(ast->statement);
-    _block->JUMP(whilecond);
+    setJumpOutLocation(_block->JUMP(whilecond), ast->statement, ast->whileToken);
 
     _block = whileend;
     leaveLoop();
diff --git a/src/qml/compiler/qv4compilationunitmapper.cpp b/src/qml/compiler/qv4compilationunitmapper.cpp
index 2e1213464c..d94f7ac238 100644
--- a/src/qml/compiler/qv4compilationunitmapper.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper.cpp
@@ -59,7 +59,7 @@ CompilationUnitMapper::~CompilationUnitMapper()
     close();
 }
 
-bool CompilationUnitMapper::verifyHeader(const CompiledData::Unit *header, const QString &sourcePath, QString *errorString)
+bool CompilationUnitMapper::verifyHeader(const CompiledData::Unit *header, QDateTime sourceTimeStamp, QString *errorString)
 {
     if (strncmp(header->magic, CompiledData::magic_str, sizeof(header->magic))) {
         *errorString = QStringLiteral("Magic bytes in the header do not match");
@@ -76,12 +76,7 @@ bool CompilationUnitMapper::verifyHeader(const CompiledData::Unit *header, const
         return false;
     }
 
-    {
-        QFileInfo sourceCode(sourcePath);
-        QDateTime sourceTimeStamp;
-        if (sourceCode.exists())
-            sourceTimeStamp = sourceCode.lastModified();
-
+    if (header->sourceTimeStamp) {
         // Files from the resource system do not have any time stamps, so fall back to the application
         // executable.
         if (!sourceTimeStamp.isValid())
diff --git a/src/qml/compiler/qv4compilationunitmapper_p.h b/src/qml/compiler/qv4compilationunitmapper_p.h
index 5b6939f1cf..b24f98df7c 100644
--- a/src/qml/compiler/qv4compilationunitmapper_p.h
+++ b/src/qml/compiler/qv4compilationunitmapper_p.h
@@ -68,11 +68,11 @@ public:
     CompilationUnitMapper();
     ~CompilationUnitMapper();
 
-    CompiledData::Unit *open(const QString &cacheFilePath, const QString &sourcePath, QString *errorString);
+    CompiledData::Unit *open(const QString &cacheFilePath, const QDateTime &sourceTimeStamp, QString *errorString);
     void close();
 
 private:
-    static bool verifyHeader(const QV4::CompiledData::Unit *header, const QString &sourcePath, QString *errorString);
+    static bool verifyHeader(const QV4::CompiledData::Unit *header, QDateTime sourceTimeStamp, QString *errorString);
 
 #if defined(Q_OS_UNIX)
     size_t length;
diff --git a/src/qml/compiler/qv4compilationunitmapper_unix.cpp b/src/qml/compiler/qv4compilationunitmapper_unix.cpp
index 1aa3e05f5f..38dabc41cf 100644
--- a/src/qml/compiler/qv4compilationunitmapper_unix.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper_unix.cpp
@@ -43,6 +43,7 @@
 #include <functional>
 #include <private/qcore_unix_p.h>
 #include <private/qdeferredcleanup_p.h>
+#include <QDateTime>
 
 #include "qv4compileddata_p.h"
 
@@ -50,7 +51,7 @@ QT_BEGIN_NAMESPACE
 
 using namespace QV4;
 
-CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, const QString &sourcePath, QString *errorString)
+CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, const QDateTime &sourceTimeStamp, QString *errorString)
 {
     close();
 
@@ -72,7 +73,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!verifyHeader(&header, sourcePath, errorString))
+    if (!verifyHeader(&header, sourceTimeStamp, errorString))
         return nullptr;
 
     // Data structure and qt version matched, so now we can access the rest of the file safely.
diff --git a/src/qml/compiler/qv4compilationunitmapper_win.cpp b/src/qml/compiler/qv4compilationunitmapper_win.cpp
index 37cac846a0..d7a93ae233 100644
--- a/src/qml/compiler/qv4compilationunitmapper_win.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper_win.cpp
@@ -49,7 +49,7 @@ QT_BEGIN_NAMESPACE
 
 using namespace QV4;
 
-CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, const QString &sourcePath, QString *errorString)
+CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, const QDateTime &sourceTimeStamp, QString *errorString)
 {
     close();
 
@@ -87,7 +87,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!verifyHeader(&header, sourcePath, errorString))
+    if (!verifyHeader(&header, sourceTimeStamp, errorString))
         return nullptr;
 
     const uint mappingFlags = header.flags & QV4::CompiledData::Unit::ContainsMachineCode
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index a8f065210b..9832e1c49b 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -77,13 +77,7 @@ namespace QV4 {
 
 namespace CompiledData {
 
-#ifdef V4_BOOTSTRAP
-static QString cacheFilePath(const QString &localSourcePath)
-{
-    const QString localCachePath = localSourcePath + QLatin1Char('c');
-    return localCachePath;
-}
-#else
+#if !defined(V4_BOOTSTRAP)
 static QString cacheFilePath(const QUrl &url)
 {
     const QString localSourcePath = QQmlFile::urlToLocalFileOrQrc(url);
@@ -102,7 +96,6 @@ static QString cacheFilePath(const QUrl &url)
 CompilationUnit::CompilationUnit()
     : data(0)
     , engine(0)
-    , runtimeStrings(0)
     , runtimeLookups(0)
     , runtimeRegularExpressions(0)
     , runtimeClasses(0)
@@ -147,7 +140,8 @@ QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
             flags |= IR::RegExp::RegExp_IgnoreCase;
         if (re->flags & CompiledData::RegExp::RegExp_Multiline)
             flags |= IR::RegExp::RegExp_Multiline;
-        runtimeRegularExpressions[i] = engine->newRegExpObject(data->stringAt(re->stringIndex), flags);
+        QV4::Heap::RegExpObject *ro = engine->newRegExpObject(data->stringAt(re->stringIndex), flags);
+        runtimeRegularExpressions[i] = ro;
     }
 
     if (data->lookupTableSize) {
@@ -174,8 +168,6 @@ QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
             l->level = -1;
             l->index = UINT_MAX;
             l->nameIndex = compiledLookups[i].nameIndex;
-            if (type == CompiledData::Lookup::Type_IndexedGetter || type == CompiledData::Lookup::Type_IndexedSetter)
-                l->engine = engine;
         }
     }
 
@@ -249,14 +241,14 @@ void CompilationUnit::unlink()
 #endif
 }
 
-void CompilationUnit::markObjects(QV4::ExecutionEngine *e)
+void CompilationUnit::markObjects(QV4::MarkStack *markStack)
 {
     for (uint i = 0; i < data->stringTableSize; ++i)
         if (runtimeStrings[i])
-            runtimeStrings[i]->mark(e);
+            runtimeStrings[i]->mark(markStack);
     if (runtimeRegularExpressions) {
         for (uint i = 0; i < data->regexpTableSize; ++i)
-            runtimeRegularExpressions[i].mark(e);
+            runtimeRegularExpressions[i].mark(markStack);
     }
 }
 
@@ -331,10 +323,9 @@ void CompilationUnit::finalize(QQmlEnginePrivate *engine)
     totalObjectCount = objectCount;
 }
 
-bool CompilationUnit::verifyChecksum(QQmlEngine *engine,
-                                     const ResolvedTypeReferenceMap &dependentTypes) const
+bool CompilationUnit::verifyChecksum(const DependentTypesHasher &dependencyHasher) const
 {
-    if (dependentTypes.isEmpty()) {
+    if (!dependencyHasher) {
         for (size_t i = 0; i < sizeof(data->dependencyMD5Checksum); ++i) {
             if (data->dependencyMD5Checksum[i] != 0)
                 return false;
@@ -342,7 +333,7 @@ bool CompilationUnit::verifyChecksum(QQmlEngine *engine,
         return true;
     }
     QCryptographicHash hash(QCryptographicHash::Md5);
-    if (!dependentTypes.addToHash(&hash, engine))
+    if (!dependencyHasher(&hash))
         return false;
     QByteArray checksum = hash.result();
     Q_ASSERT(checksum.size() == sizeof(data->dependencyMD5Checksum));
@@ -350,7 +341,7 @@ bool CompilationUnit::verifyChecksum(QQmlEngine *engine,
                   sizeof(data->dependencyMD5Checksum)) == 0;
 }
 
-bool CompilationUnit::loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory, QString *errorString)
+bool CompilationUnit::loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, EvalISelFactory *iselFactory, QString *errorString)
 {
     if (!QQmlFile::isLocalFile(url)) {
         *errorString = QStringLiteral("File has to be a local file.");
@@ -360,14 +351,14 @@ bool CompilationUnit::loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory
     const QString sourcePath = QQmlFile::urlToLocalFileOrQrc(url);
     QScopedPointer<CompilationUnitMapper> cacheFile(new CompilationUnitMapper());
 
-    CompiledData::Unit *mappedUnit = cacheFile->open(cacheFilePath(url), sourcePath, errorString);
+    CompiledData::Unit *mappedUnit = cacheFile->open(cacheFilePath(url), sourceTimeStamp, errorString);
     if (!mappedUnit)
         return false;
 
     const Unit * const oldDataPtr = (data && !(data->flags & QV4::CompiledData::Unit::StaticData)) ? data : nullptr;
     QScopedValueRollback<const Unit *> dataPtrChange(data, mappedUnit);
 
-    if (sourcePath != QQmlFile::urlToLocalFileOrQrc(stringAt(data->sourceFileIndex))) {
+    if (data->sourceFileIndex != 0 && sourcePath != QQmlFile::urlToLocalFileOrQrc(stringAt(data->sourceFileIndex))) {
         *errorString = QStringLiteral("QML source file has moved to a different location.");
         return false;
     }
@@ -408,28 +399,29 @@ bool CompilationUnit::memoryMapCode(QString *errorString)
 #endif // V4_BOOTSTRAP
 
 #if defined(V4_BOOTSTRAP)
-bool CompilationUnit::saveToDisk(const QString &unitUrl, QString *errorString)
+bool CompilationUnit::saveToDisk(const QString &outputFileName, QString *errorString)
 #else
 bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
 #endif
 {
     errorString->clear();
 
+#if !defined(V4_BOOTSTRAP)
     if (data->sourceTimeStamp == 0) {
         *errorString = QStringLiteral("Missing time stamp for source file");
         return false;
     }
 
-#if !defined(V4_BOOTSTRAP)
     if (!QQmlFile::isLocalFile(unitUrl)) {
         *errorString = QStringLiteral("File has to be a local file.");
         return false;
     }
+    const QString outputFileName = cacheFilePath(unitUrl);
 #endif
 
 #if QT_CONFIG(temporaryfile)
     // Foo.qml -> Foo.qmlc
-    QSaveFile cacheFile(cacheFilePath(unitUrl));
+    QSaveFile cacheFile(outputFileName);
     if (!cacheFile.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
         *errorString = cacheFile.errorString();
         return false;
@@ -461,6 +453,7 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
 
     return true;
 #else
+    Q_UNUSED(outputFileName)
     *errorString = QStringLiteral("features.temporaryfile is disabled.");
     return false;
 #endif // QT_CONFIG(temporaryfile)
@@ -485,10 +478,22 @@ Unit *CompilationUnit::createUnitData(QmlIR::Document *irDocument)
         return irDocument->jsGenerator.generateUnit(QV4::Compiler::JSUnitGenerator::GenerateWithoutStringTable);
 
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = irDocument->javaScriptCompilationUnit;
-    QV4::CompiledData::Unit *jsUnit = const_cast<QV4::CompiledData::Unit*>(irDocument->javaScriptCompilationUnit->data);
+    QV4::CompiledData::Unit *jsUnit = const_cast<QV4::CompiledData::Unit*>(compilationUnit->data);
+    auto ensureWritableUnit = [&jsUnit, &compilationUnit]() {
+        if (jsUnit == compilationUnit->data) {
+            char *unitCopy = (char*)malloc(jsUnit->unitSize);
+            memcpy(unitCopy, jsUnit, jsUnit->unitSize);
+            jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitCopy);
+        }
+    };
 
     QV4::Compiler::StringTableGenerator &stringTable = irDocument->jsGenerator.stringTable;
 
+    if (jsUnit->sourceFileIndex == quint32(0) || jsUnit->stringAt(jsUnit->sourceFileIndex) != irDocument->jsModule.fileName) {
+        ensureWritableUnit();
+        jsUnit->sourceFileIndex = stringTable.registerString(irDocument->jsModule.fileName);
+    }
+
     // Collect signals that have had a change in signature (from onClicked to onClicked(mouse) for example)
     // and now need fixing in the QV4::CompiledData. Also register strings at the same time, to finalize
     // the string table.
@@ -551,6 +556,7 @@ Unit *CompilationUnit::createUnitData(QmlIR::Document *irDocument)
     }
 
     if (!signalParameterNameTable.isEmpty()) {
+        ensureWritableUnit();
         Q_ASSERT(jsUnit != compilationUnit->data);
         const uint signalParameterTableSize = signalParameterNameTable.count() * sizeof(quint32);
         uint newSize = jsUnit->unitSize + signalParameterTableSize;
@@ -732,7 +738,7 @@ static QByteArray ownLibraryChecksum()
     if (dladdr(reinterpret_cast<const void *>(&ownLibraryChecksum), &libInfo) != 0) {
         QFile library(QFile::decodeName(libInfo.dli_fname));
         if (library.open(QIODevice::ReadOnly)) {
-            QCryptographicHash hash(QCryptographicHash::Sha1);
+            QCryptographicHash hash(QCryptographicHash::Md5);
             hash.addData(&library);
             libraryChecksum = hash.result();
         }
@@ -769,7 +775,7 @@ void Unit::generateChecksum()
 #ifndef V4_BOOTSTRAP
     QCryptographicHash hash(QCryptographicHash::Md5);
 
-    const int checksummableDataOffset = qOffsetOf(QV4::CompiledData::Unit, md5Checksum) + sizeof(md5Checksum);
+    const int checksummableDataOffset = offsetof(QV4::CompiledData::Unit, md5Checksum) + sizeof(md5Checksum);
 
     const char *dataPtr = reinterpret_cast<const char *>(this) + checksummableDataOffset;
     hash.addData(dataPtr, unitSize - checksummableDataOffset);
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 13a0c4b075..f4ba257cf5 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -71,7 +71,7 @@
 QT_BEGIN_NAMESPACE
 
 // Bump this whenever the compiler data structures change in an incompatible way.
-#define QV4_DATA_STRUCTURE_VERSION 0x09
+#define QV4_DATA_STRUCTURE_VERSION 0x11
 
 class QIODevice;
 class QQmlPropertyCache;
@@ -211,7 +211,8 @@ struct Function
         HasDirectEval       = 0x2,
         UsesArgumentsObject = 0x4,
         IsNamedExpression   = 0x8,
-        HasCatchOrWith      = 0x10
+        HasCatchOrWith      = 0x10,
+        CanUseSimpleCall    = 0x20
     };
 
     // Absolute offset into file where the code for this function is located. Only used when the function
@@ -786,8 +787,10 @@ struct ResolvedTypeReferenceMap: public QMap<int, ResolvedTypeReference*>
 {
     bool addToHash(QCryptographicHash *hash, QQmlEngine *engine) const;
 };
+
+using DependentTypesHasher = std::function<bool(QCryptographicHash *)>;
 #else
-struct ResolvedTypeReferenceMap {};
+struct DependentTypesHasher {};
 #endif
 
 // index is per-object binding index
@@ -795,11 +798,15 @@ typedef QVector<QQmlPropertyData*> BindingPropertyData;
 
 // This is how this hooks into the existing structures:
 
-//VM::Function
-//    CompilationUnit * (for functions that need to clean up)
-//    CompiledData::Function *compiledFunction
+struct Q_QML_PRIVATE_EXPORT CompilationUnitBase
+{
+    QV4::Heap::String **runtimeStrings = 0; // Array
+};
+
+Q_STATIC_ASSERT(std::is_standard_layout<CompilationUnitBase>::value);
+Q_STATIC_ASSERT(offsetof(CompilationUnitBase, runtimeStrings) == 0);
 
-struct Q_QML_PRIVATE_EXPORT CompilationUnit : public QQmlRefCount
+struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public QQmlRefCount
 {
 #ifdef V4_BOOTSTRAP
     CompilationUnit()
@@ -818,11 +825,7 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public QQmlRefCount
 
 #ifndef V4_BOOTSTRAP
     ExecutionEngine *engine;
-#endif
-
-    QV4::Heap::String **runtimeStrings; // Array
 
-#ifndef V4_BOOTSTRAP
     QString fileName() const { return data->stringAt(data->sourceFileIndex); }
     QUrl url() const { if (m_url.isNull) m_url = QUrl(fileName()); return m_url; }
 
@@ -860,8 +863,7 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public QQmlRefCount
     QVector<QQmlScriptData *> dependentScripts;
     ResolvedTypeReferenceMap resolvedTypes;
 
-    bool verifyChecksum(QQmlEngine *engine,
-                        const ResolvedTypeReferenceMap &dependentTypes) const;
+    bool verifyChecksum(const DependentTypesHasher &dependencyHasher) const;
 
     int metaTypeId;
     int listMetaTypeId;
@@ -895,11 +897,11 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public QQmlRefCount
     QV4::Function *linkToEngine(QV4::ExecutionEngine *engine);
     void unlink();
 
-    void markObjects(QV4::ExecutionEngine *e);
+    void markObjects(MarkStack *markStack);
 
     void destroy() Q_DECL_OVERRIDE;
 
-    bool loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory, QString *errorString);
+    bool loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, EvalISelFactory *iselFactory, QString *errorString);
 
 protected:
     virtual void linkBackendToEngine(QV4::ExecutionEngine *engine) = 0;
@@ -908,7 +910,7 @@ protected:
 
 public:
 #if defined(V4_BOOTSTRAP)
-    bool saveToDisk(const QString &unitUrl, QString *errorString);
+    bool saveToDisk(const QString &outputFileName, QString *errorString);
 #else
     bool saveToDisk(const QUrl &unitUrl, QString *errorString);
 #endif
diff --git a/src/qml/compiler/qv4compiler.cpp b/src/qml/compiler/qv4compiler.cpp
index 9cfac4a676..f7e63437e1 100644
--- a/src/qml/compiler/qv4compiler.cpp
+++ b/src/qml/compiler/qv4compiler.cpp
@@ -296,6 +296,8 @@ void QV4::Compiler::JSUnitGenerator::writeFunction(char *f, QV4::IR::Function *i
         function->flags |= CompiledData::Function::IsNamedExpression;
     if (irFunction->hasTry || irFunction->hasWith)
         function->flags |= CompiledData::Function::HasCatchOrWith;
+    if (irFunction->canUseSimpleCall())
+        function->flags |= CompiledData::Function::CanUseSimpleCall;
     function->nFormals = irFunction->formals.size();
     function->formalsOffset = currentOffset;
     currentOffset += function->nFormals * sizeof(quint32);
@@ -374,7 +376,7 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
     unit.version = QV4_DATA_STRUCTURE_VERSION;
     unit.qtVersion = QT_VERSION;
     memset(unit.md5Checksum, 0, sizeof(unit.md5Checksum));
-    unit.architectureIndex = registerString(QSysInfo::buildAbi());
+    unit.architectureIndex = registerString(irModule->targetABI.isEmpty() ? QSysInfo::buildAbi() : irModule->targetABI);
     unit.codeGeneratorIndex = registerString(codeGeneratorName);
     memset(unit.dependencyMD5Checksum, 0, sizeof(unit.dependencyMD5Checksum));
 
@@ -425,7 +427,7 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
     }
     unit.indexOfRootFunction = -1;
     unit.sourceFileIndex = getStringId(irModule->fileName);
-    unit.sourceTimeStamp = irModule->sourceTimeStamp;
+    unit.sourceTimeStamp = irModule->sourceTimeStamp.isValid() ? irModule->sourceTimeStamp.toMSecsSinceEpoch() : 0;
     unit.nImports = 0;
     unit.offsetToImports = 0;
     unit.nObjects = 0;
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index 53d9956315..fbd6ac8f99 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -690,7 +690,7 @@ union Instr
     };
     struct instr_binop {
         MOTH_INSTR_HEADER
-        uint alu; // offset inside the runtime methods
+        int alu; // QV4::Runtime::RuntimeMethods enum value
         Param lhs;
         Param rhs;
         Param result;
diff --git a/src/qml/compiler/qv4isel_moth.cpp b/src/qml/compiler/qv4isel_moth.cpp
index 04844302d9..aefb084971 100644
--- a/src/qml/compiler/qv4isel_moth.cpp
+++ b/src/qml/compiler/qv4isel_moth.cpp
@@ -55,70 +55,70 @@ using namespace QV4::Moth;
 
 namespace {
 
-inline uint aluOpFunction(IR::AluOp op)
+inline QV4::Runtime::RuntimeMethods aluOpFunction(IR::AluOp op)
 {
     switch (op) {
     case IR::OpInvalid:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpIfTrue:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpNot:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpUMinus:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpUPlus:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpCompl:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpBitAnd:
-        return offsetof(QV4::Runtime, bitAnd);
+        return QV4::Runtime::bitAnd;
     case IR::OpBitOr:
-        return offsetof(QV4::Runtime, bitOr);
+        return QV4::Runtime::bitOr;
     case IR::OpBitXor:
-        return offsetof(QV4::Runtime, bitXor);
+        return QV4::Runtime::bitXor;
     case IR::OpAdd:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpSub:
-        return offsetof(QV4::Runtime, sub);
+        return QV4::Runtime::sub;
     case IR::OpMul:
-        return offsetof(QV4::Runtime, mul);
+        return QV4::Runtime::mul;
     case IR::OpDiv:
-        return offsetof(QV4::Runtime, div);
+        return QV4::Runtime::div;
     case IR::OpMod:
-        return offsetof(QV4::Runtime, mod);
+        return QV4::Runtime::mod;
     case IR::OpLShift:
-        return offsetof(QV4::Runtime, shl);
+        return QV4::Runtime::shl;
     case IR::OpRShift:
-        return offsetof(QV4::Runtime, shr);
+        return QV4::Runtime::shr;
     case IR::OpURShift:
-        return offsetof(QV4::Runtime, ushr);
+        return QV4::Runtime::ushr;
     case IR::OpGt:
-        return offsetof(QV4::Runtime, greaterThan);
+        return QV4::Runtime::greaterThan;
     case IR::OpLt:
-        return offsetof(QV4::Runtime, lessThan);
+        return QV4::Runtime::lessThan;
     case IR::OpGe:
-        return offsetof(QV4::Runtime, greaterEqual);
+        return QV4::Runtime::greaterEqual;
     case IR::OpLe:
-        return offsetof(QV4::Runtime, lessEqual);
+        return QV4::Runtime::lessEqual;
     case IR::OpEqual:
-        return offsetof(QV4::Runtime, equal);
+        return QV4::Runtime::equal;
     case IR::OpNotEqual:
-        return offsetof(QV4::Runtime, notEqual);
+        return QV4::Runtime::notEqual;
     case IR::OpStrictEqual:
-        return offsetof(QV4::Runtime, strictEqual);
+        return QV4::Runtime::strictEqual;
     case IR::OpStrictNotEqual:
-        return offsetof(QV4::Runtime, strictNotEqual);
+        return QV4::Runtime::strictNotEqual;
     case IR::OpInstanceof:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpIn:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpAnd:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     case IR::OpOr:
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     default:
         Q_ASSERT(!"Unknown AluOp");
-        return 0;
+        return QV4::Runtime::InvalidRuntimeMethod;
     }
 };
 
@@ -889,24 +889,25 @@ Param InstructionSelection::binopHelper(IR::AluOp oper, IR::Expr *leftSource, IR
     if (oper == IR::OpInstanceof || oper == IR::OpIn || oper == IR::OpAdd) {
         Instruction::BinopContext binop;
         if (oper == IR::OpInstanceof)
-            binop.alu = offsetof(QV4::Runtime, instanceof);
+            binop.alu = QV4::Runtime::instanceof;
         else if (oper == IR::OpIn)
-            binop.alu = offsetof(QV4::Runtime, in);
+            binop.alu = QV4::Runtime::in;
         else
-            binop.alu = offsetof(QV4::Runtime, add);
+            binop.alu = QV4::Runtime::add;
         binop.lhs = getParam(leftSource);
         binop.rhs = getParam(rightSource);
         binop.result = getResultParam(target);
-        Q_ASSERT(binop.alu);
+        Q_ASSERT(binop.alu != QV4::Runtime::InvalidRuntimeMethod);
         addInstruction(binop);
         return binop.result;
     } else {
+        auto binopFunc = aluOpFunction(oper);
+        Q_ASSERT(binopFunc != QV4::Runtime::InvalidRuntimeMethod);
         Instruction::Binop binop;
-        binop.alu = aluOpFunction(oper);
+        binop.alu = binopFunc;
         binop.lhs = getParam(leftSource);
         binop.rhs = getParam(rightSource);
         binop.result = getResultParam(target);
-        Q_ASSERT(binop.alu);
         addInstruction(binop);
         return binop.result;
     }
diff --git a/src/qml/compiler/qv4isel_moth_p.h b/src/qml/compiler/qv4isel_moth_p.h
index 41469f1985..4b84bd2831 100644
--- a/src/qml/compiler/qv4isel_moth_p.h
+++ b/src/qml/compiler/qv4isel_moth_p.h
@@ -179,7 +179,7 @@ private:
 
     int scratchTempIndex() const { return _function->tempCount; }
     int callDataStart() const { return scratchTempIndex() + 1; }
-    int outgoingArgumentTempStart() const { return callDataStart() + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value); }
+    int outgoingArgumentTempStart() const { return callDataStart() + offsetof(QV4::CallData, args)/sizeof(QV4::Value); }
     int frameSize() const { return outgoingArgumentTempStart() + _function->maxNumberOfArguments; }
 
     template <int Instr>
diff --git a/src/qml/compiler/qv4isel_util_p.h b/src/qml/compiler/qv4isel_util_p.h
index 1755193d32..e949e6f0ad 100644
--- a/src/qml/compiler/qv4isel_util_p.h
+++ b/src/qml/compiler/qv4isel_util_p.h
@@ -58,6 +58,59 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
+struct TargetPrimitive32 {
+    static TargetPrimitive32 emptyValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Empty) << 32; return p; }
+    static TargetPrimitive32 nullValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Null) << 32; return p; }
+    static TargetPrimitive32 undefinedValue() { TargetPrimitive32 p; p._val = quint64(Value::Managed_Type_Internal_32) << 32; return p; }
+    static TargetPrimitive32 fromBoolean(bool b) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Boolean) << 32 | quint64(b); return p; }
+    static TargetPrimitive32 fromInt32(int v) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Integer) << 32 | quint32(v); return p; }
+    static TargetPrimitive32 fromDouble(double v) {
+        TargetPrimitive32 p;
+        memcpy(&p._val, &v, 8);
+        return p;
+    }
+    static TargetPrimitive32 fromUInt32(uint v) {
+        if (v < INT_MAX)
+            return fromInt32(qint32(v));
+        return fromDouble(double(v));
+    }
+
+    quint32 value() const { return _val & quint64(~quint32(0)); }
+    quint32 tag() const { return _val >> 32; }
+
+    quint64 rawValue() const { return _val; }
+
+private:
+    quint64 _val;
+};
+
+struct TargetPrimitive64 {
+    static TargetPrimitive64 emptyValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Empty) << 32; return p; }
+    static TargetPrimitive64 nullValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Null) << 32; return p; }
+    static TargetPrimitive64 undefinedValue() { TargetPrimitive64 p; p._val = 0; return p; }
+    static TargetPrimitive64 fromBoolean(bool b) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Boolean) << 32 | quint64(b); return p; }
+    static TargetPrimitive64 fromInt32(int v) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Integer) << 32 | quint32(v); return p; }
+    static TargetPrimitive64 fromDouble(double v) {
+        TargetPrimitive64 p;
+        memcpy(&p._val, &v, 8);
+        p._val ^= Value::NaNEncodeMask;
+        return p;
+    }
+    static TargetPrimitive64 fromUInt32(uint v) {
+        if (v < INT_MAX)
+            return fromInt32(qint32(v));
+        return fromDouble(double(v));
+    }
+
+    quint32 value() const { return _val & quint64(~quint32(0)); }
+    quint32 tag() const { return _val >> 32; }
+
+    quint64 rawValue() const { return _val; }
+
+private:
+    quint64 _val;
+};
+
 inline bool canConvertToSignedInteger(double value)
 {
     int ival = (int) value;
@@ -72,36 +125,37 @@ inline bool canConvertToUnsignedInteger(double value)
     return uval == value && !(value == 0 && isNegative(value));
 }
 
-inline Primitive convertToValue(IR::Const *c)
+template <typename PrimitiveType = Primitive>
+inline PrimitiveType convertToValue(IR::Const *c)
 {
     switch (c->type) {
     case IR::MissingType:
-        return Primitive::emptyValue();
+        return PrimitiveType::emptyValue();
     case IR::NullType:
-        return Primitive::nullValue();
+        return PrimitiveType::nullValue();
     case IR::UndefinedType:
-        return Primitive::undefinedValue();
+        return PrimitiveType::undefinedValue();
     case IR::BoolType:
-        return Primitive::fromBoolean(c->value != 0);
+        return PrimitiveType::fromBoolean(c->value != 0);
     case IR::SInt32Type:
-        return Primitive::fromInt32(int(c->value));
+        return PrimitiveType::fromInt32(int(c->value));
     case IR::UInt32Type:
-        return Primitive::fromUInt32(unsigned(c->value));
+        return PrimitiveType::fromUInt32(unsigned(c->value));
     case IR::DoubleType:
-        return Primitive::fromDouble(c->value);
+        return PrimitiveType::fromDouble(c->value);
     case IR::NumberType: {
         int ival = (int)c->value;
         if (canConvertToSignedInteger(c->value)) {
-            return Primitive::fromInt32(ival);
+            return PrimitiveType::fromInt32(ival);
         } else {
-            return Primitive::fromDouble(c->value);
+            return PrimitiveType::fromDouble(c->value);
         }
     }
     default:
         Q_UNREACHABLE();
     }
     // unreachable, but the function must return something
-    return Primitive::undefinedValue();
+    return PrimitiveType::undefinedValue();
 }
 
 class ConvertTemps
diff --git a/src/qml/compiler/qv4jsir.cpp b/src/qml/compiler/qv4jsir.cpp
index 5687834b00..cc2f9b7cf2 100644
--- a/src/qml/compiler/qv4jsir.cpp
+++ b/src/qml/compiler/qv4jsir.cpp
@@ -348,11 +348,7 @@ Module::~Module()
 
 void Module::setFileName(const QString &name)
 {
-    if (fileName.isEmpty())
-        fileName = name;
-    else {
-        Q_ASSERT(fileName == name);
-    }
+    fileName = name;
 }
 
 Function::Function(Module *module, Function *outer, const QString &name)
diff --git a/src/qml/compiler/qv4jsir_p.h b/src/qml/compiler/qv4jsir_p.h
index 23ebe0c962..35cf0fc174 100644
--- a/src/qml/compiler/qv4jsir_p.h
+++ b/src/qml/compiler/qv4jsir_p.h
@@ -61,6 +61,7 @@
 #include <QtCore/QBitArray>
 #include <QtCore/qurl.h>
 #include <QtCore/QVarLengthArray>
+#include <QtCore/QDateTime>
 #include <qglobal.h>
 
 #if defined(CONST) && defined(Q_OS_WIN)
@@ -942,9 +943,10 @@ struct Q_QML_PRIVATE_EXPORT Module {
     QVector<Function *> functions;
     Function *rootFunction;
     QString fileName;
-    qint64 sourceTimeStamp;
+    QDateTime sourceTimeStamp;
     bool isQmlModule; // implies rootFunction is always 0
     uint unitFlags; // flags merged into CompiledData::Unit::flags
+    QString targetABI; // fallback to QSysInfo::buildAbi() if empty
 #ifdef QT_NO_QML_DEBUGGER
     static const bool debugMode = false;
 #else
@@ -955,7 +957,6 @@ struct Q_QML_PRIVATE_EXPORT Module {
 
     Module(bool debugMode)
         : rootFunction(0)
-        , sourceTimeStamp(0)
         , isQmlModule(false)
         , unitFlags(0)
 #ifndef QT_NO_QML_DEBUGGER
@@ -1352,6 +1353,31 @@ struct Function {
     int getNewStatementId() { return _statementCount++; }
     int statementCount() const { return _statementCount; }
 
+    bool canUseSimpleCall() const {
+        return nestedFunctions.isEmpty() &&
+               locals.isEmpty() && formals.size() <= QV4::Global::ReservedArgumentCount &&
+               !hasTry && !hasWith && !isNamedExpression && !usesArgumentsObject && !hasDirectEval;
+    }
+
+    bool argLocalRequiresWriteBarrier(ArgLocal *al) const {
+        uint scope = al->scope;
+        const IR::Function *f = this;
+        while (scope) {
+            f = f->outer;
+            --scope;
+        }
+        return !f->canUseSimpleCall();
+    }
+    int localsCountForScope(ArgLocal *al) const {
+        uint scope = al->scope;
+        const IR::Function *f = this;
+        while (scope) {
+            f = f->outer;
+            --scope;
+        }
+        return f->locals.size();
+    }
+
 private:
     BasicBlock *getOrCreateBasicBlock(int index);
     void setStatementCount(int cnt);
@@ -1420,6 +1446,7 @@ public:
         ArgLocal *newArgLocal = f->New<ArgLocal>();
         newArgLocal->init(argLocal->kind, argLocal->index, argLocal->scope);
         newArgLocal->type = argLocal->type;
+        newArgLocal->isArgumentsOrEval = argLocal->isArgumentsOrEval;
         return newArgLocal;
     }
 
diff --git a/src/qml/compiler/qv4jssimplifier.cpp b/src/qml/compiler/qv4jssimplifier.cpp
new file mode 100644
index 0000000000..7d09218fe6
--- /dev/null
+++ b/src/qml/compiler/qv4jssimplifier.cpp
@@ -0,0 +1,384 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4jssimplifier_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QQmlJavaScriptBindingExpressionSimplificationPass::QQmlJavaScriptBindingExpressionSimplificationPass(const QVector<QmlIR::Object*> &qmlObjects, QV4::IR::Module *jsModule, QV4::Compiler::JSUnitGenerator *unitGenerator)
+    : qmlObjects(qmlObjects)
+    , jsModule(jsModule)
+    , unitGenerator(unitGenerator)
+{
+
+}
+
+void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings()
+{
+    for (int i = 0; i < qmlObjects.count(); ++i)
+        reduceTranslationBindings(i);
+    if (!irFunctionsToRemove.isEmpty()) {
+        QQmlIRFunctionCleanser cleanser(jsModule, qmlObjects, irFunctionsToRemove);
+        cleanser.clean();
+    }
+}
+
+void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings(int objectIndex)
+{
+    const QmlIR::Object *obj = qmlObjects.at(objectIndex);
+
+    for (QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
+        if (binding->type != QV4::CompiledData::Binding::Type_Script)
+            continue;
+
+        const int irFunctionIndex = obj->runtimeFunctionIndices.at(binding->value.compiledScriptIndex);
+        QV4::IR::Function *irFunction = jsModule->functions.at(irFunctionIndex);
+        if (simplifyBinding(irFunction, binding)) {
+            irFunctionsToRemove.append(irFunctionIndex);
+            jsModule->functions[irFunctionIndex] = 0;
+            delete irFunction;
+        }
+    }
+}
+
+void QQmlJavaScriptBindingExpressionSimplificationPass::visitMove(QV4::IR::Move *move)
+{
+    QV4::IR::Temp *target = move->target->asTemp();
+    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
+        discard();
+        return;
+    }
+
+    if (QV4::IR::Call *call = move->source->asCall()) {
+        if (QV4::IR::Name *n = call->base->asName()) {
+            if (n->builtin == QV4::IR::Name::builtin_invalid) {
+                visitFunctionCall(n->id, call->args, target);
+                return;
+            }
+        }
+        discard();
+        return;
+    }
+
+    if (QV4::IR::Name *n = move->source->asName()) {
+        if (n->builtin == QV4::IR::Name::builtin_qml_context
+            || n->builtin == QV4::IR::Name::builtin_qml_imported_scripts_object) {
+            // these are free of side-effects
+            return;
+        }
+        discard();
+        return;
+    }
+
+    if (!move->source->asTemp() && !move->source->asString() && !move->source->asConst()) {
+        discard();
+        return;
+    }
+
+    _temps[target->index] = move->source;
+}
+
+void QQmlJavaScriptBindingExpressionSimplificationPass::visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target)
+{
+    // more than one function call?
+    if (_nameOfFunctionCalled) {
+        discard();
+        return;
+    }
+
+    _nameOfFunctionCalled = name;
+
+    _functionParameters.clear();
+    while (args) {
+        int slot;
+        if (QV4::IR::Temp *param = args->expr->asTemp()) {
+            if (param->kind != QV4::IR::Temp::VirtualRegister) {
+                discard();
+                return;
+            }
+            slot = param->index;
+            _functionParameters.append(slot);
+        } else if (QV4::IR::Const *param = args->expr->asConst()) {
+            slot = --_synthesizedConsts;
+            Q_ASSERT(!_temps.contains(slot));
+            _temps[slot] = param;
+            _functionParameters.append(slot);
+        }
+        args = args->next;
+    }
+
+    _functionCallReturnValue = target->index;
+}
+
+void QQmlJavaScriptBindingExpressionSimplificationPass::visitRet(QV4::IR::Ret *ret)
+{
+    // nothing initialized earlier?
+    if (_returnValueOfBindingExpression != -1) {
+        discard();
+        return;
+    }
+    QV4::IR::Temp *target = ret->expr->asTemp();
+    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
+        discard();
+        return;
+    }
+    _returnValueOfBindingExpression = target->index;
+}
+
+bool QQmlJavaScriptBindingExpressionSimplificationPass::simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding)
+{
+    _canSimplify = true;
+    _nameOfFunctionCalled = 0;
+    _functionParameters.clear();
+    _functionCallReturnValue = -1;
+    _temps.clear();
+    _returnValueOfBindingExpression = -1;
+    _synthesizedConsts = 0;
+
+    // It would seem unlikely that function with some many basic blocks (after optimization)
+    // consists merely of a qsTr call or a constant value return ;-)
+    if (function->basicBlockCount() > 10)
+        return false;
+
+    for (QV4::IR::BasicBlock *bb : function->basicBlocks()) {
+        for (QV4::IR::Stmt *s : bb->statements()) {
+            visit(s);
+            if (!_canSimplify)
+                return false;
+        }
+    }
+
+    if (_returnValueOfBindingExpression == -1)
+        return false;
+
+    if (_nameOfFunctionCalled) {
+        if (_functionCallReturnValue != _returnValueOfBindingExpression)
+            return false;
+        return detectTranslationCallAndConvertBinding(binding);
+    }
+
+    return false;
+}
+
+bool QQmlJavaScriptBindingExpressionSimplificationPass::detectTranslationCallAndConvertBinding(QmlIR::Binding *binding)
+{
+    if (*_nameOfFunctionCalled == QLatin1String("qsTr")) {
+        QString translation;
+        QV4::CompiledData::TranslationData translationData;
+        translationData.number = -1;
+        translationData.commentIndex = 0; // empty string
+
+        QVector<int>::ConstIterator param = _functionParameters.constBegin();
+        QVector<int>::ConstIterator end = _functionParameters.constEnd();
+        if (param == end)
+            return false;
+
+        QV4::IR::String *stringParam = _temps[*param]->asString();
+        if (!stringParam)
+            return false;
+
+        translation = *stringParam->value;
+
+        ++param;
+        if (param != end) {
+            stringParam = _temps[*param]->asString();
+            if (!stringParam)
+                return false;
+            translationData.commentIndex = unitGenerator->registerString(*stringParam->value);
+            ++param;
+
+            if (param != end) {
+                QV4::IR::Const *constParam = _temps[*param]->asConst();
+                if (!constParam || constParam->type != QV4::IR::SInt32Type)
+                    return false;
+
+                translationData.number = int(constParam->value);
+                ++param;
+            }
+        }
+
+        if (param != end)
+            return false;
+
+        binding->type = QV4::CompiledData::Binding::Type_Translation;
+        binding->stringIndex = unitGenerator->registerString(translation);
+        binding->value.translationData = translationData;
+        return true;
+    } else if (*_nameOfFunctionCalled == QLatin1String("qsTrId")) {
+        QString id;
+        QV4::CompiledData::TranslationData translationData;
+        translationData.number = -1;
+        translationData.commentIndex = 0; // empty string, but unused
+
+        QVector<int>::ConstIterator param = _functionParameters.constBegin();
+        QVector<int>::ConstIterator end = _functionParameters.constEnd();
+        if (param == end)
+            return false;
+
+        QV4::IR::String *stringParam = _temps[*param]->asString();
+        if (!stringParam)
+            return false;
+
+        id = *stringParam->value;
+
+        ++param;
+        if (param != end) {
+            QV4::IR::Const *constParam = _temps[*param]->asConst();
+            if (!constParam || constParam->type != QV4::IR::SInt32Type)
+                return false;
+
+            translationData.number = int(constParam->value);
+            ++param;
+        }
+
+        if (param != end)
+            return false;
+
+        binding->type = QV4::CompiledData::Binding::Type_TranslationById;
+        binding->stringIndex = unitGenerator->registerString(id);
+        binding->value.translationData = translationData;
+        return true;
+    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TR_NOOP") || *_nameOfFunctionCalled == QLatin1String("QT_TRID_NOOP")) {
+        QVector<int>::ConstIterator param = _functionParameters.constBegin();
+        QVector<int>::ConstIterator end = _functionParameters.constEnd();
+        if (param == end)
+            return false;
+
+        QV4::IR::String *stringParam = _temps[*param]->asString();
+        if (!stringParam)
+            return false;
+
+        ++param;
+        if (param != end)
+            return false;
+
+        binding->type = QV4::CompiledData::Binding::Type_String;
+        binding->stringIndex = unitGenerator->registerString(*stringParam->value);
+        return true;
+    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TRANSLATE_NOOP")) {
+        QVector<int>::ConstIterator param = _functionParameters.constBegin();
+        QVector<int>::ConstIterator end = _functionParameters.constEnd();
+        if (param == end)
+            return false;
+
+        ++param;
+        if (param == end)
+            return false;
+
+        QV4::IR::String *stringParam = _temps[*param]->asString();
+        if (!stringParam)
+            return false;
+
+        ++param;
+        if (param != end)
+            return false;
+
+        binding->type = QV4::CompiledData::Binding::Type_String;
+        binding->stringIndex = unitGenerator->registerString(*stringParam->value);
+        return true;
+    }
+    return false;
+}
+
+QQmlIRFunctionCleanser::QQmlIRFunctionCleanser(QV4::IR::Module *module, const QVector<QmlIR::Object *> &qmlObjects, const QVector<int> &functionsToRemove)
+    : module(module)
+    , qmlObjects(qmlObjects)
+    , functionsToRemove(functionsToRemove)
+{
+}
+
+void QQmlIRFunctionCleanser::clean()
+{
+    QVector<QV4::IR::Function*> newFunctions;
+    newFunctions.reserve(module->functions.count() - functionsToRemove.count());
+
+    newFunctionIndices.resize(module->functions.count());
+
+    for (int i = 0; i < module->functions.count(); ++i) {
+        QV4::IR::Function *f = module->functions.at(i);
+        Q_ASSERT(f || functionsToRemove.contains(i));
+        if (f) {
+            newFunctionIndices[i] = newFunctions.count();
+            newFunctions << f;
+        }
+    }
+
+    module->functions = newFunctions;
+
+    for (QV4::IR::Function *function : qAsConst(module->functions)) {
+        for (QV4::IR::BasicBlock *block : function->basicBlocks()) {
+            for (QV4::IR::Stmt *s : block->statements()) {
+                visit(s);
+            }
+        }
+    }
+
+    for (QmlIR::Object *obj : qmlObjects) {
+        for (int i = 0; i < obj->runtimeFunctionIndices.count; ++i)
+            obj->runtimeFunctionIndices[i] = newFunctionIndices[obj->runtimeFunctionIndices.at(i)];
+    }
+}
+
+void QQmlIRFunctionCleanser::visit(QV4::IR::Stmt *s)
+{
+
+    switch (s->stmtKind) {
+    case QV4::IR::Stmt::PhiStmt:
+        // nothing to do
+        break;
+    default:
+        STMT_VISIT_ALL_KINDS(s);
+        break;
+    }
+}
+
+void QQmlIRFunctionCleanser::visit(QV4::IR::Expr *e)
+{
+    switch (e->exprKind) {
+    case QV4::IR::Expr::ClosureExpr: {
+        auto closure = e->asClosure();
+        closure->value = newFunctionIndices.at(closure->value);
+    } break;
+    default:
+        EXPR_VISIT_ALL_KINDS(e);
+        break;
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4jssimplifier_p.h b/src/qml/compiler/qv4jssimplifier_p.h
new file mode 100644
index 0000000000..ae8d74135c
--- /dev/null
+++ b/src/qml/compiler/qv4jssimplifier_p.h
@@ -0,0 +1,154 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4JSSIMPLIFIER
+#define QV4JSSIMPLIFIER
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+
+#include "qqmlirbuilder_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QmlIR {
+struct Document;
+}
+
+namespace QV4 {
+namespace CompiledData {
+struct QmlUnit;
+struct Location;
+}
+}
+
+class QQmlJavaScriptBindingExpressionSimplificationPass
+{
+public:
+    QQmlJavaScriptBindingExpressionSimplificationPass(const QVector<QmlIR::Object*> &qmlObjects, QV4::IR::Module *jsModule, QV4::Compiler::JSUnitGenerator *unitGenerator);
+
+    void reduceTranslationBindings();
+
+private:
+    void reduceTranslationBindings(int objectIndex);
+
+    void visit(QV4::IR::Stmt *s)
+    {
+        switch (s->stmtKind) {
+        case QV4::IR::Stmt::MoveStmt:
+            visitMove(s->asMove());
+            break;
+        case QV4::IR::Stmt::RetStmt:
+            visitRet(s->asRet());
+            break;
+        case QV4::IR::Stmt::CJumpStmt:
+            discard();
+            break;
+        case QV4::IR::Stmt::ExpStmt:
+            discard();
+            break;
+        case QV4::IR::Stmt::JumpStmt:
+            break;
+        case QV4::IR::Stmt::PhiStmt:
+            break;
+        }
+    }
+
+    void visitMove(QV4::IR::Move *move);
+    void visitRet(QV4::IR::Ret *ret);
+
+    void visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target);
+
+    void discard() { _canSimplify = false; }
+
+    bool simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding);
+    bool detectTranslationCallAndConvertBinding(QmlIR::Binding *binding);
+
+    const QVector<QmlIR::Object*> &qmlObjects;
+    QV4::IR::Module *jsModule;
+    QV4::Compiler::JSUnitGenerator *unitGenerator;
+
+    bool _canSimplify;
+    const QString *_nameOfFunctionCalled;
+    QVector<int> _functionParameters;
+    int _functionCallReturnValue;
+
+    QHash<int, QV4::IR::Expr*> _temps;
+    int _returnValueOfBindingExpression;
+    int _synthesizedConsts;
+
+    QVector<int> irFunctionsToRemove;
+};
+
+class QQmlIRFunctionCleanser
+{
+public:
+    QQmlIRFunctionCleanser(QV4::IR::Module *module, const QVector<QmlIR::Object*> &qmlObjects, const QVector<int> &functionsToRemove);
+
+    void clean();
+
+private:
+    virtual void visitMove(QV4::IR::Move *s) {
+        visit(s->source);
+        visit(s->target);
+    }
+
+    void visit(QV4::IR::Stmt *s);
+    void visit(QV4::IR::Expr *e);
+
+private:
+    QV4::IR::Module *module;
+    const QVector<QmlIR::Object*> &qmlObjects;
+    const QVector<int> &functionsToRemove;
+
+    QVector<int> newFunctionIndices;
+};
+
+QT_END_NAMESPACE
+
+#endif // QV4JSSIMPLIFIER
diff --git a/src/qml/configure.json b/src/qml/configure.json
index d22ba3b8f0..2c4887365f 100644
--- a/src/qml/configure.json
+++ b/src/qml/configure.json
@@ -22,6 +22,19 @@
             "label": "QML network support",
             "purpose": "Provides network transparency for QML",
             "output": [ "publicFeature" ]
+        },
+        "qml-profiler": {
+            "label": "Command line QML Profiler",
+            "purpose": "The QML Profiler retrieves QML tracing data from an application.",
+            "condition": [
+                "features.commandlineparser",
+                "features.localserver",
+                "features.process",
+                "features.qml-debug",
+                "features.qml-network",
+                "features.xmlstreamwriter"
+            ],
+            "output": [ "privateFeature" ]
         }
     },
 
diff --git a/src/qml/debugger/qqmldebug.cpp b/src/qml/debugger/qqmldebug.cpp
index 15230d75a5..681dc06215 100644
--- a/src/qml/debugger/qqmldebug.cpp
+++ b/src/qml/debugger/qqmldebug.cpp
@@ -42,6 +42,7 @@
 #include "qqmldebugserviceinterfaces_p.h"
 
 #include <private/qqmlengine_p.h>
+#include <private/qv4compileddata_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -181,12 +182,12 @@ bool QQmlDebuggingEnabler::startDebugConnector(const QString &pluginName,
     return connector ? connector->open(configuration) : false;
 }
 
-enum { HookCount = 3 };
+enum { HookCount = 4 };
 
 // Only add to the end, and bump version if you do.
 quintptr Q_QML_EXPORT qtDeclarativeHookData[] = {
     // Version of this Array. Bump if you add to end.
-    1,
+    2,
 
     // Number of entries in this array.
     HookCount,
@@ -194,7 +195,10 @@ quintptr Q_QML_EXPORT qtDeclarativeHookData[] = {
     // TypeInformationVersion, an integral value, bumped whenever private
     // object sizes or member offsets that are used in Qt Creator's
     // data structure "pretty printing" change.
-    2
+    3,
+
+    // Version of the cache data.
+    QV4_DATA_STRUCTURE_VERSION
 };
 
 Q_STATIC_ASSERT(HookCount == sizeof(qtDeclarativeHookData) / sizeof(qtDeclarativeHookData[0]));
diff --git a/src/qml/doc/src/cppintegration/definetypes.qdoc b/src/qml/doc/src/cppintegration/definetypes.qdoc
index 7d4a543089..32084bd308 100644
--- a/src/qml/doc/src/cppintegration/definetypes.qdoc
+++ b/src/qml/doc/src/cppintegration/definetypes.qdoc
@@ -687,7 +687,7 @@ class MessageBoard : public QObject
     Q_PROPERTY(QQmlListProperty<Message> messages READ messages)
     Q_CLASSINFO("DefaultProperty", "messages")
 public:
-    QQmlListProperty<Message> messages() const;
+    QQmlListProperty<Message> messages();
 
 private:
     QList<Message *> messages;
diff --git a/src/qml/doc/src/cppintegration/exposecppattributes.qdoc b/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
index 3bffd2eb6f..c4c58c2821 100644
--- a/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
+++ b/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
@@ -267,7 +267,7 @@ class MessageBoard : public QObject
     Q_OBJECT
     Q_PROPERTY(QQmlListProperty<Message> messages READ messages)
 public:
-    QQmlListProperty<Message> messages() const;
+    QQmlListProperty<Message> messages();
 
 private:
     static void append_message(QQmlListProperty<Message> *list, Message *msg);
diff --git a/src/qml/doc/src/javascript/hostenvironment.qdoc b/src/qml/doc/src/javascript/hostenvironment.qdoc
index 1e33f2f641..7e9a22f5d3 100644
--- a/src/qml/doc/src/javascript/hostenvironment.qdoc
+++ b/src/qml/doc/src/javascript/hostenvironment.qdoc
@@ -74,6 +74,19 @@ Note that QML makes the following modifications to native objects:
 \li Locale-aware conversion functions are added to the \l Date and \l Number prototypes.
 \endlist
 
+In addition, QML also extends the behavior of the instanceof function to
+allow for type checking against QML types. This means that you may use it to
+verify that a variable is indeed the type you expect, for example:
+
+\qml
+    var v = something();
+    if (!v instanceof Item) {
+        throw new TypeError("I need an Item type!");
+    }
+
+    ...
+\endqml
+
 
 \section1 JavaScript Environment Restrictions
 
diff --git a/src/qml/jit/qv4assembler.cpp b/src/qml/jit/qv4assembler.cpp
index e658977da1..d062f3bbb2 100644
--- a/src/qml/jit/qv4assembler.cpp
+++ b/src/qml/jit/qv4assembler.cpp
@@ -95,6 +95,12 @@ bool CompilationUnit::memoryMapCode(QString *errorString)
         JSC::MacroAssemblerCodeRef codeRef = JSC::MacroAssemblerCodeRef::createSelfManagedCodeRef(JSC::MacroAssemblerCodePtr(codePtr));
         JSC::ExecutableAllocator::makeExecutable(codePtr, compiledFunction->codeSize);
         codeRefs[i] = codeRef;
+
+        static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_ASM");
+        if (showCode) {
+            WTF::dataLogF("Mapped JIT code for %s\n", qPrintable(stringAt(compiledFunction->nameIndex)));
+            disassemble(codeRef.code(), compiledFunction->codeSize, "    ", WTF::dataFile());
+        }
     }
 
     return true;
@@ -150,9 +156,6 @@ bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit
 }
 
 template <typename TargetConfiguration>
-const typename Assembler<TargetConfiguration>::VoidType Assembler<TargetConfiguration>::Void;
-
-template <typename TargetConfiguration>
 Assembler<TargetConfiguration>::Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator)
     : _function(function)
     , _nextBlock(0)
@@ -246,13 +249,16 @@ void Assembler<TargetConfiguration>::generateCJumpOnCompare(RelationalCondition
 }
 
 template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadAddress(RegisterID tmp, IR::Expr *e)
+typename Assembler<TargetConfiguration>::Pointer
+Assembler<TargetConfiguration>::loadAddressForWriting(RegisterID tmp, IR::Expr *e, WriteBarrier::Type *barrier)
 {
+    if (barrier)
+        *barrier = WriteBarrier::NoBarrier;
     IR::Temp *t = e->asTemp();
     if (t)
         return loadTempAddress(t);
     else
-        return loadArgLocalAddress(tmp, e->asArgLocal());
+        return loadArgLocalAddressForWriting(tmp, e->asArgLocal(), barrier);
 }
 
 template <typename TargetConfiguration>
@@ -265,29 +271,42 @@ typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>:
 }
 
 template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al)
+typename Assembler<TargetConfiguration>::Pointer
+Assembler<TargetConfiguration>::loadArgLocalAddressForWriting(RegisterID baseReg, IR::ArgLocal *al, WriteBarrier::Type *barrier)
 {
+    if (barrier)
+        *barrier = _function->argLocalRequiresWriteBarrier(al) ? WriteBarrier::Barrier : WriteBarrier::NoBarrier;
+
     int32_t offset = 0;
     int scope = al->scope;
-    loadPtr(Address(EngineRegister, qOffsetOf(ExecutionEngine, current)), baseReg);
-    if (scope) {
-        loadPtr(Address(baseReg, qOffsetOf(ExecutionContext::Data, outer)), baseReg);
+    loadPtr(Address(EngineRegister, targetStructureOffset(offsetof(EngineBase, current))), baseReg);
+
+    const qint32 outerOffset = targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, outer));
+    const qint32 localsOffset = targetStructureOffset(Heap::CallContextData::baseOffset + offsetof(Heap::CallContextData, function))
+                                + 8 // locals is always 8 bytes away from function, regardless of pointer size.
+                                + offsetof(ValueArray<0>, values);
+
+    while (scope) {
+        loadPtr(Address(baseReg, outerOffset), baseReg);
         --scope;
-        while (scope) {
-            loadPtr(Address(baseReg, qOffsetOf(ExecutionContext::Data, outer)), baseReg);
-            --scope;
-        }
     }
     switch (al->kind) {
     case IR::ArgLocal::Formal:
     case IR::ArgLocal::ScopedFormal: {
-        loadPtr(Address(baseReg, qOffsetOf(ExecutionContext::Data, callData)), baseReg);
-        offset = sizeof(CallData) + (al->index - 1) * sizeof(Value);
+        if (barrier && *barrier == WriteBarrier::Barrier) {
+            // if we need a barrier, the baseReg has to point to the ExecutionContext
+            // callData comes directly after locals, calculate the offset using that
+            offset = localsOffset + _function->localsCountForScope(al) * sizeof(Value);
+            offset += sizeof(CallData) + (al->index - 1) * sizeof(Value);
+        } else {
+            const qint32 callDataOffset = targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, callData));
+            loadPtr(Address(baseReg, callDataOffset), baseReg);
+            offset = sizeof(CallData) + (al->index - 1) * sizeof(Value);
+        }
     } break;
     case IR::ArgLocal::Local:
     case IR::ArgLocal::ScopedLocal: {
-        loadPtr(Address(baseReg, qOffsetOf(CallContext::Data, locals)), baseReg);
-        offset = al->index * sizeof(Value);
+        offset = localsOffset + al->index * sizeof(Value);
     } break;
     default:
         Q_UNREACHABLE();
@@ -298,25 +317,25 @@ typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>:
 template <typename TargetConfiguration>
 typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadStringAddress(RegisterID reg, const QString &string)
 {
-    loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), Assembler::ScratchRegister);
-    loadPtr(Address(Assembler::ScratchRegister, qOffsetOf(QV4::Heap::ExecutionContext, compilationUnit)), Assembler::ScratchRegister);
-    loadPtr(Address(Assembler::ScratchRegister, qOffsetOf(QV4::CompiledData::CompilationUnit, runtimeStrings)), reg);
+    loadPtr(Address(Assembler::EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), Assembler::ScratchRegister);
+    loadPtr(Address(Assembler::ScratchRegister, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, compilationUnit))), Assembler::ScratchRegister);
+    loadPtr(Address(Assembler::ScratchRegister, offsetof(CompiledData::CompilationUnitBase, runtimeStrings)), reg);
     const int id = _jsGenerator->registerString(string);
-    return Pointer(reg, id * sizeof(QV4::String*));
+    return Pointer(reg, id * RegisterSize);
 }
 
 template <typename TargetConfiguration>
 typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(IR::Const *c, RegisterID baseReg)
 {
-    return loadConstant(convertToValue(c), baseReg);
+    return loadConstant(convertToValue<TargetPrimitive>(c), baseReg);
 }
 
 template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(const Primitive &v, RegisterID baseReg)
+typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(const TargetPrimitive &v, RegisterID baseReg)
 {
-    loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), baseReg);
-    loadPtr(Address(baseReg, qOffsetOf(QV4::Heap::ExecutionContext, constantTable)), baseReg);
-    const int index = _jsGenerator->registerConstant(v.asReturnedValue());
+    loadPtr(Address(Assembler::EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), baseReg);
+    loadPtr(Address(baseReg, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, constantTable))), baseReg);
+    const int index = _jsGenerator->registerConstant(v.rawValue());
     return Address(baseReg, index * sizeof(QV4::Value));
 }
 
@@ -328,10 +347,11 @@ void Assembler<TargetConfiguration>::loadStringRef(RegisterID reg, const QString
 }
 
 template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::storeValue(QV4::Primitive value, IR::Expr *destination)
+void Assembler<TargetConfiguration>::storeValue(TargetPrimitive value, IR::Expr *destination)
 {
-    Address addr = loadAddress(ScratchRegister, destination);
-    storeValue(value, addr);
+    WriteBarrier::Type barrier;
+    Address addr = loadAddressForWriting(ScratchRegister, destination, &barrier);
+    storeValue(value, addr, barrier);
 }
 
 template <typename TargetConfiguration>
@@ -420,25 +440,19 @@ typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::ge
     // It's not a number type, so it cannot be in a register.
     Q_ASSERT(src->asArgLocal() || src->asTemp()->kind != IR::Temp::PhysicalRegister || src->type == IR::BoolType);
 
-    Assembler::Pointer tagAddr = loadAddress(Assembler::ScratchRegister, src);
+    Assembler::Pointer tagAddr = loadAddressForReading(Assembler::ScratchRegister, src);
     tagAddr.offset += 4;
     load32(tagAddr, Assembler::ScratchRegister);
 
     // check if it's an int32:
     Assembler::Jump isNoInt = branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                            Assembler::TrustedImm32(Value::Integer_Type_Internal));
+                                       Assembler::TrustedImm32(quint32(ValueTypeInternal::Integer)));
     convertInt32ToDouble(toInt32Register(src, Assembler::ScratchRegister), dest);
     Assembler::Jump intDone = jump();
 
     // not an int, check if it's a double:
     isNoInt.link(this);
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    rshift32(TrustedImm32(Value::IsDoubleTag_Shift), ScratchRegister);
-    Assembler::Jump isNoDbl = branch32(RelationalCondition::Equal, JITTargetPlatform::ScratchRegister, TrustedImm32(0));
-#else
-    and32(Assembler::TrustedImm32(Value::NotDouble_Mask), Assembler::ScratchRegister);
-    Assembler::Jump isNoDbl = branch32(RelationalCondition::Equal, JITTargetPlatform::ScratchRegister, TrustedImm32(Value::NotDouble_Mask));
-#endif
+    Assembler::Jump isNoDbl = RegisterSizeDependentOps::checkIfTagRegisterIsDouble(this, ScratchRegister);
     toDoubleRegister(src, dest);
     intDone.link(this);
 
@@ -507,7 +521,7 @@ void Assembler<TargetConfiguration>::returnFromFunction(IR::Ret *s, RegisterInfo
     } else if (IR::Temp *t = s->expr->asTemp()) {
         RegisterSizeDependentOps::setFunctionReturnValueFromTemp(this, t);
     } else if (IR::Const *c = s->expr->asConst()) {
-        QV4::Primitive retVal = convertToValue(c);
+        auto retVal = convertToValue<TargetPrimitive>(c);
         RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
     } else {
         Q_UNREACHABLE();
@@ -518,15 +532,13 @@ void Assembler<TargetConfiguration>::returnFromFunction(IR::Ret *s, RegisterInfo
 
     const int locals = stackLayout().calculateJSStackFrameSize();
     subPtr(TrustedImm32(sizeof(QV4::Value)*locals), JITTargetPlatform::LocalsRegister);
-    loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), JITTargetPlatform::ScratchRegister);
-    loadPtr(Address(JITTargetPlatform::ScratchRegister, qOffsetOf(ExecutionContext::Data, engine)), JITTargetPlatform::ScratchRegister);
-    storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::ScratchRegister, qOffsetOf(ExecutionEngine, jsStackTop)));
+    storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))));
 
     leaveStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
     ret();
 
     exceptionReturnLabel = label();
-    QV4::Primitive retVal = Primitive::undefinedValue();
+    auto retVal = TargetPrimitive::undefinedValue();
     RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
     jump(leaveStackFrame);
 }
diff --git a/src/qml/jit/qv4assembler_p.h b/src/qml/jit/qv4assembler_p.h
index 720c522e1d..9e38696d7a 100644
--- a/src/qml/jit/qv4assembler_p.h
+++ b/src/qml/jit/qv4assembler_p.h
@@ -57,6 +57,7 @@
 #include "private/qv4value_p.h"
 #include "private/qv4context_p.h"
 #include "private/qv4engine_p.h"
+#include "private/qv4writebarrier_p.h"
 #include "qv4targetplatform_p.h"
 
 #include <config.h>
@@ -131,7 +132,7 @@ typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingS
 #define isel_stringIfy(s) isel_stringIfyx(s)
 
 #define generateRuntimeCall(as, t, function, ...) \
-    as->generateFunctionCallImp(Runtime::Method_##function##_NeedsExceptionCheck, t, "Runtime::" isel_stringIfy(function), typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, function)), __VA_ARGS__)
+    as->generateFunctionCallImp(Runtime::Method_##function##_NeedsExceptionCheck, t, "Runtime::" isel_stringIfy(function), typename JITAssembler::RuntimeCall(QV4::Runtime::function), __VA_ARGS__)
 
 
 template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform, int RegisterSize>
@@ -152,35 +153,86 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
     using TrustedImm64 = typename JITAssembler::TrustedImm64;
     using Jump = typename JITAssembler::Jump;
     using Label = typename JITAssembler::Label;
+    using ValueTypeInternal = Value::ValueTypeInternal_32;
+    using TargetPrimitive = TargetPrimitive32;
+
+    static void emitSetGrayBit(JITAssembler *as, RegisterID base)
+    {
+        bool returnValueUsed = (base == TargetPlatform::ReturnValueRegister);
+
+        as->push(TargetPlatform::EngineRegister); // free up one register for work
+
+        RegisterID grayBitmap = returnValueUsed ? TargetPlatform::ScratchRegister : TargetPlatform::ReturnValueRegister;
+        as->move(base, grayBitmap);
+        Q_ASSERT(base != grayBitmap);
+        as->urshift32(TrustedImm32(Chunk::ChunkShift), grayBitmap);
+        as->lshift32(TrustedImm32(Chunk::ChunkShift), grayBitmap);
+        Q_STATIC_ASSERT(offsetof(Chunk, grayBitmap) == 0);
+
+        RegisterID index = base;
+        as->move(base, index);
+        as->sub32(grayBitmap, index);
+        as->urshift32(TrustedImm32(Chunk::SlotSizeShift), index);
+        RegisterID grayIndex = TargetPlatform::EngineRegister;
+        as->move(index, grayIndex);
+        as->urshift32(TrustedImm32(Chunk::BitShift), grayIndex);
+        as->lshift32(TrustedImm32(2), grayIndex); // 4 bytes per quintptr
+        as->add32(grayIndex, grayBitmap);
+        as->and32(TrustedImm32(Chunk::Bits - 1), index);
+
+        RegisterID bit = TargetPlatform::EngineRegister;
+        as->move(TrustedImm32(1), bit);
+        as->lshift32(index, bit);
+
+        as->load32(Pointer(grayBitmap, 0), index);
+        as->or32(bit, index);
+        as->store32(index, Pointer(grayBitmap, 0));
+
+        as->pop(TargetPlatform::EngineRegister);
+    }
+
+#if WRITEBARRIER(none)
+    static Q_ALWAYS_INLINE void emitWriteBarrier(JITAssembler *, Address) {}
+#endif
 
     static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
     {
         as->MacroAssembler::loadDouble(addr, dest);
     }
 
-    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr)
+    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr, WriteBarrier::Type barrier)
     {
         as->MacroAssembler::storeDouble(source, addr);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, addr);
     }
 
     static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
     {
-        Pointer ptr = as->loadAddress(TargetPlatform::ScratchRegister, target);
-        as->storeDouble(source, ptr);
+        WriteBarrier::Type barrier;
+        Pointer ptr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
+        as->storeDouble(source, ptr, barrier);
     }
 
-    static void storeValue(JITAssembler *as, QV4::Primitive value, Address destination)
+    static void storeValue(JITAssembler *as, TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
     {
-        as->store32(TrustedImm32(value.int_32()), destination);
+        as->store32(TrustedImm32(value.value()), destination);
         destination.offset += 4;
         as->store32(TrustedImm32(value.tag()), destination);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, destination);
     }
 
     template <typename Source, typename Destination>
-    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination)
+    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination, WriteBarrier::Type barrier)
     {
         as->loadDouble(source, TargetPlatform::FPGpr0);
-        as->storeDouble(TargetPlatform::FPGpr0, destination);
+        // We need to pass NoBarrier to storeDouble and call emitWriteBarrier ourselves, as the
+        // code in storeDouble assumes the type we're storing is actually a double, something
+        // that isn't always the case here.
+        as->storeDouble(TargetPlatform::FPGpr0, destination, WriteBarrier::NoBarrier);
+        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, destination);
     }
 
     static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
@@ -193,12 +245,14 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         as->moveIntsToDouble(TargetPlatform::LowReturnValueRegister, TargetPlatform::HighReturnValueRegister, dest, TargetPlatform::FPGpr0);
     }
 
-    static void storeReturnValue(JITAssembler *as, const Pointer &dest)
+    static void storeReturnValue(JITAssembler *as, const Pointer &dest, WriteBarrier::Type barrier)
     {
         Address destination = dest;
         as->store32(TargetPlatform::LowReturnValueRegister, destination);
         destination.offset += 4;
         as->store32(TargetPlatform::HighReturnValueRegister, destination);
+        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, dest);
     }
 
     static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
@@ -219,31 +273,31 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                 Jump done = as->jump();
                 intRange.link(as);
                 as->move(srcReg, lowReg);
-                as->move(TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
+                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Integer)), highReg);
                 done.link(as);
             } break;
             case IR::SInt32Type:
                 as->move((RegisterID) t->index, lowReg);
-                as->move(TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
+                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Integer)), highReg);
                 break;
             case IR::BoolType:
                 as->move((RegisterID) t->index, lowReg);
-                as->move(TrustedImm32(QV4::Value::Boolean_Type_Internal), highReg);
+                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Boolean)), highReg);
                 break;
             default:
                 Q_UNREACHABLE();
             }
         } else {
-            Pointer addr = as->loadAddress(TargetPlatform::ScratchRegister, t);
+            Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, t);
             as->load32(addr, lowReg);
             addr.offset += 4;
             as->load32(addr, highReg);
         }
     }
 
-    static void setFunctionReturnValueFromConst(JITAssembler *as, QV4::Primitive retVal)
+    static void setFunctionReturnValueFromConst(JITAssembler *as, TargetPrimitive retVal)
     {
-        as->move(TrustedImm32(retVal.int_32()), TargetPlatform::LowReturnValueRegister);
+        as->move(TrustedImm32(retVal.value()), TargetPlatform::LowReturnValueRegister);
         as->move(TrustedImm32(retVal.tag()), TargetPlatform::HighReturnValueRegister);
     }
 
@@ -295,7 +349,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                                   IR::BasicBlock *nextBlock, IR::BasicBlock *currentBlock,
                                   IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
     {
-        Pointer tagAddr = as->loadAddress(scratchRegister, right);
+        Pointer tagAddr = as->loadAddressForReading(scratchRegister, right);
         as->load32(tagAddr, tagRegister);
         Jump j = as->branch32(JITAssembler::invert(cond), tagRegister, TrustedImm32(0));
         as->addPatch(falseBlock, j);
@@ -312,21 +366,24 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
     {
         Q_ASSERT(source->type == IR::VarType);
         // load the tag:
-        Pointer addr = as->loadAddress(TargetPlatform::ScratchRegister, source);
+        Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, source);
         Pointer tagAddr = addr;
         tagAddr.offset += 4;
         as->load32(tagAddr, TargetPlatform::ReturnValueRegister);
 
         // check if it's an int32:
         Jump fallback = as->branch32(RelationalCondition::NotEqual, TargetPlatform::ReturnValueRegister,
-                                      TrustedImm32(Value::Integer_Type_Internal));
+                                     TrustedImm32(quint32(Value::ValueTypeInternal_32::Integer)));
         IR::Temp *targetTemp = target->asTemp();
         if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
             as->load32(addr, TargetPlatform::ReturnValueRegister);
-            Pointer targetAddr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+            WriteBarrier::Type barrier;
+            Pointer targetAddr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
             as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
             targetAddr.offset += 4;
-            as->store32(TrustedImm32(Value::Integer_Type_Internal), targetAddr);
+            as->store32(TrustedImm32(quint32(Value::ValueTypeInternal_32::Integer)), targetAddr);
+            if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+                emitWriteBarrier(as, targetAddr);
         } else {
             as->load32(addr, (RegisterID) targetTemp->index);
         }
@@ -335,17 +392,19 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         // not an int:
         fallback.link(as);
         generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
-                            as->loadAddress(TargetPlatform::ScratchRegister, source));
+                            as->loadAddressForReading(TargetPlatform::ScratchRegister, source));
         as->storeInt32(TargetPlatform::ReturnValueRegister, target);
 
         intDone.link(as);
     }
 
-    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr)
+    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr, WriteBarrier::Type barrier)
     {
         as->store32(registerWithPtr, destAddr);
         destAddr.offset += 4;
         as->store32(TrustedImm32(QV4::Value::Managed_Type_Internal_32), destAddr);
+        if (WriteBarrier::isRequired<WriteBarrier::Object>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, destAddr);
     }
 
     static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
@@ -367,6 +426,13 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         Jump jump = as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), TargetPlatform::ScratchRegister);
         jump.linkTo(loop, as);
     }
+
+    static Jump checkIfTagRegisterIsDouble(JITAssembler *as, RegisterID tagRegister)
+    {
+        as->and32(TrustedImm32(Value::NotDouble_Mask), tagRegister);
+        Jump isNoDbl = as->branch32(RelationalCondition::Equal, tagRegister, TrustedImm32(Value::NotDouble_Mask));
+        return isNoDbl;
+    }
 };
 
 template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform>
@@ -383,6 +449,47 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
     using BranchTruncateType = typename JITAssembler::BranchTruncateType;
     using Jump = typename JITAssembler::Jump;
     using Label = typename JITAssembler::Label;
+    using ValueTypeInternal = Value::ValueTypeInternal_64;
+    using TargetPrimitive = TargetPrimitive64;
+
+    static void emitSetGrayBit(JITAssembler *as, RegisterID base)
+    {
+        bool returnValueUsed = (base == TargetPlatform::ReturnValueRegister);
+
+        as->push(TargetPlatform::EngineRegister); // free up one register for work
+
+        RegisterID grayBitmap = returnValueUsed ? TargetPlatform::ScratchRegister : TargetPlatform::ReturnValueRegister;
+        as->move(base, grayBitmap);
+        Q_ASSERT(base != grayBitmap);
+        as->urshift64(TrustedImm32(Chunk::ChunkShift), grayBitmap);
+        as->lshift64(TrustedImm32(Chunk::ChunkShift), grayBitmap);
+        Q_STATIC_ASSERT(offsetof(Chunk, grayBitmap) == 0);
+
+        RegisterID index = base;
+        as->move(base, index);
+        as->sub64(grayBitmap, index);
+        as->urshift64(TrustedImm32(Chunk::SlotSizeShift), index);
+        RegisterID grayIndex = TargetPlatform::EngineRegister;
+        as->move(index, grayIndex);
+        as->urshift64(TrustedImm32(Chunk::BitShift), grayIndex);
+        as->lshift64(TrustedImm32(3), grayIndex); // 8 bytes per quintptr
+        as->add64(grayIndex, grayBitmap);
+        as->and64(TrustedImm32(Chunk::Bits - 1), index);
+
+        RegisterID bit = TargetPlatform::EngineRegister;
+        as->move(TrustedImm32(1), bit);
+        as->lshift64(index, bit);
+
+        as->load64(Pointer(grayBitmap, 0), index);
+        as->or64(bit, index);
+        as->store64(index, Pointer(grayBitmap, 0));
+
+        as->pop(TargetPlatform::EngineRegister);
+    }
+
+#if WRITEBARRIER(none)
+    static Q_ALWAYS_INLINE void emitWriteBarrier(JITAssembler *, Address) {}
+#endif
 
     static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
     {
@@ -391,19 +498,24 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
     }
 
-    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr)
+    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr, WriteBarrier::Type barrier)
     {
         as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
         as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
         as->store64(TargetPlatform::ReturnValueRegister, addr);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, addr);
     }
 
     static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
     {
         as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
         as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        Pointer ptr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+        WriteBarrier::Type barrier;
+        Pointer ptr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
         as->store64(TargetPlatform::ReturnValueRegister, ptr);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, ptr);
     }
 
     static void storeReturnValue(JITAssembler *as, FPRegisterID dest)
@@ -412,9 +524,11 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
     }
 
-    static void storeReturnValue(JITAssembler *as, const Pointer &dest)
+    static void storeReturnValue(JITAssembler *as, const Pointer &dest, WriteBarrier::Type barrier)
     {
         as->store64(TargetPlatform::ReturnValueRegister, dest);
+        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, dest);
     }
 
     static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
@@ -433,7 +547,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                 Jump done = as->jump();
                 intRange.link(as);
                 as->zeroExtend32ToPtr(srcReg, TargetPlatform::ReturnValueRegister);
-                quint64 tag = QV4::Value::Integer_Type_Internal;
+                quint64 tag = quint64(QV4::Value::ValueTypeInternal_64::Integer);
                 as->or64(TrustedImm64(tag << 32),
                          TargetPlatform::ReturnValueRegister);
                 done.link(as);
@@ -442,10 +556,10 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                 quint64 tag;
                 switch (t->type) {
                 case IR::SInt32Type:
-                    tag = QV4::Value::Integer_Type_Internal;
+                    tag = quint64(QV4::Value::ValueTypeInternal_64::Integer);
                     break;
                 case IR::BoolType:
-                    tag = QV4::Value::Boolean_Type_Internal;
+                    tag = quint64(QV4::Value::ValueTypeInternal_64::Boolean);
                     break;
                 default:
                     tag = 31337; // bogus value
@@ -455,27 +569,29 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                          TargetPlatform::ReturnValueRegister);
             }
         } else {
-            as->copyValue(TargetPlatform::ReturnValueRegister, t);
+            as->copyValue(TargetPlatform::ReturnValueRegister, t, WriteBarrier::NoBarrier);
         }
     }
 
-    static void setFunctionReturnValueFromConst(JITAssembler *as, QV4::Primitive retVal)
+    static void setFunctionReturnValueFromConst(JITAssembler *as, TargetPrimitive retVal)
     {
         as->move(TrustedImm64(retVal.rawValue()), TargetPlatform::ReturnValueRegister);
     }
 
-    static void storeValue(JITAssembler *as, QV4::Primitive value, Address destination)
+    static void storeValue(JITAssembler *as, TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
     {
         as->store64(TrustedImm64(value.rawValue()), destination);
+        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, destination);
     }
 
     template <typename Source, typename Destination>
-    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination)
+    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination, WriteBarrier::Type barrier)
     {
         // Use ReturnValueRegister as "scratch" register because loadArgument
         // and storeArgument are functions that may need a scratch register themselves.
         loadArgumentInRegister(as, source, TargetPlatform::ReturnValueRegister, 0);
-        as->storeReturnValue(destination);
+        as->storeReturnValue(destination, barrier);
     }
 
     static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
@@ -501,7 +617,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
             Pointer addr = as->loadTempAddress(temp);
             as->load64(addr, dest);
         } else {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            auto undefined = TargetPrimitive::undefinedValue();
             as->move(TrustedImm64(undefined.rawValue()), dest);
         }
     }
@@ -511,10 +627,10 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         Q_UNUSED(argumentNumber);
 
         if (al) {
-            Pointer addr = as->loadArgLocalAddress(dest, al);
+            Pointer addr = as->loadArgLocalAddressForReading(dest, al);
             as->load64(addr, dest);
         } else {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            auto undefined = TargetPrimitive::undefinedValue();
             as->move(TrustedImm64(undefined.rawValue()), dest);
         }
     }
@@ -523,7 +639,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
     {
         Q_UNUSED(argumentNumber);
 
-        QV4::Value v = convertToValue(c);
+        auto v = convertToValue<TargetPrimitive64>(c);
         as->move(TrustedImm64(v.rawValue()), dest);
     }
 
@@ -532,7 +648,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         Q_UNUSED(argumentNumber);
 
         if (!expr) {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            auto undefined = TargetPrimitive::undefinedValue();
             as->move(TrustedImm64(undefined.rawValue()), dest);
         } else if (IR::Temp *t = expr->asTemp()){
             loadArgumentInRegister(as, t, dest, argumentNumber);
@@ -580,7 +696,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
                                   IR::BasicBlock *nextBlock,  IR::BasicBlock *currentBlock,
                                   IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
     {
-        Pointer addr = as->loadAddress(scratchRegister, right);
+        Pointer addr = as->loadAddressForReading(scratchRegister, right);
         as->load64(addr, tagRegister);
         const TrustedImm64 tag(0);
         generateCJumpOnCompare(as, cond, tagRegister, tag, nextBlock, currentBlock, trueBlock, falseBlock);
@@ -589,7 +705,7 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
     static void convertVarToSInt32(JITAssembler *as, IR::Expr *source, IR::Expr *target)
     {
         Q_ASSERT(source->type == IR::VarType);
-        Pointer addr = as->loadAddress(TargetPlatform::ScratchRegister, source);
+        Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, source);
         as->load64(addr, TargetPlatform::ScratchRegister);
         as->move(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
 
@@ -613,25 +729,30 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         // not an int:
         fallback.link(as);
         generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
-                            as->loadAddress(TargetPlatform::ScratchRegister, source));
+                            as->loadAddressForReading(TargetPlatform::ScratchRegister, source));
 
 
         isIntConvertible.link(as);
         success.link(as);
         IR::Temp *targetTemp = target->asTemp();
         if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            Pointer targetAddr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+            WriteBarrier::Type barrier;
+            Pointer targetAddr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
             as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
             targetAddr.offset += 4;
-            as->store32(TrustedImm32(Value::Integer_Type_Internal), targetAddr);
+            as->store32(TrustedImm32(quint32(Value::ValueTypeInternal_64::Integer)), targetAddr);
+            if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+                emitWriteBarrier(as, targetAddr);
         } else {
             as->storeInt32(TargetPlatform::ReturnValueRegister, target);
         }
     }
 
-    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr)
+    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr, WriteBarrier::Type barrier)
     {
         as->store64(registerWithPtr, destAddr);
+        if (WriteBarrier::isRequired<WriteBarrier::Object>() && barrier == WriteBarrier::Barrier)
+            emitWriteBarrier(as, destAddr);
     }
 
     static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
@@ -651,6 +772,13 @@ struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatfo
         Jump jump = as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), TargetPlatform::ScratchRegister);
         jump.linkTo(loop, as);
     }
+
+    static Jump checkIfTagRegisterIsDouble(JITAssembler *as, RegisterID tagRegister)
+    {
+        as->rshift32(TrustedImm32(Value::IsDoubleTag_Shift), tagRegister);
+        Jump isNoDbl = as->branch32(RelationalCondition::Equal, tagRegister, TrustedImm32(0));
+        return isNoDbl;
+    }
 };
 
 template <typename TargetConfiguration>
@@ -713,7 +841,11 @@ public:
     using JITTargetPlatform::platformFinishEnteringStandardStackFrame;
     using JITTargetPlatform::platformLeaveStandardStackFrame;
 
-    using RegisterSizeDependentOps = RegisterSizeDependentAssembler<Assembler<TargetConfiguration>, MacroAssembler, JITTargetPlatform, RegisterSize>;
+    static qint32 targetStructureOffset(qint32 hostOffset)
+    {
+        Q_ASSERT(hostOffset % QT_POINTER_SIZE == 0);
+        return (hostOffset * RegisterSize) / QT_POINTER_SIZE;
+    }
 
     struct LookupCall {
         Address addr;
@@ -728,7 +860,7 @@ public:
     struct RuntimeCall {
         Address addr;
 
-        inline RuntimeCall(uint offset = uint(INT_MIN));
+        inline RuntimeCall(Runtime::RuntimeMethods method = Runtime::InvalidRuntimeMethod);
         bool isValid() const { return addr.offset >= 0; }
     };
 
@@ -745,6 +877,10 @@ public:
         {}
     };
 
+    using RegisterSizeDependentOps = RegisterSizeDependentAssembler<Assembler<TargetConfiguration>, MacroAssembler, JITTargetPlatform, RegisterSize>;
+    using ValueTypeInternal = typename RegisterSizeDependentOps::ValueTypeInternal;
+    using TargetPrimitive = typename RegisterSizeDependentOps::TargetPrimitive;
+
     // V4 uses two stacks: one stack with QV4::Value items, which is checked by the garbage
     // collector, and one stack used by the native C/C++/ABI code. This C++ stack is not scanned
     // by the garbage collector, so if any JS object needs to be retained, it should be put on the
@@ -962,12 +1098,19 @@ public:
     Jump branchDouble(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
     Jump branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
 
-    Pointer loadAddress(RegisterID tmp, IR::Expr *t);
+    Pointer loadAddressForWriting(RegisterID tmp, IR::Expr *t, WriteBarrier::Type *barrier);
+    Pointer loadAddressForReading(RegisterID tmp, IR::Expr *t) {
+        return loadAddressForWriting(tmp, t, 0);
+    }
+
     Pointer loadTempAddress(IR::Temp *t);
-    Pointer loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al);
+    Pointer loadArgLocalAddressForWriting(RegisterID baseReg, IR::ArgLocal *al, WriteBarrier::Type *barrier);
+    Pointer loadArgLocalAddressForReading(RegisterID baseReg, IR::ArgLocal *al) {
+        return loadArgLocalAddressForWriting(baseReg, al, 0);
+    }
     Pointer loadStringAddress(RegisterID reg, const QString &string);
     Address loadConstant(IR::Const *c, RegisterID baseReg);
-    Address loadConstant(const Primitive &v, RegisterID baseReg);
+    Address loadConstant(const TargetPrimitive &v, RegisterID baseReg);
     void loadStringRef(RegisterID reg, const QString &string);
     Pointer stackSlotPointer(IR::Temp *t) const
     {
@@ -986,16 +1129,16 @@ public:
                 Pointer addr(_stackLayout->savedRegPointer(argumentNumber));
                 switch (t->type) {
                 case IR::BoolType:
-                    storeBool((RegisterID) t->index, addr);
+                    storeBool((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
                     break;
                 case IR::SInt32Type:
-                    storeInt32((RegisterID) t->index, addr);
+                    storeInt32((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
                     break;
                 case IR::UInt32Type:
-                    storeUInt32((RegisterID) t->index, addr);
+                    storeUInt32((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
                     break;
                 case IR::DoubleType:
-                    storeDouble((FPRegisterID) t->index, addr);
+                    storeDouble((FPRegisterID) t->index, addr, WriteBarrier::NoBarrier);
                     break;
                 default:
                     Q_UNIMPLEMENTED();
@@ -1026,7 +1169,7 @@ public:
         if (!temp.value) {
             RegisterSizeDependentOps::zeroRegister(this, dest);
         } else {
-            Pointer addr = toAddress(dest, temp.value, argumentNumber);
+            Pointer addr = toAddress(dest, temp.value, argumentNumber, 0);
             loadArgumentInRegister(addr, dest, argumentNumber);
         }
     }
@@ -1039,7 +1182,7 @@ public:
     void loadArgumentInRegister(Reference temp, RegisterID dest, int argumentNumber)
     {
         Q_ASSERT(temp.value);
-        Pointer addr = loadAddress(dest, temp.value);
+        Pointer addr = loadAddressForReading(dest, temp.value);
         loadArgumentInRegister(addr, dest, argumentNumber);
     }
 
@@ -1072,8 +1215,10 @@ public:
             move(imm32, dest);
     }
 
-    void storeReturnValue(RegisterID dest)
+    void storeReturnValue(RegisterID dest, WriteBarrier::Type barrier = WriteBarrier::NoBarrier)
     {
+        Q_UNUSED(barrier);
+        Q_ASSERT(barrier == WriteBarrier::NoBarrier);
         move(ReturnValueRegister, dest);
     }
 
@@ -1081,7 +1226,7 @@ public:
     {
         subPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
         Pointer tmp(StackPointerRegister, 0);
-        storeReturnValue(tmp);
+        storeReturnValue(tmp, WriteBarrier::NoBarrier);
         toUInt32Register(tmp, dest);
         addPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
     }
@@ -1091,9 +1236,9 @@ public:
         RegisterSizeDependentOps::storeReturnValue(this, dest);
     }
 
-    void storeReturnValue(const Pointer &dest)
+    void storeReturnValue(const Pointer &dest, WriteBarrier::Type barrier)
     {
-        RegisterSizeDependentOps::storeReturnValue(this, dest);
+        RegisterSizeDependentOps::storeReturnValue(this, dest, barrier);
     }
 
     void storeReturnValue(IR::Expr *target)
@@ -1101,22 +1246,19 @@ public:
         if (!target)
             return;
 
-        if (IR::Temp *temp = target->asTemp()) {
-            if (temp->kind == IR::Temp::PhysicalRegister) {
-                if (temp->type == IR::DoubleType)
-                    storeReturnValue((FPRegisterID) temp->index);
-                else if (temp->type == IR::UInt32Type)
-                    storeUInt32ReturnValue((RegisterID) temp->index);
-                else
-                    storeReturnValue((RegisterID) temp->index);
-                return;
-            } else {
-                Pointer addr = loadTempAddress(temp);
-                storeReturnValue(addr);
-            }
-        } else if (IR::ArgLocal *al = target->asArgLocal()) {
-            Pointer addr = loadArgLocalAddress(ScratchRegister, al);
-            storeReturnValue(addr);
+        IR::Temp *temp = target->asTemp();
+        if (temp && temp->kind == IR::Temp::PhysicalRegister) {
+            if (temp->type == IR::DoubleType)
+                storeReturnValue((FPRegisterID) temp->index);
+            else if (temp->type == IR::UInt32Type)
+                storeUInt32ReturnValue((RegisterID) temp->index);
+            else
+                storeReturnValue((RegisterID) temp->index);
+            return;
+        } else {
+            WriteBarrier::Type barrier;
+            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
+            storeReturnValue(addr, barrier);
         }
     }
 
@@ -1153,7 +1295,7 @@ public:
     void loadArgumentOnStack(PointerToValue temp, int argumentNumber)
     {
         if (temp.value) {
-            Pointer ptr = toAddress(ScratchRegister, temp.value, argumentNumber);
+            Pointer ptr = toAddress(ScratchRegister, temp.value, argumentNumber, 0);
             loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
         } else {
             RegisterSizeDependentOps::zeroStackSlot(this, StackSlot);
@@ -1173,7 +1315,7 @@ public:
     {
         Q_ASSERT (temp.value);
 
-        Pointer ptr = loadAddress(ScratchRegister, temp.value);
+        Pointer ptr = loadAddressForReading(ScratchRegister, temp.value);
         loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
     }
 
@@ -1184,7 +1326,7 @@ public:
             moveDouble((FPRegisterID) sourceTemp->index, dest);
             return;
         }
-        Pointer ptr = loadAddress(ScratchRegister, source);
+        Pointer ptr = loadAddressForReading(ScratchRegister, source);
         loadDouble(ptr, dest);
     }
 
@@ -1203,45 +1345,57 @@ public:
         RegisterSizeDependentOps::loadDouble(this, addr, dest);
     }
 
-    void storeDouble(FPRegisterID source, Address addr)
+    void storeDouble(FPRegisterID source, Address addr, WriteBarrier::Type barrier)
     {
-        RegisterSizeDependentOps::storeDouble(this, source, addr);
+        RegisterSizeDependentOps::storeDouble(this, source, addr, barrier);
     }
 
     template <typename Result, typename Source>
-    void copyValue(Result result, Source source);
+    void copyValue(Result result, Source source, WriteBarrier::Type barrier);
     template <typename Result>
-    void copyValue(Result result, IR::Expr* source);
+    void copyValue(Result result, IR::Expr* source, WriteBarrier::Type barrier);
 
     // The scratch register is used to calculate the temp address for the source.
-    void memcopyValue(Pointer target, IR::Expr *source, RegisterID scratchRegister)
+    void memcopyValue(Pointer target, IR::Expr *source, RegisterID scratchRegister, WriteBarrier::Type barrier)
     {
         Q_ASSERT(!source->asTemp() || source->asTemp()->kind != IR::Temp::PhysicalRegister);
         Q_ASSERT(target.base != scratchRegister);
-        TargetConfiguration::MacroAssembler::loadDouble(loadAddress(scratchRegister, source), FPGpr0);
-        TargetConfiguration::MacroAssembler::storeDouble(FPGpr0, target);
+        loadRawValue(loadAddressForReading(scratchRegister, source), FPGpr0);
+        storeRawValue(FPGpr0, target, barrier);
     }
 
     // The scratch register is used to calculate the temp address for the source.
     void memcopyValue(IR::Expr *target, Pointer source, FPRegisterID fpScratchRegister, RegisterID scratchRegister)
     {
-        TargetConfiguration::MacroAssembler::loadDouble(source, fpScratchRegister);
-        TargetConfiguration::MacroAssembler::storeDouble(fpScratchRegister, loadAddress(scratchRegister, target));
+        loadRawValue(source, fpScratchRegister);
+        WriteBarrier::Type barrier;
+        Pointer dest = loadAddressForWriting(scratchRegister, target, &barrier);
+        storeRawValue(fpScratchRegister, dest, barrier);
     }
 
-    void storeValue(QV4::Primitive value, RegisterID destination)
+    void loadRawValue(Pointer source, FPRegisterID dest)
     {
-        Q_UNUSED(value);
-        Q_UNUSED(destination);
-        Q_UNREACHABLE();
+        TargetConfiguration::MacroAssembler::loadDouble(source, dest);
+    }
+
+    void storeRawValue(FPRegisterID source, Pointer dest, WriteBarrier::Type barrier)
+    {
+        TargetConfiguration::MacroAssembler::storeDouble(source, dest);
+        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
+            RegisterSizeDependentOps::emitWriteBarrier(this, dest);
     }
 
-    void storeValue(QV4::Primitive value, Address destination)
+    void storeValue(TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
     {
-        RegisterSizeDependentOps::storeValue(this, value, destination);
+        RegisterSizeDependentOps::storeValue(this, value, destination, barrier);
     }
 
-    void storeValue(QV4::Primitive value, IR::Expr* temp);
+    void storeValue(TargetPrimitive value, IR::Expr* temp);
+
+    void emitWriteBarrier(Address addr, WriteBarrier::Type barrier) {
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
+    }
 
     void enterStandardStackFrame(const RegisterInformation &regularRegistersToSave,
                                  const RegisterInformation &fpRegistersToSave);
@@ -1249,7 +1403,7 @@ public:
                                  const RegisterInformation &fpRegistersToSave);
 
     void checkException() {
-        load32(Address(EngineRegister, qOffsetOf(QV4::ExecutionEngine, hasException)), ScratchRegister);
+        this->load8(Address(EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, hasException))), ScratchRegister);
         Jump exceptionThrown = branch32(RelationalCondition::NotEqual, ScratchRegister, TrustedImm32(0));
         if (catchBlock)
             addPatch(catchBlock, exceptionThrown);
@@ -1270,13 +1424,7 @@ public:
         if (argumentNumber < RegisterArgumentCount)
             loadArgumentInRegister(value, registerForArgument(argumentNumber), argumentNumber);
         else
-#if OS(WINDOWS) && CPU(X86_64)
-            loadArgumentOnStack<argumentNumber>(value, argumentNumber);
-#elif CPU(MIPS) // Stack space for 4 arguments needs to be allocated for MIPS platforms.
-            loadArgumentOnStack<argumentNumber>(value, argumentNumber + 4);
-#else // Sanity:
-            loadArgumentOnStack<argumentNumber - RegisterArgumentCount>(value, argumentNumber);
-#endif
+            loadArgumentOnStack<argumentNumber - RegisterArgumentCount + (StackShadowSpace / RegisterSize)>(value, argumentNumber);
     }
 
     template <int argumentNumber>
@@ -1300,7 +1448,7 @@ public:
     template <int ArgumentIndex, typename Parameter>
     struct SizeOnStack
     {
-        enum { Size = Select<ArgumentIndex >= RegisterArgumentCount, sizeof(void*), 0>::Chosen };
+        enum { Size = Select<ArgumentIndex >= RegisterArgumentCount, RegisterSize, 0>::Chosen };
     };
 
     template <int ArgumentIndex>
@@ -1317,8 +1465,8 @@ public:
         // IMPORTANT! See generateLookupCall in qv4isel_masm_p.h for details!
 
         // load the table from the context
-        loadPtr(Address(EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), ScratchRegister);
-        loadPtr(Address(ScratchRegister, qOffsetOf(QV4::Heap::ExecutionContext, lookups)),
+        loadPtr(Address(EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), ScratchRegister);
+        loadPtr(Address(ScratchRegister, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, lookups))),
                     lookupCall.addr.base);
         // pre-calculate the indirect address for the lookupCall table:
         if (lookupCall.addr.offset)
@@ -1411,15 +1559,17 @@ public:
         generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, VoidType(), VoidType(), VoidType(), VoidType(), VoidType());
     }
 
-    Pointer toAddress(RegisterID tmpReg, IR::Expr *e, int offset)
+    Pointer toAddress(RegisterID tmpReg, IR::Expr *e, int offset, WriteBarrier::Type *barrier)
     {
+        if (barrier)
+            *barrier = WriteBarrier::NoBarrier;
         if (IR::Const *c = e->asConst()) {
             Address addr = _stackLayout->savedRegPointer(offset);
             Address tagAddr = addr;
             tagAddr.offset += 4;
 
-            QV4::Primitive v = convertToValue(c);
-            store32(TrustedImm32(v.int_32()), addr);
+            auto v = convertToValue<TargetPrimitive>(c);
+            store32(TrustedImm32(v.value()), addr);
             store32(TrustedImm32(v.tag()), tagAddr);
             return Pointer(addr);
         }
@@ -1428,14 +1578,16 @@ public:
             if (t->kind == IR::Temp::PhysicalRegister)
                 return Pointer(_stackLayout->savedRegPointer(offset));
 
-        return loadAddress(tmpReg, e);
+        return loadAddressForWriting(tmpReg, e, barrier);
     }
 
-    void storeBool(RegisterID reg, Pointer addr)
+    void storeBool(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
     {
         store32(reg, addr);
         addr.offset += 4;
-        store32(TrustedImm32(QV4::Primitive::fromBoolean(0).tag()), addr);
+        store32(TrustedImm32(TargetPrimitive::fromBoolean(0).tag()), addr);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
     }
 
     void storeBool(RegisterID src, RegisterID dest)
@@ -1452,8 +1604,9 @@ public:
             }
         }
 
-        Pointer addr = loadAddress(ScratchRegister, target);
-        storeBool(reg, addr);
+        WriteBarrier::Type barrier;
+        Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
+        storeBool(reg, addr, barrier);
     }
 
     void storeBool(bool value, IR::Expr *target) {
@@ -1475,25 +1628,24 @@ public:
         move(src, dest);
     }
 
-    void storeInt32(RegisterID reg, Pointer addr)
+    void storeInt32(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
     {
         store32(reg, addr);
         addr.offset += 4;
-        store32(TrustedImm32(QV4::Primitive::fromInt32(0).tag()), addr);
+        store32(TrustedImm32(TargetPrimitive::fromInt32(0).tag()), addr);
+        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
+            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
     }
 
     void storeInt32(RegisterID reg, IR::Expr *target)
     {
-        if (IR::Temp *targetTemp = target->asTemp()) {
-            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                move(reg, (RegisterID) targetTemp->index);
-            } else {
-                Pointer addr = loadTempAddress(targetTemp);
-                storeInt32(reg, addr);
-            }
-        } else if (IR::ArgLocal *al = target->asArgLocal()) {
-            Pointer addr = loadArgLocalAddress(ScratchRegister, al);
-            storeInt32(reg, addr);
+        IR::Temp *targetTemp = target->asTemp();
+        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
+            move(reg, (RegisterID) targetTemp->index);
+        } else {
+            WriteBarrier::Type barrier;
+            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
+            storeInt32(reg, addr, barrier);
         }
     }
 
@@ -1502,15 +1654,15 @@ public:
         move(src, dest);
     }
 
-    void storeUInt32(RegisterID reg, Pointer addr)
+    void storeUInt32(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
     {
         // The UInt32 representation in QV4::Value is really convoluted. See also toUInt32Register.
         Jump intRange = branch32(RelationalCondition::GreaterThanOrEqual, reg, TrustedImm32(0));
         convertUInt32ToDouble(reg, FPGpr0, ReturnValueRegister);
-        storeDouble(FPGpr0, addr);
+        storeDouble(FPGpr0, addr, barrier);
         Jump done = jump();
         intRange.link(this);
-        storeInt32(reg, addr);
+        storeInt32(reg, addr, barrier);
         done.link(this);
     }
 
@@ -1520,8 +1672,9 @@ public:
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
             move(reg, (RegisterID) targetTemp->index);
         } else {
-            Pointer addr = loadAddress(ScratchRegister, target);
-            storeUInt32(reg, addr);
+            WriteBarrier::Type barrier;
+            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
+            storeUInt32(reg, addr, barrier);
         }
     }
 
@@ -1548,7 +1701,7 @@ public:
     RegisterID toInt32Register(IR::Expr *e, RegisterID scratchReg)
     {
         if (IR::Const *c = e->asConst()) {
-            move(TrustedImm32(convertToValue(c).int_32()), scratchReg);
+            move(TrustedImm32(convertToValue<Primitive>(c).int_32()), scratchReg);
             return scratchReg;
         }
 
@@ -1556,7 +1709,7 @@ public:
             if (t->kind == IR::Temp::PhysicalRegister)
                 return (RegisterID) t->index;
 
-        return toInt32Register(loadAddress(scratchReg, e), scratchReg);
+        return toInt32Register(loadAddressForReading(scratchReg, e), scratchReg);
     }
 
     RegisterID toInt32Register(Pointer addr, RegisterID scratchReg)
@@ -1576,7 +1729,7 @@ public:
             if (t->kind == IR::Temp::PhysicalRegister)
                 return (RegisterID) t->index;
 
-        return toUInt32Register(loadAddress(scratchReg, e), scratchReg);
+        return toUInt32Register(loadAddressForReading(scratchReg, e), scratchReg);
     }
 
     RegisterID toUInt32Register(Pointer addr, RegisterID scratchReg)
@@ -1587,11 +1740,11 @@ public:
         Pointer tagAddr = addr;
         tagAddr.offset += 4;
         load32(tagAddr, scratchReg);
-        Jump inIntRange = branch32(RelationalCondition::Equal, scratchReg, TrustedImm32(QV4::Value::Integer_Type_Internal));
+        Jump inIntRange = branch32(RelationalCondition::Equal, scratchReg, TrustedImm32(quint32(ValueTypeInternal::Integer)));
 
         // it's not in signed int range, so load it as a double, and truncate it down
         loadDouble(addr, FPGpr0);
-        Address inversionAddress = loadConstant(QV4::Primitive::fromDouble(double(INT_MAX) + 1), scratchReg);
+        Address inversionAddress = loadConstant(TargetPrimitive::fromDouble(double(INT_MAX) + 1), scratchReg);
         subDouble(inversionAddress, FPGpr0);
         Jump canNeverHappen = branchTruncateDoubleToUint32(FPGpr0, scratchReg);
         canNeverHappen.link(this);
@@ -1616,9 +1769,9 @@ public:
         const int locals = _stackLayout->calculateJSStackFrameSize();
         if (locals <= 0)
             return;
-        loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)), JITTargetPlatform::LocalsRegister);
+        loadPtr(Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))), JITTargetPlatform::LocalsRegister);
         RegisterSizeDependentOps::initializeLocalVariables(this, locals);
-        storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)));
+        storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))));
     }
 
     Label exceptionReturnLabel;
@@ -1647,40 +1800,44 @@ private:
 };
 
 template <typename TargetConfiguration>
+const typename Assembler<TargetConfiguration>::VoidType Assembler<TargetConfiguration>::Void;
+
+template <typename TargetConfiguration>
 template <typename Result, typename Source>
-void Assembler<TargetConfiguration>::copyValue(Result result, Source source)
+void Assembler<TargetConfiguration>::copyValue(Result result, Source source, WriteBarrier::Type barrier)
 {
-    RegisterSizeDependentOps::copyValueViaRegisters(this, source, result);
+    RegisterSizeDependentOps::copyValueViaRegisters(this, source, result, barrier);
 }
 
 template <typename TargetConfiguration>
 template <typename Result>
-void Assembler<TargetConfiguration>::copyValue(Result result, IR::Expr* source)
+void Assembler<TargetConfiguration>::copyValue(Result result, IR::Expr* source, WriteBarrier::Type barrier)
 {
     if (source->type == IR::BoolType) {
         RegisterID reg = toInt32Register(source, ScratchRegister);
-        storeBool(reg, result);
+        storeBool(reg, result, barrier);
     } else if (source->type == IR::SInt32Type) {
         RegisterID reg = toInt32Register(source, ScratchRegister);
-        storeInt32(reg, result);
+        storeInt32(reg, result, barrier);
     } else if (source->type == IR::UInt32Type) {
         RegisterID reg = toUInt32Register(source, ScratchRegister);
-        storeUInt32(reg, result);
+        storeUInt32(reg, result, barrier);
     } else if (source->type == IR::DoubleType) {
-        storeDouble(toDoubleRegister(source), result);
+        storeDouble(toDoubleRegister(source), result, barrier);
     } else if (source->asTemp() || source->asArgLocal()) {
-        RegisterSizeDependentOps::copyValueViaRegisters(this, source, result);
+        RegisterSizeDependentOps::copyValueViaRegisters(this, source, result, barrier);
     } else if (IR::Const *c = source->asConst()) {
-        QV4::Primitive v = convertToValue(c);
-        storeValue(v, result);
+        auto v = convertToValue<TargetPrimitive>(c);
+        storeValue(v, result, barrier);
     } else {
         Q_UNREACHABLE();
     }
 }
 
 template <typename TargetConfiguration>
-inline Assembler<TargetConfiguration>::RuntimeCall::RuntimeCall(uint offset)
-    : addr(Assembler::EngineRegister, offset + qOffsetOf(QV4::ExecutionEngine, runtime))
+inline Assembler<TargetConfiguration>::RuntimeCall::RuntimeCall(Runtime::RuntimeMethods method)
+    : addr(Assembler::EngineRegister,
+           method == Runtime::InvalidRuntimeMethod ? -1 : (Assembler<TargetConfiguration>::targetStructureOffset(offsetof(EngineBase, runtime) + Runtime::runtimeMethodOffset(method))))
 {
 }
 
diff --git a/src/qml/jit/qv4binop.cpp b/src/qml/jit/qv4binop.cpp
index 22067bbb13..a1c65f644c 100644
--- a/src/qml/jit/qv4binop.cpp
+++ b/src/qml/jit/qv4binop.cpp
@@ -165,17 +165,17 @@ struct ArchitectureSpecificBinaryOperation<Assembler<AssemblerTargetConfiguratio
 #endif
 
 #define OP(op) \
-    { "Runtime::" isel_stringIfy(op), offsetof(QV4::Runtime, op), INT_MIN, 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
+    { "Runtime::" isel_stringIfy(op), QV4::Runtime::op, QV4::Runtime::InvalidRuntimeMethod, 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
 #define OPCONTEXT(op) \
-    { "Runtime::" isel_stringIfy(op), INT_MIN, offsetof(QV4::Runtime, op), 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
+    { "Runtime::" isel_stringIfy(op), QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::op, 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
 
 #define INLINE_OP(op, memOp, immOp) \
-    { "Runtime::" isel_stringIfy(op), offsetof(QV4::Runtime, op), INT_MIN, memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
+    { "Runtime::" isel_stringIfy(op), QV4::Runtime::op, QV4::Runtime::InvalidRuntimeMethod, memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
 #define INLINE_OPCONTEXT(op, memOp, immOp) \
-    { "Runtime::" isel_stringIfy(op), INT_MIN, offsetof(QV4::Runtime, op), memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
+    { "Runtime::" isel_stringIfy(op), QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::op, memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
 
 #define NULL_OP \
-    { 0, 0, 0, 0, 0, false }
+    { 0, QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::InvalidRuntimeMethod, 0, 0, false }
 
 template <typename JITAssembler>
 const typename Binop<JITAssembler>::OpInfo Binop<JITAssembler>::operations[IR::LastAluOp + 1] = {
@@ -492,7 +492,7 @@ bool Binop<JITAssembler>::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource
             return false;
         }
     } else if (inplaceOpWithAddress) { // All cases of X = X op [address-of-Y]
-        Pointer rhsAddr = as->loadAddress(JITAssembler::ScratchRegister, rightSource);
+        Pointer rhsAddr = as->loadAddressForReading(JITAssembler::ScratchRegister, rightSource);
         switch (op) {
         case IR::OpBitAnd: as->and32(rhsAddr, targetReg); break;
         case IR::OpBitOr:  as->or32 (rhsAddr, targetReg); break;
diff --git a/src/qml/jit/qv4binop_p.h b/src/qml/jit/qv4binop_p.h
index d2d9ba7753..1b1ab7f24d 100644
--- a/src/qml/jit/qv4binop_p.h
+++ b/src/qml/jit/qv4binop_p.h
@@ -88,8 +88,8 @@ struct Binop {
 
     struct OpInfo {
         const char *name;
-        int fallbackImplementation; // offsetOf(Runtime,...)
-        int contextImplementation; // offsetOf(Runtime,...)
+        Runtime::RuntimeMethods fallbackImplementation;
+        Runtime::RuntimeMethods contextImplementation;
         MemRegOp inlineMemRegOp;
         ImmRegOp inlineImmRegOp;
         bool needsExceptionCheck;
diff --git a/src/qml/jit/qv4isel_masm.cpp b/src/qml/jit/qv4isel_masm.cpp
index 69d6951bb9..599370f73d 100644
--- a/src/qml/jit/qv4isel_masm.cpp
+++ b/src/qml/jit/qv4isel_masm.cpp
@@ -132,8 +132,8 @@ void InstructionSelection<JITAssembler>::run(int functionIndex)
         for (IR::Stmt *s : _block->statements()) {
             if (s->location.isValid()) {
                 if (int(s->location.startLine) != lastLine) {
-                    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), JITTargetPlatform::ScratchRegister);
-                    Address lineAddr(JITTargetPlatform::ScratchRegister, qOffsetOf(QV4::ExecutionContext::Data, lineNumber));
+                    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, JITAssembler::targetStructureOffset(offsetof(QV4::EngineBase, current))), JITTargetPlatform::ScratchRegister);
+                    Address lineAddr(JITTargetPlatform::ScratchRegister, JITAssembler::targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, lineNumber)));
                     _as->store32(TrustedImm32(s->location.startLine), lineAddr);
                     lastLine = s->location.startLine;
                 }
@@ -256,7 +256,7 @@ void InstructionSelection<JITAssembler>::callBuiltinDeleteName(const QString &na
 template <typename JITAssembler>
 void InstructionSelection<JITAssembler>::callBuiltinDeleteValue(IR::Expr *result)
 {
-    _as->storeValue(Primitive::fromBoolean(false), result);
+    _as->storeValue(JITAssembler::TargetPrimitive::fromBoolean(false), result);
 }
 
 template <typename JITAssembler>
@@ -350,11 +350,11 @@ void InstructionSelection<JITAssembler>::callBuiltinDefineObjectLiteral(IR::Expr
         bool isData = it->expr->asConst()->value;
         it = it->next;
 
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr);
+        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
 
         if (!isData) {
             it = it->next;
-            _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr);
+            _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
         }
     }
 
@@ -376,10 +376,10 @@ void InstructionSelection<JITAssembler>::callBuiltinDefineObjectLiteral(IR::Expr
         ++arrayValueCount;
 
         // Index
-        _as->storeValue(QV4::Primitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++));
+        _as->storeValue(JITAssembler::TargetPrimitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++), WriteBarrier::NoBarrier);
 
         // Value
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr);
+        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
         it = it->next;
     }
 
@@ -400,14 +400,14 @@ void InstructionSelection<JITAssembler>::callBuiltinDefineObjectLiteral(IR::Expr
         ++arrayGetterSetterCount;
 
         // Index
-        _as->storeValue(QV4::Primitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++));
+        _as->storeValue(JITAssembler::TargetPrimitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++), WriteBarrier::NoBarrier);
 
         // Getter
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr);
+        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
         it = it->next;
 
         // Setter
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr);
+        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
         it = it->next;
     }
 
@@ -447,9 +447,11 @@ void InstructionSelection<JITAssembler>::callValue(IR::Expr *value, IR::ExprList
 template <typename JITAssembler>
 void InstructionSelection<JITAssembler>::loadThisObject(IR::Expr *temp)
 {
-    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), JITTargetPlatform::ScratchRegister);
-    _as->loadPtr(Address(JITTargetPlatform::ScratchRegister, qOffsetOf(ExecutionContext::Data, callData)), JITTargetPlatform::ScratchRegister);
-    _as->copyValue(temp, Address(JITTargetPlatform::ScratchRegister, qOffsetOf(CallData, thisObject)));
+    WriteBarrier::Type barrier;
+    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, temp, &barrier);
+    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, JITAssembler::targetStructureOffset(offsetof(QV4::EngineBase, current))), JITTargetPlatform::ReturnValueRegister);
+    _as->loadPtr(Address(JITTargetPlatform::ReturnValueRegister,JITAssembler::targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, callData))), JITTargetPlatform::ReturnValueRegister);
+    _as->copyValue(addr, Address(JITTargetPlatform::ReturnValueRegister, offsetof(CallData, thisObject)), barrier);
 }
 
 template <typename JITAssembler>
@@ -486,7 +488,7 @@ void InstructionSelection<JITAssembler>::loadConst(IR::Const *sourceConst, IR::E
                 _as->toUInt32Register(sourceConst, (RegisterID) targetTemp->index);
             } else if (targetTemp->type == IR::BoolType) {
                 Q_ASSERT(sourceConst->type == IR::BoolType);
-                _as->move(TrustedImm32(convertToValue(sourceConst).int_32()),
+                _as->move(TrustedImm32(convertToValue<Primitive>(sourceConst).int_32()),
                           (RegisterID) targetTemp->index);
             } else {
                 Q_UNREACHABLE();
@@ -495,7 +497,7 @@ void InstructionSelection<JITAssembler>::loadConst(IR::Const *sourceConst, IR::E
         }
     }
 
-    _as->storeValue(convertToValue(sourceConst), target);
+    _as->storeValue(convertToValue<typename JITAssembler::TargetPrimitive>(sourceConst), target);
 }
 
 template <typename JITAssembler>
@@ -503,8 +505,9 @@ void InstructionSelection<JITAssembler>::loadString(const QString &str, IR::Expr
 {
     Pointer srcAddr = _as->loadStringAddress(JITTargetPlatform::ReturnValueRegister, str);
     _as->loadPtr(srcAddr, JITTargetPlatform::ReturnValueRegister);
-    Pointer destAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, target);
-    JITAssembler::RegisterSizeDependentOps::loadManagedPointer(_as, JITTargetPlatform::ReturnValueRegister, destAddr);
+    WriteBarrier::Type barrier;
+    Pointer destAddr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, target, &barrier);
+    JITAssembler::RegisterSizeDependentOps::loadManagedPointer(_as, JITTargetPlatform::ReturnValueRegister, destAddr, barrier);
 }
 
 template <typename JITAssembler>
@@ -519,7 +522,7 @@ void InstructionSelection<JITAssembler>::getActivationProperty(const IR::Name *n
 {
     if (useFastLookups && name->global) {
         uint index = registerGlobalGetterLookup(*name->id);
-        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, globalGetter), JITTargetPlatform::EngineRegister, JITAssembler::Void);
+        generateLookupCall(target, index, offsetof(QV4::Lookup, globalGetter), JITTargetPlatform::EngineRegister, JITAssembler::Void);
         return;
     }
     generateRuntimeCall(_as, target, getActivationProperty, JITTargetPlatform::EngineRegister, StringToIndex(*name->id));
@@ -545,7 +548,7 @@ void InstructionSelection<JITAssembler>::getProperty(IR::Expr *base, const QStri
 {
     if (useFastLookups) {
         uint index = registerGetterLookup(name);
-        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, getter), JITTargetPlatform::EngineRegister, PointerToValue(base), JITAssembler::Void);
+        generateLookupCall(target, index, offsetof(QV4::Lookup, getter), JITTargetPlatform::EngineRegister, PointerToValue(base), JITAssembler::Void);
     } else {
         generateRuntimeCall(_as, target, getProperty, JITTargetPlatform::EngineRegister,
                              PointerToValue(base), StringToIndex(name));
@@ -584,7 +587,7 @@ void InstructionSelection<JITAssembler>::setProperty(IR::Expr *source, IR::Expr
 {
     if (useFastLookups) {
         uint index = registerSetterLookup(targetName);
-        generateLookupCall(JITAssembler::Void, index, qOffsetOf(QV4::Lookup, setter),
+        generateLookupCall(JITAssembler::Void, index, offsetof(QV4::Lookup, setter),
                            JITTargetPlatform::EngineRegister,
                            PointerToValue(targetBase),
                            PointerToValue(source));
@@ -620,7 +623,8 @@ void InstructionSelection<JITAssembler>::getElement(IR::Expr *base, IR::Expr *in
 {
     if (useFastLookups) {
         uint lookup = registerIndexedGetterLookup();
-        generateLookupCall(target, lookup, qOffsetOf(QV4::Lookup, indexedGetter),
+        generateLookupCall(target, lookup, offsetof(QV4::Lookup, indexedGetter),
+                           JITTargetPlatform::EngineRegister,
                            PointerToValue(base),
                            PointerToValue(index));
         return;
@@ -635,7 +639,8 @@ void InstructionSelection<JITAssembler>::setElement(IR::Expr *source, IR::Expr *
 {
     if (useFastLookups) {
         uint lookup = registerIndexedSetterLookup();
-        generateLookupCall(JITAssembler::Void, lookup, qOffsetOf(QV4::Lookup, indexedSetter),
+        generateLookupCall(JITAssembler::Void, lookup, offsetof(QV4::Lookup, indexedSetter),
+                           JITTargetPlatform::EngineRegister,
                            PointerToValue(targetBase), PointerToValue(targetIndex),
                            PointerToValue(source));
         return;
@@ -711,8 +716,10 @@ void InstructionSelection<JITAssembler>::copyValue(IR::Expr *source, IR::Expr *t
         }
     }
 
+    WriteBarrier::Type barrier;
+    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, target, &barrier);
     // The target is not a physical register, nor is the source. So we can do a memory-to-memory copy:
-    _as->memcopyValue(_as->loadAddress(JITTargetPlatform::ReturnValueRegister, target), source, JITTargetPlatform::ScratchRegister);
+    _as->memcopyValue(addr, source, JITTargetPlatform::ScratchRegister, barrier);
 }
 
 template <typename JITAssembler>
@@ -739,14 +746,13 @@ void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *
     } else if (!sourceTemp || sourceTemp->kind == IR::Temp::StackSlot) {
         if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
             // Note: a swap for two stack-slots can involve different types.
-            Pointer sAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
-            Pointer tAddr = _as->loadAddress(JITTargetPlatform::ReturnValueRegister, target);
-            // use the implementation in JSC::MacroAssembler, as it doesn't do bit swizzling
-            auto platformAs = static_cast<typename JITAssembler::MacroAssembler*>(_as);
-            platformAs->loadDouble(sAddr, JITTargetPlatform::FPGpr0);
-            platformAs->loadDouble(tAddr, JITTargetPlatform::FPGpr1);
-            platformAs->storeDouble(JITTargetPlatform::FPGpr1, sAddr);
-            platformAs->storeDouble(JITTargetPlatform::FPGpr0, tAddr);
+            WriteBarrier::Type barrierForSource, barrierForTarget;
+            Pointer sAddr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, source, &barrierForSource);
+            Pointer tAddr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, target, &barrierForTarget);
+            _as->loadRawValue(sAddr, JITTargetPlatform::FPGpr0);
+            _as->loadRawValue(tAddr, JITTargetPlatform::FPGpr1);
+            _as->storeRawValue(JITTargetPlatform::FPGpr1, sAddr, barrierForSource);
+            _as->storeRawValue(JITTargetPlatform::FPGpr0, tAddr, barrierForTarget);
             return;
         }
     }
@@ -757,14 +763,15 @@ void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *
     Q_ASSERT(memExpr);
     Q_ASSERT(regTemp);
 
-    Pointer addr = _as->loadAddress(JITTargetPlatform::ReturnValueRegister, memExpr);
+    WriteBarrier::Type barrier;
+    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, memExpr, &barrier);
     if (regTemp->type == IR::DoubleType) {
         _as->loadDouble(addr, JITTargetPlatform::FPGpr0);
-        _as->storeDouble((FPRegisterID) regTemp->index, addr);
+        _as->storeDouble((FPRegisterID) regTemp->index, addr, barrier);
         _as->moveDouble(JITTargetPlatform::FPGpr0, (FPRegisterID) regTemp->index);
     } else if (regTemp->type == IR::UInt32Type) {
         _as->toUInt32Register(addr, JITTargetPlatform::ScratchRegister);
-        _as->storeUInt32((RegisterID) regTemp->index, addr);
+        _as->storeUInt32((RegisterID) regTemp->index, addr, barrier);
         _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
     } else {
         _as->load32(addr, JITTargetPlatform::ScratchRegister);
@@ -774,16 +781,17 @@ void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *
             quint32 tag;
             switch (regTemp->type) {
             case IR::BoolType:
-                tag = QV4::Value::Boolean_Type_Internal;
+                tag = quint32(JITAssembler::ValueTypeInternal::Boolean);
                 break;
             case IR::SInt32Type:
-                tag = QV4::Value::Integer_Type_Internal;
+                tag = quint32(JITAssembler::ValueTypeInternal::Integer);
                 break;
             default:
                 tag = 31337; // bogus value
                 Q_UNREACHABLE();
             }
             _as->store32(TrustedImm32(tag), addr);
+            _as->emitWriteBarrier(addr, barrier);
         }
         _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
     }
@@ -791,12 +799,12 @@ void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *
 
 #define setOp(op, opName, operation) \
     do { \
-        op = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
+        op = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); opName = "Runtime::" isel_stringIfy(operation); \
         needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 #define setOpContext(op, opName, operation) \
     do { \
-        opContext = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
+        opContext = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); opName = "Runtime::" isel_stringIfy(operation); \
         needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 
@@ -913,19 +921,19 @@ void InstructionSelection<JITAssembler>::convertTypeToDouble(IR::Expr *source, I
         convertUIntToDouble(source, target);
         break;
     case IR::UndefinedType:
-        _as->loadDouble(_as->loadAddress(JITTargetPlatform::ScratchRegister, source), JITTargetPlatform::FPGpr0);
+        _as->loadDouble(_as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source), JITTargetPlatform::FPGpr0);
         _as->storeDouble(JITTargetPlatform::FPGpr0, target);
         break;
     case IR::StringType:
     case IR::VarType: {
         // load the tag:
-        Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
         tagAddr.offset += 4;
         _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
 
         // check if it's an int32:
         Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                                TrustedImm32(Value::Integer_Type_Internal));
+                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
         convertIntToDouble(source, target);
         Jump intDone = _as->jump();
 
@@ -938,7 +946,7 @@ void InstructionSelection<JITAssembler>::convertTypeToDouble(IR::Expr *source, I
 
         // it is a double:
         isDbl.link(_as);
-        Pointer addr2 = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        Pointer addr2 = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
         IR::Temp *targetTemp = target->asTemp();
         if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
             _as->memcopyValue(target, addr2, JITTargetPlatform::FPGpr0, JITTargetPlatform::ReturnValueRegister);
@@ -996,20 +1004,20 @@ void InstructionSelection<JITAssembler>::convertTypeToBool(IR::Expr *source, IR:
         _as->storeBool(JITTargetPlatform::ReturnValueRegister, target);
     case IR::VarType:
     default:
-        Pointer addr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        Pointer addr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
         Pointer tagAddr = addr;
         tagAddr.offset += 4;
         _as->load32(tagAddr, JITTargetPlatform::ReturnValueRegister);
 
         // checkif it's a bool:
         Jump notBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
-                                                TrustedImm32(Value::Boolean_Type_Internal));
+                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
         _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
         Jump boolDone = _as->jump();
         // check if it's an int32:
         notBool.link(_as);
         Jump fallback = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
-                                                 TrustedImm32(Value::Integer_Type_Internal));
+                                      TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
         _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
         Jump isZero = _as->branch32(RelationalCondition::Equal, JITTargetPlatform::ReturnValueRegister,
                                                TrustedImm32(0));
@@ -1061,7 +1069,7 @@ void InstructionSelection<JITAssembler>::convertTypeToSInt32(IR::Expr *source, I
     case IR::StringType:
     default:
         generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toInt,
-                             _as->loadAddress(JITTargetPlatform::ScratchRegister, source));
+                             _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source));
         _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
         break;
     } // switch (source->type)
@@ -1073,21 +1081,21 @@ void InstructionSelection<JITAssembler>::convertTypeToUInt32(IR::Expr *source, I
     switch (source->type) {
     case IR::VarType: {
         // load the tag:
-        Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
         tagAddr.offset += 4;
         _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
 
         // check if it's an int32:
         Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                                TrustedImm32(Value::Integer_Type_Internal));
-        Pointer addr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
+        Pointer addr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
         _as->storeUInt32(_as->toInt32Register(addr, JITTargetPlatform::ScratchRegister), target);
         Jump intDone = _as->jump();
 
         // not an int:
         isNoInt.link(_as);
         generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toUInt,
-                             _as->loadAddress(JITTargetPlatform::ScratchRegister, source));
+                             _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source));
         _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
 
         intDone.link(_as);
@@ -1192,10 +1200,11 @@ void InstructionSelection<JITAssembler>::visitCJump(IR::CJump *s)
             reg = JITTargetPlatform::ReturnValueRegister;
             _as->toInt32Register(t, reg);
         } else {
-            Address temp = _as->loadAddress(JITTargetPlatform::ScratchRegister, s->cond);
+            Address temp = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, s->cond);
             Address tag = temp;
             tag.offset += QV4::Value::tagOffset();
-            Jump booleanConversion = _as->branch32(RelationalCondition::NotEqual, tag, TrustedImm32(QV4::Value::Boolean_Type_Internal));
+            Jump booleanConversion = _as->branch32(RelationalCondition::NotEqual, tag,
+                                                   TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
 
             Address data = temp;
             data.offset += QV4::Value::valueOffset();
@@ -1297,9 +1306,9 @@ int InstructionSelection<JITAssembler>::prepareVariableArguments(IR::ExprList* a
         Q_ASSERT(arg != 0);
         Pointer dst(_as->stackLayout().argumentAddressForCall(i));
         if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister);
+            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister, WriteBarrier::NoBarrier);
         else
-            _as->copyValue(dst, arg);
+            _as->copyValue(dst, arg, WriteBarrier::NoBarrier);
     }
 
     return argc;
@@ -1313,15 +1322,15 @@ int InstructionSelection<JITAssembler>::prepareCallData(IR::ExprList* args, IR::
         ++argc;
     }
 
-    Pointer p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, tag));
-    _as->store32(TrustedImm32(QV4::Value::Integer_Type_Internal), p);
-    p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, argc));
+    Pointer p = _as->stackLayout().callDataAddress(offsetof(CallData, tag));
+    _as->store32(TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)), p);
+    p = _as->stackLayout().callDataAddress(offsetof(CallData, argc));
     _as->store32(TrustedImm32(argc), p);
-    p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, thisObject));
+    p = _as->stackLayout().callDataAddress(offsetof(CallData, thisObject));
     if (!thisObject)
-        _as->storeValue(QV4::Primitive::undefinedValue(), p);
+        _as->storeValue(JITAssembler::TargetPrimitive::undefinedValue(), p, WriteBarrier::NoBarrier);
     else
-        _as->copyValue(p, thisObject);
+        _as->copyValue(p, thisObject, WriteBarrier::NoBarrier);
 
     int i = 0;
     for (IR::ExprList *it = args; it; it = it->next, ++i) {
@@ -1329,9 +1338,9 @@ int InstructionSelection<JITAssembler>::prepareCallData(IR::ExprList* args, IR::
         Q_ASSERT(arg != 0);
         Pointer dst(_as->stackLayout().argumentAddressForCall(i));
         if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister);
+            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister, WriteBarrier::NoBarrier);
         else
-            _as->copyValue(dst, arg);
+            _as->copyValue(dst, arg, WriteBarrier::NoBarrier);
     }
     return argc;
 }
@@ -1449,14 +1458,14 @@ bool InstructionSelection<JITAssembler>::visitCJumpStrictNull(IR::Binop *binop,
         return true;
     }
 
-    Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, varSrc);
+    Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, varSrc);
     tagAddr.offset += 4;
     const RegisterID tagReg = JITTargetPlatform::ScratchRegister;
     _as->load32(tagAddr, tagReg);
 
     RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
                                                                          : RelationalCondition::NotEqual;
-    const TrustedImm32 tag(QV4::Value::Null_Type_Internal);
+    const TrustedImm32 tag{quint32(JITAssembler::ValueTypeInternal::Null)};
     _as->generateCJumpOnCompare(cond, tagReg, tag, _block, trueBlock, falseBlock);
     return true;
 }
@@ -1532,13 +1541,13 @@ bool InstructionSelection<JITAssembler>::visitCJumpStrictBool(IR::Binop *binop,
         return true;
     }
 
-    Pointer otherAddr = _as->loadAddress(JITTargetPlatform::ReturnValueRegister, otherSrc);
+    Pointer otherAddr = _as->loadAddressForReading(JITTargetPlatform::ReturnValueRegister, otherSrc);
     otherAddr.offset += 4; // tag address
 
     // check if the tag of the var operand is indicates 'boolean'
     _as->load32(otherAddr, JITTargetPlatform::ScratchRegister);
     Jump noBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                           TrustedImm32(QV4::Value::Boolean_Type_Internal));
+                                TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
     if (binop->op == IR::OpStrictEqual)
         _as->addPatch(falseBlock, noBool);
     else
@@ -1581,14 +1590,14 @@ bool InstructionSelection<JITAssembler>::visitCJumpNullUndefined(IR::Type nullOr
         return true;
     }
 
-    Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, varSrc);
+    Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, varSrc);
     tagAddr.offset += 4;
     const RegisterID tagReg = JITTargetPlatform::ReturnValueRegister;
     _as->load32(tagAddr, tagReg);
 
     if (binop->op == IR::OpNotEqual)
         qSwap(trueBlock, falseBlock);
-    Jump isNull = _as->branch32(RelationalCondition::Equal, tagReg, TrustedImm32(int(QV4::Value::Null_Type_Internal)));
+    Jump isNull = _as->branch32(RelationalCondition::Equal, tagReg, TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Null)));
     Jump isNotUndefinedTag = _as->branch32(RelationalCondition::NotEqual, tagReg, TrustedImm32(int(QV4::Value::Managed_Type_Internal)));
     tagAddr.offset -= 4;
     _as->load32(tagAddr, tagReg);
@@ -1640,18 +1649,18 @@ Q_QML_EXPORT QV4::EvalISelFactory *createISelForArchitecture(const QString &arch
     using ARMv7CrossAssembler = QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>;
     using ARM64CrossAssembler = QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>>;
 
-    if (architecture == QLatin1String("armv7"))
+    if (architecture == QLatin1String("arm"))
         return new ISelFactory<ARMv7CrossAssembler>;
-    else if (architecture == QLatin1String("armv8"))
+    else if (architecture == QLatin1String("arm64"))
         return new ISelFactory<ARM64CrossAssembler>;
 
     QString hostArch;
 #if CPU(ARM_THUMB2)
-    hostArch = QStringLiteral("armv7");
+    hostArch = QStringLiteral("arm");
 #elif CPU(MIPS)
     hostArch = QStringLiteral("mips");
 #elif CPU(X86)
-    hostArch = QStringLiteral("x86");
+    hostArch = QStringLiteral("i386");
 #elif CPU(X86_64)
     hostArch = QStringLiteral("x86_64");
 #endif
diff --git a/src/qml/jit/qv4isel_masm_p.h b/src/qml/jit/qv4isel_masm_p.h
index 5c046cb397..7019a117a2 100644
--- a/src/qml/jit/qv4isel_masm_p.h
+++ b/src/qml/jit/qv4isel_masm_p.h
@@ -160,7 +160,7 @@ protected:
         // FramePointerRegister points to its old value on the stack, and above
         // it we have the return address, hence the need to step over two
         // values before reaching the first argument.
-        return Address(JITTargetPlatform::FramePointerRegister, (index + 2) * sizeof(void*));
+        return Address(JITTargetPlatform::FramePointerRegister, (index + 2) * JITTargetPlatform::RegisterSize);
     }
 
     Pointer baseAddressForCallArguments()
@@ -209,7 +209,7 @@ private:
                         _as->convertInt32ToDouble((RegisterID) sourceTemp->index,
                                                   (FPRegisterID) targetTemp->index);
                     } else {
-                        _as->convertInt32ToDouble(_as->loadAddress(JITTargetPlatform::ReturnValueRegister, sourceTemp),
+                        _as->convertInt32ToDouble(_as->loadAddressForReading(JITTargetPlatform::ReturnValueRegister, sourceTemp),
                                                   (FPRegisterID) targetTemp->index);
                     }
                 } else {
@@ -223,7 +223,7 @@ private:
 
         _as->convertInt32ToDouble(_as->toInt32Register(source, JITTargetPlatform::ScratchRegister),
                                   JITTargetPlatform::FPGpr0);
-        _as->storeDouble(JITTargetPlatform::FPGpr0, _as->loadAddress(JITTargetPlatform::ReturnValueRegister, target));
+        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
     }
 
     void convertUIntToDouble(IR::Expr *source, IR::Expr *target)
@@ -240,7 +240,7 @@ private:
 
         _as->convertUInt32ToDouble(_as->toUInt32Register(source, tmpReg),
                                    JITTargetPlatform::FPGpr0, tmpReg);
-        _as->storeDouble(JITTargetPlatform::FPGpr0, _as->loadAddress(tmpReg, target));
+        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
     }
 
     void convertIntToBool(IR::Expr *source, IR::Expr *target)
@@ -260,8 +260,8 @@ private:
 
     void calculateRegistersToSave(const RegisterInformation &used);
 
-    template <typename Retval, typename Arg1, typename Arg2, typename Arg3>
-    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2, Arg3 arg3)
+    template <typename Retval, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
+    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
     {
         // Note: using the return value register is intentional: for ABIs where the first parameter
         // goes into the same register as the return value (currently only ARM), the prepareCall
@@ -271,7 +271,7 @@ private:
 
          _as->generateFunctionCallImp(true, retval, "lookup getter/setter",
                                       typename JITAssembler::LookupCall(lookupAddr, getterSetterOffset), lookupAddr,
-                                      arg1, arg2, arg3);
+                                      arg1, arg2, arg3, arg4);
     }
 
     template <typename Retval, typename Arg1, typename Arg2>
@@ -280,6 +280,12 @@ private:
         generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, typename JITAssembler::VoidType());
     }
 
+    template <typename Retval, typename Arg1, typename Arg2, typename Arg3>
+    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2, Arg3 arg3)
+    {
+        generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, arg3, typename JITAssembler::VoidType());
+    }
+
     IR::BasicBlock *_block;
     BitVector _removableJumps;
     JITAssembler* _as;
diff --git a/src/qml/jit/qv4targetplatform_p.h b/src/qml/jit/qv4targetplatform_p.h
index d9f8034b1f..6d788f4a93 100644
--- a/src/qml/jit/qv4targetplatform_p.h
+++ b/src/qml/jit/qv4targetplatform_p.h
@@ -370,7 +370,7 @@ public:
     // There are two designated frame-pointer registers on ARM, depending on which instruction set
     // is used for the subroutine: r7 for Thumb or Thumb2, and r11 for ARM. We assign the constants
     // accordingly, and assign the locals-register to the "other" register.
-#if CPU(ARM_THUMB2)
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
     static const RegisterID FramePointerRegister = JSC::ARMRegisters::r7;
     static const RegisterID LocalsRegister = JSC::ARMRegisters::r11;
 #else // Thumbs down
@@ -397,7 +397,7 @@ public:
                 << RI(JSC::ARMRegisters::r4,  QStringLiteral("r4"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
                 << RI(JSC::ARMRegisters::r5,  QStringLiteral("r5"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
                 << RI(JSC::ARMRegisters::r6,  QStringLiteral("r6"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#if !CPU(ARM_THUMB2)
+#if !CPU(ARM_THUMB2) && !defined(V4_BOOTSTRAP)
                 << RI(JSC::ARMRegisters::r7,  QStringLiteral("r7"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
 #endif
                 << RI(JSC::ARMRegisters::r8,  QStringLiteral("r8"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
@@ -405,7 +405,7 @@ public:
                 << RI(JSC::ARMRegisters::r9,  QStringLiteral("r9"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
 #endif
                 << RI(JSC::ARMRegisters::r10, QStringLiteral("r10"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#if CPU(ARM_THUMB2)
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
                 << RI(JSC::ARMRegisters::r11, QStringLiteral("r11"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
 #endif
                 << RI(JSC::ARMRegisters::d2,  QStringLiteral("d2"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
diff --git a/src/qml/jit/qv4unop.cpp b/src/qml/jit/qv4unop.cpp
index 76c6457d67..896be07ed5 100644
--- a/src/qml/jit/qv4unop.cpp
+++ b/src/qml/jit/qv4unop.cpp
@@ -48,7 +48,7 @@ using namespace JIT;
 #define stringIfy(s) stringIfyx(s)
 #define setOp(operation) \
     do { \
-        call = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); name = "Runtime::" stringIfy(operation); \
+        call = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); name = "Runtime::" stringIfy(operation); \
         needsExceptionCheck = Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 
diff --git a/src/qml/jsapi/qjsvalue.h b/src/qml/jsapi/qjsvalue.h
index ab20a2607d..56bd64eec1 100644
--- a/src/qml/jsapi/qjsvalue.h
+++ b/src/qml/jsapi/qjsvalue.h
@@ -133,9 +133,9 @@ public:
     bool deleteProperty(const QString &name);
 
     bool isCallable() const;
-    QJSValue call(const QJSValueList &args = QJSValueList());
-    QJSValue callWithInstance(const QJSValue &instance, const QJSValueList &args = QJSValueList());
-    QJSValue callAsConstructor(const QJSValueList &args = QJSValueList());
+    QJSValue call(const QJSValueList &args = QJSValueList()); // ### Qt6: Make const
+    QJSValue callWithInstance(const QJSValue &instance, const QJSValueList &args = QJSValueList()); // ### Qt6: Make const
+    QJSValue callAsConstructor(const QJSValueList &args = QJSValueList()); // ### Qt6: Make const
 
 #ifdef QT_DEPRECATED
     QT_DEPRECATED QJSEngine *engine() const;
diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 7c1cc92a13..318db4f904 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -48,32 +48,33 @@ DEFINE_OBJECT_VTABLE(ArgumentsObject);
 
 void Heap::ArgumentsObject::init(QV4::CallContext *context)
 {
+    ExecutionEngine *v4 = context->d()->engine;
+
     Object::init();
     fullyCreated = false;
-    this->context = context->d();
+    this->context.set(v4, context->d());
     Q_ASSERT(vtable() == QV4::ArgumentsObject::staticVTable());
 
-    ExecutionEngine *v4 = context->d()->engine;
     Scope scope(v4);
     Scoped<QV4::ArgumentsObject> args(scope, this);
 
     if (context->d()->strictMode) {
         Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(context->d()->engine->id_callee()));
         Q_ASSERT(CallerPropertyIndex == args->internalClass()->find(context->d()->engine->id_caller()));
-        *args->propertyData(CalleePropertyIndex + QV4::Object::GetterOffset) = v4->thrower();
-        *args->propertyData(CalleePropertyIndex + QV4::Object::SetterOffset) = v4->thrower();
-        *args->propertyData(CallerPropertyIndex + QV4::Object::GetterOffset) = v4->thrower();
-        *args->propertyData(CallerPropertyIndex + QV4::Object::SetterOffset) = v4->thrower();
+        args->setProperty(CalleePropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
+        args->setProperty(CalleePropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
+        args->setProperty(CallerPropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
+        args->setProperty(CallerPropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
 
         args->arrayReserve(context->argc());
         args->arrayPut(0, context->args(), context->argc());
         args->d()->fullyCreated = true;
     } else {
         Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(context->d()->engine->id_callee()));
-        *args->propertyData(CalleePropertyIndex) = context->d()->function->asReturnedValue();
+        args->setProperty(CalleePropertyIndex, context->d()->function);
     }
     Q_ASSERT(LengthPropertyIndex == args->internalClass()->find(context->d()->engine->id_length()));
-    *args->propertyData(LengthPropertyIndex) = Primitive::fromInt32(context->d()->callData->argc);
+    args->setProperty(LengthPropertyIndex, Primitive::fromInt32(context->d()->callData->argc));
 }
 
 void ArgumentsObject::fullyCreate()
@@ -89,9 +90,9 @@ void ArgumentsObject::fullyCreate()
     Scope scope(engine());
     Scoped<MemberData> md(scope, d()->mappedArguments);
     if (numAccessors) {
-        d()->mappedArguments = md->allocate(engine(), numAccessors);
+        d()->mappedArguments.set(scope.engine, md->allocate(engine(), numAccessors));
         for (uint i = 0; i < numAccessors; ++i) {
-            d()->mappedArguments->data[i] = context()->callData->args[i];
+            d()->mappedArguments->values.set(scope.engine, i, context()->callData->args[i]);
             arraySet(i, context()->engine->argumentsAccessors + i, Attr_Accessor);
         }
     }
@@ -107,22 +108,22 @@ bool ArgumentsObject::defineOwnProperty(ExecutionEngine *engine, uint index, con
     fullyCreate();
 
     Scope scope(engine);
-    Property *pd = arrayData() ? arrayData()->getProperty(index) : 0;
     ScopedProperty map(scope);
     PropertyAttributes mapAttrs;
+    uint numAccessors = qMin(context()->formalParameterCount(), static_cast<uint>(context()->callData->argc));
     bool isMapped = false;
-    uint numAccessors = qMin((int)context()->formalParameterCount(), context()->callData->argc);
-    if (pd && index < (uint)numAccessors)
-        isMapped = arrayData()->attributes(index).isAccessor() &&
-                pd->getter() == context()->engine->argumentsAccessors[index].getter();
+    if (arrayData() && index < numAccessors &&
+        arrayData()->attributes(index).isAccessor() &&
+        arrayData()->get(index) == context()->engine->argumentsAccessors[index].getter()->asReturnedValue())
+        isMapped = true;
 
     if (isMapped) {
         Q_ASSERT(arrayData());
         mapAttrs = arrayData()->attributes(index);
-        map->copy(pd, mapAttrs);
+        arrayData()->getProperty(index, map, &mapAttrs);
         setArrayAttributes(index, Attr_Data);
-        pd = arrayData()->getProperty(index);
-        pd->value = d()->mappedArguments->data[index];
+        ArrayData::Index arrayIndex{ arrayData(), arrayData()->mappedIndex(index) };
+        arrayIndex.set(scope.engine, d()->mappedArguments->values[index]);
     }
 
     bool strict = engine->current->strictMode;
@@ -140,8 +141,7 @@ bool ArgumentsObject::defineOwnProperty(ExecutionEngine *engine, uint index, con
 
         if (attrs.isWritable()) {
             setArrayAttributes(index, mapAttrs);
-            pd = arrayData()->getProperty(index);
-            pd->copy(map, mapAttrs);
+            arrayData()->setProperty(engine, index, map);
         }
     }
 
@@ -235,17 +235,6 @@ void ArgumentsSetterFunction::call(const Managed *setter, Scope &scope, CallData
     scope.result = Encode::undefined();
 }
 
-void ArgumentsObject::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    ArgumentsObject::Data *o = static_cast<ArgumentsObject::Data *>(that);
-    if (o->context)
-        o->context->mark(e);
-    if (o->mappedArguments)
-        o->mappedArguments->mark(e);
-
-    Object::markObjects(that, e);
-}
-
 uint ArgumentsObject::getLength(const Managed *m)
 {
     const ArgumentsObject *a = static_cast<const ArgumentsObject *>(m);
diff --git a/src/qml/jsruntime/qv4argumentsobject_p.h b/src/qml/jsruntime/qv4argumentsobject_p.h
index f80ade9611..46e1f884e8 100644
--- a/src/qml/jsruntime/qv4argumentsobject_p.h
+++ b/src/qml/jsruntime/qv4argumentsobject_p.h
@@ -59,26 +59,35 @@ namespace QV4 {
 
 namespace Heap {
 
-struct ArgumentsGetterFunction : FunctionObject {
+#define ArgumentsGetterFunctionMembers(class, Member) \
+    Member(class, NoMark, uint, index)
+
+DECLARE_HEAP_OBJECT(ArgumentsGetterFunction, FunctionObject) {
+    DECLARE_MARK_TABLE(ArgumentsGetterFunction);
     inline void init(QV4::ExecutionContext *scope, uint index);
-    uint index;
 };
 
-struct ArgumentsSetterFunction : FunctionObject {
+#define ArgumentsSetterFunctionMembers(class, Member) \
+    Member(class, NoMark, uint, index)
+
+DECLARE_HEAP_OBJECT(ArgumentsSetterFunction, FunctionObject) {
+    DECLARE_MARK_TABLE(ArgumentsSetterFunction);
     inline void init(QV4::ExecutionContext *scope, uint index);
-    uint index;
 };
 
-struct ArgumentsObject : Object {
+#define ArgumentsObjectMembers(class, Member) \
+    Member(class, Pointer, CallContext *, context) \
+    Member(class, Pointer, MemberData *, mappedArguments) \
+    Member(class, NoMark, bool, fullyCreated)
+
+DECLARE_HEAP_OBJECT(ArgumentsObject, Object) {
+    DECLARE_MARK_TABLE(ArgumentsObject);
     enum {
         LengthPropertyIndex = 0,
         CalleePropertyIndex = 1,
         CallerPropertyIndex = 3
     };
     void init(QV4::CallContext *context);
-    Pointer<CallContext> context;
-    bool fullyCreated;
-    Pointer<MemberData> mappedArguments;
 };
 
 }
@@ -131,7 +140,6 @@ struct ArgumentsObject: Object {
     static bool putIndexed(Managed *m, uint index, const Value &value);
     static bool deleteIndexedProperty(Managed *m, uint index);
     static PropertyAttributes queryIndexed(const Managed *m, uint index);
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
     static uint getLength(const Managed *m);
 
     void fullyCreate();
diff --git a/src/qml/jsruntime/qv4arraydata.cpp b/src/qml/jsruntime/qv4arraydata.cpp
index d8a7de5466..4a619858b4 100644
--- a/src/qml/jsruntime/qv4arraydata.cpp
+++ b/src/qml/jsruntime/qv4arraydata.cpp
@@ -50,6 +50,7 @@ QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON
 
 const QV4::VTable QV4::ArrayData::static_vtbl = {
     0,
+    0,
     QV4::ArrayData::IsExecutionContext,
     QV4::ArrayData::IsString,
     QV4::ArrayData::IsObject,
@@ -128,7 +129,7 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
 
         if (d->type() < Heap::ArrayData::Sparse) {
             offset = d->d()->offset;
-            toCopy = d->d()->len;
+            toCopy = d->d()->values.size;
         } else {
             toCopy = d->alloc();
         }
@@ -149,7 +150,7 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
         Heap::SimpleArrayData *n = scope.engine->memoryManager->allocManaged<SimpleArrayData>(size);
         n->init();
         n->offset = 0;
-        n->len = d ? d->d()->len : 0;
+        n->values.size = d ? d->d()->values.size : 0;
         newData = n;
     } else {
         Heap::SparseArrayData *n = scope.engine->memoryManager->allocManaged<SparseArrayData>(size);
@@ -158,7 +159,7 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
     }
     newData->setAlloc(alloc);
     newData->setType(newType);
-    newData->setAttrs(enforceAttributes ? reinterpret_cast<PropertyAttributes *>(newData->d()->arrayData + alloc) : 0);
+    newData->setAttrs(enforceAttributes ? reinterpret_cast<PropertyAttributes *>(newData->d()->values.values + alloc) : 0);
     o->setArrayData(newData);
 
     if (d) {
@@ -170,12 +171,14 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
                     newData->attrs()[i] = Attr_Data;
         }
 
-        if (toCopy > d->d()->alloc - offset) {
-            uint copyFromStart = toCopy - (d->d()->alloc - offset);
-            memcpy(newData->d()->arrayData + toCopy - copyFromStart, d->d()->arrayData, sizeof(Value)*copyFromStart);
+        if (toCopy > d->d()->values.alloc - offset) {
+            uint copyFromStart = toCopy - (d->d()->values.alloc - offset);
+            // no write barrier required here
+            memcpy(newData->d()->values.values + toCopy - copyFromStart, d->d()->values.values, sizeof(Value)*copyFromStart);
             toCopy -= copyFromStart;
         }
-        memcpy(newData->d()->arrayData, d->d()->arrayData + offset, sizeof(Value)*toCopy);
+        // no write barrier required here
+        memcpy(newData->d()->values.values, d->d()->values.values + offset, sizeof(Value)*toCopy);
     }
 
     if (newType != Heap::ArrayData::Sparse)
@@ -195,22 +198,22 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
         lastFree = &sparse->freeList;
         storeValue(lastFree, 0);
         for (uint i = 0; i < toCopy; ++i) {
-            if (!sparse->arrayData[i].isEmpty()) {
+            if (!sparse->values[i].isEmpty()) {
                 SparseArrayNode *n = sparse->sparse->insert(i);
                 n->value = i;
             } else {
                 storeValue(lastFree, i);
-                sparse->arrayData[i].setEmpty();
-                lastFree = &sparse->arrayData[i].rawValueRef();
+                sparse->values.values[i].setEmpty();
+                lastFree = &sparse->values.values[i].rawValueRef();
             }
         }
     }
 
-    if (toCopy < sparse->alloc) {
-        for (uint i = toCopy; i < sparse->alloc; ++i) {
+    if (toCopy < sparse->values.alloc) {
+        for (uint i = toCopy; i < sparse->values.alloc; ++i) {
             storeValue(lastFree, i);
-            sparse->arrayData[i].setEmpty();
-            lastFree = &sparse->arrayData[i].rawValueRef();
+            sparse->values.values[i].setEmpty();
+            lastFree = &sparse->values.values[i].rawValueRef();
         }
         storeValue(lastFree, UINT_MAX);
     }
@@ -233,24 +236,10 @@ void ArrayData::ensureAttributes(Object *o)
     ArrayData::realloc(o, Heap::ArrayData::Simple, 0, true);
 }
 
-
-void SimpleArrayData::markObjects(Heap::Base *d, ExecutionEngine *e)
-{
-    Heap::SimpleArrayData *dd = static_cast<Heap::SimpleArrayData *>(d);
-    uint end = dd->offset + dd->len;
-    if (end > dd->alloc) {
-        for (uint i = 0; i < end - dd->alloc; ++i)
-            dd->arrayData[i].mark(e);
-        end = dd->alloc;
-    }
-    for (uint i = dd->offset; i < end; ++i)
-        dd->arrayData[i].mark(e);
-}
-
 ReturnedValue SimpleArrayData::get(const Heap::ArrayData *d, uint index)
 {
     const Heap::SimpleArrayData *dd = static_cast<const Heap::SimpleArrayData *>(d);
-    if (index >= dd->len)
+    if (index >= dd->values.size)
         return Primitive::emptyValue().asReturnedValue();
     return dd->data(index).asReturnedValue();
 }
@@ -258,13 +247,13 @@ ReturnedValue SimpleArrayData::get(const Heap::ArrayData *d, uint index)
 bool SimpleArrayData::put(Object *o, uint index, const Value &value)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-    Q_ASSERT(index >= dd->len || !dd->attrs || !dd->attrs[index].isAccessor());
+    Q_ASSERT(index >= dd->values.size || !dd->attrs || !dd->attrs[index].isAccessor());
     // ### honour attributes
-    dd->data(index) = value;
-    if (index >= dd->len) {
+    dd->setData(o->engine(), index, value);
+    if (index >= dd->values.size) {
         if (dd->attrs)
             dd->attrs[index] = Attr_Data;
-        dd->len = index + 1;
+        dd->values.size = index + 1;
     }
     return true;
 }
@@ -272,11 +261,11 @@ bool SimpleArrayData::put(Object *o, uint index, const Value &value)
 bool SimpleArrayData::del(Object *o, uint index)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-    if (index >= dd->len)
+    if (index >= dd->values.size)
         return true;
 
     if (!dd->attrs || dd->attrs[index].isConfigurable()) {
-        dd->data(index) = Primitive::emptyValue();
+        dd->setData(o->engine(), index, Primitive::emptyValue());
         if (dd->attrs)
             dd->attrs[index] = Attr_Data;
         return true;
@@ -295,8 +284,8 @@ void SimpleArrayData::push_front(Object *o, const Value *values, uint n)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
     Q_ASSERT(!dd->attrs);
-    if (dd->len + n > dd->alloc) {
-        realloc(o, Heap::ArrayData::Simple, dd->len + n, false);
+    if (dd->values.size + n > dd->values.alloc) {
+        realloc(o, Heap::ArrayData::Simple, dd->values.size + n, false);
         Q_ASSERT(o->d()->arrayData->type == Heap::ArrayData::Simple);
         dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
     }
@@ -304,70 +293,71 @@ void SimpleArrayData::push_front(Object *o, const Value *values, uint n)
         dd->offset -= n; // there is enough space left in front
     } else {
          // we need to wrap around, so:
-        dd->offset = dd->alloc - // start at the back, but subtract:
+        dd->offset = dd->values.alloc - // start at the back, but subtract:
                 (n - dd->offset); // the number of items we can put in the free space at the start of the allocated array
     }
-    dd->len += n;
+    dd->values.size += n;
     for (uint i = 0; i < n; ++i)
-        dd->data(i) = values[i].asReturnedValue();
+        dd->setData(o->engine(), i, values[i]);
 }
 
 ReturnedValue SimpleArrayData::pop_front(Object *o)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
     Q_ASSERT(!dd->attrs);
-    if (!dd->len)
+    if (!dd->values.size)
         return Encode::undefined();
 
     ReturnedValue v = dd->data(0).isEmpty() ? Encode::undefined() : dd->data(0).asReturnedValue();
-    dd->offset = (dd->offset + 1) % dd->alloc;
-    --dd->len;
+    dd->offset = (dd->offset + 1) % dd->values.alloc;
+    --dd->values.size;
     return v;
 }
 
 uint SimpleArrayData::truncate(Object *o, uint newLen)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-    if (dd->len < newLen)
+    if (dd->values.size < newLen)
         return newLen;
 
     if (!dd->attrs) {
-        dd->len = newLen;
+        dd->values.size = newLen;
         return newLen;
     }
 
-    while (dd->len > newLen) {
-        if (!dd->data(dd->len - 1).isEmpty() && !dd->attrs[dd->len - 1].isConfigurable())
-            return dd->len;
-        --dd->len;
+    while (dd->values.size > newLen) {
+        if (!dd->data(dd->values.size - 1).isEmpty() && !dd->attrs[dd->values.size - 1].isConfigurable())
+            return dd->values.size;
+        --dd->values.size;
     }
-    return dd->len;
+    return dd->values.size;
 }
 
 uint SimpleArrayData::length(const Heap::ArrayData *d)
 {
-    return d->len;
+    return d->values.size;
 }
 
 bool SimpleArrayData::putArray(Object *o, uint index, const Value *values, uint n)
 {
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-    if (index + n > dd->alloc) {
+    if (index + n > dd->values.alloc) {
         reallocate(o, index + n + 1, false);
         dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
     }
-    for (uint i = dd->len; i < index; ++i)
-        dd->data(i) = Primitive::emptyValue();
+    QV4::ExecutionEngine *e = o->engine();
+    for (uint i = dd->values.size; i < index; ++i)
+        dd->setData(e, i, Primitive::emptyValue());
     for (uint i = 0; i < n; ++i)
-        dd->data(index + i) = values[i];
-    dd->len = qMax(dd->len, index + n);
+        dd->setData(e, index + i, values[i]);
+    dd->values.size = qMax(dd->values.size, index + n);
     return true;
 }
 
 void SparseArrayData::free(Heap::ArrayData *d, uint idx)
 {
     Q_ASSERT(d && d->type == Heap::ArrayData::Sparse);
-    Value *v = d->arrayData + idx;
+    Value *v = d->values.values + idx;
     if (d->attrs && d->attrs[idx].isAccessor()) {
         // double slot, free both. Order is important, so we have a double slot for allocation again afterwards.
         v[1].setEmpty(Value::fromReturnedValue(d->freeList).emptyValue());
@@ -380,15 +370,6 @@ void SparseArrayData::free(Heap::ArrayData *d, uint idx)
         d->attrs[idx].clear();
 }
 
-
-void SparseArrayData::markObjects(Heap::Base *d, ExecutionEngine *e)
-{
-    Heap::SparseArrayData *dd = static_cast<Heap::SparseArrayData *>(d);
-    uint l = dd->alloc;
-    for (uint i = 0; i < l; ++i)
-        dd->arrayData[i].mark(e);
-}
-
 Heap::ArrayData *SparseArrayData::reallocate(Object *o, uint n, bool enforceAttributes)
 {
     realloc(o, Heap::ArrayData::Sparse, n, enforceAttributes);
@@ -404,32 +385,32 @@ uint SparseArrayData::allocate(Object *o, bool doubleSlot)
         ReturnedValue *last = &dd->freeList;
         while (1) {
             if (Value::fromReturnedValue(*last).value() == UINT_MAX) {
-                reallocate(o, dd->alloc + 2, true);
+                reallocate(o, dd->values.alloc + 2, true);
                 dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
                 last = &dd->freeList;
                 Q_ASSERT(Value::fromReturnedValue(*last).value() != UINT_MAX);
             }
 
-            Q_ASSERT(dd->arrayData[Value::fromReturnedValue(*last).value()].value() != Value::fromReturnedValue(*last).value());
-            if (dd->arrayData[Value::fromReturnedValue(*last).value()].value() == (Value::fromReturnedValue(*last).value() + 1)) {
+            Q_ASSERT(dd->values[Value::fromReturnedValue(*last).value()].value() != Value::fromReturnedValue(*last).value());
+            if (dd->values[Value::fromReturnedValue(*last).value()].value() == (Value::fromReturnedValue(*last).value() + 1)) {
                 // found two slots in a row
                 uint idx = Value::fromReturnedValue(*last).emptyValue();
                 Value lastV = Value::fromReturnedValue(*last);
-                lastV.setEmpty(dd->arrayData[lastV.emptyValue() + 1].value());
+                lastV.setEmpty(dd->values[lastV.emptyValue() + 1].value());
                 *last = lastV.rawValue();
                 dd->attrs[idx] = Attr_Accessor;
                 return idx;
             }
-            last = &dd->arrayData[Value::fromReturnedValue(*last).value()].rawValueRef();
+            last = &dd->values.values[Value::fromReturnedValue(*last).value()].rawValueRef();
         }
     } else {
         if (Value::fromReturnedValue(dd->freeList).value() == UINT_MAX) {
-            reallocate(o, dd->alloc + 1, false);
+            reallocate(o, dd->values.alloc + 1, false);
             dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
         }
         uint idx = Value::fromReturnedValue(dd->freeList).value();
         Q_ASSERT(idx != UINT_MAX);
-        dd->freeList = dd->arrayData[idx].asReturnedValue();
+        dd->freeList = dd->values[idx].asReturnedValue();
         Q_ASSERT(Value::fromReturnedValue(dd->freeList).isEmpty());
         if (dd->attrs)
             dd->attrs[idx] = Attr_Data;
@@ -443,7 +424,7 @@ ReturnedValue SparseArrayData::get(const Heap::ArrayData *d, uint index)
     index = s->mappedIndex(index);
     if (index == UINT_MAX)
         return Primitive::emptyValue().asReturnedValue();
-    return s->arrayData[index].asReturnedValue();
+    return s->values[index].asReturnedValue();
 }
 
 bool SparseArrayData::put(Object *o, uint index, const Value &value)
@@ -457,7 +438,7 @@ bool SparseArrayData::put(Object *o, uint index, const Value &value)
     if (n->value == UINT_MAX)
         n->value = allocate(o);
     s = o->d()->arrayData.cast<Heap::SparseArrayData>();
-    s->arrayData[n->value] = value;
+    s->setArrayData(o->engine(), n->value, value);
     if (s->attrs)
         s->attrs[n->value] = Attr_Data;
     return true;
@@ -472,7 +453,7 @@ bool SparseArrayData::del(Object *o, uint index)
         return true;
 
     uint pidx = n->value;
-    Q_ASSERT(!dd->arrayData[pidx].isEmpty());
+    Q_ASSERT(!dd->values[pidx].isEmpty());
 
     bool isAccessor = false;
     if (dd->attrs) {
@@ -485,11 +466,11 @@ bool SparseArrayData::del(Object *o, uint index)
 
     if (isAccessor) {
         // free up both indices
-        dd->arrayData[pidx + 1].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
-        dd->arrayData[pidx].setEmpty(pidx + 1);
+        dd->values.values[pidx + 1].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
+        dd->values.values[pidx].setEmpty(pidx + 1);
     } else {
         Q_ASSERT(dd->type == Heap::ArrayData::Sparse);
-        dd->arrayData[pidx].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
+        dd->values.values[pidx].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
     }
 
     dd->freeList = Primitive::emptyValue(pidx).asReturnedValue();
@@ -518,10 +499,10 @@ void SparseArrayData::push_front(Object *o, const Value *values, uint n)
 {
     Heap::SparseArrayData *d = o->d()->arrayData.cast<Heap::SparseArrayData>();
     Q_ASSERT(!d->attrs);
-    for (int i = n - 1; i >= 0; --i) {
+    for (int i = static_cast<int>(n) - 1; i >= 0; --i) {
         uint idx = allocate(o);
         d = o->d()->arrayData.cast<Heap::SparseArrayData>();
-        d->arrayData[idx] = values[i];
+        d->setArrayData(o->engine(), idx, values[i]);
         d->sparse->push_front(idx);
     }
 }
@@ -533,7 +514,7 @@ ReturnedValue SparseArrayData::pop_front(Object *o)
     uint idx = d->sparse->pop_front();
     ReturnedValue v;
     if (idx != UINT_MAX) {
-        v = d->arrayData[idx].asReturnedValue();
+        v = d->values[idx].asReturnedValue();
         free(o->arrayData(), idx);
     } else {
         v = Encode::undefined();
@@ -611,24 +592,24 @@ uint ArrayData::append(Object *obj, ArrayObject *otherObj, uint n)
             ScopedValue v(scope);
             for (const SparseArrayNode *it = os->sparse->begin();
                  it != os->sparse->end(); it = it->nextNode()) {
-                v = otherObj->getValue(os->arrayData[it->value], other->d()->attrs[it->value]);
+                v = otherObj->getValue(os->values[it->value], other->d()->attrs[it->value]);
                 obj->arraySet(oldSize + it->key(), v);
             }
         } else {
             for (const SparseArrayNode *it = other->d()->sparse->begin();
                  it != os->sparse->end(); it = it->nextNode())
-                obj->arraySet(oldSize + it->key(), os->arrayData[it->value]);
+                obj->arraySet(oldSize + it->key(), os->values[it->value]);
         }
     } else {
         Heap::SimpleArrayData *os = static_cast<Heap::SimpleArrayData *>(other->d());
         uint toCopy = n;
         uint chunk = toCopy;
-        if (chunk > os->alloc - os->offset)
-            chunk -= os->alloc - os->offset;
-        obj->arrayPut(oldSize, os->arrayData + os->offset, chunk);
+        if (chunk > os->values.alloc - os->offset)
+            chunk -= os->values.alloc - os->offset;
+        obj->arrayPut(oldSize, os->values.data() + os->offset, chunk);
         toCopy -= chunk;
         if (toCopy)
-            obj->arrayPut(oldSize + chunk, os->arrayData, toCopy);
+            obj->arrayPut(oldSize + chunk, os->values.data(), toCopy);
     }
 
     return oldSize + n;
@@ -638,18 +619,18 @@ void ArrayData::insert(Object *o, uint index, const Value *v, bool isAccessor)
 {
     if (!isAccessor && o->d()->arrayData->type != Heap::ArrayData::Sparse) {
         Heap::SimpleArrayData *d = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-        if (index < 0x1000 || index < d->len + (d->len >> 2)) {
-            if (index >= d->alloc) {
+        if (index < 0x1000 || index < d->values.size + (d->values.size >> 2)) {
+            if (index >= d->values.alloc) {
                 o->arrayReserve(index + 1);
                 d = o->d()->arrayData.cast<Heap::SimpleArrayData>();
             }
-            if (index >= d->len) {
+            if (index >= d->values.size) {
                 // mark possible hole in the array
-                for (uint i = d->len; i < index; ++i)
-                    d->data(i) = Primitive::emptyValue();
-                d->len = index + 1;
+                for (uint i = d->values.size; i < index; ++i)
+                    d->setData(o->engine(), i, Primitive::emptyValue());
+                d->values.size = index + 1;
             }
-            d->arrayData[d->mappedIndex(index)] = *v;
+            d->setData(o->engine(), index, *v);
             return;
         }
     }
@@ -660,9 +641,9 @@ void ArrayData::insert(Object *o, uint index, const Value *v, bool isAccessor)
     if (n->value == UINT_MAX)
         n->value = SparseArrayData::allocate(o, isAccessor);
     s = o->d()->arrayData.cast<Heap::SparseArrayData>();
-    s->arrayData[n->value] = *v;
+    s->setArrayData(o->engine(), n->value, *v);
     if (isAccessor)
-        s->arrayData[n->value + Object::SetterOffset] = v[Object::SetterOffset];
+        s->setArrayData(o->engine(), n->value + Object::SetterOffset, v[Object::SetterOffset]);
 }
 
 
@@ -697,7 +678,7 @@ bool ArrayElementLessThan::operator()(Value v1, Value v2) const
         callData->thisObject = Primitive::undefinedValue();
         callData->args[0] = v1;
         callData->args[1] = v2;
-        result = scope.engine->runtime.callValue(scope.engine, m_comparefn, callData);
+        result = QV4::Runtime::method_callValue(scope.engine, m_comparefn, callData);
 
         return result->toNumber() < 0;
     }
@@ -799,7 +780,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
                     break;
 
                 PropertyAttributes a = sparse->attrs() ? sparse->attrs()[n->value] : Attr_Data;
-                d->data(i) = thisObject->getValue(sparse->arrayData()[n->value], a);
+                d->setData(engine, i, Value::fromReturnedValue(thisObject->getValue(sparse->arrayData()[n->value], a)));
                 d->attrs[i] = a.isAccessor() ? Attr_Data : a;
 
                 n = n->nextNode();
@@ -809,12 +790,12 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
             while (n != sparse->sparse()->end()) {
                 if (n->value >= len)
                     break;
-                d->data(i) = sparse->arrayData()[n->value];
+                d->setData(engine, i, sparse->arrayData()[n->value]);
                 n = n->nextNode();
                 ++i;
             }
         }
-        d->len = i;
+        d->values.size = i;
         if (len > i)
             len = i;
         if (n != sparse->sparse()->end()) {
@@ -822,7 +803,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
             thisObject->initSparseArray();
             while (n != sparse->sparse()->end()) {
                 PropertyAttributes a = sparse->attrs() ? sparse->attrs()[n->value] : Attr_Data;
-                thisObject->arraySet(n->value, reinterpret_cast<Property *>(sparse->arrayData() + n->value), a);
+                thisObject->arraySet(n->value, reinterpret_cast<const Property *>(sparse->arrayData() + n->value), a);
 
                 n = n->nextNode();
             }
@@ -830,8 +811,8 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
         }
     } else {
         Heap::SimpleArrayData *d = thisObject->d()->arrayData.cast<Heap::SimpleArrayData>();
-        if (len > d->len)
-            len = d->len;
+        if (len > d->values.size)
+            len = d->values.size;
 
         // sort empty values to the end
         for (uint i = 0; i < len; i++) {
@@ -840,8 +821,8 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
                     if (!d->data(len).isEmpty())
                         break;
                 Q_ASSERT(!d->attrs || !d->attrs[len].isAccessor());
-                d->data(i) = d->data(len);
-                d->data(len) = Primitive::emptyValue();
+                d->setData(engine, i, d->data(len));
+                d->setData(engine, len, Primitive::emptyValue());
             }
         }
 
@@ -852,7 +833,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
 
     ArrayElementLessThan lessThan(engine, thisObject, comparefn);
 
-    Value *begin = thisObject->arrayData()->arrayData;
+    Value *begin = thisObject->arrayData()->values.values;
     sortHelper(begin, begin + len, *begin, lessThan);
 
 #ifdef CHECK_SPARSE_ARRAYS
diff --git a/src/qml/jsruntime/qv4arraydata_p.h b/src/qml/jsruntime/qv4arraydata_p.h
index 24b948f01e..c2c81e886b 100644
--- a/src/qml/jsruntime/qv4arraydata_p.h
+++ b/src/qml/jsruntime/qv4arraydata_p.h
@@ -90,27 +90,31 @@ struct ArrayVTable
 
 namespace Heap {
 
-struct ArrayData : public Base {
-    enum Type {
-        Simple = 0,
-        Complex = 1,
-        Sparse = 2,
-        Custom = 3
+#define ArrayDataMembers(class, Member) \
+    Member(class, NoMark, uint, type) \
+    Member(class, NoMark, uint, offset) \
+    Member(class, NoMark, PropertyAttributes *, attrs) \
+    Member(class, NoMark, ReturnedValue, freeList) \
+    Member(class, NoMark, SparseArray *, sparse) \
+    Member(class, ValueArray, ValueArray, values)
+
+DECLARE_HEAP_OBJECT(ArrayData, Base) {
+    DECLARE_MARK_TABLE(ArrayData);
+
+    enum Type { Simple = 0, Complex = 1, Sparse = 2, Custom = 3 };
+
+    struct Index {
+        Heap::ArrayData *arrayData;
+        uint index;
+
+        void set(ExecutionEngine *e, Value newVal) {
+            arrayData->values.set(e, index, newVal);
+        }
+        const Value *operator->() const { return &arrayData->values[index]; }
+        const Value &operator*() const { return arrayData->values[index]; }
+        bool isNull() const { return !arrayData; }
     };
 
-    uint alloc;
-    Type type;
-    PropertyAttributes *attrs;
-    union {
-        uint len;
-        ReturnedValue freeList;
-    };
-    union {
-        uint offset;
-        SparseArray *sparse;
-    };
-    Value arrayData[1];
-
     bool isSparse() const { return type == Sparse; }
 
     const ArrayVTable *vtable() const { return reinterpret_cast<const ArrayVTable *>(Base::vtable()); }
@@ -118,35 +122,32 @@ struct ArrayData : public Base {
     inline ReturnedValue get(uint i) const {
         return vtable()->get(this, i);
     }
-    inline void getProperty(uint index, Property *p, PropertyAttributes *attrs);
-    inline void setProperty(uint index, const Property *p);
-    inline Property *getProperty(uint index);
-    inline Value *getValueOrSetter(uint index, PropertyAttributes *attrs);
+    inline bool getProperty(uint index, Property *p, PropertyAttributes *attrs);
+    inline void setProperty(ExecutionEngine *e, uint index, const Property *p);
+    inline Index getValueOrSetter(uint index, PropertyAttributes *attrs);
     inline PropertyAttributes attributes(uint i) const;
 
     bool isEmpty(uint i) const {
         return get(i) == Primitive::emptyValue().asReturnedValue();
     }
 
-    inline ReturnedValue length() const {
+    inline uint length() const {
         return vtable()->length(this);
     }
 
+    void setArrayData(ExecutionEngine *e, uint index, Value newVal) {
+        values.set(e, index, newVal);
+    }
+
+    uint mappedIndex(uint index) const;
 };
 V4_ASSERT_IS_TRIVIAL(ArrayData)
 
 struct SimpleArrayData : public ArrayData {
-    uint mappedIndex(uint index) const { return (index + offset) % alloc; }
-    Value data(uint index) const { return arrayData[mappedIndex(index)]; }
-    Value &data(uint index) { return arrayData[mappedIndex(index)]; }
-
-    Property *getProperty(uint index) {
-        if (index >= len)
-            return 0;
-        index = mappedIndex(index);
-        if (arrayData[index].isEmpty())
-            return 0;
-        return reinterpret_cast<Property *>(arrayData + index);
+    uint mappedIndex(uint index) const { return (index + offset) % values.alloc; }
+    const Value &data(uint index) const { return values[mappedIndex(index)]; }
+    void setData(ExecutionEngine *e, uint index, Value newVal) {
+        values.set(e, mappedIndex(index), newVal);
     }
 
     PropertyAttributes attributes(uint i) const {
@@ -168,13 +169,6 @@ struct SparseArrayData : public ArrayData {
         return n->value;
     }
 
-    Property *getProperty(uint index) {
-        SparseArrayNode *n = sparse->findNode(index);
-        if (!n)
-            return 0;
-        return reinterpret_cast<Property *>(arrayData + n->value);
-    }
-
     PropertyAttributes attributes(uint i) const {
         if (!attrs)
             return Attr_Data;
@@ -189,16 +183,23 @@ struct Q_QML_EXPORT ArrayData : public Managed
 {
     typedef Heap::ArrayData::Type Type;
     V4_MANAGED(ArrayData, Managed)
+    enum {
+        IsArrayData = true
+    };
 
-    uint alloc() const { return d()->alloc; }
-    uint &alloc() { return d()->alloc; }
-    void setAlloc(uint a) { d()->alloc = a; }
-    Type type() const { return d()->type; }
+    typedef Heap::ArrayData::Index Index;
+
+    uint alloc() const { return d()->values.alloc; }
+    uint &alloc() { return d()->values.alloc; }
+    void setAlloc(uint a) { d()->values.alloc = a; }
+    Type type() const { return static_cast<Type>(d()->type); }
     void setType(Type t) { d()->type = t; }
     PropertyAttributes *attrs() const { return d()->attrs; }
     void setAttrs(PropertyAttributes *a) { d()->attrs = a; }
-    const Value *arrayData() const { return &d()->arrayData[0]; }
-    Value *arrayData() { return &d()->arrayData[0]; }
+    const Value *arrayData() const { return d()->values.data(); }
+    void setArrayData(ExecutionEngine *e, uint index, Value newVal) {
+        d()->setArrayData(e, index, newVal);
+    }
 
     const ArrayVTable *vtable() const { return d()->vtable(); }
     bool isSparse() const { return type() == Heap::ArrayData::Sparse; }
@@ -221,9 +222,6 @@ struct Q_QML_EXPORT ArrayData : public Managed
     ReturnedValue get(uint i) const {
         return d()->get(i);
     }
-    inline Property *getProperty(uint index) {
-        return d()->getProperty(index);
-    }
 
     static void ensureAttributes(Object *o);
     static void realloc(Object *o, Type newType, uint alloc, bool enforceAttributes);
@@ -239,15 +237,12 @@ struct Q_QML_EXPORT SimpleArrayData : public ArrayData
 
     uint mappedIndex(uint index) const { return d()->mappedIndex(index); }
     Value data(uint index) const { return d()->data(index); }
-    Value &data(uint index) { return d()->data(index); }
 
-    uint &len() { return d()->len; }
-    uint len() const { return d()->len; }
+    uint &len() { return d()->values.size; }
+    uint len() const { return d()->values.size; }
 
     static Heap::ArrayData *reallocate(Object *o, uint n, bool enforceAttributes);
 
-    static void markObjects(Heap::Base *d, ExecutionEngine *e);
-
     static ReturnedValue get(const Heap::ArrayData *d, uint index);
     static bool put(Object *o, uint index, const Value &value);
     static bool putArray(Object *o, uint index, const Value *values, uint n);
@@ -274,8 +269,6 @@ struct Q_QML_EXPORT SparseArrayData : public ArrayData
 
     uint mappedIndex(uint index) const { return d()->mappedIndex(index); }
 
-    static void markObjects(Heap::Base *d, ExecutionEngine *e);
-
     static Heap::ArrayData *reallocate(Object *o, uint n, bool enforceAttributes);
     static ReturnedValue get(const Heap::ArrayData *d, uint index);
     static bool put(Object *o, uint index, const Value &value);
@@ -290,30 +283,38 @@ struct Q_QML_EXPORT SparseArrayData : public ArrayData
 
 namespace Heap {
 
-void ArrayData::getProperty(uint index, Property *p, PropertyAttributes *attrs)
+inline uint ArrayData::mappedIndex(uint index) const
 {
-    Property *pd = getProperty(index);
-    Q_ASSERT(pd);
-    *attrs = attributes(index);
-    p->value = pd->value;
-    if (attrs->isAccessor())
-        p->set = pd->set;
+    if (isSparse())
+        return static_cast<const SparseArrayData *>(this)->mappedIndex(index);
+    if (index >= values.size)
+        return UINT_MAX;
+    uint idx = static_cast<const SimpleArrayData *>(this)->mappedIndex(index);
+    return values[idx].isEmpty() ? UINT_MAX : idx;
 }
 
-void ArrayData::setProperty(uint index, const Property *p)
+bool ArrayData::getProperty(uint index, Property *p, PropertyAttributes *attrs)
 {
-    Property *pd = getProperty(index);
-    Q_ASSERT(pd);
-    pd->value = p->value;
-    if (attributes(index).isAccessor())
-        pd->set = p->set;
+    uint mapped = mappedIndex(index);
+    if (mapped == UINT_MAX) {
+        *attrs = Attr_Invalid;
+        return false;
+    }
+
+    *attrs = attributes(index);
+    p->value = *(Index{ this, mapped });
+    if (attrs->isAccessor())
+        p->set = *(Index{ this, mapped + 1 /*Object::SetterOffset*/ });
+    return true;
 }
 
-inline Property *ArrayData::getProperty(uint index)
+void ArrayData::setProperty(QV4::ExecutionEngine *e, uint index, const Property *p)
 {
-    if (isSparse())
-        return static_cast<SparseArrayData *>(this)->getProperty(index);
-    return static_cast<SimpleArrayData *>(this)->getProperty(index);
+    uint mapped = mappedIndex(index);
+    Q_ASSERT(mapped != UINT_MAX);
+    values.set(e, mapped, p->value);
+    if (attributes(index).isAccessor())
+        values.set(e, mapped + 1 /*QV4::Object::SetterOffset*/, p->set);
 }
 
 inline PropertyAttributes ArrayData::attributes(uint i) const
@@ -323,16 +324,16 @@ inline PropertyAttributes ArrayData::attributes(uint i) const
     return static_cast<const SimpleArrayData *>(this)->attributes(i);
 }
 
-Value *ArrayData::getValueOrSetter(uint index, PropertyAttributes *attrs)
+ArrayData::Index ArrayData::getValueOrSetter(uint index, PropertyAttributes *attrs)
 {
-    Property *p = getProperty(index);
-    if (!p) {
+    uint idx = mappedIndex(index);
+    if (idx == UINT_MAX) {
         *attrs = Attr_Invalid;
-        return 0;
+        return { 0, 0 };
     }
 
     *attrs = attributes(index);
-    return attrs->isAccessor() ? &p->set : &p->value;
+    return { this, attrs->isAccessor() ? idx + 1 /* QV4::Object::SetterOffset*/ : idx };
 }
 
 
diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index 759354f4e2..a2c19e1f2d 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -690,8 +690,8 @@ void ArrayPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallD
     } else {
         Q_ASSERT(instance->arrayType() == Heap::ArrayData::Simple || instance->arrayType() == Heap::ArrayData::Complex);
         Heap::SimpleArrayData *sa = instance->d()->arrayData.cast<Heap::SimpleArrayData>();
-        if (len > sa->len)
-            len = sa->len;
+        if (len > sa->values.size)
+            len = sa->values.size;
         uint idx = fromIndex;
         while (idx < len) {
             value = sa->data(idx);
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 740ebbe359..02d3af619e 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -54,58 +54,49 @@
 using namespace QV4;
 
 DEFINE_MANAGED_VTABLE(ExecutionContext);
+DEFINE_MANAGED_VTABLE(SimpleCallContext);
 DEFINE_MANAGED_VTABLE(CallContext);
 DEFINE_MANAGED_VTABLE(WithContext);
 DEFINE_MANAGED_VTABLE(CatchContext);
 DEFINE_MANAGED_VTABLE(GlobalContext);
 
-/* Function *f, int argc */
-#define requiredMemoryForExecutionContect(f, argc) \
-    ((sizeof(CallContext::Data) + 7) & ~7) + \
-    sizeof(Value) * (f->compiledFunction->nLocals + qMax((uint)argc, f->nFormals)) + sizeof(CallData)
-
 Heap::CallContext *ExecutionContext::newCallContext(Function *function, CallData *callData)
 {
-    Heap::CallContext *c = d()->engine->memoryManager->allocManaged<CallContext>(
-                requiredMemoryForExecutionContect(function, callData->argc));
+    uint localsAndFormals = function->compiledFunction->nLocals + sizeof(CallData)/sizeof(Value) - 1 + qMax(static_cast<uint>(callData->argc), function->nFormals);
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * (localsAndFormals);
+
+    Heap::CallContext *c = d()->engine->memoryManager->allocManaged<CallContext>(requiredMemory);
     c->init(d()->engine, Heap::ExecutionContext::Type_CallContext);
 
     c->v4Function = function;
 
     c->strictMode = function->isStrict();
-    c->outer = this->d();
-
-    c->activation = 0;
+    c->outer.set(d()->engine, this->d());
 
     c->compilationUnit = function->compilationUnit;
-    c->lookups = c->compilationUnit->runtimeLookups;
-    c->constantTable = c->compilationUnit->constants;
-    c->locals = (Value *)((quintptr(c + 1) + 7) & ~7);
+    c->lookups = function->compilationUnit->runtimeLookups;
+    c->constantTable = function->compilationUnit->constants;
 
     const CompiledData::Function *compiledFunction = function->compiledFunction;
-    int nLocals = compiledFunction->nLocals;
+    uint nLocals = compiledFunction->nLocals;
+    c->locals.size = nLocals;
+    c->locals.alloc = localsAndFormals;
+#if QT_POINTER_SIZE == 8
+    // memory allocated from the JS heap is 0 initialized, so skip the std::fill() below
+    Q_ASSERT(Primitive::undefinedValue().asReturnedValue() == 0);
+#else
     if (nLocals)
-        std::fill(c->locals, c->locals + nLocals, Primitive::undefinedValue());
+        std::fill(c->locals.values, c->locals.values + nLocals, Primitive::undefinedValue());
+#endif
 
-    c->callData = reinterpret_cast<CallData *>(c->locals + nLocals);
-    ::memcpy(c->callData, callData, sizeof(CallData) + (callData->argc - 1) * sizeof(Value));
+    c->callData = reinterpret_cast<CallData *>(c->locals.values + nLocals);
+    ::memcpy(c->callData, callData, sizeof(CallData) - sizeof(Value) + static_cast<uint>(callData->argc) * sizeof(Value));
     if (callData->argc < static_cast<int>(compiledFunction->nFormals))
         std::fill(c->callData->args + c->callData->argc, c->callData->args + compiledFunction->nFormals, Primitive::undefinedValue());
 
     return c;
 }
 
-Heap::CallContext *Heap::CallContext::createSimpleContext(ExecutionEngine *v4)
-{
-    Heap::CallContext *ctxt = v4->memoryManager->allocSimpleCallContext(v4);
-    return ctxt;
-}
-
-void Heap::CallContext::freeSimpleCallContext()
-{
-    engine->memoryManager->freeSimpleCallContext();
-}
-
 Heap::WithContext *ExecutionContext::newWithContext(Heap::Object *with)
 {
     return d()->engine->memoryManager->alloc<WithContext>(d(), with);
@@ -129,10 +120,10 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
         switch (ctx->d()->type) {
         case Heap::ExecutionContext::Type_CallContext:
         case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
+            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             if (!activation) {
                 if (!c->activation)
-                    c->activation = scope.engine->newObject();
+                    c->activation.set(scope.engine, scope.engine->newObject());
                 activation = c->activation;
             }
             break;
@@ -166,41 +157,52 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
 void Heap::GlobalContext::init(ExecutionEngine *eng)
 {
     Heap::ExecutionContext::init(eng, Heap::ExecutionContext::Type_GlobalContext);
-    global = eng->globalObject->d();
+    global.set(eng, eng->globalObject->d());
 }
 
 void Heap::CatchContext::init(ExecutionContext *outerContext, String *exceptionVarName,
                               const Value &exceptionValue)
 {
     Heap::ExecutionContext::init(outerContext->engine, Heap::ExecutionContext::Type_CatchContext);
-    outer = outerContext;
+    outer.set(engine, outerContext);
     strictMode = outer->strictMode;
     callData = outer->callData;
     lookups = outer->lookups;
     constantTable = outer->constantTable;
     compilationUnit = outer->compilationUnit;
 
-    this->exceptionVarName = exceptionVarName;
-    this->exceptionValue = exceptionValue;
+    this->exceptionVarName.set(engine, exceptionVarName);
+    this->exceptionValue.set(engine, exceptionValue);
 }
 
+void Heap::WithContext::init(ExecutionContext *outerContext, Object *with)
+{
+    Heap::ExecutionContext::init(outerContext->engine, Heap::ExecutionContext::Type_WithContext);
+    outer.set(engine, outerContext);
+    callData = outer->callData;
+    lookups = outer->lookups;
+    constantTable = outer->constantTable;
+    compilationUnit = outer->compilationUnit;
+
+    withObject.set(engine, with);
+}
 
-Identifier * const *CallContext::formals() const
+Identifier * const *SimpleCallContext::formals() const
 {
     return d()->v4Function ? d()->v4Function->internalClass->nameMap.constData() : 0;
 }
 
-unsigned int CallContext::formalCount() const
+unsigned int SimpleCallContext::formalCount() const
 {
     return d()->v4Function ? d()->v4Function->nFormals : 0;
 }
 
-Identifier * const *CallContext::variables() const
+Identifier * const *SimpleCallContext::variables() const
 {
     return d()->v4Function ? d()->v4Function->internalClass->nameMap.constData() + d()->v4Function->nFormals : 0;
 }
 
-unsigned int CallContext::variableCount() const
+unsigned int SimpleCallContext::variableCount() const
 {
     return d()->v4Function ? d()->v4Function->compiledFunction->nLocals : 0;
 }
@@ -210,7 +212,6 @@ unsigned int CallContext::variableCount() const
 bool ExecutionContext::deleteProperty(String *name)
 {
     Scope scope(this);
-    bool hasWith = false;
     ScopedContext ctx(scope, this);
     for (; ctx; ctx = ctx->d()->outer) {
         switch (ctx->d()->type) {
@@ -221,7 +222,6 @@ bool ExecutionContext::deleteProperty(String *name)
             break;
         }
         case Heap::ExecutionContext::Type_WithContext: {
-            hasWith = true;
             ScopedObject withObject(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
             if (withObject->hasProperty(name))
                 return withObject->deleteProperty(name);
@@ -233,15 +233,16 @@ bool ExecutionContext::deleteProperty(String *name)
                 return global->deleteProperty(name);
             break;
         }
-        case Heap::ExecutionContext::Type_CallContext:
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
+        case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            if (c->v4Function && (c->v4Function->needsActivation() || hasWith)) {
-                uint index = c->v4Function->internalClass->find(name);
-                if (index < UINT_MAX)
-                    // ### throw in strict mode?
-                    return false;
-            }
+            uint index = c->v4Function->internalClass->find(name);
+            if (index < UINT_MAX)
+                // ### throw in strict mode?
+                return false;
+            Q_FALLTHROUGH();
+        }
+        case Heap::ExecutionContext::Type_SimpleCallContext: {
+            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             ScopedObject qml(scope, c->activation);
             if (qml && qml->hasProperty(name))
                 return qml->deleteProperty(name);
@@ -258,61 +259,6 @@ bool ExecutionContext::deleteProperty(String *name)
     return true;
 }
 
-bool CallContext::needsOwnArguments() const
-{
-    QV4::Function *f = d()->v4Function;
-    return (f && f->needsActivation()) || (argc() < (f ? static_cast<int>(f->nFormals) : 0));
-}
-
-void ExecutionContext::markObjects(Heap::Base *m, ExecutionEngine *engine)
-{
-    ExecutionContext::Data *ctx = static_cast<ExecutionContext::Data *>(m);
-
-    if (ctx->outer)
-        ctx->outer->mark(engine);
-
-    switch (ctx->type) {
-    case Heap::ExecutionContext::Type_CatchContext: {
-        CatchContext::Data *c = static_cast<CatchContext::Data *>(ctx);
-        c->exceptionVarName->mark(engine);
-        c->exceptionValue.mark(engine);
-        break;
-    }
-    case Heap::ExecutionContext::Type_WithContext: {
-        WithContext::Data *w = static_cast<WithContext::Data *>(ctx);
-        if (w->withObject)
-            w->withObject->mark(engine);
-        break;
-    }
-    case Heap::ExecutionContext::Type_GlobalContext: {
-        GlobalContext::Data *g = static_cast<GlobalContext::Data *>(ctx);
-        g->global->mark(engine);
-        break;
-    }
-    case Heap::ExecutionContext::Type_SimpleCallContext:
-        break;
-    case Heap::ExecutionContext::Type_CallContext: {
-        QV4::Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
-        Q_ASSERT(c->v4Function);
-        ctx->callData->thisObject.mark(engine);
-        for (int arg = 0; arg < qMax(ctx->callData->argc, (int)c->v4Function->nFormals); ++arg)
-            ctx->callData->args[arg].mark(engine);
-        for (unsigned local = 0, lastLocal = c->v4Function->compiledFunction->nLocals; local < lastLocal; ++local)
-            c->locals[local].mark(engine);
-        if (c->activation)
-            c->activation->mark(engine);
-        if (c->function)
-            c->function->mark(engine);
-        break;
-    }
-    case Heap::ExecutionContext::Type_QmlContext: {
-        QmlContext::Data *g = static_cast<QmlContext::Data *>(ctx);
-        g->qml->mark(engine);
-        break;
-    }
-    }
-}
-
 // Do a standard call with this execution context as the outer scope
 void ExecutionContext::call(Scope &scope, CallData *callData, Function *function, const FunctionObject *f)
 {
@@ -320,7 +266,7 @@ void ExecutionContext::call(Scope &scope, CallData *callData, Function *function
 
     Scoped<CallContext> ctx(scope, newCallContext(function, callData));
     if (f)
-        ctx->d()->function = f->d();
+        ctx->d()->function.set(scope.engine, f->d());
     scope.engine->pushContext(ctx);
 
     scope.result = Q_V4_PROFILE(scope.engine, function);
@@ -336,7 +282,7 @@ void QV4::ExecutionContext::simpleCall(Scope &scope, CallData *callData, Functio
 
     ExecutionContextSaver ctxSaver(scope);
 
-    CallContext::Data *ctx = scope.engine->memoryManager->allocSimpleCallContext(scope.engine);
+    SimpleCallContext::Data *ctx = scope.engine->memoryManager->allocSimpleCallContext(scope.engine);
 
     ctx->strictMode = function->isStrict();
     ctx->callData = callData;
@@ -344,8 +290,7 @@ void QV4::ExecutionContext::simpleCall(Scope &scope, CallData *callData, Functio
     ctx->compilationUnit = function->compilationUnit;
     ctx->lookups = function->compilationUnit->runtimeLookups;
     ctx->constantTable = function->compilationUnit->constants;
-    ctx->outer = this->d();
-    ctx->locals = scope.alloc(function->compiledFunction->nLocals);
+    ctx->outer.set(scope.engine, this->d());
     for (int i = callData->argc; i < (int)function->nFormals; ++i)
         callData->args[i] = Encode::undefined();
 
@@ -371,7 +316,7 @@ void ExecutionContext::setProperty(String *name, const Value &value)
         case Heap::ExecutionContext::Type_CatchContext: {
             Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
             if (c->exceptionVarName->isEqualTo(name->d())) {
-                    c->exceptionValue = value;
+                    c->exceptionValue.set(scope.engine, value);
                     return;
             }
             break;
@@ -390,15 +335,16 @@ void ExecutionContext::setProperty(String *name, const Value &value)
         }
         case Heap::ExecutionContext::Type_CallContext:
         case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
+            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             if (c->v4Function) {
                 uint index = c->v4Function->internalClass->find(name);
                 if (index < UINT_MAX) {
                     if (index < c->v4Function->nFormals) {
                         c->callData->args[c->v4Function->nFormals - index - 1] = value;
                     } else {
+                        Q_ASSERT(c->type == Heap::ExecutionContext::Type_CallContext);
                         index -= c->v4Function->nFormals;
-                        c->locals[index] = value;
+                        static_cast<Heap::CallContext *>(c)->locals.set(scope.engine, index, value);
                     }
                     return;
                 }
@@ -439,13 +385,10 @@ ReturnedValue ExecutionContext::getProperty(String *name)
     if (name->equals(d()->engine->id_this()))
         return thisObject().asReturnedValue();
 
-    bool hasWith = false;
-    bool hasCatchScope = false;
     ScopedContext ctx(scope, this);
     for (; ctx; ctx = ctx->d()->outer) {
         switch (ctx->d()->type) {
         case Heap::ExecutionContext::Type_CatchContext: {
-            hasCatchScope = true;
             Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
             if (c->exceptionVarName->isEqualTo(name->d()))
                 return c->exceptionValue.asReturnedValue();
@@ -453,7 +396,6 @@ ReturnedValue ExecutionContext::getProperty(String *name)
         }
         case Heap::ExecutionContext::Type_WithContext: {
             ScopedObject w(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            hasWith = true;
             bool hasProperty = false;
             v = w->get(name, &hasProperty);
             if (hasProperty) {
@@ -469,17 +411,23 @@ ReturnedValue ExecutionContext::getProperty(String *name)
                 return v->asReturnedValue();
             break;
         }
-        case Heap::ExecutionContext::Type_CallContext:
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
+        case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            if (c->v4Function && (c->v4Function->needsActivation() || hasWith || hasCatchScope)) {
-                uint index = c->v4Function->internalClass->find(name);
-                if (index < UINT_MAX) {
-                    if (index < c->v4Function->nFormals)
-                        return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
-                    return c->locals[index - c->v4Function->nFormals].asReturnedValue();
-                }
+            uint index = c->v4Function->internalClass->find(name);
+            if (index < UINT_MAX) {
+                if (index < c->v4Function->nFormals)
+                    return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
+                Q_ASSERT(c->type == Heap::ExecutionContext::Type_CallContext);
+                return c->locals[index - c->v4Function->nFormals].asReturnedValue();
             }
+            if (c->v4Function->isNamedExpression()) {
+                if (c->function && name->equals(ScopedString(scope, c->v4Function->name())))
+                    return c->function->asReturnedValue();
+            }
+            Q_FALLTHROUGH();
+        }
+        case Heap::ExecutionContext::Type_SimpleCallContext: {
+            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             ScopedObject activation(scope, c->activation);
             if (activation) {
                 bool hasProperty = false;
@@ -487,9 +435,6 @@ ReturnedValue ExecutionContext::getProperty(String *name)
                 if (hasProperty)
                     return v->asReturnedValue();
             }
-            if (c->function && c->v4Function->isNamedExpression()
-                && name->equals(ScopedString(scope, c->v4Function->name())))
-                return c->function->asReturnedValue();
             break;
         }
         case Heap::ExecutionContext::Type_QmlContext: {
@@ -516,13 +461,10 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
     if (name->equals(d()->engine->id_this()))
         return thisObject().asReturnedValue();
 
-    bool hasWith = false;
-    bool hasCatchScope = false;
     ScopedContext ctx(scope, this);
     for (; ctx; ctx = ctx->d()->outer) {
         switch (ctx->d()->type) {
         case Heap::ExecutionContext::Type_CatchContext: {
-            hasCatchScope = true;
             Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
             if (c->exceptionVarName->isEqualTo(name->d()))
                 return c->exceptionValue.asReturnedValue();
@@ -530,7 +472,6 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
         }
         case Heap::ExecutionContext::Type_WithContext: {
             ScopedObject w(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            hasWith = true;
             bool hasProperty = false;
             v = w->get(name, &hasProperty);
             if (hasProperty) {
@@ -547,17 +488,22 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
                 return v->asReturnedValue();
             break;
         }
-        case Heap::ExecutionContext::Type_CallContext:
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
+        case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            if (c->v4Function && (c->v4Function->needsActivation() || hasWith || hasCatchScope)) {
-                uint index = c->v4Function->internalClass->find(name);
-                if (index < UINT_MAX) {
-                    if (index < c->v4Function->nFormals)
-                        return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
-                    return c->locals[index - c->v4Function->nFormals].asReturnedValue();
-                }
+            uint index = c->v4Function->internalClass->find(name);
+            if (index < UINT_MAX) {
+                if (index < c->v4Function->nFormals)
+                    return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
+                return c->locals[index - c->v4Function->nFormals].asReturnedValue();
             }
+            if (c->v4Function->isNamedExpression()) {
+                if (c->function && name->equals(ScopedString(scope, c->v4Function->name())))
+                    return c->function->asReturnedValue();
+            }
+            Q_FALLTHROUGH();
+        }
+        case Heap::ExecutionContext::Type_SimpleCallContext: {
+            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             ScopedObject activation(scope, c->activation);
             if (activation) {
                 bool hasProperty = false;
@@ -565,9 +511,6 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
                 if (hasProperty)
                     return v->asReturnedValue();
             }
-            if (c->function && c->v4Function->isNamedExpression()
-                && name->equals(ScopedString(scope, c->v4Function->name())))
-                return c->function->asReturnedValue();
             break;
         }
         case Heap::ExecutionContext::Type_QmlContext: {
@@ -591,7 +534,7 @@ Function *ExecutionContext::getFunction() const
     Scope scope(d()->engine);
     ScopedContext it(scope, this->d());
     for (; it; it = it->d()->outer) {
-        if (const CallContext *callCtx = it->asCallContext())
+        if (const SimpleCallContext *callCtx = it->asSimpleCallContext())
             return callCtx->d()->v4Function;
         else if (it->asCatchContext() || it->asWithContext())
             continue; // look in the parent context for a FunctionObject
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index bcfee2e1f8..3b37ea69dc 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -61,18 +61,21 @@ class QQmlContextData;
 namespace QV4 {
 
 namespace CompiledData {
-struct CompilationUnit;
+struct CompilationUnitBase;
 struct Function;
 }
 
 struct Function;
 struct Identifier;
 struct CallContext;
+struct SimpleCallContext;
 struct CatchContext;
 struct WithContext;
 struct QmlContext;
 struct QmlContextWrapper;
 
+// Attention: Make sure that this structure is the same size on 32-bit and 64-bit
+// architecture or you'll have to change the JIT code.
 struct CallData
 {
     // below is to be compatible with Value. Initialize tag to 0
@@ -91,11 +94,27 @@ struct CallData
     Value args[1];
 };
 
+Q_STATIC_ASSERT(std::is_standard_layout<CallData>::value);
+Q_STATIC_ASSERT(offsetof(CallData, thisObject) == 8);
+Q_STATIC_ASSERT(offsetof(CallData, args) == 16);
+
 namespace Heap {
 
 struct QmlContext;
 
-struct ExecutionContext : Base {
+#define ExecutionContextMembers(class, Member) \
+    Member(class, NoMark, CallData *, callData)  \
+    Member(class, NoMark, ExecutionEngine *, engine) \
+    Member(class, Pointer, ExecutionContext *, outer) \
+    Member(class, NoMark, Lookup *, lookups) \
+    Member(class, NoMark, const QV4::Value *, constantTable) \
+    Member(class, NoMark, CompiledData::CompilationUnitBase *, compilationUnit) \
+    Member(class, NoMark, int, lineNumber) // as member of non-pointer size this has to come last to preserve the ability to
+                                           // translate offsetof of it between 64-bit and 32-bit.
+
+DECLARE_HEAP_OBJECT(ExecutionContext, Base) {
+    DECLARE_MARK_TABLE(ExecutionContext);
+
     enum ContextType {
         Type_GlobalContext = 0x1,
         Type_CatchContext = 0x2,
@@ -114,23 +133,32 @@ struct ExecutionContext : Base {
         lineNumber = -1;
     }
 
-    CallData *callData;
-
-    ExecutionEngine *engine;
-    Pointer<ExecutionContext> outer;
-    Lookup *lookups;
-    const QV4::Value *constantTable;
-    CompiledData::CompilationUnit *compilationUnit;
-
-    ContextType type : 8;
+    quint8 type;
     bool strictMode : 8;
-    int lineNumber;
+#if QT_POINTER_SIZE == 8
+    quint8 padding_[6];
+#else
+    quint8 padding_[2];
+#endif
 };
 V4_ASSERT_IS_TRIVIAL(ExecutionContext)
+Q_STATIC_ASSERT(sizeof(ExecutionContext) == sizeof(Base) + sizeof(ExecutionContextData) + QT_POINTER_SIZE);
+
+Q_STATIC_ASSERT(std::is_standard_layout<ExecutionContextData>::value);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, callData) == 0);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, engine) == offsetof(ExecutionContextData, callData) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, outer) == offsetof(ExecutionContextData, engine) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, lookups) == offsetof(ExecutionContextData, outer) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, constantTable) == offsetof(ExecutionContextData, lookups) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, compilationUnit) == offsetof(ExecutionContextData, constantTable) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, lineNumber) == offsetof(ExecutionContextData, compilationUnit) + QT_POINTER_SIZE);
 
-struct CallContext : ExecutionContext {
-    static CallContext *createSimpleContext(ExecutionEngine *v4);
-    void freeSimpleCallContext();
+#define SimpleCallContextMembers(class, Member) \
+    Member(class, Pointer, Object *, activation) \
+    Member(class, NoMark, QV4::Function *, v4Function)
+
+DECLARE_HEAP_OBJECT(SimpleCallContext, ExecutionContext) {
+    DECLARE_MARK_TABLE(SimpleCallContext);
 
     void init(ExecutionEngine *engine, ContextType t = Type_SimpleCallContext)
     {
@@ -139,40 +167,66 @@ struct CallContext : ExecutionContext {
 
     inline unsigned int formalParameterCount() const;
 
-    Pointer<FunctionObject> function;
-    QV4::Function *v4Function;
-    Value *locals;
-    Pointer<Object> activation;
 };
-V4_ASSERT_IS_TRIVIAL(CallContext)
+V4_ASSERT_IS_TRIVIAL(SimpleCallContext)
+Q_STATIC_ASSERT(std::is_standard_layout<SimpleCallContextData>::value);
+Q_STATIC_ASSERT(offsetof(SimpleCallContextData, activation) == 0);
+Q_STATIC_ASSERT(offsetof(SimpleCallContextData, v4Function) == offsetof(SimpleCallContextData, activation) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(sizeof(SimpleCallContextData) == 2 * QT_POINTER_SIZE);
+Q_STATIC_ASSERT(sizeof(SimpleCallContext) == sizeof(ExecutionContext) + sizeof(SimpleCallContextData));
+
+#if QT_POINTER_SIZE == 8
+#define CallContextMembers(class, Member) \
+    Member(class, Pointer, FunctionObject *, function) \
+    Member(class, ValueArray, ValueArray, locals)
+#else
+#define CallContextMembers(class, Member) \
+    Member(class, Pointer, FunctionObject *, function) \
+    Member(class, NoMark, void *, padding) \
+    Member(class, ValueArray, ValueArray, locals)
+#endif
+
+DECLARE_HEAP_OBJECT(CallContext, SimpleCallContext) {
+    DECLARE_MARK_TABLE(CallContext);
+
+    using SimpleCallContext::formalParameterCount;
+};
+
+Q_STATIC_ASSERT(std::is_standard_layout<CallContextData>::value);
+Q_STATIC_ASSERT(offsetof(CallContextData, function) == 0);
+// IMPORTANT: we cannot do offsetof(CallContextData, locals) in the JIT as the offset does not scale with
+// the pointer size. On 32-bit ARM the offset of the ValueArray is aligned to 8 bytes, on 32-bit x86 for
+// example it is not. Therefore we have a padding in place and always have a distance of 8 bytes.
+Q_STATIC_ASSERT(offsetof(CallContextData, locals) == offsetof(CallContextData, function) + 8);
+
+#define GlobalContextMembers(class, Member) \
+    Member(class, Pointer, Object *, global)
+
+DECLARE_HEAP_OBJECT(GlobalContext, ExecutionContext) {
+    DECLARE_MARK_TABLE(GlobalContext);
 
-struct GlobalContext : ExecutionContext {
     void init(ExecutionEngine *engine);
-    Pointer<Object> global;
 };
 V4_ASSERT_IS_TRIVIAL(GlobalContext)
 
-struct CatchContext : ExecutionContext {
+#define CatchContextMembers(class, Member) \
+    Member(class, Pointer, String *, exceptionVarName) \
+    Member(class, HeapValue, HeapValue, exceptionValue)
+
+DECLARE_HEAP_OBJECT(CatchContext, ExecutionContext) {
+    DECLARE_MARK_TABLE(CatchContext);
+
     void init(ExecutionContext *outerContext, String *exceptionVarName, const Value &exceptionValue);
-    Pointer<String> exceptionVarName;
-    Value exceptionValue;
 };
 V4_ASSERT_IS_TRIVIAL(CatchContext)
 
-struct WithContext : ExecutionContext {
-    void init(ExecutionContext *outerContext, Object *with)
-    {
-        Heap::ExecutionContext::init(outerContext->engine, Heap::ExecutionContext::Type_WithContext);
-        outer = outerContext;
-        callData = outer->callData;
-        lookups = outer->lookups;
-        constantTable = outer->constantTable;
-        compilationUnit = outer->compilationUnit;
-
-        withObject = with;
-    }
+#define WithContextMembers(class, Member) \
+    Member(class, Pointer, Object *, withObject)
 
-    Pointer<Object> withObject;
+DECLARE_HEAP_OBJECT(WithContext, ExecutionContext) {
+    DECLARE_MARK_TABLE(WithContext);
+
+    void init(ExecutionContext *outerContext, Object *with);
 };
 V4_ASSERT_IS_TRIVIAL(WithContext)
 
@@ -200,15 +254,13 @@ struct Q_QML_EXPORT ExecutionContext : public Managed
     ReturnedValue getPropertyAndBase(String *name, Value *base);
     bool deleteProperty(String *name);
 
-    inline CallContext *asCallContext();
-    inline const CallContext *asCallContext() const;
+    inline SimpleCallContext *asSimpleCallContext();
+    inline const SimpleCallContext *asSimpleCallContext() const;
     inline const CatchContext *asCatchContext() const;
     inline const WithContext *asWithContext() const;
 
     Function *getFunction() const;
 
-    static void markObjects(Heap::Base *m, ExecutionEngine *e);
-
     Value &thisObject() const {
         return d()->callData->thisObject;
     }
@@ -226,9 +278,9 @@ struct Q_QML_EXPORT ExecutionContext : public Managed
     void simpleCall(Scope &scope, CallData *callData, QV4::Function *function);
 };
 
-struct Q_QML_EXPORT CallContext : public ExecutionContext
+struct Q_QML_EXPORT SimpleCallContext : public ExecutionContext
 {
-    V4_MANAGED(CallContext, ExecutionContext)
+    V4_MANAGED(SimpleCallContext, ExecutionContext)
 
     // formals are in reverse order
     Identifier * const *formals() const;
@@ -237,14 +289,17 @@ struct Q_QML_EXPORT CallContext : public ExecutionContext
     unsigned int variableCount() const;
 
     inline ReturnedValue argument(int i) const;
-    bool needsOwnArguments() const;
-
 };
 
-inline ReturnedValue CallContext::argument(int i) const {
+inline ReturnedValue SimpleCallContext::argument(int i) const {
     return i < argc() ? args()[i].asReturnedValue() : Primitive::undefinedValue().asReturnedValue();
 }
 
+struct Q_QML_EXPORT CallContext : public SimpleCallContext
+{
+    V4_MANAGED(CallContext, SimpleCallContext)
+};
+
 struct GlobalContext : public ExecutionContext
 {
     V4_MANAGED(GlobalContext, ExecutionContext)
@@ -261,14 +316,14 @@ struct WithContext : public ExecutionContext
     V4_MANAGED(WithContext, ExecutionContext)
 };
 
-inline CallContext *ExecutionContext::asCallContext()
+inline SimpleCallContext *ExecutionContext::asSimpleCallContext()
 {
-    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<CallContext *>(this) : 0;
+    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<SimpleCallContext *>(this) : 0;
 }
 
-inline const CallContext *ExecutionContext::asCallContext() const
+inline const SimpleCallContext *ExecutionContext::asSimpleCallContext() const
 {
-    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<const CallContext *>(this) : 0;
+    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<const SimpleCallContext *>(this) : 0;
 }
 
 inline const CatchContext *ExecutionContext::asCatchContext() const
diff --git a/src/qml/jsruntime/qv4dataview.cpp b/src/qml/jsruntime/qv4dataview.cpp
index a810b38f24..f1405e08ee 100644
--- a/src/qml/jsruntime/qv4dataview.cpp
+++ b/src/qml/jsruntime/qv4dataview.cpp
@@ -73,7 +73,7 @@ void DataViewCtor::construct(const Managed *, Scope &scope, CallData *callData)
     }
 
     Scoped<DataView> a(scope, scope.engine->memoryManager->allocObject<DataView>());
-    a->d()->buffer = buffer->d();
+    a->d()->buffer.set(scope.engine, buffer->d());
     a->d()->byteLength = byteLength;
     a->d()->byteOffset = byteOffset;
     scope.result = a.asReturnedValue();
@@ -84,13 +84,6 @@ void DataViewCtor::call(const Managed *that, Scope &scope, CallData *callData)
     construct(that, scope, callData);
 }
 
-
-void DataView::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    DataView::Data *v = static_cast<DataView::Data *>(that);
-    v->buffer->mark(e);
-}
-
 void DataViewPrototype::init(ExecutionEngine *engine, Object *ctor)
 {
     Scope scope(engine);
diff --git a/src/qml/jsruntime/qv4dataview_p.h b/src/qml/jsruntime/qv4dataview_p.h
index 11cc0a6bd9..5c50df4655 100644
--- a/src/qml/jsruntime/qv4dataview_p.h
+++ b/src/qml/jsruntime/qv4dataview_p.h
@@ -63,11 +63,14 @@ struct DataViewCtor : FunctionObject {
     void init(QV4::ExecutionContext *scope);
 };
 
-struct DataView : Object {
+#define DataViewMembers(class, Member) \
+    Member(class, Pointer, ArrayBuffer *, buffer) \
+    Member(class, NoMark, uint, byteLength) \
+    Member(class, NoMark, uint, byteOffset)
+
+DECLARE_HEAP_OBJECT(DataView, Object) {
+    DECLARE_MARK_TABLE(DataView);
     void init() { Object::init(); }
-    Pointer<ArrayBuffer> buffer;
-    uint byteLength;
-    uint byteOffset;
 };
 
 }
@@ -84,8 +87,6 @@ struct DataView : Object
 {
     V4_OBJECT2(DataView, Object)
     V4_PROTOTYPE(dataViewPrototype)
-
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 struct DataViewPrototype: Object
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 39b433e5f9..806a614e95 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -130,15 +130,13 @@ QQmlEngine *ExecutionEngine::qmlEngine() const
 qint32 ExecutionEngine::maxCallDepth = -1;
 
 ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
-    : current(0)
-    , hasException(false)
-    , callDepth(0)
-    , memoryManager(new QV4::MemoryManager(this))
+    : callDepth(0)
     , executableAllocator(new QV4::ExecutableAllocator)
     , regExpAllocator(new QV4::ExecutableAllocator)
     , currentContext(0)
     , bumperPointerAllocator(new WTF::BumpPointerAllocator)
     , jsStack(new WTF::PageAllocation)
+    , gcStack(new WTF::PageAllocation)
     , globalCode(0)
     , v8Engine(0)
     , argumentsAccessors(0)
@@ -151,6 +149,8 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     , m_profiler(0)
 #endif
 {
+    memoryManager = new QV4::MemoryManager(this);
+
     if (maxCallDepth == -1) {
         bool ok = false;
         maxCallDepth = qEnvironmentVariableIntValue("QV4_MAX_CALL_DEPTH", &ok);
@@ -189,18 +189,22 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     iselFactory.reset(factory);
 
     // reserve space for the JS stack
-    // we allow it to grow to 2 times JSStackLimit, as we can overshoot due to garbage collection
-    // and ScopedValues allocated outside of JIT'ed methods.
-    *jsStack = WTF::PageAllocation::allocate(2 * JSStackLimit, WTF::OSAllocator::JSVMStackPages,
+    // we allow it to grow to a bit more than JSStackLimit, as we can overshoot due to ScopedValues
+    // allocated outside of JIT'ed methods.
+    *jsStack = WTF::PageAllocation::allocate(JSStackLimit + 256*1024, WTF::OSAllocator::JSVMStackPages,
                                              /* writable */ true, /* executable */ false,
                                              /* includesGuardPages */ true);
     jsStackBase = (Value *)jsStack->base();
 #ifdef V4_USE_VALGRIND
-    VALGRIND_MAKE_MEM_UNDEFINED(jsStackBase, 2*JSStackLimit);
+    VALGRIND_MAKE_MEM_UNDEFINED(jsStackBase, JSStackLimit + 256*1024);
 #endif
 
     jsStackTop = jsStackBase;
 
+    *gcStack = WTF::PageAllocation::allocate(GCStackLimit, WTF::OSAllocator::JSVMStackPages,
+                                             /* writable */ true, /* executable */ false,
+                                             /* includesGuardPages */ true);
+
     exceptionValue = jsAlloca(1);
     globalObject = static_cast<Object *>(jsAlloca(1));
     jsObjects = jsAlloca(NJSObjects);
@@ -398,7 +402,7 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     //
     // set up the global object
     //
-    rootContext()->d()->global = globalObject->d();
+    rootContext()->d()->global.set(scope.engine, globalObject->d());
     rootContext()->d()->callData->thisObject = globalObject;
     Q_ASSERT(globalObject->d()->vtable());
 
@@ -494,6 +498,8 @@ ExecutionEngine::~ExecutionEngine()
     delete executableAllocator;
     jsStack->deallocate();
     delete jsStack;
+    gcStack->deallocate();
+    delete gcStack;
     delete [] argumentsAccessors;
 }
 
@@ -518,7 +524,7 @@ void ExecutionEngine::initRootContext()
                                 sizeof(GlobalContext::Data) + sizeof(CallData)));
     r->d_unchecked()->init(this);
     r->d()->callData = reinterpret_cast<CallData *>(r->d() + 1);
-    r->d()->callData->tag = QV4::Value::Integer_Type_Internal;
+    r->d()->callData->tag = quint32(Value::ValueTypeInternal::Integer);
     r->d()->callData->argc = 0;
     r->d()->callData->thisObject = globalObject;
     r->d()->callData->args[0] = Encode::undefined();
@@ -600,12 +606,14 @@ Heap::ArrayObject *ExecutionEngine::newArrayObject(const Value *values, int leng
         size_t size = sizeof(Heap::ArrayData) + (length-1)*sizeof(Value);
         Heap::SimpleArrayData *d = scope.engine->memoryManager->allocManaged<SimpleArrayData>(size);
         d->init();
-        d->alloc = length;
         d->type = Heap::ArrayData::Simple;
         d->offset = 0;
-        d->len = length;
-        memcpy(&d->arrayData, values, length*sizeof(Value));
-        a->d()->arrayData = d;
+        d->values.alloc = length;
+        d->values.size = length;
+        // this doesn't require a write barrier, things will be ok, when the new array data gets inserted into
+        // the parent object
+        memcpy(&d->values.values, values, length*sizeof(Value));
+        a->d()->arrayData.set(this, d);
         a->setArrayLengthUnchecked(length);
     }
     return a->d();
@@ -886,7 +894,7 @@ QUrl ExecutionEngine::resolvedUrl(const QString &file)
     QUrl base;
     ExecutionContext *c = currentContext;
     while (c) {
-        CallContext *callCtx = c->asCallContext();
+        SimpleCallContext *callCtx = c->asSimpleCallContext();
         if (callCtx && callCtx->d()->v4Function) {
             base.setUrl(callCtx->d()->v4Function->sourceFile());
             break;
@@ -929,23 +937,23 @@ void ExecutionEngine::requireArgumentsAccessors(int n)
     }
 }
 
-void ExecutionEngine::markObjects()
+void ExecutionEngine::markObjects(MarkStack *markStack)
 {
-    identifierTable->mark(this);
+    identifierTable->mark(markStack);
 
     for (int i = 0; i < nArgumentsAccessors; ++i) {
         const Property &pd = argumentsAccessors[i];
         if (Heap::FunctionObject *getter = pd.getter())
-            getter->mark(this);
+            getter->mark(markStack);
         if (Heap::FunctionObject *setter = pd.setter())
-            setter->mark(this);
+            setter->mark(markStack);
     }
 
-    classPool->markObjects(this);
+    classPool->markObjects(markStack);
 
     for (QSet<CompiledData::CompilationUnit*>::ConstIterator it = compilationUnits.constBegin(), end = compilationUnits.constEnd();
          it != end; ++it)
-        (*it)->markObjects(this);
+        (*it)->markObjects(markStack);
 }
 
 ReturnedValue ExecutionEngine::throwError(const Value &value)
@@ -1563,12 +1571,6 @@ QV4::ReturnedValue ExecutionEngine::metaTypeToJS(int type, const void *data)
     return 0;
 }
 
-void ExecutionEngine::assertObjectBelongsToEngine(const Heap::Base &baseObject)
-{
-    Q_ASSERT(!baseObject.vtable()->isObject || static_cast<const Heap::Object&>(baseObject).internalClass->engine == this);
-    Q_UNUSED(baseObject);
-}
-
 void ExecutionEngine::failStackLimitCheck(Scope &scope)
 {
     scope.result = throwRangeError(QStringLiteral("Maximum call stack size exceeded."));
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index 69aa389c44..a2c774c295 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -54,7 +54,6 @@
 #include "private/qv4isel_p.h"
 #include "qv4managed_p.h"
 #include "qv4context_p.h"
-#include "qv4runtimeapi_p.h"
 #include <private/qintrusivelist_p.h>
 
 #ifndef V4_BOOTSTRAP
@@ -88,7 +87,7 @@ struct CompilationUnit;
 struct InternalClass;
 struct InternalClassPool;
 
-struct Q_QML_EXPORT ExecutionEngine
+struct Q_QML_EXPORT ExecutionEngine : public EngineBase
 {
 private:
     static qint32 maxCallDepth;
@@ -97,13 +96,8 @@ private:
     friend struct ExecutionContext;
     friend struct Heap::ExecutionContext;
 public:
-    Heap::ExecutionContext *current;
-
-    Value *jsStackTop;
-    quint32 hasException;
     qint32 callDepth;
 
-    MemoryManager *memoryManager;
     ExecutableAllocator *executableAllocator;
     ExecutableAllocator *regExpAllocator;
     QScopedPointer<EvalISelFactory> iselFactory;
@@ -112,22 +106,16 @@ public:
 
     Value *jsStackLimit;
 
-    Runtime runtime;
-
     WTF::BumpPointerAllocator *bumperPointerAllocator; // Used by Yarr Regex engine.
 
-    enum { JSStackLimit = 4*1024*1024 };
+    enum {
+        JSStackLimit = 4*1024*1024,
+        GCStackLimit = 2*1024*1024
+    };
     WTF::PageAllocation *jsStack;
     Value *jsStackBase;
 
-    void pushForGC(Heap::Base *m) {
-        *jsStackTop = m;
-        ++jsStackTop;
-    }
-    Heap::Base *popForGC() {
-        --jsStackTop;
-        return jsStackTop->heapObject();
-    }
+    WTF::PageAllocation *gcStack;
 
     QML_NEARLY_ALWAYS_INLINE Value *jsAlloca(int nValues) {
         Value *ptr = jsStackTop;
@@ -454,7 +442,7 @@ public:
 
     void requireArgumentsAccessors(int n);
 
-    void markObjects();
+    void markObjects(MarkStack *markStack);
 
     void initRootContext();
 
@@ -491,8 +479,6 @@ public:
     bool metaTypeFromJS(const Value *value, int type, void *data);
     QV4::ReturnedValue metaTypeToJS(int type, const void *data);
 
-    void assertObjectBelongsToEngine(const Heap::Base &baseObject);
-
     bool checkStackLimits(Scope &scope);
 
 private:
@@ -551,23 +537,32 @@ inline ExecutionContext *ExecutionEngine::parentContext(ExecutionContext *contex
 }
 
 inline
-void Heap::Base::mark(QV4::ExecutionEngine *engine)
+void Heap::Base::mark(QV4::MarkStack *markStack)
 {
     Q_ASSERT(inUse());
-    if (isMarked())
-        return;
-#ifndef QT_NO_DEBUG
-    engine->assertObjectBelongsToEngine(*this);
-#endif
-    setMarkBit();
-    engine->pushForGC(this);
+    const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
+    Chunk *c = h->chunk();
+    size_t index = h - c->realBase();
+    Q_ASSERT(!Chunk::testBit(c->extendsBitmap, index));
+    quintptr *bitmap = c->blackBitmap + Chunk::bitmapIndex(index);
+    quintptr bit = Chunk::bitForIndex(index);
+    if (!(*bitmap & bit)) {
+        *bitmap |= bit;
+        markStack->push(this);
+    }
 }
 
-inline void Value::mark(ExecutionEngine *e)
+inline void Value::mark(MarkStack *markStack)
 {
     Heap::Base *o = heapObject();
     if (o)
-        o->mark(e);
+        o->mark(markStack);
+}
+
+inline void Managed::mark(MarkStack *markStack)
+{
+    Q_ASSERT(m());
+    m()->mark(markStack);
 }
 
 #define CHECK_STACK_LIMITS(v4, scope) if ((v4)->checkStackLimits(scope)) return; \
diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index f290bc5136..58742a0b84 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -78,10 +78,10 @@ void Heap::ErrorObject::init()
     if (internalClass == scope.engine->errorProtoClass)
         return;
 
-    *propertyData(QV4::ErrorObject::Index_Stack) = scope.engine->getStackFunction();
-    *propertyData(QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset) = Encode::undefined();
-    *propertyData(QV4::ErrorObject::Index_FileName) = Encode::undefined();
-    *propertyData(QV4::ErrorObject::Index_LineNumber) = Encode::undefined();
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_FileName, Primitive::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::undefinedValue());
 }
 
 void Heap::ErrorObject::init(const Value &message, ErrorType t)
@@ -92,17 +92,17 @@ void Heap::ErrorObject::init(const Value &message, ErrorType t)
     Scope scope(internalClass->engine);
     Scoped<QV4::ErrorObject> e(scope, this);
 
-    *propertyData(QV4::ErrorObject::Index_Stack) = scope.engine->getStackFunction();
-    *propertyData(QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset) = Encode::undefined();
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
 
     e->d()->stackTrace = new StackTrace(scope.engine->stackTrace());
     if (!e->d()->stackTrace->isEmpty()) {
-        *propertyData(QV4::ErrorObject::Index_FileName) = scope.engine->newString(e->d()->stackTrace->at(0).source);
-        *propertyData(QV4::ErrorObject::Index_LineNumber) = Primitive::fromInt32(e->d()->stackTrace->at(0).line);
+        setProperty(scope.engine, QV4::ErrorObject::Index_FileName, scope.engine->newString(e->d()->stackTrace->at(0).source));
+        setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::fromInt32(e->d()->stackTrace->at(0).line));
     }
 
     if (!message.isUndefined())
-        *propertyData(QV4::ErrorObject::Index_Message) = message;
+        setProperty(scope.engine, QV4::ErrorObject::Index_Message, message);
 }
 
 void Heap::ErrorObject::init(const Value &message, const QString &fileName, int line, int column, ErrorObject::ErrorType t)
@@ -113,8 +113,8 @@ void Heap::ErrorObject::init(const Value &message, const QString &fileName, int
     Scope scope(internalClass->engine);
     Scoped<QV4::ErrorObject> e(scope, this);
 
-    *propertyData(QV4::ErrorObject::Index_Stack) = scope.engine->getStackFunction();
-    *propertyData(QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset) = Encode::undefined();
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
+    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
 
     e->d()->stackTrace = new StackTrace(scope.engine->stackTrace());
     StackFrame frame;
@@ -124,12 +124,12 @@ void Heap::ErrorObject::init(const Value &message, const QString &fileName, int
     e->d()->stackTrace->prepend(frame);
 
     if (!e->d()->stackTrace->isEmpty()) {
-        *propertyData(QV4::ErrorObject::Index_FileName) = scope.engine->newString(e->d()->stackTrace->at(0).source);
-        *propertyData(QV4::ErrorObject::Index_LineNumber) = Primitive::fromInt32(e->d()->stackTrace->at(0).line);
+        setProperty(scope.engine, QV4::ErrorObject::Index_FileName, scope.engine->newString(e->d()->stackTrace->at(0).source));
+        setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::fromInt32(e->d()->stackTrace->at(0).line));
     }
 
     if (!message.isUndefined())
-        *propertyData(QV4::ErrorObject::Index_Message) = message;
+        setProperty(scope.engine, QV4::ErrorObject::Index_Message, message);
 }
 
 const char *ErrorObject::className(Heap::ErrorObject::ErrorType t)
@@ -168,19 +168,11 @@ void ErrorObject::method_get_stack(const BuiltinFunction *, Scope &scope, CallDa
             if (frame.line >= 0)
                 trace += QLatin1Char(':') + QString::number(frame.line);
         }
-        This->d()->stack = scope.engine->newString(trace);
+        This->d()->stack.set(scope.engine, scope.engine->newString(trace));
     }
     scope.result = This->d()->stack;
 }
 
-void ErrorObject::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    ErrorObject::Data *This = static_cast<ErrorObject::Data *>(that);
-    if (This->stack)
-        This->stack->mark(e);
-    Object::markObjects(that, e);
-}
-
 DEFINE_OBJECT_VTABLE(ErrorObject);
 
 DEFINE_OBJECT_VTABLE(SyntaxErrorObject);
@@ -327,9 +319,9 @@ void ErrorPrototype::init(ExecutionEngine *engine, Object *ctor, Object *obj, He
     ScopedObject o(scope);
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = obj));
     ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
-    *obj->propertyData(Index_Constructor) = ctor;
-    *obj->propertyData(Index_Message) = engine->id_empty();
-    *obj->propertyData(Index_Name) = engine->newString(QString::fromLatin1(ErrorObject::className(t)));
+    obj->setProperty(Index_Constructor, ctor->d());
+    obj->setProperty(Index_Message, engine->id_empty()->d());
+    obj->setProperty(Index_Name, engine->newString(QString::fromLatin1(ErrorObject::className(t))));
     if (t == Heap::ErrorObject::Error)
         obj->defineDefaultProperty(engine->id_toString(), method_toString, 0);
 }
diff --git a/src/qml/jsruntime/qv4errorobject_p.h b/src/qml/jsruntime/qv4errorobject_p.h
index 9ba9f05234..5afd9efcba 100644
--- a/src/qml/jsruntime/qv4errorobject_p.h
+++ b/src/qml/jsruntime/qv4errorobject_p.h
@@ -62,7 +62,12 @@ struct SyntaxErrorObject;
 
 namespace Heap {
 
-struct ErrorObject : Object {
+
+#define ErrorObjectMembers(class, Member) \
+    Member(class, Pointer, String *, stack)
+
+DECLARE_HEAP_OBJECT(ErrorObject, Object) {
+    DECLARE_MARK_TABLE(ErrorObject);
     enum ErrorType {
         Error,
         EvalError,
@@ -72,6 +77,8 @@ struct ErrorObject : Object {
         TypeError,
         URIError
     };
+    StackTrace *stackTrace;
+    ErrorType errorType;
 
     void init();
     void init(const Value &message, ErrorType t = Error);
@@ -80,10 +87,6 @@ struct ErrorObject : Object {
         delete stackTrace;
         Object::destroy();
     }
-
-    ErrorType errorType;
-    StackTrace *stackTrace;
-    Pointer<String> stack;
 };
 
 struct EvalErrorObject : ErrorObject {
@@ -173,7 +176,6 @@ struct ErrorObject: Object {
     static const char *className(Heap::ErrorObject::ErrorType t);
 
     static void method_get_stack(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 template<>
diff --git a/src/qml/jsruntime/qv4function.cpp b/src/qml/jsruntime/qv4function.cpp
index 358c2d079c..ed9e3699f2 100644
--- a/src/qml/jsruntime/qv4function.cpp
+++ b/src/qml/jsruntime/qv4function.cpp
@@ -83,10 +83,7 @@ Function::Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit,
     for (quint32 i = 0; i < compiledFunction->nLocals; ++i)
         internalClass = internalClass->addMember(compilationUnit->runtimeStrings[localsIndices[i]]->identifier, Attr_NotConfigurable);
 
-    activationRequired = compiledFunction->nInnerFunctions > 0 || (compiledFunction->flags & (CompiledData::Function::HasDirectEval | CompiledData::Function::UsesArgumentsObject));
-
-    canUseSimpleCall = !needsActivation() && !(compiledFunction->flags & CompiledData::Function::HasCatchOrWith) &&
-                       !(compiledFunction->nFormals > QV4::Global::ReservedArgumentCount) && !isNamedExpression();
+    canUseSimpleCall = compiledFunction->flags & CompiledData::Function::CanUseSimpleCall;
 }
 
 Function::~Function()
@@ -118,7 +115,7 @@ void Function::updateInternalClass(ExecutionEngine *engine, const QList<QByteArr
     for (quint32 i = 0; i < compiledFunction->nLocals; ++i)
         internalClass = internalClass->addMember(compilationUnit->runtimeStrings[localsIndices[i]]->identifier, Attr_NotConfigurable);
 
-    activationRequired = true;
+    canUseSimpleCall = false;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4function_p.h b/src/qml/jsruntime/qv4function_p.h
index 54d0528c42..b11c8af94a 100644
--- a/src/qml/jsruntime/qv4function_p.h
+++ b/src/qml/jsruntime/qv4function_p.h
@@ -69,7 +69,6 @@ struct Q_QML_EXPORT Function {
     // first nArguments names in internalClass are the actual arguments
     InternalClass *internalClass;
     uint nFormals;
-    bool activationRequired;
     bool hasQmlDependencies;
     bool canUseSimpleCall;
 
@@ -89,9 +88,6 @@ struct Q_QML_EXPORT Function {
     inline bool isStrict() const { return compiledFunction->flags & CompiledData::Function::IsStrict; }
     inline bool isNamedExpression() const { return compiledFunction->flags & CompiledData::Function::IsNamedExpression; }
 
-    inline bool needsActivation() const
-    { return activationRequired; }
-
     inline bool canUseSimpleFunction() const { return canUseSimpleCall; }
 
     QQmlSourceLocation sourceLocation() const
@@ -102,7 +98,7 @@ struct Q_QML_EXPORT Function {
 };
 
 
-inline unsigned int Heap::CallContext::formalParameterCount() const
+inline unsigned int Heap::SimpleCallContext::formalParameterCount() const
 {
     return v4Function ? v4Function->nFormals : 0;
 }
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index e9431ed25e..5c8f03dc72 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -69,11 +69,13 @@ using namespace QV4;
 
 DEFINE_OBJECT_VTABLE(FunctionObject);
 
+Q_STATIC_ASSERT((Heap::FunctionObject::markTable & Heap::Object::markTable) == Heap::Object::markTable);
+
 void Heap::FunctionObject::init(QV4::ExecutionContext *scope, QV4::String *name, bool createProto)
 {
     Object::init();
     function = nullptr;
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
     ScopedFunctionObject f(s, this);
     f->init(name, createProto);
@@ -84,7 +86,7 @@ void Heap::FunctionObject::init(QV4::ExecutionContext *scope, Function *function
     Object::init();
     this->function = function;
     function->compilationUnit->addref();
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
     ScopedString name(s, function->name());
     ScopedFunctionObject f(s, this);
@@ -102,9 +104,9 @@ void Heap::FunctionObject::init()
 {
     Object::init();
     function = nullptr;
-    this->scope = internalClass->engine->rootContext()->d();
+    this->scope.set(internalClass->engine, internalClass->engine->rootContext()->d());
     Q_ASSERT(internalClass && internalClass->find(internalClass->engine->id_prototype()) == Index_Prototype);
-    *propertyData(Index_Prototype) = Encode::undefined();
+    setProperty(internalClass->engine, Index_Prototype, Primitive::undefinedValue());
 }
 
 
@@ -124,10 +126,10 @@ void FunctionObject::init(String *n, bool createProto)
     if (createProto) {
         ScopedObject proto(s, scope()->engine->newObject(s.engine->protoClass, s.engine->objectPrototype()));
         Q_ASSERT(s.engine->protoClass->find(s.engine->id_constructor()) == Heap::FunctionObject::Index_ProtoConstructor);
-        *proto->propertyData(Heap::FunctionObject::Index_ProtoConstructor) = this->asReturnedValue();
-        *propertyData(Heap::FunctionObject::Index_Prototype) = proto.asReturnedValue();
+        proto->setProperty(Heap::FunctionObject::Index_ProtoConstructor, d());
+        setProperty(Heap::FunctionObject::Index_Prototype, proto);
     } else {
-        *propertyData(Heap::FunctionObject::Index_Prototype) = Encode::undefined();
+        setProperty(Heap::FunctionObject::Index_Prototype, Primitive::undefinedValue());
     }
 
     if (n)
@@ -149,15 +151,6 @@ void FunctionObject::call(const Managed *, Scope &scope, CallData *)
     scope.result = Encode::undefined();
 }
 
-void FunctionObject::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    Heap::FunctionObject *o = static_cast<Heap::FunctionObject *>(that);
-    if (o->scope)
-        o->scope->mark(e);
-
-    Object::markObjects(that, e);
-}
-
 Heap::FunctionObject *FunctionObject::createScriptFunction(ExecutionContext *scope, Function *function)
 {
     return scope->d()->engine->memoryManager->allocObject<ScriptFunction>(scope, function);
@@ -309,7 +302,7 @@ void FunctionPrototype::method_apply(const BuiltinFunction *, Scope &scope, Call
                 cData->args[i] = Primitive::undefinedValue();
         } else if (arr->arrayType() == Heap::ArrayData::Simple && !arr->protoHasArray()) {
             auto sad = static_cast<Heap::SimpleArrayData *>(arr->arrayData());
-            uint alen = sad ? sad->len : 0;
+            uint alen = sad ? sad->values.size : 0;
             if (alen > len)
                 alen = len;
             for (uint i = 0; i < alen; ++i)
@@ -352,8 +345,9 @@ void FunctionPrototype::method_bind(const BuiltinFunction *, Scope &scope, CallD
     Scoped<MemberData> boundArgs(scope, (Heap::MemberData *)0);
     if (callData->argc > 1) {
         boundArgs = MemberData::allocate(scope.engine, callData->argc - 1);
-        boundArgs->d()->size = callData->argc - 1;
-        memcpy(boundArgs->data(), callData->args + 1, (callData->argc - 1)*sizeof(Value));
+        boundArgs->d()->values.size = callData->argc - 1;
+        for (uint i = 0; i < static_cast<uint>(callData->argc - 1); ++i)
+            boundArgs->set(scope.engine, i, callData->args[i + 1]);
     }
 
     ExecutionContext *global = scope.engine->rootContext();
@@ -420,7 +414,7 @@ void ScriptFunction::call(const Managed *that, Scope &scope, CallData *callData)
 void Heap::ScriptFunction::init(QV4::ExecutionContext *scope, Function *function)
 {
     FunctionObject::init();
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
 
     this->function = function;
     function->compilationUnit->addref();
@@ -433,7 +427,7 @@ void Heap::ScriptFunction::init(QV4::ExecutionContext *scope, Function *function
     ScopedString name(s, function->name());
     f->init(name, true);
     Q_ASSERT(internalClass && internalClass->find(s.engine->id_length()) == Index_Length);
-    *propertyData(Index_Length) = Primitive::fromInt32(f->formalParameterCount());
+    setProperty(s.engine, Index_Length, Primitive::fromInt32(f->formalParameterCount()));
 
     if (scope->d()->strictMode) {
         ScopedProperty pd(s);
@@ -479,7 +473,7 @@ void OldBuiltinFunction::call(const Managed *that, Scope &scope, CallData *callD
 
     ExecutionContextSaver ctxSaver(scope);
 
-    CallContext::Data *ctx = v4->memoryManager->allocSimpleCallContext(v4);
+    SimpleCallContext::Data *ctx = v4->memoryManager->allocSimpleCallContext(v4);
     ctx->strictMode = f->scope()->strictMode; // ### needed? scope or parent context?
     ctx->callData = callData;
     v4->pushContext(ctx);
@@ -526,7 +520,7 @@ void IndexedBuiltinFunction::call(const Managed *that, Scope &scope, CallData *c
 
     ExecutionContextSaver ctxSaver(scope);
 
-    CallContext::Data *ctx = v4->memoryManager->allocSimpleCallContext(v4);
+    SimpleCallContext::Data *ctx = v4->memoryManager->allocSimpleCallContext(v4);
     ctx->strictMode = f->scope()->strictMode; // ### needed? scope or parent context?
     ctx->callData = callData;
     v4->pushContext(ctx);
@@ -543,12 +537,12 @@ DEFINE_OBJECT_VTABLE(BoundFunction);
 void Heap::BoundFunction::init(QV4::ExecutionContext *scope, QV4::FunctionObject *target,
                                const Value &boundThis, QV4::MemberData *boundArgs)
 {
+    Scope s(scope);
     Heap::FunctionObject::init(scope, QStringLiteral("__bound function__"));
-    this->target = target->d();
-    this->boundArgs = boundArgs ? boundArgs->d() : 0;
-    this->boundThis = boundThis;
+    this->target.set(s.engine, target->d());
+    this->boundArgs.set(s.engine, boundArgs ? boundArgs->d() : 0);
+    this->boundThis.set(scope->engine(), boundThis);
 
-    Scope s(scope);
     ScopedObject f(s, this);
 
     ScopedValue l(s, target->get(s.engine->id_length()));
@@ -606,14 +600,3 @@ void BoundFunction::construct(const Managed *that, Scope &scope, CallData *dd)
     ScopedFunctionObject t(scope, f->target());
     t->construct(scope, callData);
 }
-
-void BoundFunction::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    BoundFunction::Data *o = static_cast<BoundFunction::Data *>(that);
-    if (o->target)
-        o->target->mark(e);
-    o->boundThis.mark(e);
-    if (o->boundArgs)
-        o->boundArgs->mark(e);
-    FunctionObject::markObjects(that, e);
-}
diff --git a/src/qml/jsruntime/qv4functionobject_p.h b/src/qml/jsruntime/qv4functionobject_p.h
index 45d7485f1b..d8929026ca 100644
--- a/src/qml/jsruntime/qv4functionobject_p.h
+++ b/src/qml/jsruntime/qv4functionobject_p.h
@@ -65,7 +65,12 @@ struct BuiltinFunction;
 
 namespace Heap {
 
-struct Q_QML_PRIVATE_EXPORT FunctionObject : Object {
+#define FunctionObjectMembers(class, Member) \
+    Member(class, Pointer, ExecutionContext *, scope) \
+    Member(class, NoMark, Function *, function)
+
+DECLARE_HEAP_OBJECT(FunctionObject, Object) {
+    DECLARE_MARK_TABLE(FunctionObject);
     enum {
         Index_Prototype = 0,
         Index_ProtoConstructor = 0
@@ -79,12 +84,8 @@ struct Q_QML_PRIVATE_EXPORT FunctionObject : Object {
 
     unsigned int formalParameterCount() { return function ? function->nFormals : 0; }
     unsigned int varCount() { return function ? function->compiledFunction->nLocals : 0; }
-    bool needsActivation() const { return function ? function->needsActivation() : false; }
-
-    const QV4::Object *protoProperty() const { return propertyData(Index_Prototype)->cast<QV4::Object>(); }
 
-    Pointer<ExecutionContext> scope;
-    Function *function;
+    const QV4::Object *protoProperty() const { return propertyData(Index_Prototype)->as<QV4::Object>(); }
 };
 
 struct FunctionCtor : FunctionObject {
@@ -119,11 +120,15 @@ struct ScriptFunction : FunctionObject {
     void init(QV4::ExecutionContext *scope, Function *function);
 };
 
-struct BoundFunction : FunctionObject {
+#define BoundFunctionMembers(class, Member) \
+    Member(class, Pointer, FunctionObject *, target) \
+    Member(class, HeapValue, HeapValue, boundThis) \
+    Member(class, Pointer, MemberData *, boundArgs)
+
+DECLARE_HEAP_OBJECT(BoundFunction, FunctionObject) {
+    DECLARE_MARK_TABLE(BoundFunction);
+
     void init(QV4::ExecutionContext *scope, QV4::FunctionObject *target, const Value &boundThis, QV4::MemberData *boundArgs);
-    Pointer<FunctionObject> target;
-    Value boundThis;
-    Pointer<MemberData> boundArgs;
 };
 
 }
@@ -154,14 +159,11 @@ struct Q_QML_EXPORT FunctionObject: Object {
 
     static Heap::FunctionObject *createScriptFunction(ExecutionContext *scope, Function *function);
 
-    bool needsActivation() const { return d()->needsActivation(); }
     bool strictMode() const { return d()->function ? d()->function->isStrict() : false; }
     bool isBinding() const;
     bool isBoundFunction() const;
 
     QQmlSourceLocation sourceLocation() const;
-
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 template<>
@@ -259,8 +261,6 @@ struct BoundFunction: FunctionObject {
 
     static void construct(const Managed *, Scope &scope, CallData *d);
     static void call(const Managed *that, Scope &scope, CallData *dd);
-
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4global_p.h b/src/qml/jsruntime/qv4global_p.h
index b0d14fc2b4..0665295287 100644
--- a/src/qml/jsruntime/qv4global_p.h
+++ b/src/qml/jsruntime/qv4global_p.h
@@ -89,8 +89,6 @@ inline bool signbit(double d) { return _copysign(1.0, d) < 0; }
 inline double trunc(double d) { return d > 0 ? floor(d) : ceil(d); }
 #endif
 
-#define qOffsetOf(s, m) ((size_t)((((char *)&(((s *)64)->m)) - 64)))
-
 // Decide whether to enable or disable the JIT
 
 // White list architectures
@@ -184,6 +182,7 @@ namespace Heap {
     struct DataView;
     struct TypedArray;
 
+    template <typename T, size_t> struct Pointer;
 }
 
 class MemoryManager;
@@ -198,9 +197,12 @@ struct ScriptFunction;
 struct InternalClass;
 struct Property;
 struct Value;
+template<size_t> struct HeapValue;
+template<size_t> struct ValueArray;
 struct Lookup;
 struct ArrayData;
 struct VTable;
+struct Function;
 
 struct BooleanObject;
 struct NumberObject;
diff --git a/src/qml/jsruntime/qv4globalobject.cpp b/src/qml/jsruntime/qv4globalobject.cpp
index 1bc91f832b..f0630660d4 100644
--- a/src/qml/jsruntime/qv4globalobject.cpp
+++ b/src/qml/jsruntime/qv4globalobject.cpp
@@ -394,6 +394,7 @@ void EvalFunction::evalCall(Scope &scope, CallData *callData, bool directCall) c
     // set the correct strict mode flag on the context
     ctx->d()->strictMode = false;
     ctx->d()->compilationUnit = function->compilationUnit;
+    ctx->d()->constantTable = function->compilationUnit->constants;
 
     scope.result = Q_V4_PROFILE(ctx->engine(), function);
 }
diff --git a/src/qml/jsruntime/qv4identifiertable_p.h b/src/qml/jsruntime/qv4identifiertable_p.h
index 89af5db731..b0b08f1e54 100644
--- a/src/qml/jsruntime/qv4identifiertable_p.h
+++ b/src/qml/jsruntime/qv4identifiertable_p.h
@@ -93,14 +93,14 @@ public:
 
     Heap::String *stringFromIdentifier(Identifier *i);
 
-    void mark(ExecutionEngine *e) {
+    void mark(MarkStack *markStack) {
         for (int i = 0; i < alloc; ++i) {
             Heap::String *entry = entries[i];
             if (!entry || entry->isMarked())
                 continue;
             entry->setMarkBit();
             Q_ASSERT(entry->vtable()->markObjects);
-            entry->vtable()->markObjects(entry, e);
+            entry->vtable()->markObjects(entry, markStack);
         }
     }
 };
diff --git a/src/qml/jsruntime/qv4internalclass.cpp b/src/qml/jsruntime/qv4internalclass.cpp
index bac71b4537..3d9a672f2f 100644
--- a/src/qml/jsruntime/qv4internalclass.cpp
+++ b/src/qml/jsruntime/qv4internalclass.cpp
@@ -126,26 +126,6 @@ InternalClass::InternalClass(const QV4::InternalClass &other)
     Q_ASSERT(extensible);
 }
 
-static void insertHoleIntoPropertyData(Object *object, int idx)
-{
-    int icSize = object->internalClass()->size;
-    int from = idx;
-    int to = from + 1;
-    if (from < icSize)
-        memmove(object->propertyData(to), object->propertyData(from),
-                (icSize - from - 1) * sizeof(Value));
-}
-
-static void removeFromPropertyData(Object *object, int idx, bool accessor = false)
-{
-    int delta = (accessor ? 2 : 1);
-    int oldSize = object->internalClass()->size + delta;
-    int to = idx;
-    int from = to + delta;
-    if (from < oldSize)
-        memmove(object->propertyData(to), object->d()->propertyData(from), (oldSize - to)*sizeof(Value));
-}
-
 void InternalClass::changeMember(Object *object, String *string, PropertyAttributes data, uint *index)
 {
     uint idx;
@@ -157,10 +137,10 @@ void InternalClass::changeMember(Object *object, String *string, PropertyAttribu
     object->setInternalClass(newClass);
     if (newClass->size > oldClass->size) {
         Q_ASSERT(newClass->size == oldClass->size + 1);
-        insertHoleIntoPropertyData(object, idx + 1);
+        object->d()->memberData->values.insertData(newClass->engine, idx + 1, Primitive::emptyValue());
     } else if (newClass->size < oldClass->size) {
         Q_ASSERT(newClass->size == oldClass->size - 1);
-        removeFromPropertyData(object, idx + 1);
+        object->d()->memberData->values.removeData(newClass->engine, idx + 1);
     }
 }
 
@@ -318,7 +298,7 @@ void InternalClass::removeMember(Object *object, Identifier *id)
     Q_ASSERT(object->internalClass()->size == oldClass->size - (accessor ? 2 : 1));
 
     // remove the entry in the property data
-    removeFromPropertyData(object, propIdx, accessor);
+    object->d()->memberData->values.removeData(oldClass->engine, propIdx, accessor ? 2 : 1);
 
     t.lookup = object->internalClass();
     Q_ASSERT(t.lookup);
@@ -408,9 +388,9 @@ void InternalClass::destroy()
     }
 }
 
-void InternalClassPool::markObjects(ExecutionEngine *engine)
+void InternalClassPool::markObjects(MarkStack *markStack)
 {
-    Q_UNUSED(engine);
+    Q_UNUSED(markStack);
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4internalclass_p.h b/src/qml/jsruntime/qv4internalclass_p.h
index 1d8ef4b0fb..a29ce5b5ff 100644
--- a/src/qml/jsruntime/qv4internalclass_p.h
+++ b/src/qml/jsruntime/qv4internalclass_p.h
@@ -291,7 +291,7 @@ inline uint InternalClass::find(const String *string)
 
 struct InternalClassPool : public QQmlJS::MemoryPool
 {
-    void markObjects(ExecutionEngine *engine);
+    void markObjects(MarkStack *markStack);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index 52ed449664..11d7767e05 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -59,7 +59,7 @@ ReturnedValue Lookup::lookup(const Value &thisObject, Object *o, PropertyAttribu
         if (index != UINT_MAX) {
             level = i;
             *attrs = obj->internalClass->propertyData.at(index);
-            Value *v = obj->propertyData(index);
+            const Value *v = obj->propertyData(index);
             return !attrs->isAccessor() ? v->asReturnedValue() : Object::getValue(thisObject, *v, *attrs);
         }
 
@@ -72,7 +72,7 @@ ReturnedValue Lookup::lookup(const Value &thisObject, Object *o, PropertyAttribu
         index = obj->internalClass->find(name);
         if (index != UINT_MAX) {
             *attrs = obj->internalClass->propertyData.at(index);
-            Value *v = obj->propertyData(index);
+            const Value *v = obj->propertyData(index);
             return !attrs->isAccessor() ? v->asReturnedValue() : Object::getValue(thisObject, *v, *attrs);
         }
 
@@ -94,7 +94,7 @@ ReturnedValue Lookup::lookup(const Object *thisObject, PropertyAttributes *attrs
         if (index != UINT_MAX) {
             level = i;
             *attrs = obj->internalClass->propertyData.at(index);
-            Value *v = obj->propertyData(index);
+            const Value *v = obj->propertyData(index);
             return !attrs->isAccessor() ? v->asReturnedValue() : thisObject->getValue(*v, *attrs);
         }
 
@@ -107,7 +107,7 @@ ReturnedValue Lookup::lookup(const Object *thisObject, PropertyAttributes *attrs
         index = obj->internalClass->find(name);
         if (index != UINT_MAX) {
             *attrs = obj->internalClass->propertyData.at(index);
-            Value *v = obj->propertyData(index);
+            const Value *v = obj->propertyData(index);
             return !attrs->isAccessor() ? v->asReturnedValue() : thisObject->getValue(*v, *attrs);
         }
 
@@ -116,20 +116,20 @@ ReturnedValue Lookup::lookup(const Object *thisObject, PropertyAttributes *attrs
     return Primitive::emptyValue().asReturnedValue();
 }
 
-ReturnedValue Lookup::indexedGetterGeneric(Lookup *l, const Value &object, const Value &index)
+ReturnedValue Lookup::indexedGetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
 {
     uint idx;
     if (object.isObject() && index.asArrayIndex(idx)) {
         l->indexedGetter = indexedGetterObjectInt;
-        return indexedGetterObjectInt(l, object, index);
+        return indexedGetterObjectInt(l, engine, object, index);
     }
-    return indexedGetterFallback(l, object, index);
+    return indexedGetterFallback(l, engine, object, index);
 }
 
-ReturnedValue Lookup::indexedGetterFallback(Lookup *l, const Value &object, const Value &index)
+ReturnedValue Lookup::indexedGetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
 {
     Q_UNUSED(l);
-    Scope scope(l->engine);
+    Scope scope(engine);
     uint idx = 0;
     bool isInt = index.asArrayIndex(idx);
 
@@ -147,7 +147,7 @@ ReturnedValue Lookup::indexedGetterFallback(Lookup *l, const Value &object, cons
 
         if (object.isNullOrUndefined()) {
             QString message = QStringLiteral("Cannot read property '%1' of %2").arg(index.toQStringNoThrow()).arg(object.toQStringNoThrow());
-            return l->engine->throwTypeError(message);
+            return engine->throwTypeError(message);
         }
 
         o = RuntimeHelpers::convertToObject(scope.engine, object);
@@ -173,7 +173,7 @@ ReturnedValue Lookup::indexedGetterFallback(Lookup *l, const Value &object, cons
 }
 
 
-ReturnedValue Lookup::indexedGetterObjectInt(Lookup *l, const Value &object, const Value &index)
+ReturnedValue Lookup::indexedGetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
 {
     uint idx;
     if (index.asArrayIndex(idx)) {
@@ -182,7 +182,7 @@ ReturnedValue Lookup::indexedGetterObjectInt(Lookup *l, const Value &object, con
                 Heap::Object *o = static_cast<Heap::Object *>(b);
                 if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
                     Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
-                    if (idx < s->len)
+                    if (idx < s->values.size)
                         if (!s->data(idx).isEmpty())
                             return s->data(idx).asReturnedValue();
                 }
@@ -190,25 +190,25 @@ ReturnedValue Lookup::indexedGetterObjectInt(Lookup *l, const Value &object, con
         }
     }
 
-    return indexedGetterFallback(l, object, index);
+    return indexedGetterFallback(l, engine, object, index);
 }
 
-void Lookup::indexedSetterGeneric(Lookup *l, const Value &object, const Value &index, const Value &v)
+void Lookup::indexedSetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v)
 {
     if (Object *o = object.objectValue()) {
         uint idx;
         if (o->d()->arrayData && o->d()->arrayData->type == Heap::ArrayData::Simple && index.asArrayIndex(idx)) {
             l->indexedSetter = indexedSetterObjectInt;
-            indexedSetterObjectInt(l, object, index, v);
+            indexedSetterObjectInt(l, engine, object, index, v);
             return;
         }
     }
-    indexedSetterFallback(l, object, index, v);
+    indexedSetterFallback(l, engine, object, index, v);
 }
 
-void Lookup::indexedSetterFallback(Lookup *l, const Value &object, const Value &index, const Value &value)
+void Lookup::indexedSetterFallback(Lookup *, ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
 {
-    Scope scope(l->engine);
+    Scope scope(engine);
     ScopedObject o(scope, object.toObject(scope.engine));
     if (scope.engine->hasException)
         return;
@@ -217,8 +217,8 @@ void Lookup::indexedSetterFallback(Lookup *l, const Value &object, const Value &
     if (index.asArrayIndex(idx)) {
         if (o->d()->arrayData && o->d()->arrayData->type == Heap::ArrayData::Simple) {
             Heap::SimpleArrayData *s = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-            if (idx < s->len) {
-                s->data(idx) = value;
+            if (idx < s->values.size) {
+                s->setData(engine, idx, value);
                 return;
             }
         }
@@ -230,7 +230,7 @@ void Lookup::indexedSetterFallback(Lookup *l, const Value &object, const Value &
     o->put(name, value);
 }
 
-void Lookup::indexedSetterObjectInt(Lookup *l, const Value &object, const Value &index, const Value &v)
+void Lookup::indexedSetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v)
 {
     uint idx;
     if (index.asArrayIndex(idx)) {
@@ -239,15 +239,15 @@ void Lookup::indexedSetterObjectInt(Lookup *l, const Value &object, const Value
                 Heap::Object *o = static_cast<Heap::Object *>(b);
                 if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
                     Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
-                    if (idx < s->len) {
-                        s->data(idx) = v;
+                    if (idx < s->values.size) {
+                        s->setData(engine, idx, v);
                         return;
                     }
                 }
             }
         }
     }
-    indexedSetterFallback(l, object, index, v);
+    indexedSetterFallback(l, engine, object, index, v);
 }
 
 ReturnedValue Lookup::getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object)
@@ -772,7 +772,7 @@ void Lookup::setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Va
 {
     Object *o = object.as<Object>();
     if (o && o->internalClass() == l->classList[0]) {
-        *o->propertyData(l->index) = value;
+        o->setProperty(engine, l->index, value);
         return;
     }
 
@@ -785,7 +785,7 @@ void Lookup::setterInsert0(Lookup *l, ExecutionEngine *engine, Value &object, co
     if (o && o->internalClass() == l->classList[0]) {
         if (!o->prototype()) {
             o->setInternalClass(l->classList[3]);
-            *o->propertyData(l->index) = value;
+            o->setProperty(l->index, value);
             return;
         }
     }
@@ -801,7 +801,7 @@ void Lookup::setterInsert1(Lookup *l, ExecutionEngine *engine, Value &object, co
         Heap::Object *p = o->prototype();
         if (p && p->internalClass == l->classList[1]) {
             o->setInternalClass(l->classList[3]);
-            *o->propertyData(l->index) = value;
+            o->setProperty(l->index, value);
             return;
         }
     }
@@ -819,7 +819,7 @@ void Lookup::setterInsert2(Lookup *l, ExecutionEngine *engine, Value &object, co
             p = p->prototype;
             if (p && p->internalClass == l->classList[2]) {
                 o->setInternalClass(l->classList[3]);
-                *o->propertyData(l->index) = value;
+                o->setProperty(l->index, value);
                 return;
             }
         }
@@ -834,11 +834,11 @@ void Lookup::setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, c
     Object *o = object.as<Object>();
     if (o) {
         if (o->internalClass() == l->classList[0]) {
-            *o->propertyData(l->index) = value;
+            o->setProperty(l->index, value);
             return;
         }
         if (o->internalClass() == l->classList[1]) {
-            *o->propertyData(l->index2) = value;
+            o->setProperty(l->index2, value);
             return;
         }
     }
diff --git a/src/qml/jsruntime/qv4lookup_p.h b/src/qml/jsruntime/qv4lookup_p.h
index c5ee92fedd..daf3c71e27 100644
--- a/src/qml/jsruntime/qv4lookup_p.h
+++ b/src/qml/jsruntime/qv4lookup_p.h
@@ -67,14 +67,13 @@ namespace QV4 {
 struct Lookup {
     enum { Size = 4 };
     union {
-        ReturnedValue (*indexedGetter)(Lookup *l, const Value &object, const Value &index);
-        void (*indexedSetter)(Lookup *l, const Value &object, const Value &index, const Value &v);
+        ReturnedValue (*indexedGetter)(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
+        void (*indexedSetter)(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
         ReturnedValue (*getter)(Lookup *l, ExecutionEngine *engine, const Value &object);
         ReturnedValue (*globalGetter)(Lookup *l, ExecutionEngine *engine);
         void (*setter)(Lookup *l, ExecutionEngine *engine, Value &object, const Value &v);
     };
     union {
-        ExecutionEngine *engine;
         InternalClass *classList[Size];
         struct {
             void *dummy0;
@@ -90,13 +89,13 @@ struct Lookup {
     uint index;
     uint nameIndex;
 
-    static ReturnedValue indexedGetterGeneric(Lookup *l, const Value &object, const Value &index);
-    static ReturnedValue indexedGetterFallback(Lookup *l, const Value &object, const Value &index);
-    static ReturnedValue indexedGetterObjectInt(Lookup *l, const Value &object, const Value &index);
+    static ReturnedValue indexedGetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
+    static ReturnedValue indexedGetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
+    static ReturnedValue indexedGetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
 
-    static void indexedSetterGeneric(Lookup *l, const Value &object, const Value &index, const Value &v);
-    static void indexedSetterFallback(Lookup *l, const Value &object, const Value &index, const Value &value);
-    static void indexedSetterObjectInt(Lookup *l, const Value &object, const Value &index, const Value &v);
+    static void indexedSetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
+    static void indexedSetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &value);
+    static void indexedSetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
 
     static ReturnedValue getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getterTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
@@ -141,6 +140,12 @@ struct Lookup {
 
 };
 
+Q_STATIC_ASSERT(std::is_standard_layout<Lookup>::value);
+// Ensure that these offsets are always at this point to keep generated code compatible
+// across 32-bit and 64-bit (matters when cross-compiling).
+Q_STATIC_ASSERT(offsetof(Lookup, indexedGetter) == 0);
+Q_STATIC_ASSERT(offsetof(Lookup, getter) == 0);
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index 3a84a83b9c..1b43fd86e8 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -47,6 +47,7 @@ using namespace QV4;
 const VTable Managed::static_vtbl =
 {
     0,
+    0,
     Managed::IsExecutionContext,
     Managed::IsString,
     Managed::IsObject,
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 5c764e7ff0..f97771831c 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -53,6 +53,7 @@
 #include "qv4global_p.h"
 #include "qv4value_p.h"
 #include <private/qv4heap_p.h>
+#include <private/qv4writebarrier_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -91,6 +92,7 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
             dptr->_checkIsInitialized(); \
             return dptr; \
         } \
+        static Q_CONSTEXPR quint64 markTable = QV4::Heap::DataClass::markTable; \
         V4_ASSERT_IS_TRIVIAL(QV4::Heap::DataClass)
 
 #define V4_MANAGED(DataClass, superClass) \
@@ -129,6 +131,7 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
 #define DEFINE_MANAGED_VTABLE_INT(classname, parentVTable) \
 {     \
     parentVTable, \
+    markTable, \
     classname::IsExecutionContext,   \
     classname::IsString,   \
     classname::IsObject,   \
@@ -139,7 +142,7 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
     classname::MyType,                          \
     #classname, \
     Q_VTABLE_FUNCTION(classname, destroy),                                    \
-    markObjects,                                \
+    Q_VTABLE_FUNCTION(classname, markObjects),                                    \
     isEqualTo                                  \
 }
 
@@ -204,8 +207,10 @@ public:
 
     bool inUse() const { return d()->inUse(); }
     bool markBit() const { return d()->isMarked(); }
+    inline void mark(MarkStack *markStack);
 
     static void destroy(Heap::Base *) {}
+    static void markObjects(Heap::Base *, MarkStack *) {}
 
     Q_ALWAYS_INLINE Heap::Base *heapObject() const {
         return m();
diff --git a/src/qml/jsruntime/qv4memberdata.cpp b/src/qml/jsruntime/qv4memberdata.cpp
index db45c77472..8f862d63e9 100644
--- a/src/qml/jsruntime/qv4memberdata.cpp
+++ b/src/qml/jsruntime/qv4memberdata.cpp
@@ -45,24 +45,19 @@ using namespace QV4;
 
 DEFINE_MANAGED_VTABLE(MemberData);
 
-void MemberData::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    Heap::MemberData *m = static_cast<Heap::MemberData *>(that);
-    for (uint i = 0; i < m->size; ++i)
-        m->data[i].mark(e);
-}
-
 Heap::MemberData *MemberData::allocate(ExecutionEngine *e, uint n, Heap::MemberData *old)
 {
-    Q_ASSERT(!old || old->size < n);
+    Q_ASSERT(!old || old->values.size < n);
     Q_ASSERT(n);
 
     size_t alloc = MemoryManager::align(sizeof(Heap::MemberData) + (n - 1)*sizeof(Value));
     Heap::MemberData *m = e->memoryManager->allocManaged<MemberData>(alloc);
     if (old)
-        memcpy(m, old, sizeof(Heap::MemberData) + (old->size - 1)* sizeof(Value));
+        // no write barrier required here
+        memcpy(m, old, sizeof(Heap::MemberData) + (old->values.size - 1) * sizeof(Value));
     else
         m->init();
-    m->size = static_cast<uint>((alloc - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
+    m->values.alloc = static_cast<uint>((alloc - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
+    m->values.size = m->values.alloc;
     return m;
 }
diff --git a/src/qml/jsruntime/qv4memberdata_p.h b/src/qml/jsruntime/qv4memberdata_p.h
index 5c89dfe8ec..fbe66757e0 100644
--- a/src/qml/jsruntime/qv4memberdata_p.h
+++ b/src/qml/jsruntime/qv4memberdata_p.h
@@ -59,12 +59,11 @@ namespace QV4 {
 
 namespace Heap {
 
-struct MemberData : Base {
-    union {
-        uint size;
-        double _dummy;
-    };
-    Value data[1];
+#define MemberDataMembers(class, Member) \
+    Member(class, ValueArray, ValueArray, values)
+
+DECLARE_HEAP_OBJECT(MemberData, Base) {
+    DECLARE_MARK_TABLE(MemberData);
 };
 V4_ASSERT_IS_TRIVIAL(MemberData)
 
@@ -74,14 +73,26 @@ struct MemberData : Managed
 {
     V4_MANAGED(MemberData, Managed)
 
-    Value &operator[] (uint idx) { return d()->data[idx]; }
-    const Value *data() const { return d()->data; }
-    Value *data() { return d()->data; }
-    inline uint size() const { return d()->size; }
+    struct Index {
+        Heap::MemberData *memberData;
+        uint index;
 
-    static Heap::MemberData *allocate(QV4::ExecutionEngine *e, uint n, Heap::MemberData *old = 0);
+        void set(ExecutionEngine *e, Value newVal) {
+            memberData->values.set(e, index, newVal);
+        }
+        const Value *operator->() const { return &memberData->values[index]; }
+        const Value &operator*() const { return memberData->values[index]; }
+        bool isNull() const { return !memberData; }
+    };
 
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
+    const Value &operator[] (uint idx) const { return d()->values[idx]; }
+    const Value *data() const { return d()->values.data(); }
+    void set(ExecutionEngine *e, uint index, Value v) { d()->values.set(e, index, v); }
+    void set(ExecutionEngine *e, uint index, Heap::Base *b) { d()->values.set(e, index, b); }
+
+    inline uint size() const { return d()->values.size; }
+
+    static Heap::MemberData *allocate(QV4::ExecutionEngine *e, uint n, Heap::MemberData *old = 0);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index dd3bbccde3..d400c2ae64 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -62,8 +62,8 @@ void Object::setInternalClass(InternalClass *ic)
 {
     d()->internalClass = ic;
     bool hasMD = d()->memberData != nullptr;
-    if ((!hasMD && ic->size) || (hasMD && d()->memberData->size < ic->size))
-        d()->memberData = MemberData::allocate(ic->engine, ic->size, d()->memberData);
+    if ((!hasMD && ic->size) || (hasMD && d()->memberData->values.size < ic->size))
+        d()->memberData.set(engine(), MemberData::allocate(ic->engine, ic->size, d()->memberData));
 }
 
 void Object::getProperty(uint index, Property *p, PropertyAttributes *attrs) const
@@ -76,9 +76,9 @@ void Object::getProperty(uint index, Property *p, PropertyAttributes *attrs) con
 
 void Object::setProperty(uint index, const Property *p)
 {
-    *propertyData(index) = p->value;
+    setProperty(index, p->value);
     if (internalClass()->propertyData.at(index).isAccessor())
-        *propertyData(index + SetterOffset) = p->set;
+        setProperty(index + SetterOffset, p->set);
 }
 
 bool Object::setPrototype(Object *proto)
@@ -89,7 +89,7 @@ bool Object::setPrototype(Object *proto)
             return false;
         pp = pp->prototype;
     }
-    d()->prototype = proto ? proto->d() : 0;
+    d()->prototype.set(engine(), proto ? proto->d() : 0);
     return true;
 }
 
@@ -117,7 +117,7 @@ bool Object::putValue(uint memberIndex, const Value &value)
     PropertyAttributes attrs = ic->propertyData[memberIndex];
 
     if (attrs.isAccessor()) {
-        FunctionObject *set = propertyData(memberIndex + SetterOffset)->as<FunctionObject>();
+        const FunctionObject *set = propertyData(memberIndex + SetterOffset)->as<FunctionObject>();
         if (set) {
             Scope scope(ic->engine);
             ScopedFunctionObject setter(scope, set);
@@ -133,7 +133,7 @@ bool Object::putValue(uint memberIndex, const Value &value)
     if (!attrs.isWritable())
         goto reject;
 
-    *propertyData(memberIndex) = value;
+    setProperty(memberIndex, value);
     return true;
 
   reject:
@@ -258,28 +258,16 @@ void Object::defineReadonlyConfigurableProperty(String *name, const Value &value
     insertMember(name, value, Attr_ReadOnly_ButConfigurable);
 }
 
-void Object::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    Heap::Object *o = static_cast<Heap::Object *>(that);
-
-    if (o->memberData)
-        o->memberData->mark(e);
-    if (o->arrayData)
-        o->arrayData->mark(e);
-    if (o->prototype)
-        o->prototype->mark(e);
-}
-
 void Object::insertMember(String *s, const Property *p, PropertyAttributes attributes)
 {
     uint idx;
     InternalClass::addMember(this, s, attributes, &idx);
 
     if (attributes.isAccessor()) {
-        *propertyData(idx + GetterOffset) = p->value;
-        *propertyData(idx + SetterOffset) = p->set;
+        setProperty(idx + GetterOffset, p->value);
+        setProperty(idx + SetterOffset, p->set);
     } else {
-        *propertyData(idx) = p->value;
+        setProperty(idx, p->value);
     }
 }
 
@@ -308,12 +296,9 @@ void Object::getOwnProperty(String *name, PropertyAttributes *attrs, Property *p
 
 void Object::getOwnProperty(uint index, PropertyAttributes *attrs, Property *p)
 {
-    Property *pd = arrayData() ? arrayData()->getProperty(index) : 0;
-    if (pd) {
-        *attrs = arrayData()->attributes(index);
-        if (p)
-            p->copy(pd, *attrs);
-        return;
+    if (arrayData()) {
+        if (arrayData()->getProperty(index, p, attrs))
+            return;
     }
     if (isStringObject()) {
         *attrs = Attr_NotConfigurable|Attr_NotWritable;
@@ -328,7 +313,7 @@ void Object::getOwnProperty(uint index, PropertyAttributes *attrs, Property *p)
 }
 
 // Section 8.12.2
-Value *Object::getValueOrSetter(String *name, PropertyAttributes *attrs)
+MemberData::Index Object::getValueOrSetter(String *name, PropertyAttributes *attrs)
 {
     Q_ASSERT(name->asArrayIndex() == UINT_MAX);
 
@@ -337,36 +322,38 @@ Value *Object::getValueOrSetter(String *name, PropertyAttributes *attrs)
         uint idx = o->internalClass->find(name);
         if (idx < UINT_MAX) {
             *attrs = o->internalClass->propertyData[idx];
-            return o->propertyData(attrs->isAccessor() ? idx + SetterOffset : idx);
+            return MemberData::Index{ o->memberData, attrs->isAccessor() ? idx + SetterOffset : idx };
         }
 
         o = o->prototype;
     }
     *attrs = Attr_Invalid;
-    return 0;
+    return { 0, 0 };
 }
 
-Value *Object::getValueOrSetter(uint index, PropertyAttributes *attrs)
+ArrayData::Index Object::getValueOrSetter(uint index, PropertyAttributes *attrs)
 {
     Heap::Object *o = d();
     while (o) {
-        Property *p = o->arrayData ? o->arrayData->getProperty(index) : 0;
-        if (p) {
-            *attrs = o->arrayData->attributes(index);
-            return attrs->isAccessor() ? &p->set : &p->value;
+        if (o->arrayData) {
+            uint idx = o->arrayData->mappedIndex(index);
+            if (idx != UINT_MAX) {
+                *attrs = o->arrayData->attributes(index);
+                return { o->arrayData , attrs->isAccessor() ? idx + SetterOffset : idx };
+            }
         }
         if (o->vtable()->type == Type_StringObject) {
             if (index < static_cast<const Heap::StringObject *>(o)->length()) {
                 // this is an evil hack, but it works, as the method is only ever called from putIndexed,
                 // where we don't use the returned pointer there for non writable attributes
                 *attrs = (Attr_NotWritable|Attr_NotConfigurable);
-                return reinterpret_cast<Value *>(0x1);
+                return { reinterpret_cast<Heap::ArrayData *>(0x1), 0 };
             }
         }
         o = o->prototype;
     }
     *attrs = Attr_Invalid;
-    return 0;
+    return { 0, 0 };
 }
 
 bool Object::hasProperty(String *name) const
@@ -539,7 +526,7 @@ void Object::setLookup(Managed *m, Lookup *l, const Value &value)
             l->classList[0] = o->internalClass();
             l->index = idx;
             l->setter = Lookup::setter0;
-            *o->propertyData(idx) = value;
+            o->setProperty(idx, value);
             return;
         }
 
@@ -594,7 +581,7 @@ void Object::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *
                 int k = it->arrayNode->key();
                 uint pidx = it->arrayNode->value;
                 Heap::SparseArrayData *sa = o->d()->arrayData.cast<Heap::SparseArrayData>();
-                Property *p = reinterpret_cast<Property *>(sa->arrayData + pidx);
+                const Property *p = reinterpret_cast<const Property *>(sa->values.data() + pidx);
                 it->arrayNode = it->arrayNode->nextNode();
                 PropertyAttributes a = sa->attrs ? sa->attrs[pidx] : Attr_Data;
                 if (!(it->flags & ObjectIterator::EnumerableOnly) || a.isEnumerable()) {
@@ -609,9 +596,9 @@ void Object::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *
             it->arrayIndex = UINT_MAX;
         }
         // dense arrays
-        while (it->arrayIndex < o->d()->arrayData->len) {
+        while (it->arrayIndex < o->d()->arrayData->values.size) {
             Heap::SimpleArrayData *sa = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-            Value &val = sa->data(it->arrayIndex);
+            const Value &val = sa->data(it->arrayIndex);
             PropertyAttributes a = o->arrayData()->attributes(it->arrayIndex);
             ++it->arrayIndex;
             if (!val.isEmpty()
@@ -677,15 +664,14 @@ ReturnedValue Object::internalGet(String *name, bool *hasProperty) const
 
 ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty) const
 {
-    Property *pd = 0;
     PropertyAttributes attrs;
     Scope scope(engine());
     ScopedObject o(scope, this);
+    ScopedProperty pd(scope);
+    bool exists = false;
     while (o) {
-        Property *p = o->arrayData() ? o->arrayData()->getProperty(index) : 0;
-        if (p) {
-            pd = p;
-            attrs = o->arrayData()->attributes(index);
+        if (o->arrayData() && o->arrayData()->getProperty(index, pd, &attrs)) {
+            exists = true;
             break;
         }
         if (o->isStringObject()) {
@@ -700,7 +686,7 @@ ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty) const
         o = o->prototype();
     }
 
-    if (pd) {
+    if (exists) {
         if (hasProperty)
             *hasProperty = true;
         return getValue(pd->value, attrs);
@@ -715,43 +701,44 @@ ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty) const
 // Section 8.12.5
 bool Object::internalPut(String *name, const Value &value)
 {
-    if (internalClass()->engine->hasException)
+    ExecutionEngine *engine = this->engine();
+    if (engine->hasException)
         return false;
 
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
         return putIndexed(idx, value);
 
-    name->makeIdentifier(engine());
+    name->makeIdentifier(engine);
 
+    MemberData::Index memberIndex{0, 0};
     uint member = internalClass()->find(name);
-    Value *v = 0;
     PropertyAttributes attrs;
     if (member < UINT_MAX) {
         attrs = internalClass()->propertyData[member];
-        v = propertyData(attrs.isAccessor() ? member + SetterOffset : member);
+        memberIndex = { d()->memberData, (attrs.isAccessor() ? member + SetterOffset : member) };
     }
 
     // clause 1
-    if (v) {
+    if (!memberIndex.isNull()) {
         if (attrs.isAccessor()) {
-            if (v->as<FunctionObject>())
+            if (memberIndex->as<FunctionObject>())
                 goto cont;
             goto reject;
         } else if (!attrs.isWritable())
             goto reject;
-        else if (isArrayObject() && name->equals(engine()->id_length())) {
+        else if (isArrayObject() && name->equals(engine->id_length())) {
             bool ok;
             uint l = value.asArrayLength(&ok);
             if (!ok) {
-                engine()->throwRangeError(value);
+                engine->throwRangeError(value);
                 return false;
             }
             ok = setArrayLength(l);
             if (!ok)
                 goto reject;
         } else {
-            *v = value;
+            memberIndex.set(engine, value);
         }
         return true;
     } else if (!prototype()) {
@@ -759,10 +746,11 @@ bool Object::internalPut(String *name, const Value &value)
             goto reject;
     } else {
         // clause 4
-        Scope scope(engine());
-        if ((v = ScopedObject(scope, prototype())->getValueOrSetter(name, &attrs))) {
+        Scope scope(engine);
+        memberIndex = ScopedObject(scope, prototype())->getValueOrSetter(name, &attrs);
+        if (!memberIndex.isNull()) {
             if (attrs.isAccessor()) {
-                if (!v->as<FunctionObject>())
+                if (!memberIndex->as<FunctionObject>())
                     goto reject;
             } else if (!isExtensible() || !attrs.isWritable()) {
                 goto reject;
@@ -775,11 +763,11 @@ bool Object::internalPut(String *name, const Value &value)
     cont:
 
     // Clause 5
-    if (v && attrs.isAccessor()) {
-        Q_ASSERT(v->as<FunctionObject>());
+    if (!memberIndex.isNull() && attrs.isAccessor()) {
+        Q_ASSERT(memberIndex->as<FunctionObject>());
 
-        Scope scope(engine());
-        ScopedFunctionObject setter(scope, *v);
+        Scope scope(engine);
+        ScopedFunctionObject setter(scope, *memberIndex);
         ScopedCallData callData(scope, 1);
         callData->args[0] = value;
         callData->thisObject = this;
@@ -792,49 +780,51 @@ bool Object::internalPut(String *name, const Value &value)
 
   reject:
     // ### this should be removed once everything is ported to use Object::set()
-    if (engine()->current->strictMode) {
+    if (engine->current->strictMode) {
         QString message = QLatin1String("Cannot assign to read-only property \"") +
                 name->toQString() + QLatin1Char('\"');
-        engine()->throwTypeError(message);
+        engine->throwTypeError(message);
     }
     return false;
 }
 
 bool Object::internalPutIndexed(uint index, const Value &value)
 {
-    if (internalClass()->engine->hasException)
+    ExecutionEngine *engine = this->engine();
+    if (engine->hasException)
         return false;
 
     PropertyAttributes attrs;
 
-    Value *v = arrayData() ? arrayData()->getValueOrSetter(index, &attrs) : 0;
+    ArrayData::Index arrayIndex = arrayData() ? arrayData()->getValueOrSetter(index, &attrs) : ArrayData::Index{ 0, 0 };
 
-    if (!v && isStringObject()) {
+    if (arrayIndex.isNull() && isStringObject()) {
         if (index < static_cast<StringObject *>(this)->length())
             // not writable
             goto reject;
     }
 
     // clause 1
-    if (v) {
+    if (!arrayIndex.isNull()) {
         if (attrs.isAccessor()) {
-            if (v->as<FunctionObject>())
+            if (arrayIndex->as<FunctionObject>())
                 goto cont;
             goto reject;
         } else if (!attrs.isWritable())
             goto reject;
-        else
-            *v = value;
+
+        arrayIndex.set(engine, value);
         return true;
     } else if (!prototype()) {
         if (!isExtensible())
             goto reject;
     } else {
         // clause 4
-        Scope scope(engine());
-        if ((v = ScopedObject(scope, prototype())->getValueOrSetter(index, &attrs))) {
+        Scope scope(engine);
+        arrayIndex = ScopedObject(scope, prototype())->getValueOrSetter(index, &attrs);
+        if (!arrayIndex.isNull()) {
             if (attrs.isAccessor()) {
-                if (!v->as<FunctionObject>())
+                if (!arrayIndex->as<FunctionObject>())
                     goto reject;
             } else if (!isExtensible() || !attrs.isWritable()) {
                 goto reject;
@@ -847,11 +837,11 @@ bool Object::internalPutIndexed(uint index, const Value &value)
     cont:
 
     // Clause 5
-    if (v && attrs.isAccessor()) {
-        Q_ASSERT(v->as<FunctionObject>());
+    if (!arrayIndex.isNull() && attrs.isAccessor()) {
+        Q_ASSERT(arrayIndex->as<FunctionObject>());
 
-        Scope scope(engine());
-        ScopedFunctionObject setter(scope, *v);
+        Scope scope(engine);
+        ScopedFunctionObject setter(scope, *arrayIndex);
         ScopedCallData callData(scope, 1);
         callData->args[0] = value;
         callData->thisObject = this;
@@ -864,8 +854,8 @@ bool Object::internalPutIndexed(uint index, const Value &value)
 
   reject:
     // ### this should be removed once everything is ported to use Object::setIndexed()
-    if (engine()->current->strictMode)
-        engine()->throwTypeError();
+    if (engine->current->strictMode)
+        engine->throwTypeError();
     return false;
 }
 
@@ -995,8 +985,8 @@ bool Object::defineOwnProperty2(ExecutionEngine *engine, uint index, const Prope
 
     // Clause 1
     if (arrayData()) {
-        hasProperty = arrayData()->getProperty(index);
-        if (!hasProperty  && isStringObject())
+        hasProperty = arrayData()->mappedIndex(index) != UINT_MAX;
+        if (!hasProperty && isStringObject())
             hasProperty = (index < static_cast<StringObject *>(this)->length());
     }
 
@@ -1108,7 +1098,7 @@ bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, String *
         setProperty(index, current);
     } else {
         setArrayAttributes(index, cattrs);
-        arrayData()->setProperty(index, current);
+        arrayData()->setProperty(scope.engine, index, current);
     }
     return true;
   reject:
@@ -1144,7 +1134,8 @@ void Object::copyArrayData(Object *other)
         ;
     } else {
         Q_ASSERT(!arrayData() && other->arrayData());
-        ArrayData::realloc(this, other->d()->arrayData->type, other->d()->arrayData->alloc, false);
+        ArrayData::realloc(this, static_cast<ArrayData::Type>(other->d()->arrayData->type),
+                           other->d()->arrayData->values.alloc, false);
         if (other->arrayType() == Heap::ArrayData::Sparse) {
             Heap::ArrayData *od = other->d()->arrayData;
             Heap::ArrayData *dd = d()->arrayData;
@@ -1152,10 +1143,11 @@ void Object::copyArrayData(Object *other)
             dd->freeList = od->freeList;
         } else {
             Heap::ArrayData *dd = d()->arrayData;
-            dd->len = other->d()->arrayData->len;
+            dd->values.size = other->d()->arrayData->values.size;
             dd->offset = other->d()->arrayData->offset;
         }
-        memcpy(d()->arrayData->arrayData, other->d()->arrayData->arrayData, other->d()->arrayData->alloc*sizeof(Value));
+        // ### need a write barrier
+        memcpy(d()->arrayData->values.values, other->d()->arrayData->values.values, other->d()->arrayData->values.alloc*sizeof(Value));
     }
     setArrayLengthUnchecked(other->getLength());
 }
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 0d17afbf41..df9d68525d 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -67,19 +67,24 @@ struct BuiltinFunction;
 
 namespace Heap {
 
-struct Object : Base {
+#define ObjectMembers(class, Member) \
+    Member(class, NoMark, InternalClass *, internalClass) \
+    Member(class, Pointer, Object *, prototype) \
+    Member(class, Pointer, MemberData *, memberData) \
+    Member(class, Pointer, ArrayData *, arrayData)
+
+DECLARE_HEAP_OBJECT(Object, Base) {
+    DECLARE_MARK_TABLE(Object);
     void init() { Base::init(); }
     void destroy() { Base::destroy(); }
 
-    const Value *propertyData(uint index) const { return memberData->data + index; }
-    Value *propertyData(uint index) { return memberData->data + index; }
-
-    InternalClass *internalClass;
-    Pointer<Object> prototype;
-    Pointer<MemberData> memberData;
-    Pointer<ArrayData> arrayData;
+    const Value *propertyData(uint index) const { return memberData->values.data() + index; }
+    void setProperty(ExecutionEngine *e, uint index, Value v) const { memberData->values.set(e, index, v); }
+    void setProperty(ExecutionEngine *e, uint index, Heap::Base *b) const { memberData->values.set(e, index, b); }
 };
 
+Q_STATIC_ASSERT(Object::markTable == ((2 << 4) | (2 << 6) | (2 << 8)));
+
 }
 
 #define V4_OBJECT(superClass) \
@@ -114,7 +119,8 @@ struct Object : Base {
             dptr->_checkIsInitialized(); \
             return dptr; \
         } \
-        V4_ASSERT_IS_TRIVIAL(QV4::Heap::DataClass);
+        V4_ASSERT_IS_TRIVIAL(QV4::Heap::DataClass); \
+        static Q_CONSTEXPR quint64 markTable = QV4::Heap::DataClass::markTable;
 
 #define V4_INTERNALCLASS(c) \
     static QV4::InternalClass *defaultInternalClass(QV4::ExecutionEngine *e) \
@@ -190,13 +196,16 @@ struct Q_QML_EXPORT Object: Managed {
     void setInternalClass(InternalClass *ic);
 
     const Value *propertyData(uint index) const { return d()->propertyData(index); }
-    Value *propertyData(uint index) { return d()->propertyData(index); }
 
     Heap::ArrayData *arrayData() const { return d()->arrayData; }
-    void setArrayData(ArrayData *a) { d()->arrayData = a->d(); }
+    void setArrayData(ArrayData *a) { d()->arrayData.set(engine(), a->d()); }
 
     void getProperty(uint index, Property *p, PropertyAttributes *attrs) const;
     void setProperty(uint index, const Property *p);
+    void setProperty(uint index, Value v) const { d()->setProperty(engine(), index, v); }
+    void setProperty(uint index, Heap::Base *b) const { d()->setProperty(engine(), index, b); }
+    void setProperty(ExecutionEngine *engine, uint index, Value v) const { d()->setProperty(engine, index, v); }
+    void setProperty(ExecutionEngine *engine, uint index, Heap::Base *b) const { d()->setProperty(engine, index, b); }
 
     const ObjectVTable *vtable() const { return reinterpret_cast<const ObjectVTable *>(d()->vtable()); }
     Heap::Object *prototype() const { return d()->prototype; }
@@ -205,8 +214,8 @@ struct Q_QML_EXPORT Object: Managed {
     void getOwnProperty(String *name, PropertyAttributes *attrs, Property *p = 0);
     void getOwnProperty(uint index, PropertyAttributes *attrs, Property *p = 0);
 
-    Value *getValueOrSetter(String *name, PropertyAttributes *attrs);
-    Value *getValueOrSetter(uint index, PropertyAttributes *attrs);
+    MemberData::Index getValueOrSetter(String *name, PropertyAttributes *attrs);
+    ArrayData::Index getValueOrSetter(uint index, PropertyAttributes *attrs);
 
     bool hasProperty(String *name) const;
     bool hasProperty(uint index) const;
@@ -296,7 +305,7 @@ public:
     void push_back(const Value &v);
 
     ArrayData::Type arrayType() const {
-        return arrayData() ? d()->arrayData->type : Heap::ArrayData::Simple;
+        return arrayData() ? static_cast<ArrayData::Type>(d()->arrayData->type) : Heap::ArrayData::Simple;
     }
     // ### remove me
     void setArrayType(ArrayData::Type t) {
@@ -400,7 +409,6 @@ public:
     inline void call(Scope &scope, CallData *d) const
     { vtable()->call(this, scope, d); }
 protected:
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
     static void construct(const Managed *m, Scope &scope, CallData *);
     static void call(const Managed *m, Scope &scope, CallData *);
     static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
@@ -465,7 +473,7 @@ struct ArrayObject : Object {
 
 private:
     void commonInit()
-    { *propertyData(LengthPropertyIndex) = Primitive::fromInt32(0); }
+    { setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(0)); }
 };
 
 }
@@ -505,7 +513,7 @@ struct ArrayObject: Object {
 inline void Object::setArrayLengthUnchecked(uint l)
 {
     if (isArrayObject())
-        *propertyData(Heap::ArrayObject::LengthPropertyIndex) = Primitive::fromUInt32(l);
+        setProperty(Heap::ArrayObject::LengthPropertyIndex, Primitive::fromUInt32(l));
 }
 
 inline void Object::push_back(const Value &v)
@@ -522,7 +530,7 @@ inline void Object::arraySet(uint index, const Property *p, PropertyAttributes a
 {
     // ### Clean up
     arrayCreate();
-    if (attributes.isAccessor() || (index > 0x1000 && index > 2*d()->arrayData->alloc)) {
+    if (attributes.isAccessor() || (index > 0x1000 && index > 2*d()->arrayData->values.alloc)) {
         initSparseArray();
     } else {
         arrayData()->vtable()->reallocate(this, index + 1, false);
@@ -537,7 +545,7 @@ inline void Object::arraySet(uint index, const Property *p, PropertyAttributes a
 inline void Object::arraySet(uint index, const Value &value)
 {
     arrayCreate();
-    if (index > 0x1000 && index > 2*d()->arrayData->alloc) {
+    if (index > 0x1000 && index > 2*d()->arrayData->values.alloc) {
         initSparseArray();
     }
     ArrayData::insert(this, index, &value);
diff --git a/src/qml/jsruntime/qv4objectiterator.cpp b/src/qml/jsruntime/qv4objectiterator.cpp
index 59115dfe21..3427ee89fe 100644
--- a/src/qml/jsruntime/qv4objectiterator.cpp
+++ b/src/qml/jsruntime/qv4objectiterator.cpp
@@ -177,10 +177,10 @@ ReturnedValue ObjectIterator::nextPropertyNameAsString()
 
 DEFINE_OBJECT_VTABLE(ForEachIteratorObject);
 
-void ForEachIteratorObject::markObjects(Heap::Base *that, ExecutionEngine *e)
+void ForEachIteratorObject::markObjects(Heap::Base *that, MarkStack *markStack)
 {
     ForEachIteratorObject::Data *o = static_cast<ForEachIteratorObject::Data *>(that);
-    o->workArea[0].mark(e);
-    o->workArea[1].mark(e);
-    Object::markObjects(that, e);
+    o->workArea[0].mark(markStack);
+    o->workArea[1].mark(markStack);
+    Object::markObjects(that, markStack);
 }
diff --git a/src/qml/jsruntime/qv4objectiterator_p.h b/src/qml/jsruntime/qv4objectiterator_p.h
index 98e94a95ea..6168d59914 100644
--- a/src/qml/jsruntime/qv4objectiterator_p.h
+++ b/src/qml/jsruntime/qv4objectiterator_p.h
@@ -129,7 +129,7 @@ struct ForEachIteratorObject: Object {
     ReturnedValue nextPropertyName() { return d()->it().nextPropertyNameAsString(); }
 
 protected:
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
 };
 
 inline
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index f650ffc7b1..2e72c0f13f 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -295,7 +295,7 @@ void ObjectPrototype::method_seal(const BuiltinFunction *, Scope &scope, CallDat
 
     if (o->arrayData()) {
         ArrayData::ensureAttributes(o);
-        for (uint i = 0; i < o->d()->arrayData->alloc; ++i) {
+        for (uint i = 0; i < o->d()->arrayData->values.alloc; ++i) {
             if (!o->arrayData()->isEmpty(i))
                 o->d()->arrayData->attrs[i].setConfigurable(false);
         }
@@ -320,7 +320,7 @@ void ObjectPrototype::method_freeze(const BuiltinFunction *, Scope &scope, CallD
 
     if (o->arrayData()) {
         ArrayData::ensureAttributes(o);
-        for (uint i = 0; i < o->arrayData()->alloc; ++i) {
+        for (uint i = 0; i < o->arrayData()->values.alloc; ++i) {
             if (!o->arrayData()->isEmpty(i))
                 o->arrayData()->attrs[i].setConfigurable(false);
             if (o->arrayData()->attrs[i].isData())
@@ -371,7 +371,7 @@ void ObjectPrototype::method_isSealed(const BuiltinFunction *, Scope &scope, Cal
         return;
     }
 
-    for (uint i = 0; i < o->arrayData()->alloc; ++i) {
+    for (uint i = 0; i < o->arrayData()->values.alloc; ++i) {
         if (!o->arrayData()->isEmpty(i))
             if (o->arrayData()->attributes(i).isConfigurable()) {
                 scope.result = Encode(false);
@@ -411,7 +411,7 @@ void ObjectPrototype::method_isFrozen(const BuiltinFunction *, Scope &scope, Cal
         return;
     }
 
-    for (uint i = 0; i < o->arrayData()->alloc; ++i) {
+    for (uint i = 0; i < o->arrayData()->values.alloc; ++i) {
         if (!o->arrayData()->isEmpty(i))
             if (o->arrayData()->attributes(i).isConfigurable() || o->arrayData()->attributes(i).isWritable()) {
                 scope.result = Encode(false);
diff --git a/src/qml/jsruntime/qv4persistent.cpp b/src/qml/jsruntime/qv4persistent.cpp
index 987c322e47..0b31c971f9 100644
--- a/src/qml/jsruntime/qv4persistent.cpp
+++ b/src/qml/jsruntime/qv4persistent.cpp
@@ -215,26 +215,15 @@ void PersistentValueStorage::free(Value *v)
         freePage(p);
 }
 
-static void drainMarkStack(QV4::ExecutionEngine *engine, Value *markBase)
+void PersistentValueStorage::mark(MarkStack *markStack)
 {
-    while (engine->jsStackTop > markBase) {
-        Heap::Base *h = engine->popForGC();
-        Q_ASSERT (h->vtable()->markObjects);
-        h->vtable()->markObjects(h, engine);
-    }
-}
-
-void PersistentValueStorage::mark(ExecutionEngine *e)
-{
-    Value *markBase = e->jsStackTop;
-
     Page *p = static_cast<Page *>(firstPage);
     while (p) {
         for (int i = 0; i < kEntriesPerPage; ++i) {
             if (Managed *m = p->values[i].as<Managed>())
-                m->mark(e);
+                m->mark(markStack);
         }
-        drainMarkStack(e, markBase);
+        markStack->drain();
 
         p = p->header.next;
     }
@@ -393,11 +382,11 @@ void WeakValue::allocVal(ExecutionEngine *engine)
     val = engine->memoryManager->m_weakValues->allocate();
 }
 
-void WeakValue::markOnce(ExecutionEngine *e)
+void WeakValue::markOnce(MarkStack *markStack)
 {
     if (!val)
         return;
-    val->mark(e);
+    val->mark(markStack);
 }
 
 void WeakValue::free()
diff --git a/src/qml/jsruntime/qv4persistent_p.h b/src/qml/jsruntime/qv4persistent_p.h
index c1cd1f34df..1f838f5531 100644
--- a/src/qml/jsruntime/qv4persistent_p.h
+++ b/src/qml/jsruntime/qv4persistent_p.h
@@ -65,7 +65,7 @@ struct Q_QML_EXPORT PersistentValueStorage
     Value *allocate();
     static void free(Value *e);
 
-    void mark(ExecutionEngine *e);
+    void mark(MarkStack *markStack);
 
     struct Iterator {
         Iterator(void *p, int idx);
@@ -203,7 +203,7 @@ public:
     bool isNullOrUndefined() const { return !val || val->isNullOrUndefined(); }
     void clear() { free(); }
 
-    void markOnce(ExecutionEngine *e);
+    void markOnce(MarkStack *markStack);
 
 private:
     Value *val;
diff --git a/src/qml/jsruntime/qv4property_p.h b/src/qml/jsruntime/qv4property_p.h
index 5069d7690b..2a5b6f7f74 100644
--- a/src/qml/jsruntime/qv4property_p.h
+++ b/src/qml/jsruntime/qv4property_p.h
@@ -78,12 +78,6 @@ struct Property {
         attrs->resolve();
     }
 
-    static Property genericDescriptor() {
-        Property pd;
-        pd.value = Primitive::emptyValue();
-        return pd;
-    }
-
     inline bool isSubset(const PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs) const;
     inline void merge(PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs);
 
@@ -99,19 +93,12 @@ struct Property {
     }
 
     explicit Property()  { value = Encode::undefined(); set = Value::fromHeapObject(0); }
-    explicit Property(Value v) : value(v) { set = Value::fromHeapObject(0); }
-    Property(FunctionObject *getter, FunctionObject *setter) {
-        value = reinterpret_cast<Managed *>(getter);
-        set = reinterpret_cast<Managed *>(setter);
-    }
     Property(Heap::FunctionObject *getter, Heap::FunctionObject *setter) {
         value.setM(reinterpret_cast<Heap::Base *>(getter));
         set.setM(reinterpret_cast<Heap::Base *>(setter));
     }
-    Property &operator=(Value v) { value = v; return *this; }
 private:
-    Property(const Property &);
-    Property &operator=(const Property &);
+    Q_DISABLE_COPY(Property)
 };
 
 inline bool Property::isSubset(const PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs) const
diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index cdc29c8b9c..56ecc9f682 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -298,14 +298,14 @@ bool QmlContextWrapper::put(Managed *m, String *name, const Value &value)
 void Heap::QmlContext::init(QV4::ExecutionContext *outerContext, QV4::QmlContextWrapper *qml)
 {
     Heap::ExecutionContext::init(outerContext->engine(), Heap::ExecutionContext::Type_QmlContext);
-    outer = outerContext->d();
+    outer.set(engine, outerContext->d());
     strictMode = false;
     callData = outer->callData;
     lookups = outer->lookups;
     constantTable = outer->constantTable;
     compilationUnit = outer->compilationUnit;
 
-    this->qml = qml->d();
+    this->qml.set(engine, qml->d());
 }
 
 Heap::QmlContext *QmlContext::createWorkerContext(ExecutionContext *parent, const QUrl &source, Value *sendFunction)
diff --git a/src/qml/jsruntime/qv4qmlcontext_p.h b/src/qml/jsruntime/qv4qmlcontext_p.h
index 6e5e743609..835c9236fe 100644
--- a/src/qml/jsruntime/qv4qmlcontext_p.h
+++ b/src/qml/jsruntime/qv4qmlcontext_p.h
@@ -77,10 +77,13 @@ struct QmlContextWrapper : Object {
     QQmlQPointer<QObject> scopeObject;
 };
 
-struct QmlContext : ExecutionContext {
-    void init(QV4::ExecutionContext *outerContext, QV4::QmlContextWrapper *qml);
+#define QmlContextMembers(class, Member) \
+    Member(class, Pointer, QmlContextWrapper *, qml)
+
+DECLARE_HEAP_OBJECT(QmlContext, ExecutionContext) {
+    DECLARE_MARK_TABLE(QmlContext);
 
-    Pointer<QmlContextWrapper> qml;
+    void init(QV4::ExecutionContext *outerContext, QV4::QmlContextWrapper *qml);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index c9b4b433bd..2ac2b0b64d 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -539,7 +539,7 @@ ReturnedValue QObjectWrapper::wrap_slowPath(ExecutionEngine *engine, QObject *ob
     }
 }
 
-void QObjectWrapper::markWrapper(QObject *object, ExecutionEngine *engine)
+void QObjectWrapper::markWrapper(QObject *object, MarkStack *markStack)
 {
     if (QQmlData::wasDeleted(object))
         return;
@@ -548,10 +548,10 @@ void QObjectWrapper::markWrapper(QObject *object, ExecutionEngine *engine)
     if (!ddata)
         return;
 
-    if (ddata->jsEngineId == engine->m_engineId)
-        ddata->jsWrapper.markOnce(engine);
-    else  if (engine->m_multiplyWrappedQObjects && ddata->hasTaintedV4Object)
-        engine->m_multiplyWrappedQObjects->mark(object, engine);
+    if (ddata->jsEngineId == markStack->engine->m_engineId)
+        ddata->jsWrapper.markOnce(markStack);
+    else  if (markStack->engine->m_multiplyWrappedQObjects && ddata->hasTaintedV4Object)
+        markStack->engine->m_multiplyWrappedQObjects->mark(object, markStack);
 }
 
 ReturnedValue QObjectWrapper::getProperty(ExecutionEngine *engine, QObject *object, int propertyIndex, bool captureRequired)
@@ -938,36 +938,36 @@ void QObjectWrapper::method_disconnect(const BuiltinFunction *, Scope &scope, Ca
     RETURN_UNDEFINED();
 }
 
-static void markChildQObjectsRecursively(QObject *parent, QV4::ExecutionEngine *e)
+static void markChildQObjectsRecursively(QObject *parent, QV4::MarkStack *markStack)
 {
     const QObjectList &children = parent->children();
     for (int i = 0; i < children.count(); ++i) {
         QObject *child = children.at(i);
         if (!child)
             continue;
-        QObjectWrapper::markWrapper(child, e);
-        markChildQObjectsRecursively(child, e);
+        QObjectWrapper::markWrapper(child, markStack);
+        markChildQObjectsRecursively(child, markStack);
     }
 }
 
-void QObjectWrapper::markObjects(Heap::Base *that, QV4::ExecutionEngine *e)
+void QObjectWrapper::markObjects(Heap::Base *that, QV4::MarkStack *markStack)
 {
     QObjectWrapper::Data *This = static_cast<QObjectWrapper::Data *>(that);
 
     if (QObject *o = This->object()) {
         QQmlVMEMetaObject *vme = QQmlVMEMetaObject::get(o);
         if (vme)
-            vme->mark(e);
+            vme->mark(markStack);
 
         // Children usually don't need to be marked, the gc keeps them alive.
         // But in the rare case of a "floating" QObject without a parent that
         // _gets_ marked (we've been called here!) then we also need to
         // propagate the marking down to the children recursively.
         if (!o->parent())
-            markChildQObjectsRecursively(o, e);
+            markChildQObjectsRecursively(o, markStack);
     }
 
-    QV4::Object::markObjects(that, e);
+    QV4::Object::markObjects(that, markStack);
 }
 
 void QObjectWrapper::destroyObject(bool lastCall)
@@ -1704,7 +1704,7 @@ ReturnedValue QObjectMethod::create(ExecutionContext *scope, const QQmlValueType
     Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocObject<QObjectMethod>(scope));
     method->d()->setPropertyCache(valueType->d()->propertyCache());
     method->d()->index = index;
-    method->d()->valueTypeWrapper = valueType->d();
+    method->d()->valueTypeWrapper.set(valueScope.engine, valueType->d());
     return method.asReturnedValue();
 }
 
@@ -1841,15 +1841,6 @@ void QObjectMethod::callInternal(CallData *callData, Scope &scope) const
     }
 }
 
-void QObjectMethod::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    QObjectMethod::Data *This = static_cast<QObjectMethod::Data*>(that);
-    if (This->valueTypeWrapper)
-        This->valueTypeWrapper->mark(e);
-
-    FunctionObject::markObjects(that, e);
-}
-
 DEFINE_OBJECT_VTABLE(QObjectMethod);
 
 
@@ -2075,12 +2066,12 @@ void MultiplyWrappedQObjectMap::remove(QObject *key)
     erase(it);
 }
 
-void MultiplyWrappedQObjectMap::mark(QObject *key, ExecutionEngine *engine)
+void MultiplyWrappedQObjectMap::mark(QObject *key, MarkStack *markStack)
 {
     Iterator it = find(key);
     if (it == end())
         return;
-    it->markOnce(engine);
+    it->markOnce(markStack);
 }
 
 void MultiplyWrappedQObjectMap::removeDestroyedObject(QObject *object)
diff --git a/src/qml/jsruntime/qv4qobjectwrapper_p.h b/src/qml/jsruntime/qv4qobjectwrapper_p.h
index d81ef2a680..55700d17c1 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper_p.h
+++ b/src/qml/jsruntime/qv4qobjectwrapper_p.h
@@ -95,7 +95,15 @@ private:
     QQmlQPointer<QObject> qObj;
 };
 
-struct QObjectMethod : FunctionObject {
+#define QObjectMethodMembers(class, Member) \
+    Member(class, Pointer, QQmlValueTypeWrapper *, valueTypeWrapper) \
+    Member(class, NoMark, QQmlQPointer<QObject>, qObj) \
+    Member(class, NoMark, QQmlPropertyCache *, _propertyCache) \
+    Member(class, NoMark, int, index)
+
+DECLARE_HEAP_OBJECT(QObjectMethod, FunctionObject) {
+    DECLARE_MARK_TABLE(QObjectMethod);
+
     void init(QV4::ExecutionContext *scope);
     void destroy()
     {
@@ -113,18 +121,10 @@ struct QObjectMethod : FunctionObject {
         _propertyCache = c;
     }
 
-    Pointer<QQmlValueTypeWrapper> valueTypeWrapper;
-
     const QMetaObject *metaObject();
     QObject *object() const { return qObj.data(); }
     void setObject(QObject *o) { qObj = o; }
 
-private:
-    QQmlQPointer<QObject> qObj;
-    QQmlPropertyCache *_propertyCache;
-
-public:
-    int index;
 };
 
 struct QMetaObjectWrapper : FunctionObject {
@@ -171,7 +171,7 @@ struct Q_QML_EXPORT QObjectWrapper : public Object
     static bool setQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, const Value &value);
 
     static ReturnedValue wrap(ExecutionEngine *engine, QObject *object);
-    static void markWrapper(QObject *object, ExecutionEngine *engine);
+    static void markWrapper(QObject *object, MarkStack *markStack);
 
     using Object::get;
 
@@ -195,7 +195,7 @@ protected:
     static bool put(Managed *m, String *name, const Value &value);
     static PropertyAttributes query(const Managed *, String *name);
     static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-    static void markObjects(Heap::Base *that, QV4::ExecutionEngine *e);
+    static void markObjects(Heap::Base *that, QV4::MarkStack *markStack);
 
     static void method_connect(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_disconnect(const BuiltinFunction *, Scope &scope, CallData *callData);
@@ -209,13 +209,10 @@ inline ReturnedValue QObjectWrapper::wrap(ExecutionEngine *engine, QObject *obje
     if (Q_UNLIKELY(QQmlData::wasDeleted(object)))
         return QV4::Encode::null();
 
-    QObjectPrivate *priv = QObjectPrivate::get(const_cast<QObject *>(object));
-    if (Q_LIKELY(priv->declarativeData)) {
-        auto ddata = static_cast<QQmlData *>(priv->declarativeData);
-        if (Q_LIKELY(ddata->jsEngineId == engine->m_engineId && !ddata->jsWrapper.isUndefined())) {
-            // We own the JS object
-            return ddata->jsWrapper.value();
-        }
+    auto ddata = QQmlData::get(object);
+    if (Q_LIKELY(ddata && ddata->jsEngineId == engine->m_engineId && !ddata->jsWrapper.isUndefined())) {
+        // We own the JS object
+        return ddata->jsWrapper.value();
     }
 
     return wrap_slowPath(engine, object);
@@ -243,8 +240,6 @@ struct Q_QML_EXPORT QObjectMethod : public QV4::FunctionObject
 
     void callInternal(CallData *callData, Scope &scope) const;
 
-    static void markObjects(Heap::Base *that, QV4::ExecutionEngine *e);
-
     static QPair<QObject *, int> extractQtMethod(const QV4::FunctionObject *function);
 };
 
@@ -297,7 +292,7 @@ public:
     ReturnedValue value(QObject *key) const { return QHash<QObject*, QV4::WeakValue>::value(key).value(); }
     Iterator erase(Iterator it);
     void remove(QObject *key);
-    void mark(QObject *key, ExecutionEngine *engine);
+    void mark(QObject *key, MarkStack *markStack);
 
 private Q_SLOTS:
     void removeDestroyedObject(QObject*);
diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index 9e94c58432..6778145ff1 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -126,9 +126,3 @@ void Heap::RegExp::destroy()
     delete pattern;
     Base::destroy();
 }
-
-void RegExp::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    Q_UNUSED(that);
-    Q_UNUSED(e);
-}
diff --git a/src/qml/jsruntime/qv4regexp_p.h b/src/qml/jsruntime/qv4regexp_p.h
index d3e63375a5..348af0fb14 100644
--- a/src/qml/jsruntime/qv4regexp_p.h
+++ b/src/qml/jsruntime/qv4regexp_p.h
@@ -119,8 +119,6 @@ struct RegExp : public Managed
 
     int captureCount() const { return subPatternCount() + 1; }
 
-    static void markObjects(Heap::Base *that, QV4::ExecutionEngine *e);
-
     friend class RegExpCache;
 };
 
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 0894d0c25b..85e37ebe82 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -74,17 +74,17 @@ void Heap::RegExpObject::init()
     Object::init();
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
-    o->d()->value = QV4::RegExp::create(scope.engine, QString(), false, false);
-    o->d()->global = false;
+    value.set(scope.engine, QV4::RegExp::create(scope.engine, QString(), false, false));
+    global = false;
     o->initProperties();
 }
 
 void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
 {
     Object::init();
-    this->global = global;
-    this->value = value->d();
     Scope scope(internalClass->engine);
+    this->global = global;
+    this->value.set(scope.engine, value->d());
     Scoped<QV4::RegExpObject> o(scope, this);
     o->initProperties();
 }
@@ -137,14 +137,15 @@ void Heap::RegExpObject::init(const QRegExp &re)
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
 
-    o->d()->value = QV4::RegExp::create(scope.engine, pattern, re.caseSensitivity() == Qt::CaseInsensitive, false);
+    o->d()->value.set(scope.engine,
+                        QV4::RegExp::create(scope.engine, pattern, re.caseSensitivity() == Qt::CaseInsensitive, false));
 
     o->initProperties();
 }
 
 void RegExpObject::initProperties()
 {
-    *propertyData(Index_LastIndex) = Primitive::fromInt32(0);
+    setProperty(Index_LastIndex, Primitive::fromInt32(0));
 
     Q_ASSERT(value());
 
@@ -156,25 +157,10 @@ void RegExpObject::initProperties()
         p.replace('/', QLatin1String("\\/"));
     }
 
-    *propertyData(Index_Source) = engine()->newString(p);
-    *propertyData(Index_Global) = Primitive::fromBoolean(global());
-    *propertyData(Index_IgnoreCase) = Primitive::fromBoolean(value()->ignoreCase);
-    *propertyData(Index_Multiline) = Primitive::fromBoolean(value()->multiLine);
-}
-
-
-void RegExpObject::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    RegExpObject::Data *re = static_cast<RegExpObject::Data *>(that);
-    if (re->value)
-        re->value->mark(e);
-    Object::markObjects(that, e);
-}
-
-Value *RegExpObject::lastIndexProperty()
-{
-    Q_ASSERT(0 == internalClass()->find(engine()->id_lastIndex()));
-    return propertyData(0);
+    setProperty(Index_Source, engine()->newString(p));
+    setProperty(Index_Global, Primitive::fromBoolean(global()));
+    setProperty(Index_IgnoreCase, Primitive::fromBoolean(value()->ignoreCase));
+    setProperty(Index_Multiline, Primitive::fromBoolean(value()->multiLine));
 }
 
 // Converts a JS RegExp to a QRegExp.
@@ -228,8 +214,8 @@ void Heap::RegExpCtor::init(QV4::ExecutionContext *scope)
 
 void Heap::RegExpCtor::clearLastMatch()
 {
-    lastMatch = Primitive::nullValue();
-    lastInput = internalClass->engine->id_empty()->d();
+    lastMatch.set(internalClass->engine, Primitive::nullValue());
+    lastInput.set(internalClass->engine, internalClass->engine->id_empty()->d());
     lastMatchStart = 0;
     lastMatchEnd = 0;
 }
@@ -303,15 +289,6 @@ void RegExpCtor::call(const Managed *that, Scope &scope, CallData *callData)
     construct(that, scope, callData);
 }
 
-void RegExpCtor::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    RegExpCtor::Data *This = static_cast<RegExpCtor::Data *>(that);
-    This->lastMatch.mark(e);
-    if (This->lastInput)
-        This->lastInput->mark(e);
-    FunctionObject::markObjects(that, e);
-}
-
 void RegExpPrototype::init(ExecutionEngine *engine, Object *constructor)
 {
     Scope scope(engine);
@@ -361,9 +338,9 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
         RETURN_UNDEFINED();
     QString s = str->toQString();
 
-    int offset = r->global() ? r->lastIndexProperty()->toInt32() : 0;
+    int offset = r->global() ? r->lastIndex() : 0;
     if (offset < 0 || offset > s.length()) {
-        *r->lastIndexProperty() = Primitive::fromInt32(0);
+        r->setLastIndex(0);
         RETURN_RESULT(Encode::null());
     }
 
@@ -374,7 +351,7 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
     regExpCtor->d()->clearLastMatch();
 
     if (result == -1) {
-        *r->lastIndexProperty() = Primitive::fromInt32(0);
+        r->setLastIndex(0);
         RETURN_RESULT(Encode::null());
     }
 
@@ -390,17 +367,17 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
         array->arrayPut(i, v);
     }
     array->setArrayLengthUnchecked(len);
-    *array->propertyData(Index_ArrayIndex) = Primitive::fromInt32(result);
-    *array->propertyData(Index_ArrayInput) = str;
+    array->setProperty(Index_ArrayIndex, Primitive::fromInt32(result));
+    array->setProperty(Index_ArrayInput, str);
 
     RegExpCtor::Data *dd = regExpCtor->d();
-    dd->lastMatch = array;
-    dd->lastInput = str->d();
+    dd->lastMatch.set(scope.engine, array);
+    dd->lastInput.set(scope.engine, str->d());
     dd->lastMatchStart = matchOffsets[0];
     dd->lastMatchEnd = matchOffsets[1];
 
     if (r->global())
-        *r->lastIndexProperty() = Primitive::fromInt32(matchOffsets[1]);
+        r->setLastIndex(matchOffsets[1]);
 
     scope.result = array;
 }
@@ -432,7 +409,7 @@ void RegExpPrototype::method_compile(const BuiltinFunction *, Scope &scope, Call
     scope.engine->regExpCtor()->as<FunctionObject>()->construct(scope, cData);
     Scoped<RegExpObject> re(scope, scope.result.asReturnedValue());
 
-    r->d()->value = re->value();
+    r->d()->value.set(scope.engine, re->value());
     r->d()->global = re->global();
     RETURN_UNDEFINED();
 }
diff --git a/src/qml/jsruntime/qv4regexpobject_p.h b/src/qml/jsruntime/qv4regexpobject_p.h
index c0c7dfa78a..0fcfe93135 100644
--- a/src/qml/jsruntime/qv4regexpobject_p.h
+++ b/src/qml/jsruntime/qv4regexpobject_p.h
@@ -73,21 +73,28 @@ namespace QV4 {
 
 namespace Heap {
 
-struct RegExpObject : Object {
+#define RegExpObjectMembers(class, Member) \
+    Member(class, Pointer, RegExp *, value) \
+    Member(class, NoMark, bool, global)
+
+DECLARE_HEAP_OBJECT(RegExpObject, Object) {
+    DECLARE_MARK_TABLE(RegExpObject);
+
     void init();
     void init(QV4::RegExp *value, bool global);
     void init(const QRegExp &re);
-
-    Pointer<RegExp> value;
-    bool global;
 };
 
-struct RegExpCtor : FunctionObject {
+#define RegExpCtorMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, lastMatch) \
+    Member(class, Pointer, String *, lastInput) \
+    Member(class, NoMark, int, lastMatchStart) \
+    Member(class, NoMark, int, lastMatchEnd)
+
+DECLARE_HEAP_OBJECT(RegExpCtor, FunctionObject) {
+    DECLARE_MARK_TABLE(RegExpCtor);
+
     void init(QV4::ExecutionContext *scope);
-    Value lastMatch;
-    Pointer<String> lastInput;
-    int lastMatchStart;
-    int lastMatchEnd;
     void clearLastMatch();
 };
 
@@ -121,14 +128,19 @@ struct RegExpObject: Object {
 
     void initProperties();
 
-    Value *lastIndexProperty();
+    int lastIndex() const {
+        Q_ASSERT(Index_LastIndex == internalClass()->find(engine()->id_lastIndex()));
+        return propertyData(Index_LastIndex)->toInt32();
+    }
+    void setLastIndex(int index) {
+        Q_ASSERT(Index_LastIndex == internalClass()->find(engine()->id_lastIndex()));
+        return setProperty(Index_LastIndex, Primitive::fromInt32(index));
+    }
+
     QRegExp toQRegExp() const;
     QString toString() const;
     QString source() const;
     uint flags() const;
-
-protected:
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 struct RegExpCtor: FunctionObject
@@ -142,7 +154,6 @@ struct RegExpCtor: FunctionObject
 
     static void construct(const Managed *m, Scope &scope, CallData *callData);
     static void call(const Managed *that, Scope &scope, CallData *callData);
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 struct RegExpPrototype: RegExpObject
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 6590054bf3..b28a5f9000 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -219,6 +219,14 @@ void RuntimeCounters::count(const char *func, uint tag1, uint tag2)
 #endif // QV4_COUNT_RUNTIME_FUNCTIONS
 
 #ifndef V4_BOOTSTRAP
+
+Runtime::Runtime()
+{
+#define INIT_METHOD(returnvalue, name, args) runtimeMethods[name] = reinterpret_cast<void*>(&method_##name);
+FOR_EACH_RUNTIME_METHOD(INIT_METHOD)
+#undef INIT_METHOD
+}
+
 void RuntimeHelpers::numberToString(QString *result, double num, int radix)
 {
     Q_ASSERT(result);
@@ -300,7 +308,7 @@ void RuntimeHelpers::numberToString(QString *result, double num, int radix)
 
 ReturnedValue Runtime::method_closure(ExecutionEngine *engine, int functionId)
 {
-    QV4::Function *clos = engine->current->compilationUnit->runtimeFunctions[functionId];
+    QV4::Function *clos = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeFunctions[functionId];
     Q_ASSERT(clos);
     return FunctionObject::createScriptFunction(engine->currentContext, clos)->asReturnedValue();
 }
@@ -643,8 +651,8 @@ void Runtime::method_setElement(ExecutionEngine *engine, const Value &object, co
     if (idx < UINT_MAX) {
         if (o->arrayType() == Heap::ArrayData::Simple) {
             Heap::SimpleArrayData *s = static_cast<Heap::SimpleArrayData *>(o->arrayData());
-            if (s && idx < s->len && !s->data(idx).isEmpty()) {
-                s->data(idx) = value;
+            if (s && idx < s->values.size && !s->data(idx).isEmpty()) {
+                s->setData(engine, idx, value);
                 return;
             }
         }
@@ -1301,7 +1309,7 @@ ReturnedValue Runtime::method_arrayLiteral(ExecutionEngine *engine, Value *value
 ReturnedValue Runtime::method_objectLiteral(ExecutionEngine *engine, const QV4::Value *args, int classId, int arrayValueCount, int arrayGetterSetterCountAndFlags)
 {
     Scope scope(engine);
-    QV4::InternalClass *klass = engine->current->compilationUnit->runtimeClasses[classId];
+    QV4::InternalClass *klass = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeClasses[classId];
     ScopedObject o(scope, engine->newObject(klass, engine->objectPrototype()));
 
     {
@@ -1311,7 +1319,7 @@ ReturnedValue Runtime::method_objectLiteral(ExecutionEngine *engine, const QV4::
     }
 
     for (uint i = 0; i < klass->size; ++i)
-        *o->propertyData(i) = *args++;
+        o->setProperty(i, *args++);
 
     if (arrayValueCount > 0) {
         ScopedValue entry(scope);
@@ -1413,7 +1421,7 @@ ReturnedValue Runtime::method_getQmlContext(NoThrowEngine *engine)
 
 ReturnedValue Runtime::method_regexpLiteral(ExecutionEngine *engine, int id)
 {
-    return engine->current->compilationUnit->runtimeRegularExpressions[id].asReturnedValue();
+    return static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeRegularExpressions[id].asReturnedValue();
 }
 
 ReturnedValue Runtime::method_getQmlQObjectProperty(ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)
@@ -1743,6 +1751,8 @@ Bool Runtime::method_compareEqual(const Value &left, const Value &right)
         return !left.isNaN();
 
     if (left.type() == right.type()) {
+        if (left.isDouble() && left.doubleValue() == 0 && right.doubleValue() == 0)
+            return true; // this takes care of -0 == +0 (which obviously have different raw values)
         if (!left.isManaged())
             return false;
         if (left.isString() == right.isString())
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index 355b7890b6..302facba06 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -56,6 +56,7 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
+typedef uint Bool;
 struct NoThrowEngine;
 
 namespace {
@@ -90,256 +91,169 @@ struct ExceptionCheck<void (*)(QV4::NoThrowEngine *, A, B, C)> {
 };
 } // anonymous namespace
 
-#define RUNTIME_METHOD(returnvalue, name, args) \
-    typedef returnvalue (*Method_##name)args; \
-    enum { Method_##name##_NeedsExceptionCheck = ExceptionCheck<Method_##name>::NeedsCheck }; \
-    static returnvalue method_##name args; \
-    const Method_##name name
-
-#define INIT_RUNTIME_METHOD(name) \
-    name(method_##name)
+#define FOR_EACH_RUNTIME_METHOD(F) \
+    /* call */ \
+    F(ReturnedValue, callGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
+    F(ReturnedValue, callActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
+    F(ReturnedValue, callQmlScopeObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData)) \
+    F(ReturnedValue, callQmlContextObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData)) \
+    F(ReturnedValue, callProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
+    F(ReturnedValue, callPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
+    F(ReturnedValue, callElement, (ExecutionEngine *engine, const Value &index, CallData *callData)) \
+    F(ReturnedValue, callValue, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
+    \
+    /* construct */ \
+    F(ReturnedValue, constructGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
+    F(ReturnedValue, constructActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
+    F(ReturnedValue, constructProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
+    F(ReturnedValue, constructPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
+    F(ReturnedValue, constructValue, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
+    \
+    /* set & get */ \
+    F(void, setActivationProperty, (ExecutionEngine *engine, int nameIndex, const Value &value)) \
+    F(void, setProperty, (ExecutionEngine *engine, const Value &object, int nameIndex, const Value &value)) \
+    F(void, setElement, (ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)) \
+    F(ReturnedValue, getProperty, (ExecutionEngine *engine, const Value &object, int nameIndex)) \
+    F(ReturnedValue, getActivationProperty, (ExecutionEngine *engine, int nameIndex)) \
+    F(ReturnedValue, getElement, (ExecutionEngine *engine, const Value &object, const Value &index)) \
+    \
+    /* typeof */  \
+    F(ReturnedValue, typeofValue, (ExecutionEngine *engine, const Value &val)) \
+    F(ReturnedValue, typeofName, (ExecutionEngine *engine, int nameIndex)) \
+    F(ReturnedValue, typeofScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex)) \
+    F(ReturnedValue, typeofContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex)) \
+    F(ReturnedValue, typeofMember, (ExecutionEngine *engine, const Value &base, int nameIndex)) \
+    F(ReturnedValue, typeofElement, (ExecutionEngine *engine, const Value &base, const Value &index)) \
+    \
+    /* delete */ \
+    F(ReturnedValue, deleteElement, (ExecutionEngine *engine, const Value &base, const Value &index)) \
+    F(ReturnedValue, deleteMember, (ExecutionEngine *engine, const Value &base, int nameIndex)) \
+    F(ReturnedValue, deleteMemberString, (ExecutionEngine *engine, const Value &base, String *name)) \
+    F(ReturnedValue, deleteName, (ExecutionEngine *engine, int nameIndex)) \
+    \
+    /* exceptions & scopes */ \
+    F(void, throwException, (ExecutionEngine *engine, const Value &value)) \
+    F(ReturnedValue, unwindException, (ExecutionEngine *engine)) \
+    F(void, pushWithScope, (const Value &o, NoThrowEngine *engine)) \
+    F(void, pushCatchScope, (NoThrowEngine *engine, int exceptionVarNameIndex)) \
+    F(void, popScope, (NoThrowEngine *engine)) \
+    \
+    /* closures */ \
+    F(ReturnedValue, closure, (ExecutionEngine *engine, int functionId)) \
+    \
+    /* function header */ \
+    F(void, declareVar, (ExecutionEngine *engine, bool deletable, int nameIndex)) \
+    F(ReturnedValue, setupArgumentsObject, (ExecutionEngine *engine)) \
+    F(void, convertThisToObject, (ExecutionEngine *engine)) \
+    \
+    /* literals */ \
+    F(ReturnedValue, arrayLiteral, (ExecutionEngine *engine, Value *values, uint length)) \
+    F(ReturnedValue, objectLiteral, (ExecutionEngine *engine, const Value *args, int classId, int arrayValueCount, int arrayGetterSetterCountAndFlags)) \
+    F(ReturnedValue, regexpLiteral, (ExecutionEngine *engine, int id)) \
+    \
+    /* foreach */ \
+    F(ReturnedValue, foreachIterator, (ExecutionEngine *engine, const Value &in)) \
+    F(ReturnedValue, foreachNextPropertyName, (const Value &foreach_iterator)) \
+    \
+    /* unary operators */ \
+    F(ReturnedValue, uPlus, (const Value &value)) \
+    F(ReturnedValue, uMinus, (const Value &value)) \
+    F(ReturnedValue, uNot, (const Value &value)) \
+    F(ReturnedValue, complement, (const Value &value)) \
+    F(ReturnedValue, increment, (const Value &value)) \
+    F(ReturnedValue, decrement, (const Value &value)) \
+    \
+    /* binary operators */ \
+    F(ReturnedValue, instanceof, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    F(ReturnedValue, in, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    F(ReturnedValue, add, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    F(ReturnedValue, addString, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    F(ReturnedValue, bitOr, (const Value &left, const Value &right)) \
+    F(ReturnedValue, bitXor, (const Value &left, const Value &right)) \
+    F(ReturnedValue, bitAnd, (const Value &left, const Value &right)) \
+    F(ReturnedValue, sub, (const Value &left, const Value &right)) \
+    F(ReturnedValue, mul, (const Value &left, const Value &right)) \
+    F(ReturnedValue, div, (const Value &left, const Value &right)) \
+    F(ReturnedValue, mod, (const Value &left, const Value &right)) \
+    F(ReturnedValue, shl, (const Value &left, const Value &right)) \
+    F(ReturnedValue, shr, (const Value &left, const Value &right)) \
+    F(ReturnedValue, ushr, (const Value &left, const Value &right)) \
+    F(ReturnedValue, greaterThan, (const Value &left, const Value &right)) \
+    F(ReturnedValue, lessThan, (const Value &left, const Value &right)) \
+    F(ReturnedValue, greaterEqual, (const Value &left, const Value &right)) \
+    F(ReturnedValue, lessEqual, (const Value &left, const Value &right)) \
+    F(ReturnedValue, equal, (const Value &left, const Value &right)) \
+    F(ReturnedValue, notEqual, (const Value &left, const Value &right)) \
+    F(ReturnedValue, strictEqual, (const Value &left, const Value &right)) \
+    F(ReturnedValue, strictNotEqual, (const Value &left, const Value &right)) \
+    \
+    /* comparisons */ \
+    F(Bool, compareGreaterThan, (const Value &l, const Value &r)) \
+    F(Bool, compareLessThan, (const Value &l, const Value &r)) \
+    F(Bool, compareGreaterEqual, (const Value &l, const Value &r)) \
+    F(Bool, compareLessEqual, (const Value &l, const Value &r)) \
+    F(Bool, compareEqual, (const Value &left, const Value &right)) \
+    F(Bool, compareNotEqual, (const Value &left, const Value &right)) \
+    F(Bool, compareStrictEqual, (const Value &left, const Value &right)) \
+    F(Bool, compareStrictNotEqual, (const Value &left, const Value &right)) \
+    \
+    F(Bool, compareInstanceof, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    F(Bool, compareIn, (ExecutionEngine *engine, const Value &left, const Value &right)) \
+    \
+    /* conversions */ \
+    F(Bool, toBoolean, (const Value &value)) \
+    F(ReturnedValue, toDouble, (const Value &value)) \
+    F(int, toInt, (const Value &value)) \
+    F(int, doubleToInt, (const double &d)) \
+    F(unsigned, toUInt, (const Value &value)) \
+    F(unsigned, doubleToUInt, (const double &d)) \
+    \
+    /* qml */ \
+    F(ReturnedValue, getQmlContext, (NoThrowEngine *engine)) \
+    F(ReturnedValue, getQmlImportedScripts, (NoThrowEngine *engine)) \
+    F(ReturnedValue, getQmlSingleton, (NoThrowEngine *engine, int nameIndex)) \
+    F(ReturnedValue, getQmlAttachedProperty, (ExecutionEngine *engine, int attachedPropertiesId, int propertyIndex)) \
+    F(ReturnedValue, getQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
+    F(ReturnedValue, getQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
+    F(ReturnedValue, getQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)) \
+    F(ReturnedValue, getQmlSingletonQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)) \
+    F(ReturnedValue, getQmlIdObject, (ExecutionEngine *engine, const Value &context, uint index)) \
+    \
+    F(void, setQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
+    F(void, setQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
+    F(void, setQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, const Value &value))
 
 struct Q_QML_PRIVATE_EXPORT Runtime {
-    Runtime()
-        : INIT_RUNTIME_METHOD(callGlobalLookup)
-        , INIT_RUNTIME_METHOD(callActivationProperty)
-        , INIT_RUNTIME_METHOD(callQmlScopeObjectProperty)
-        , INIT_RUNTIME_METHOD(callQmlContextObjectProperty)
-        , INIT_RUNTIME_METHOD(callProperty)
-        , INIT_RUNTIME_METHOD(callPropertyLookup)
-        , INIT_RUNTIME_METHOD(callElement)
-        , INIT_RUNTIME_METHOD(callValue)
-        , INIT_RUNTIME_METHOD(constructGlobalLookup)
-        , INIT_RUNTIME_METHOD(constructActivationProperty)
-        , INIT_RUNTIME_METHOD(constructProperty)
-        , INIT_RUNTIME_METHOD(constructPropertyLookup)
-        , INIT_RUNTIME_METHOD(constructValue)
-        , INIT_RUNTIME_METHOD(setActivationProperty)
-        , INIT_RUNTIME_METHOD(setProperty)
-        , INIT_RUNTIME_METHOD(setElement)
-        , INIT_RUNTIME_METHOD(getProperty)
-        , INIT_RUNTIME_METHOD(getActivationProperty)
-        , INIT_RUNTIME_METHOD(getElement)
-        , INIT_RUNTIME_METHOD(typeofValue)
-        , INIT_RUNTIME_METHOD(typeofName)
-        , INIT_RUNTIME_METHOD(typeofScopeObjectProperty)
-        , INIT_RUNTIME_METHOD(typeofContextObjectProperty)
-        , INIT_RUNTIME_METHOD(typeofMember)
-        , INIT_RUNTIME_METHOD(typeofElement)
-        , INIT_RUNTIME_METHOD(deleteElement)
-        , INIT_RUNTIME_METHOD(deleteMember)
-        , INIT_RUNTIME_METHOD(deleteMemberString)
-        , INIT_RUNTIME_METHOD(deleteName)
-        , INIT_RUNTIME_METHOD(throwException)
-        , INIT_RUNTIME_METHOD(unwindException)
-        , INIT_RUNTIME_METHOD(pushWithScope)
-        , INIT_RUNTIME_METHOD(pushCatchScope)
-        , INIT_RUNTIME_METHOD(popScope)
-        , INIT_RUNTIME_METHOD(closure)
-        , INIT_RUNTIME_METHOD(declareVar)
-        , INIT_RUNTIME_METHOD(setupArgumentsObject)
-        , INIT_RUNTIME_METHOD(convertThisToObject)
-        , INIT_RUNTIME_METHOD(arrayLiteral)
-        , INIT_RUNTIME_METHOD(objectLiteral)
-        , INIT_RUNTIME_METHOD(regexpLiteral)
-        , INIT_RUNTIME_METHOD(foreachIterator)
-        , INIT_RUNTIME_METHOD(foreachNextPropertyName)
-        , INIT_RUNTIME_METHOD(uPlus)
-        , INIT_RUNTIME_METHOD(uMinus)
-        , INIT_RUNTIME_METHOD(uNot)
-        , INIT_RUNTIME_METHOD(complement)
-        , INIT_RUNTIME_METHOD(increment)
-        , INIT_RUNTIME_METHOD(decrement)
-        , INIT_RUNTIME_METHOD(instanceof)
-        , INIT_RUNTIME_METHOD(in)
-        , INIT_RUNTIME_METHOD(add)
-        , INIT_RUNTIME_METHOD(addString)
-        , INIT_RUNTIME_METHOD(bitOr)
-        , INIT_RUNTIME_METHOD(bitXor)
-        , INIT_RUNTIME_METHOD(bitAnd)
-        , INIT_RUNTIME_METHOD(sub)
-        , INIT_RUNTIME_METHOD(mul)
-        , INIT_RUNTIME_METHOD(div)
-        , INIT_RUNTIME_METHOD(mod)
-        , INIT_RUNTIME_METHOD(shl)
-        , INIT_RUNTIME_METHOD(shr)
-        , INIT_RUNTIME_METHOD(ushr)
-        , INIT_RUNTIME_METHOD(greaterThan)
-        , INIT_RUNTIME_METHOD(lessThan)
-        , INIT_RUNTIME_METHOD(greaterEqual)
-        , INIT_RUNTIME_METHOD(lessEqual)
-        , INIT_RUNTIME_METHOD(equal)
-        , INIT_RUNTIME_METHOD(notEqual)
-        , INIT_RUNTIME_METHOD(strictEqual)
-        , INIT_RUNTIME_METHOD(strictNotEqual)
-        , INIT_RUNTIME_METHOD(compareGreaterThan)
-        , INIT_RUNTIME_METHOD(compareLessThan)
-        , INIT_RUNTIME_METHOD(compareGreaterEqual)
-        , INIT_RUNTIME_METHOD(compareLessEqual)
-        , INIT_RUNTIME_METHOD(compareEqual)
-        , INIT_RUNTIME_METHOD(compareNotEqual)
-        , INIT_RUNTIME_METHOD(compareStrictEqual)
-        , INIT_RUNTIME_METHOD(compareStrictNotEqual)
-        , INIT_RUNTIME_METHOD(compareInstanceof)
-        , INIT_RUNTIME_METHOD(compareIn)
-        , INIT_RUNTIME_METHOD(toBoolean)
-        , INIT_RUNTIME_METHOD(toDouble)
-        , INIT_RUNTIME_METHOD(toInt)
-        , INIT_RUNTIME_METHOD(doubleToInt)
-        , INIT_RUNTIME_METHOD(toUInt)
-        , INIT_RUNTIME_METHOD(doubleToUInt)
-        , INIT_RUNTIME_METHOD(getQmlContext)
-        , INIT_RUNTIME_METHOD(getQmlImportedScripts)
-        , INIT_RUNTIME_METHOD(getQmlSingleton)
-        , INIT_RUNTIME_METHOD(getQmlAttachedProperty)
-        , INIT_RUNTIME_METHOD(getQmlScopeObjectProperty)
-        , INIT_RUNTIME_METHOD(getQmlContextObjectProperty)
-        , INIT_RUNTIME_METHOD(getQmlQObjectProperty)
-        , INIT_RUNTIME_METHOD(getQmlSingletonQObjectProperty)
-        , INIT_RUNTIME_METHOD(getQmlIdObject)
-        , INIT_RUNTIME_METHOD(setQmlScopeObjectProperty)
-        , INIT_RUNTIME_METHOD(setQmlContextObjectProperty)
-        , INIT_RUNTIME_METHOD(setQmlQObjectProperty)
-    { }
-
-    // call
-    RUNTIME_METHOD(ReturnedValue, callGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callQmlScopeObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callQmlContextObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callElement, (ExecutionEngine *engine, const Value &index, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, callValue, (ExecutionEngine *engine, const Value &func, CallData *callData));
-
-    // construct
-    RUNTIME_METHOD(ReturnedValue, constructGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, constructActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, constructProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, constructPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData));
-    RUNTIME_METHOD(ReturnedValue, constructValue, (ExecutionEngine *engine, const Value &func, CallData *callData));
-
-    // set & get
-    RUNTIME_METHOD(void, setActivationProperty, (ExecutionEngine *engine, int nameIndex, const Value &value));
-    RUNTIME_METHOD(void, setProperty, (ExecutionEngine *engine, const Value &object, int nameIndex, const Value &value));
-    RUNTIME_METHOD(void, setElement, (ExecutionEngine *engine, const Value &object, const Value &index, const Value &value));
-    RUNTIME_METHOD(ReturnedValue, getProperty, (ExecutionEngine *engine, const Value &object, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, getActivationProperty, (ExecutionEngine *engine, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, getElement, (ExecutionEngine *engine, const Value &object, const Value &index));
-
-    // typeof
-    RUNTIME_METHOD(ReturnedValue, typeofValue, (ExecutionEngine *engine, const Value &val));
-    RUNTIME_METHOD(ReturnedValue, typeofName, (ExecutionEngine *engine, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, typeofScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex));
-    RUNTIME_METHOD(ReturnedValue, typeofContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex));
-    RUNTIME_METHOD(ReturnedValue, typeofMember, (ExecutionEngine *engine, const Value &base, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, typeofElement, (ExecutionEngine *engine, const Value &base, const Value &index));
-
-    // delete
-    RUNTIME_METHOD(ReturnedValue, deleteElement, (ExecutionEngine *engine, const Value &base, const Value &index));
-    RUNTIME_METHOD(ReturnedValue, deleteMember, (ExecutionEngine *engine, const Value &base, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, deleteMemberString, (ExecutionEngine *engine, const Value &base, String *name));
-    RUNTIME_METHOD(ReturnedValue, deleteName, (ExecutionEngine *engine, int nameIndex));
-
-    // exceptions & scopes
-    RUNTIME_METHOD(void, throwException, (ExecutionEngine *engine, const Value &value));
-    RUNTIME_METHOD(ReturnedValue, unwindException, (ExecutionEngine *engine));
-    RUNTIME_METHOD(void, pushWithScope, (const Value &o, NoThrowEngine *engine));
-    RUNTIME_METHOD(void, pushCatchScope, (NoThrowEngine *engine, int exceptionVarNameIndex));
-    RUNTIME_METHOD(void, popScope, (NoThrowEngine *engine));
-
-    // closures
-    RUNTIME_METHOD(ReturnedValue, closure, (ExecutionEngine *engine, int functionId));
+    Runtime();
 
-    // function header
-    RUNTIME_METHOD(void, declareVar, (ExecutionEngine *engine, bool deletable, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, setupArgumentsObject, (ExecutionEngine *engine));
-    RUNTIME_METHOD(void, convertThisToObject, (ExecutionEngine *engine));
-
-    // literals
-    RUNTIME_METHOD(ReturnedValue, arrayLiteral, (ExecutionEngine *engine, Value *values, uint length));
-    RUNTIME_METHOD(ReturnedValue, objectLiteral, (ExecutionEngine *engine, const Value *args, int classId, int arrayValueCount, int arrayGetterSetterCountAndFlags));
-    RUNTIME_METHOD(ReturnedValue, regexpLiteral, (ExecutionEngine *engine, int id));
-
-    // foreach
-    RUNTIME_METHOD(ReturnedValue, foreachIterator, (ExecutionEngine *engine, const Value &in));
-    RUNTIME_METHOD(ReturnedValue, foreachNextPropertyName, (const Value &foreach_iterator));
-
-    // unary operators
     typedef ReturnedValue (*UnaryOperation)(const Value &value);
-    RUNTIME_METHOD(ReturnedValue, uPlus, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, uMinus, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, uNot, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, complement, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, increment, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, decrement, (const Value &value));
-
-    // binary operators
     typedef ReturnedValue (*BinaryOperation)(const Value &left, const Value &right);
     typedef ReturnedValue (*BinaryOperationContext)(ExecutionEngine *engine, const Value &left, const Value &right);
 
-    RUNTIME_METHOD(ReturnedValue, instanceof, (ExecutionEngine *engine, const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, in, (ExecutionEngine *engine, const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, add, (ExecutionEngine *engine, const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, addString, (ExecutionEngine *engine, const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, bitOr, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, bitXor, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, bitAnd, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, sub, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, mul, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, div, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, mod, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, shl, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, shr, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, ushr, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, greaterThan, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, lessThan, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, greaterEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, lessEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, equal, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, notEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, strictEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(ReturnedValue, strictNotEqual, (const Value &left, const Value &right));
-
-    // comparisons
-    RUNTIME_METHOD(Bool, compareGreaterThan, (const Value &l, const Value &r));
-    RUNTIME_METHOD(Bool, compareLessThan, (const Value &l, const Value &r));
-    RUNTIME_METHOD(Bool, compareGreaterEqual, (const Value &l, const Value &r));
-    RUNTIME_METHOD(Bool, compareLessEqual, (const Value &l, const Value &r));
-    RUNTIME_METHOD(Bool, compareEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(Bool, compareNotEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(Bool, compareStrictEqual, (const Value &left, const Value &right));
-    RUNTIME_METHOD(Bool, compareStrictNotEqual, (const Value &left, const Value &right));
+#define DEFINE_RUNTIME_METHOD_ENUM(returnvalue, name, args) name,
+    enum RuntimeMethods {
+        FOR_EACH_RUNTIME_METHOD(DEFINE_RUNTIME_METHOD_ENUM)
+        RuntimeMethodCount,
+        InvalidRuntimeMethod = RuntimeMethodCount
+    };
+#undef DEFINE_RUNTIME_METHOD_ENUM
 
-    RUNTIME_METHOD(Bool, compareInstanceof, (ExecutionEngine *engine, const Value &left, const Value &right));
-    RUNTIME_METHOD(Bool, compareIn, (ExecutionEngine *engine, const Value &left, const Value &right));
+    void *runtimeMethods[RuntimeMethodCount];
 
-    // conversions
-    RUNTIME_METHOD(Bool, toBoolean, (const Value &value));
-    RUNTIME_METHOD(ReturnedValue, toDouble, (const Value &value));
-    RUNTIME_METHOD(int, toInt, (const Value &value));
-    RUNTIME_METHOD(int, doubleToInt, (const double &d));
-    RUNTIME_METHOD(unsigned, toUInt, (const Value &value));
-    RUNTIME_METHOD(unsigned, doubleToUInt, (const double &d));
+    static uint runtimeMethodOffset(RuntimeMethods method) { return method*QT_POINTER_SIZE; }
 
-    // qml
-    RUNTIME_METHOD(ReturnedValue, getQmlContext, (NoThrowEngine *engine));
-    RUNTIME_METHOD(ReturnedValue, getQmlImportedScripts, (NoThrowEngine *engine));
-    RUNTIME_METHOD(ReturnedValue, getQmlSingleton, (NoThrowEngine *engine, int nameIndex));
-    RUNTIME_METHOD(ReturnedValue, getQmlAttachedProperty, (ExecutionEngine *engine, int attachedPropertiesId, int propertyIndex));
-    RUNTIME_METHOD(ReturnedValue, getQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired));
-    RUNTIME_METHOD(ReturnedValue, getQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired));
-    RUNTIME_METHOD(ReturnedValue, getQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired));
-    RUNTIME_METHOD(ReturnedValue, getQmlSingletonQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired));
-    RUNTIME_METHOD(ReturnedValue, getQmlIdObject, (ExecutionEngine *engine, const Value &context, uint index));
+#define RUNTIME_METHOD(returnvalue, name, args) \
+    typedef returnvalue (*Method_##name)args; \
+    enum { Method_##name##_NeedsExceptionCheck = ExceptionCheck<Method_##name>::NeedsCheck }; \
+    static returnvalue method_##name args;
+    FOR_EACH_RUNTIME_METHOD(RUNTIME_METHOD)
+#undef RUNTIME_METHOD
 
-    RUNTIME_METHOD(void, setQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value));
-    RUNTIME_METHOD(void, setQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value));
-    RUNTIME_METHOD(void, setQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, const Value &value));
 };
 
-#undef RUNTIME_METHOD
-#undef INIT_RUNTIME_METHOD
+static_assert(std::is_standard_layout<Runtime>::value, "Runtime needs to be standard layout in order for us to be able to use offsetof");
+static_assert(offsetof(Runtime, runtimeMethods) == 0, "JIT expects this to be the first member");
+static_assert(sizeof(Runtime::BinaryOperation) == sizeof(void*), "JIT expects a function pointer to fit into a regular pointer, for cross-compilation offset translation");
 
 } // namespace QV4
 
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index 6775028272..e9dcc9172f 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -366,9 +366,9 @@ struct Scoped
 struct ScopedCallData {
     ScopedCallData(const Scope &scope, int argc = 0)
     {
-        int size = qMax(argc, (int)QV4::Global::ReservedArgumentCount) + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value);
+        int size = qMax(argc, QV4::Global::ReservedArgumentCount + int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)));
         ptr = reinterpret_cast<CallData *>(scope.alloc(size));
-        ptr->tag = QV4::Value::Integer_Type_Internal;
+        ptr->tag = quint32(QV4::Value::ValueTypeInternal::Integer);
         ptr->argc = argc;
     }
 
diff --git a/src/qml/jsruntime/qv4script_p.h b/src/qml/jsruntime/qv4script_p.h
index f96f0254a5..4ebe2dd609 100644
--- a/src/qml/jsruntime/qv4script_p.h
+++ b/src/qml/jsruntime/qv4script_p.h
@@ -72,7 +72,7 @@ struct ContextStateSaver {
     bool strictMode;
     Lookup *lookups;
     const QV4::Value *constantTable;
-    CompiledData::CompilationUnit *compilationUnit;
+    CompiledData::CompilationUnitBase *compilationUnit;
     int lineNumber;
 
     ContextStateSaver(const Scope &scope, ExecutionContext *context)
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index cde2131aab..71f85c2d71 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -54,12 +54,12 @@ using namespace QV4;
 
 DEFINE_MANAGED_VTABLE(String);
 
-void String::markObjects(Heap::Base *that, ExecutionEngine *e)
+void String::markObjects(Heap::Base *that, MarkStack *markStack)
 {
     String::Data *s = static_cast<String::Data *>(that);
     if (s->largestSubLength) {
-        s->left->mark(e);
-        s->right->mark(e);
+        s->left->mark(markStack);
+        s->right->mark(markStack);
     }
 }
 
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 5b0fd292d6..71e55cbcd4 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -204,7 +204,7 @@ struct Q_QML_PRIVATE_EXPORT String : public Managed {
     Identifier *identifier() const { return d()->identifier; }
 
 protected:
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
     static bool isEqualTo(Managed *that, Managed *o);
     static uint getLength(const Managed *m);
 #endif
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index 72be11eca0..81f5c3566c 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -77,15 +77,15 @@ void Heap::StringObject::init()
 {
     Object::init();
     Q_ASSERT(vtable() == QV4::StringObject::staticVTable());
-    string = internalClass->engine->id_empty()->d();
-    *propertyData(LengthPropertyIndex) = Primitive::fromInt32(0);
+    string.set(internalClass->engine, internalClass->engine->id_empty()->d());
+    setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(0));
 }
 
 void Heap::StringObject::init(const QV4::String *str)
 {
     Object::init();
-    string = str->d();
-    *propertyData(LengthPropertyIndex) = Primitive::fromInt32(length());
+    string.set(internalClass->engine, str->d());
+    setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(length()));
 }
 
 Heap::String *Heap::StringObject::getIndex(uint index) const
@@ -145,13 +145,6 @@ void StringObject::advanceIterator(Managed *m, ObjectIterator *it, Value *name,
     return Object::advanceIterator(m, it, name, index, p, attrs);
 }
 
-void StringObject::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    StringObject::Data *o = static_cast<StringObject::Data *>(that);
-    o->string->mark(e);
-    Object::markObjects(that, e);
-}
-
 DEFINE_OBJECT_VTABLE(StringCtor);
 
 void Heap::StringCtor::init(QV4::ExecutionContext *scope)
@@ -563,7 +556,7 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
             offset = qMax(offset + 1, matchOffsets[oldSize + 1]);
         }
         if (regExp->global())
-            *regExp->lastIndexProperty() = Primitive::fromUInt32(0);
+            regExp->setLastIndex(0);
         numStringMatches = nMatchOffsets / (regExp->value()->captureCount() * 2);
         numCaptures = regExp->value()->captureCount();
     } else {
diff --git a/src/qml/jsruntime/qv4stringobject_p.h b/src/qml/jsruntime/qv4stringobject_p.h
index aed3bc1e28..5ccee3335e 100644
--- a/src/qml/jsruntime/qv4stringobject_p.h
+++ b/src/qml/jsruntime/qv4stringobject_p.h
@@ -60,14 +60,18 @@ namespace QV4 {
 
 namespace Heap {
 
-struct StringObject : Object {
+#define StringObjectMembers(class, Member) \
+    Member(class, Pointer, String *, string)
+
+DECLARE_HEAP_OBJECT(StringObject, Object) {
+    DECLARE_MARK_TABLE(StringObject);
+
     enum {
         LengthPropertyIndex = 0
     };
 
     void init();
     void init(const QV4::String *string);
-    String *string;
 
     Heap::String *getIndex(uint index) const;
     uint length() const;
@@ -96,7 +100,6 @@ struct StringObject: Object {
 
 protected:
     static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs);
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
 };
 
 struct StringCtor: FunctionObject
diff --git a/src/qml/jsruntime/qv4typedarray.cpp b/src/qml/jsruntime/qv4typedarray.cpp
index 5573a2e57f..a34a8922e1 100644
--- a/src/qml/jsruntime/qv4typedarray.cpp
+++ b/src/qml/jsruntime/qv4typedarray.cpp
@@ -229,8 +229,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             return;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = buffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = 0;
 
@@ -252,8 +252,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             return;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = newBuffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, newBuffer->d());
         array->d()->byteLength = destByteLength;
         array->d()->byteOffset = 0;
 
@@ -311,8 +311,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             byteLength = (uint)l;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = buffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = byteOffset;
         scope.result = array.asReturnedValue();
@@ -335,8 +335,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
         return;
     }
 
-    Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-    array->d()->buffer = newBuffer->d();
+    Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+    array->d()->buffer.set(scope.engine, newBuffer->d());
     array->d()->byteLength = l * elementSize;
     array->d()->byteOffset = 0;
 
@@ -375,12 +375,6 @@ Heap::TypedArray *TypedArray::create(ExecutionEngine *e, Heap::TypedArray::Type
     return e->memoryManager->allocObject<TypedArray>(e->emptyClass, e->typedArrayPrototype + t, t);
 }
 
-void TypedArray::markObjects(Heap::Base *that, ExecutionEngine *e)
-{
-    static_cast<TypedArray::Data *>(that)->buffer->mark(e);
-    Object::markObjects(that, e);
-}
-
 ReturnedValue TypedArray::getIndexed(const Managed *m, uint index, bool *hasProperty)
 {
     Scope scope(static_cast<const Object *>(m)->engine());
diff --git a/src/qml/jsruntime/qv4typedarray_p.h b/src/qml/jsruntime/qv4typedarray_p.h
index fbf13c9815..96786c8231 100644
--- a/src/qml/jsruntime/qv4typedarray_p.h
+++ b/src/qml/jsruntime/qv4typedarray_p.h
@@ -72,7 +72,15 @@ struct TypedArrayOperations {
 
 namespace Heap {
 
-struct TypedArray : Object {
+#define TypedArrayMembers(class, Member) \
+    Member(class, Pointer, ArrayBuffer *, buffer) \
+    Member(class, NoMark, const TypedArrayOperations *, type) \
+    Member(class, NoMark, uint, byteLength) \
+    Member(class, NoMark, uint, byteOffset) \
+    Member(class, NoMark, uint, arrayType)
+
+DECLARE_HEAP_OBJECT(TypedArray, Object) {
+    DECLARE_MARK_TABLE(TypedArray);
     enum Type {
         Int8Array,
         UInt8Array,
@@ -87,12 +95,6 @@ struct TypedArray : Object {
     };
 
     void init(Type t);
-
-    const TypedArrayOperations *type;
-    Pointer<ArrayBuffer> buffer;
-    uint byteLength;
-    uint byteOffset;
-    Type arrayType;
 };
 
 struct TypedArrayCtor : FunctionObject {
@@ -128,10 +130,9 @@ struct Q_QML_PRIVATE_EXPORT TypedArray : Object
     }
 
     Heap::TypedArray::Type arrayType() const {
-        return d()->arrayType;
+        return static_cast<Heap::TypedArray::Type>(d()->arrayType);
     }
 
-    static void markObjects(Heap::Base *that, ExecutionEngine *e);
     static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
     static bool putIndexed(Managed *m, uint index, const Value &value);
 };
diff --git a/src/qml/jsruntime/qv4value_p.h b/src/qml/jsruntime/qv4value_p.h
index 4ff0565f9b..50cecb6598 100644
--- a/src/qml/jsruntime/qv4value_p.h
+++ b/src/qml/jsruntime/qv4value_p.h
@@ -68,8 +68,6 @@ namespace Heap {
     struct Base;
 }
 
-typedef uint Bool;
-
 struct Q_QML_PRIVATE_EXPORT Value
 {
 private:
@@ -209,23 +207,23 @@ public:
     }
     QML_NEARLY_ALWAYS_INLINE void setInt_32(int i)
     {
-        setTagValue(Integer_Type_Internal, quint32(i));
+        setTagValue(quint32(ValueTypeInternal::Integer), quint32(i));
     }
     QML_NEARLY_ALWAYS_INLINE uint uint_32() const { return value(); }
 
     QML_NEARLY_ALWAYS_INLINE void setEmpty()
     {
-        setTagValue(Empty_Type_Internal, value());
+        setTagValue(quint32(ValueTypeInternal::Empty), value());
     }
 
     QML_NEARLY_ALWAYS_INLINE void setEmpty(int i)
     {
-        setTagValue(Empty_Type_Internal, quint32(i));
+        setTagValue(quint32(ValueTypeInternal::Empty), quint32(i));
     }
 
     QML_NEARLY_ALWAYS_INLINE void setEmpty(quint32 i)
     {
-        setTagValue(Empty_Type_Internal, i);
+        setTagValue(quint32(ValueTypeInternal::Empty), i);
     }
 
     QML_NEARLY_ALWAYS_INLINE quint32 emptyValue()
@@ -268,8 +266,17 @@ public:
         IsDoubleTag_Shift = IsDouble_Shift - Tag_Shift,
         Managed_Type_Internal_64 = 0
     };
+
     static const quint64 Immediate_Mask_64 = 0x00020000u; // bit 49
 
+    enum class ValueTypeInternal_64 {
+        Empty            = Immediate_Mask_64| 0,
+        ConvertibleToInt = Immediate_Mask_64| 0x10000u, // bit 48
+        Null             = ConvertibleToInt | 0x08000u,
+        Boolean          = ConvertibleToInt | 0x04000u,
+        Integer          = ConvertibleToInt | 0x02000u
+    };
+
     // Used only by 32-bit encoding
     enum Masks {
         SilentNaNBit           =                  0x00040000,
@@ -277,6 +284,14 @@ public:
     };
     static const quint64 Immediate_Mask_32 = NotDouble_Mask | 0x00020000u | SilentNaNBit;
 
+    enum class ValueTypeInternal_32 {
+        Empty            = Immediate_Mask_32| 0,
+        ConvertibleToInt = Immediate_Mask_32| 0x10000u, // bit 48
+        Null             = ConvertibleToInt | 0x08000u,
+        Boolean          = ConvertibleToInt | 0x04000u,
+        Integer          = ConvertibleToInt | 0x02000u
+    };
+
     enum {
         Managed_Type_Internal_32  = NotDouble_Mask
     };
@@ -286,28 +301,23 @@ public:
         Managed_Type_Internal  = Managed_Type_Internal_64
     };
     static const quint64 Immediate_Mask = Immediate_Mask_64;
+    using ValueTypeInternal = ValueTypeInternal_64;
 #else
     enum {
         Managed_Type_Internal  = Managed_Type_Internal_32
     };
     static const quint64 Immediate_Mask = Immediate_Mask_32;
+    using ValueTypeInternal = ValueTypeInternal_32;
 #endif
     enum {
         NaN_Mask = 0x7ff80000,
     };
-    enum ValueTypeInternal {
-        Empty_Type_Internal   = Immediate_Mask   | 0,
-        ConvertibleToInt      = Immediate_Mask   | 0x10000u, // bit 48
-        Null_Type_Internal    = ConvertibleToInt | 0x08000u,
-        Boolean_Type_Internal = ConvertibleToInt | 0x04000u,
-        Integer_Type_Internal = ConvertibleToInt | 0x02000u
-    };
 
     // used internally in property
-    inline bool isEmpty() const { return tag() == Empty_Type_Internal; }
-    inline bool isNull() const { return tag() == Null_Type_Internal; }
-    inline bool isBoolean() const { return tag() == Boolean_Type_Internal; }
-    inline bool isInteger() const { return tag() == Integer_Type_Internal; }
+    inline bool isEmpty() const { return tag() == quint32(ValueTypeInternal::Empty); }
+    inline bool isNull() const { return tag() == quint32(ValueTypeInternal::Null); }
+    inline bool isBoolean() const { return tag() == quint32(ValueTypeInternal::Boolean); }
+    inline bool isInteger() const { return tag() == quint32(ValueTypeInternal::Integer); }
     inline bool isNullOrUndefined() const { return isNull() || isUndefined(); }
     inline bool isNumber() const { return isDouble() || isInteger(); }
 
@@ -332,9 +342,9 @@ public:
     inline bool isDouble() const { return (tag() & NotDouble_Mask) != NotDouble_Mask; }
     inline bool isManaged() const { return tag() == Managed_Type_Internal && !isUndefined(); }
     inline bool isManagedOrUndefined() const { return tag() == Managed_Type_Internal; }
-    inline bool integerCompatible() const { return (tag() & ConvertibleToInt) == ConvertibleToInt; }
+    inline bool integerCompatible() const { return (tag() & quint32(ValueTypeInternal::ConvertibleToInt)) == quint32(ValueTypeInternal::ConvertibleToInt); }
     static inline bool integerCompatible(Value a, Value b) {
-        return ((a.tag() & b.tag()) & ConvertibleToInt) == ConvertibleToInt;
+        return ((a.tag() & b.tag()) & quint32(ValueTypeInternal::ConvertibleToInt)) == quint32(ValueTypeInternal::ConvertibleToInt);
     }
     static inline bool bothDouble(Value a, Value b) {
         return ((a.tag() | b.tag()) & NotDouble_Mask) != NotDouble_Mask;
@@ -361,7 +371,7 @@ public:
     inline bool isString() const;
     inline bool isObject() const;
     inline bool isInt32() {
-        if (tag() == Integer_Type_Internal)
+        if (tag() == quint32(ValueTypeInternal::Integer))
             return true;
         if (isDouble()) {
             double d = doubleValue();
@@ -374,7 +384,7 @@ public:
         return false;
     }
     double asDouble() const {
-        if (tag() == Integer_Type_Internal)
+        if (tag() == quint32(ValueTypeInternal::Integer))
             return int_32();
         return doubleValue();
     }
@@ -429,7 +439,7 @@ public:
     inline bool tryIntegerConversion() {
         bool b = integerCompatible();
         if (b)
-            setTagValue(Integer_Type_Internal, value());
+            setTagValue(quint32(ValueTypeInternal::Integer), value());
         return b;
     }
 
@@ -477,7 +487,7 @@ public:
     // Section 9.12
     bool sameValue(Value other) const;
 
-    inline void mark(ExecutionEngine *e);
+    inline void mark(MarkStack *markStack);
 
     Value &operator =(const ScopedValue &v);
     Value &operator=(ReturnedValue v) { _val = v; return *this; }
@@ -612,14 +622,14 @@ inline Primitive Primitive::emptyValue(uint e)
 inline Primitive Primitive::nullValue()
 {
     Primitive v;
-    v.setTagValue(Null_Type_Internal, 0);
+    v.setTagValue(quint32(ValueTypeInternal::Null), 0);
     return v;
 }
 
 inline Primitive Primitive::fromBoolean(bool b)
 {
     Primitive v;
-    v.setTagValue(Boolean_Type_Internal, b);
+    v.setTagValue(quint32(ValueTypeInternal::Boolean), b);
     return v;
 }
 
@@ -641,7 +651,7 @@ inline Primitive Primitive::fromUInt32(uint i)
 {
     Primitive v;
     if (i < INT_MAX) {
-        v.setTagValue(Integer_Type_Internal, i);
+        v.setTagValue(quint32(ValueTypeInternal::Integer), i);
     } else {
         v.setDouble(i);
     }
@@ -708,7 +718,6 @@ inline unsigned int Value::toUInt32() const
     return (unsigned int)toInt32();
 }
 
-
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4variantobject.cpp b/src/qml/jsruntime/qv4variantobject.cpp
index 5cab4c5386..f2ff5d307e 100644
--- a/src/qml/jsruntime/qv4variantobject.cpp
+++ b/src/qml/jsruntime/qv4variantobject.cpp
@@ -84,7 +84,7 @@ bool VariantObject::isEqualTo(Managed *m, Managed *other)
     return false;
 }
 
-void VariantObject::addVmePropertyReference()
+void VariantObject::addVmePropertyReference() const
 {
     if (d()->isScarce() && ++d()->vmePropertyReferenceCount == 1) {
         // remove from the ep->scarceResources list
@@ -94,7 +94,7 @@ void VariantObject::addVmePropertyReference()
     }
 }
 
-void VariantObject::removeVmePropertyReference()
+void VariantObject::removeVmePropertyReference() const
 {
     if (d()->isScarce() && --d()->vmePropertyReferenceCount == 0) {
         // and add to the ep->scarceResources list
diff --git a/src/qml/jsruntime/qv4variantobject_p.h b/src/qml/jsruntime/qv4variantobject_p.h
index ef51b6632d..e281602bb5 100644
--- a/src/qml/jsruntime/qv4variantobject_p.h
+++ b/src/qml/jsruntime/qv4variantobject_p.h
@@ -96,8 +96,8 @@ struct VariantObject : Object
     V4_PROTOTYPE(variantPrototype)
     V4_NEEDS_DESTROY
 
-    void addVmePropertyReference();
-    void removeVmePropertyReference();
+    void addVmePropertyReference() const;
+    void removeVmePropertyReference() const;
 
     static bool isEqualTo(Managed *m, Managed *other);
 };
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index be2772c23f..e16df8dc60 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -249,10 +249,11 @@ int qt_v4DebuggerHook(const char *json)
     return -NoSuchCommand; // Failure.
 }
 
-static void qt_v4CheckForBreak(QV4::ExecutionContext *context, QV4::Value **scopes, int scopeDepth)
+static void qt_v4CheckForBreak(QV4::ExecutionContext *context)
 {
-    Q_UNUSED(scopes);
-    Q_UNUSED(scopeDepth);
+    if (!qt_v4IsStepping && !qt_v4Breakpoints.size())
+        return;
+
     const int lineNumber = context->d()->lineNumber;
     QV4::Function *function = qt_v4ExtractFunction(context);
     QString engineName = function->sourceFile();
@@ -335,18 +336,24 @@ Param traceParam(const Param &param)
     return param;
 }
 # define VALUE(param) (*VALUEPTR(param))
-# define VALUEPTR(param) (scopes[traceParam(param).scope] + param.index)
+# define VALUEPTR(param) (scopes[traceParam(param).scope].values + param.index)
 #else
 # define VALUE(param) (*VALUEPTR(param))
-# define VALUEPTR(param) (scopes[param.scope] + param.index)
+# define VALUEPTR(param) (scopes[param.scope].values + param.index)
 #endif
 
+// ### add write barrier here
 #define STOREVALUE(param, value) { \
     QV4::ReturnedValue tmp = (value); \
     if (engine->hasException) \
         goto catchException; \
-    VALUE(param) = tmp; \
-    }
+    if (Q_LIKELY(!engine->writeBarrierActive || !scopes[param.scope].base)) { \
+        VALUE(param) = tmp; \
+    } else { \
+        QV4::WriteBarrier::write(engine, scopes[param.scope].base, VALUEPTR(param), QV4::Value::fromReturnedValue(tmp)); \
+    } \
+}
+
 // qv4scopedvalue_p.h also defines a CHECK_EXCEPTION macro
 #ifdef CHECK_EXCEPTION
 #undef CHECK_EXCEPTION
@@ -402,21 +409,29 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
         }
     }
 
-    Q_ALLOCA_VAR(QV4::Value*, scopes, sizeof(QV4::Value *)*(2 + 2*scopeDepth));
+    struct Scopes {
+        QV4::Value *values;
+        QV4::Heap::Base *base; // non 0 if a write barrier is required
+    };
+    Q_ALLOCA_VAR(Scopes, scopes, sizeof(Scopes)*(2 + 2*scopeDepth));
     {
-        scopes[0] = const_cast<QV4::Value *>(context->d()->compilationUnit->constants);
+        scopes[0] = { const_cast<QV4::Value *>(static_cast<CompiledData::CompilationUnit*>(context->d()->compilationUnit)->constants), 0 };
         // stack gets setup in push instruction
-        scopes[1] = 0;
+        scopes[1] = { 0, 0 };
         QV4::Heap::ExecutionContext *scope = context->d();
         int i = 0;
         while (scope) {
-            if (scope->type >= QV4::Heap::ExecutionContext::Type_SimpleCallContext) {
+            if (scope->type == QV4::Heap::ExecutionContext::Type_SimpleCallContext) {
+                QV4::Heap::SimpleCallContext *cc = static_cast<QV4::Heap::SimpleCallContext *>(scope);
+                scopes[2*i + 2] = { cc->callData->args, 0 };
+                scopes[2*i + 3] = { 0, 0 };
+            } else if (scope->type == QV4::Heap::ExecutionContext::Type_CallContext) {
                 QV4::Heap::CallContext *cc = static_cast<QV4::Heap::CallContext *>(scope);
-                scopes[2*i + 2] = cc->callData->args;
-                scopes[2*i + 3] = cc->locals;
+                scopes[2*i + 2] = { cc->callData->args, cc };
+                scopes[2*i + 3] = { cc->locals.values, cc };
             } else {
-                scopes[2*i + 2] = 0;
-                scopes[2*i + 3] = 0;
+                scopes[2*i + 2] = { 0, 0 };
+                scopes[2*i + 3] = { 0, 0 };
             }
             ++i;
             scope = scope->outer;
@@ -451,16 +466,16 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
 
     MOTH_BEGIN_INSTR(LoadRegExp)
 //        TRACE(value, "%s", instr.value.toString(context)->toQString().toUtf8().constData());
-        VALUE(instr.result) = context->d()->compilationUnit->runtimeRegularExpressions[instr.regExpId];
+        VALUE(instr.result) = static_cast<CompiledData::CompilationUnit*>(context->d()->compilationUnit)->runtimeRegularExpressions[instr.regExpId];
     MOTH_END_INSTR(LoadRegExp)
 
     MOTH_BEGIN_INSTR(LoadClosure)
-        STOREVALUE(instr.result, engine->runtime.closure(engine, instr.value));
+        STOREVALUE(instr.result, Runtime::method_closure(engine, instr.value));
     MOTH_END_INSTR(LoadClosure)
 
     MOTH_BEGIN_INSTR(LoadName)
         TRACE(inline, "property name = %s", runtimeStrings[instr.name]->toQString().toUtf8().constData());
-        STOREVALUE(instr.result, engine->runtime.getActivationProperty(engine, instr.name));
+        STOREVALUE(instr.result, Runtime::method_getActivationProperty(engine, instr.name));
     MOTH_END_INSTR(LoadName)
 
     MOTH_BEGIN_INSTR(GetGlobalLookup)
@@ -470,32 +485,32 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
 
     MOTH_BEGIN_INSTR(StoreName)
         TRACE(inline, "property name = %s", runtimeStrings[instr.name]->toQString().toUtf8().constData());
-        engine->runtime.setActivationProperty(engine, instr.name, VALUE(instr.source));
+        Runtime::method_setActivationProperty(engine, instr.name, VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreName)
 
     MOTH_BEGIN_INSTR(LoadElement)
-        STOREVALUE(instr.result, engine->runtime.getElement(engine, VALUE(instr.base), VALUE(instr.index)));
+        STOREVALUE(instr.result, Runtime::method_getElement(engine, VALUE(instr.base), VALUE(instr.index)));
     MOTH_END_INSTR(LoadElement)
 
     MOTH_BEGIN_INSTR(LoadElementLookup)
         QV4::Lookup *l = context->d()->lookups + instr.lookup;
-        STOREVALUE(instr.result, l->indexedGetter(l, VALUE(instr.base), VALUE(instr.index)));
+        STOREVALUE(instr.result, l->indexedGetter(l, engine, VALUE(instr.base), VALUE(instr.index)));
     MOTH_END_INSTR(LoadElementLookup)
 
     MOTH_BEGIN_INSTR(StoreElement)
-        engine->runtime.setElement(engine, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
+        Runtime::method_setElement(engine, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreElement)
 
     MOTH_BEGIN_INSTR(StoreElementLookup)
         QV4::Lookup *l = context->d()->lookups + instr.lookup;
-        l->indexedSetter(l, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
+        l->indexedSetter(l, engine, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreElementLookup)
 
     MOTH_BEGIN_INSTR(LoadProperty)
-        STOREVALUE(instr.result, engine->runtime.getProperty(engine, VALUE(instr.base), instr.name));
+        STOREVALUE(instr.result, Runtime::method_getProperty(engine, VALUE(instr.base), instr.name));
     MOTH_END_INSTR(LoadProperty)
 
     MOTH_BEGIN_INSTR(GetLookup)
@@ -504,7 +519,7 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(GetLookup)
 
     MOTH_BEGIN_INSTR(StoreProperty)
-        engine->runtime.setProperty(engine, VALUE(instr.base), instr.name, VALUE(instr.source));
+        Runtime::method_setProperty(engine, VALUE(instr.base), instr.name, VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreProperty)
 
@@ -515,49 +530,49 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(SetLookup)
 
     MOTH_BEGIN_INSTR(StoreQObjectProperty)
-        engine->runtime.setQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+        Runtime::method_setQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreQObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadQObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.getQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STOREVALUE(instr.result, Runtime::method_getQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
     MOTH_END_INSTR(LoadQObjectProperty)
 
     MOTH_BEGIN_INSTR(StoreScopeObjectProperty)
-        engine->runtime.setQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+        Runtime::method_setQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadScopeObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.getQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STOREVALUE(instr.result, Runtime::method_getQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
     MOTH_END_INSTR(LoadScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(StoreContextObjectProperty)
-        engine->runtime.setQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+        Runtime::method_setQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreContextObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadContextObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.getQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STOREVALUE(instr.result, Runtime::method_getQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
     MOTH_END_INSTR(LoadContextObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadIdObject)
-        STOREVALUE(instr.result, engine->runtime.getQmlIdObject(engine, VALUE(instr.base), instr.index));
+        STOREVALUE(instr.result, Runtime::method_getQmlIdObject(engine, VALUE(instr.base), instr.index));
     MOTH_END_INSTR(LoadIdObject)
 
     MOTH_BEGIN_INSTR(LoadAttachedQObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.getQmlAttachedProperty(engine, instr.attachedPropertiesId, instr.propertyIndex));
+        STOREVALUE(instr.result, Runtime::method_getQmlAttachedProperty(engine, instr.attachedPropertiesId, instr.propertyIndex));
     MOTH_END_INSTR(LoadAttachedQObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadSingletonQObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.getQmlSingletonQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STOREVALUE(instr.result, Runtime::method_getQmlSingletonQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
     MOTH_END_INSTR(LoadSingletonQObjectProperty)
 
     MOTH_BEGIN_INSTR(Push)
         TRACE(inline, "stack size: %u", instr.value);
         stackSize = instr.value;
         stack = scope.alloc(stackSize);
-        scopes[1] = stack;
+        scopes[1].values = stack;
     MOTH_END_INSTR(Push)
 
     MOTH_BEGIN_INSTR(CallValue)
@@ -571,75 +586,75 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
             }
         }
 #endif // DO_TRACE_INSTR
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, engine->runtime.callValue(engine, VALUE(instr.dest), callData));
+        STOREVALUE(instr.result, Runtime::method_callValue(engine, VALUE(instr.dest), callData));
     MOTH_END_INSTR(CallValue)
 
     MOTH_BEGIN_INSTR(CallProperty)
         TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(context)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.callProperty(engine, instr.name, callData));
+        STOREVALUE(instr.result, Runtime::method_callProperty(engine, instr.name, callData));
     MOTH_END_INSTR(CallProperty)
 
     MOTH_BEGIN_INSTR(CallPropertyLookup)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.callPropertyLookup(engine, instr.lookupIndex, callData));
+        STOREVALUE(instr.result, Runtime::method_callPropertyLookup(engine, instr.lookupIndex, callData));
     MOTH_END_INSTR(CallPropertyLookup)
 
     MOTH_BEGIN_INSTR(CallScopeObjectProperty)
         TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(context)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.callQmlScopeObjectProperty(engine, instr.index, callData));
+        STOREVALUE(instr.result, Runtime::method_callQmlScopeObjectProperty(engine, instr.index, callData));
     MOTH_END_INSTR(CallScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(CallContextObjectProperty)
         TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(context)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.callQmlContextObjectProperty(engine, instr.index, callData));
+        STOREVALUE(instr.result, Runtime::method_callQmlContextObjectProperty(engine, instr.index, callData));
     MOTH_END_INSTR(CallContextObjectProperty)
 
     MOTH_BEGIN_INSTR(CallElement)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.callElement(engine, VALUE(instr.index), callData));
+        STOREVALUE(instr.result, Runtime::method_callElement(engine, VALUE(instr.index), callData));
     MOTH_END_INSTR(CallElement)
 
     MOTH_BEGIN_INSTR(CallActivationProperty)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, engine->runtime.callActivationProperty(engine, instr.name, callData));
+        STOREVALUE(instr.result, Runtime::method_callActivationProperty(engine, instr.name, callData));
     MOTH_END_INSTR(CallActivationProperty)
 
     MOTH_BEGIN_INSTR(CallGlobalLookup)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
         STOREVALUE(instr.result, Runtime::method_callGlobalLookup(engine, instr.index, callData));
@@ -650,141 +665,141 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(SetExceptionHandler)
 
     MOTH_BEGIN_INSTR(CallBuiltinThrow)
-        engine->runtime.throwException(engine, VALUE(instr.arg));
+        Runtime::method_throwException(engine, VALUE(instr.arg));
         CHECK_EXCEPTION;
     MOTH_END_INSTR(CallBuiltinThrow)
 
     MOTH_BEGIN_INSTR(CallBuiltinUnwindException)
-        STOREVALUE(instr.result, engine->runtime.unwindException(engine));
+        STOREVALUE(instr.result, Runtime::method_unwindException(engine));
     MOTH_END_INSTR(CallBuiltinUnwindException)
 
     MOTH_BEGIN_INSTR(CallBuiltinPushCatchScope)
-        engine->runtime.pushCatchScope(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
+        Runtime::method_pushCatchScope(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
         context = engine->currentContext;
     MOTH_END_INSTR(CallBuiltinPushCatchScope)
 
     MOTH_BEGIN_INSTR(CallBuiltinPushScope)
-        engine->runtime.pushWithScope(VALUE(instr.arg), static_cast<QV4::NoThrowEngine*>(engine));
+        Runtime::method_pushWithScope(VALUE(instr.arg), static_cast<QV4::NoThrowEngine*>(engine));
         context = engine->currentContext;
         CHECK_EXCEPTION;
     MOTH_END_INSTR(CallBuiltinPushScope)
 
     MOTH_BEGIN_INSTR(CallBuiltinPopScope)
-        engine->runtime.popScope(static_cast<QV4::NoThrowEngine*>(engine));
+        Runtime::method_popScope(static_cast<QV4::NoThrowEngine*>(engine));
         context = engine->currentContext;
     MOTH_END_INSTR(CallBuiltinPopScope)
 
     MOTH_BEGIN_INSTR(CallBuiltinForeachIteratorObject)
-        STOREVALUE(instr.result, engine->runtime.foreachIterator(engine, VALUE(instr.arg)));
+        STOREVALUE(instr.result, Runtime::method_foreachIterator(engine, VALUE(instr.arg)));
     MOTH_END_INSTR(CallBuiltinForeachIteratorObject)
 
     MOTH_BEGIN_INSTR(CallBuiltinForeachNextPropertyName)
-        STOREVALUE(instr.result, engine->runtime.foreachNextPropertyName(VALUE(instr.arg)));
+        STOREVALUE(instr.result, Runtime::method_foreachNextPropertyName(VALUE(instr.arg)));
     MOTH_END_INSTR(CallBuiltinForeachNextPropertyName)
 
     MOTH_BEGIN_INSTR(CallBuiltinDeleteMember)
-        STOREVALUE(instr.result, engine->runtime.deleteMember(engine, VALUE(instr.base), instr.member));
+        STOREVALUE(instr.result, Runtime::method_deleteMember(engine, VALUE(instr.base), instr.member));
     MOTH_END_INSTR(CallBuiltinDeleteMember)
 
     MOTH_BEGIN_INSTR(CallBuiltinDeleteSubscript)
-        STOREVALUE(instr.result, engine->runtime.deleteElement(engine, VALUE(instr.base), VALUE(instr.index)));
+        STOREVALUE(instr.result, Runtime::method_deleteElement(engine, VALUE(instr.base), VALUE(instr.index)));
     MOTH_END_INSTR(CallBuiltinDeleteSubscript)
 
     MOTH_BEGIN_INSTR(CallBuiltinDeleteName)
-        STOREVALUE(instr.result, engine->runtime.deleteName(engine, instr.name));
+        STOREVALUE(instr.result, Runtime::method_deleteName(engine, instr.name));
     MOTH_END_INSTR(CallBuiltinDeleteName)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofScopeObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.typeofScopeObjectProperty(engine, VALUE(instr.base), instr.index));
+        STOREVALUE(instr.result, Runtime::method_typeofScopeObjectProperty(engine, VALUE(instr.base), instr.index));
     MOTH_END_INSTR(CallBuiltinTypeofMember)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofContextObjectProperty)
-        STOREVALUE(instr.result, engine->runtime.typeofContextObjectProperty(engine, VALUE(instr.base), instr.index));
+        STOREVALUE(instr.result, Runtime::method_typeofContextObjectProperty(engine, VALUE(instr.base), instr.index));
     MOTH_END_INSTR(CallBuiltinTypeofMember)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofMember)
-        STOREVALUE(instr.result, engine->runtime.typeofMember(engine, VALUE(instr.base), instr.member));
+        STOREVALUE(instr.result, Runtime::method_typeofMember(engine, VALUE(instr.base), instr.member));
     MOTH_END_INSTR(CallBuiltinTypeofMember)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofSubscript)
-        STOREVALUE(instr.result, engine->runtime.typeofElement(engine, VALUE(instr.base), VALUE(instr.index)));
+        STOREVALUE(instr.result, Runtime::method_typeofElement(engine, VALUE(instr.base), VALUE(instr.index)));
     MOTH_END_INSTR(CallBuiltinTypeofSubscript)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofName)
-        STOREVALUE(instr.result, engine->runtime.typeofName(engine, instr.name));
+        STOREVALUE(instr.result, Runtime::method_typeofName(engine, instr.name));
     MOTH_END_INSTR(CallBuiltinTypeofName)
 
     MOTH_BEGIN_INSTR(CallBuiltinTypeofValue)
-        STOREVALUE(instr.result, engine->runtime.typeofValue(engine, VALUE(instr.value)));
+        STOREVALUE(instr.result, Runtime::method_typeofValue(engine, VALUE(instr.value)));
     MOTH_END_INSTR(CallBuiltinTypeofValue)
 
     MOTH_BEGIN_INSTR(CallBuiltinDeclareVar)
-        engine->runtime.declareVar(engine, instr.isDeletable, instr.varName);
+        Runtime::method_declareVar(engine, instr.isDeletable, instr.varName);
     MOTH_END_INSTR(CallBuiltinDeclareVar)
 
     MOTH_BEGIN_INSTR(CallBuiltinDefineArray)
         Q_ASSERT(instr.args + instr.argc <= stackSize);
         QV4::Value *args = stack + instr.args;
-        STOREVALUE(instr.result, engine->runtime.arrayLiteral(engine, args, instr.argc));
+        STOREVALUE(instr.result, Runtime::method_arrayLiteral(engine, args, instr.argc));
     MOTH_END_INSTR(CallBuiltinDefineArray)
 
     MOTH_BEGIN_INSTR(CallBuiltinDefineObjectLiteral)
         QV4::Value *args = stack + instr.args;
-    STOREVALUE(instr.result, engine->runtime.objectLiteral(engine, args, instr.internalClassId, instr.arrayValueCount, instr.arrayGetterSetterCountAndFlags));
+    STOREVALUE(instr.result, Runtime::method_objectLiteral(engine, args, instr.internalClassId, instr.arrayValueCount, instr.arrayGetterSetterCountAndFlags));
     MOTH_END_INSTR(CallBuiltinDefineObjectLiteral)
 
     MOTH_BEGIN_INSTR(CallBuiltinSetupArgumentsObject)
-        STOREVALUE(instr.result, engine->runtime.setupArgumentsObject(engine));
+        STOREVALUE(instr.result, Runtime::method_setupArgumentsObject(engine));
     MOTH_END_INSTR(CallBuiltinSetupArgumentsObject)
 
     MOTH_BEGIN_INSTR(CallBuiltinConvertThisToObject)
-        engine->runtime.convertThisToObject(engine);
+        Runtime::method_convertThisToObject(engine);
         CHECK_EXCEPTION;
     MOTH_END_INSTR(CallBuiltinConvertThisToObject)
 
     MOTH_BEGIN_INSTR(CreateValue)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, engine->runtime.constructValue(engine, VALUE(instr.func), callData));
+        STOREVALUE(instr.result, Runtime::method_constructValue(engine, VALUE(instr.func), callData));
     MOTH_END_INSTR(CreateValue)
 
     MOTH_BEGIN_INSTR(CreateProperty)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.constructProperty(engine, instr.name, callData));
+        STOREVALUE(instr.result, Runtime::method_constructProperty(engine, instr.name, callData));
     MOTH_END_INSTR(CreateProperty)
 
     MOTH_BEGIN_INSTR(ConstructPropertyLookup)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, engine->runtime.constructPropertyLookup(engine, instr.index, callData));
+        STOREVALUE(instr.result, Runtime::method_constructPropertyLookup(engine, instr.index, callData));
     MOTH_END_INSTR(ConstructPropertyLookup)
 
     MOTH_BEGIN_INSTR(CreateActivationProperty)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, engine->runtime.constructActivationProperty(engine, instr.name, callData));
+        STOREVALUE(instr.result, Runtime::method_constructActivationProperty(engine, instr.name, callData));
     MOTH_END_INSTR(CreateActivationProperty)
 
     MOTH_BEGIN_INSTR(ConstructGlobalLookup)
-        Q_ASSERT(instr.callData + instr.argc + qOffsetOf(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
+        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = QV4::Value::Integer_Type_Internal;
+        callData->tag = quint32(Value::ValueTypeInternal::Integer);
         callData->argc = instr.argc;
         callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, engine->runtime.constructGlobalLookup(engine, instr.index, callData));
+        STOREVALUE(instr.result, Runtime::method_constructGlobalLookup(engine, instr.index, callData));
     MOTH_END_INSTR(ConstructGlobalLookup)
 
     MOTH_BEGIN_INSTR(Jump)
@@ -806,7 +821,7 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(JumpNe)
 
     MOTH_BEGIN_INSTR(UNot)
-        STOREVALUE(instr.result, engine->runtime.uNot(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_uNot(VALUE(instr.source)));
     MOTH_END_INSTR(UNot)
 
     MOTH_BEGIN_INSTR(UNotBool)
@@ -815,15 +830,15 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(UNotBool)
 
     MOTH_BEGIN_INSTR(UPlus)
-        STOREVALUE(instr.result, engine->runtime.uPlus(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_uPlus(VALUE(instr.source)));
     MOTH_END_INSTR(UPlus)
 
     MOTH_BEGIN_INSTR(UMinus)
-        STOREVALUE(instr.result, engine->runtime.uMinus(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_uMinus(VALUE(instr.source)));
     MOTH_END_INSTR(UMinus)
 
     MOTH_BEGIN_INSTR(UCompl)
-        STOREVALUE(instr.result, engine->runtime.complement(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_complement(VALUE(instr.source)));
     MOTH_END_INSTR(UCompl)
 
     MOTH_BEGIN_INSTR(UComplInt)
@@ -831,32 +846,32 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(UComplInt)
 
     MOTH_BEGIN_INSTR(Increment)
-        STOREVALUE(instr.result, engine->runtime.increment(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_increment(VALUE(instr.source)));
     MOTH_END_INSTR(Increment)
 
     MOTH_BEGIN_INSTR(Decrement)
-        STOREVALUE(instr.result, engine->runtime.decrement(VALUE(instr.source)));
+        STOREVALUE(instr.result, Runtime::method_decrement(VALUE(instr.source)));
     MOTH_END_INSTR(Decrement)
 
     MOTH_BEGIN_INSTR(Binop)
-        QV4::Runtime::BinaryOperation op = *reinterpret_cast<QV4::Runtime::BinaryOperation *>(reinterpret_cast<char *>(&engine->runtime) + instr.alu);
+        QV4::Runtime::BinaryOperation op = *reinterpret_cast<QV4::Runtime::BinaryOperation *>(reinterpret_cast<char *>(&engine->runtime.runtimeMethods[instr.alu]));
         STOREVALUE(instr.result, op(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(Binop)
 
     MOTH_BEGIN_INSTR(Add)
-        STOREVALUE(instr.result, engine->runtime.add(engine, VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_add(engine, VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(Add)
 
     MOTH_BEGIN_INSTR(BitAnd)
-        STOREVALUE(instr.result, engine->runtime.bitAnd(VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_bitAnd(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(BitAnd)
 
     MOTH_BEGIN_INSTR(BitOr)
-        STOREVALUE(instr.result, engine->runtime.bitOr(VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_bitOr(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(BitOr)
 
     MOTH_BEGIN_INSTR(BitXor)
-        STOREVALUE(instr.result, engine->runtime.bitXor(VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_bitXor(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(BitXor)
 
     MOTH_BEGIN_INSTR(Shr)
@@ -891,15 +906,15 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(ShlConst)
 
     MOTH_BEGIN_INSTR(Mul)
-        STOREVALUE(instr.result, engine->runtime.mul(VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_mul(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(Mul)
 
     MOTH_BEGIN_INSTR(Sub)
-        STOREVALUE(instr.result, engine->runtime.sub(VALUE(instr.lhs), VALUE(instr.rhs)));
+        STOREVALUE(instr.result, Runtime::method_sub(VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(Sub)
 
     MOTH_BEGIN_INSTR(BinopContext)
-        QV4::Runtime::BinaryOperationContext op = *reinterpret_cast<QV4::Runtime::BinaryOperationContext *>(reinterpret_cast<char *>(&engine->runtime) + instr.alu);
+        QV4::Runtime::BinaryOperationContext op = *reinterpret_cast<QV4::Runtime::BinaryOperationContext *>(reinterpret_cast<char *>(&engine->runtime.runtimeMethods[instr.alu]));
         STOREVALUE(instr.result, op(engine, VALUE(instr.lhs), VALUE(instr.rhs)));
     MOTH_END_INSTR(BinopContext)
 
@@ -915,13 +930,13 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
         if (debugger && debugger->pauseAtNextOpportunity())
             debugger->maybeBreakAtInstruction();
         if (qt_v4IsDebugging)
-            qt_v4CheckForBreak(context, scopes, scopeDepth);
+            qt_v4CheckForBreak(context);
     MOTH_END_INSTR(Debug)
 
     MOTH_BEGIN_INSTR(Line)
         engine->current->lineNumber = instr.lineNumber;
         if (qt_v4IsDebugging)
-            qt_v4CheckForBreak(context, scopes, scopeDepth);
+            qt_v4CheckForBreak(context);
     MOTH_END_INSTR(Line)
 #endif // QT_NO_QML_DEBUGGER
 
@@ -930,15 +945,15 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(LoadThis)
 
     MOTH_BEGIN_INSTR(LoadQmlContext)
-        VALUE(instr.result) = engine->runtime.getQmlContext(static_cast<QV4::NoThrowEngine*>(engine));
+        VALUE(instr.result) = Runtime::method_getQmlContext(static_cast<QV4::NoThrowEngine*>(engine));
     MOTH_END_INSTR(LoadQmlContext)
 
     MOTH_BEGIN_INSTR(LoadQmlImportedScripts)
-        VALUE(instr.result) = engine->runtime.getQmlImportedScripts(static_cast<QV4::NoThrowEngine*>(engine));
+        VALUE(instr.result) = Runtime::method_getQmlImportedScripts(static_cast<QV4::NoThrowEngine*>(engine));
     MOTH_END_INSTR(LoadQmlImportedScripts)
 
     MOTH_BEGIN_INSTR(LoadQmlSingleton)
-        VALUE(instr.result) = engine->runtime.getQmlSingleton(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
+        VALUE(instr.result) = Runtime::method_getQmlSingleton(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
     MOTH_END_INSTR(LoadQmlSingleton)
 
 #ifdef MOTH_THREADED_INTERPRETER
diff --git a/src/qml/memory/memory.pri b/src/qml/memory/memory.pri
index 38fadbf23f..7956e4a9a1 100644
--- a/src/qml/memory/memory.pri
+++ b/src/qml/memory/memory.pri
@@ -7,7 +7,8 @@ SOURCES += \
 
 HEADERS += \
     $$PWD/qv4mm_p.h \
-    $$PWD/qv4mmdefs_p.h
+    $$PWD/qv4mmdefs_p.h \
+    $$PWD/qv4writebarrier_p.h
 }
 
 HEADERS += \
diff --git a/src/qml/memory/qv4heap_p.h b/src/qml/memory/qv4heap_p.h
index 8285ef4de7..a38a938588 100644
--- a/src/qml/memory/qv4heap_p.h
+++ b/src/qml/memory/qv4heap_p.h
@@ -72,6 +72,7 @@ namespace QV4 {
 struct VTable
 {
     const VTable * const parent;
+    const quint64 markTable;
     uint isExecutionContext : 1;
     uint isString : 1;
     uint isObject : 1;
@@ -82,7 +83,7 @@ struct VTable
     uint type : 8;
     const char *className;
     void (*destroy)(Heap::Base *);
-    void (*markObjects)(Heap::Base *, ExecutionEngine *e);
+    void (*markObjects)(Heap::Base *, MarkStack *markStack);
     bool (*isEqualTo)(Managed *m, Managed *other);
 };
 
@@ -91,10 +92,12 @@ namespace Heap {
 struct Q_QML_EXPORT Base {
     void *operator new(size_t) = delete;
 
+    static Q_CONSTEXPR quint64 markTable = 0;
+
     const VTable *vt;
 
     inline ReturnedValue asReturnedValue() const;
-    inline void mark(QV4::ExecutionEngine *engine);
+    inline void mark(QV4::MarkStack *markStack);
 
     void setVtable(const VTable *v) { vt = v; }
     const VTable *vtable() const { return vt; }
@@ -110,6 +113,12 @@ struct Q_QML_EXPORT Base {
         Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase()));
         return Chunk::setBit(c->blackBitmap, h - c->realBase());
     }
+    inline void setGrayBit() {
+        const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
+        Chunk *c = h->chunk();
+        Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase()));
+        return Chunk::setBit(c->grayBitmap, h - c->realBase());
+    }
 
     inline bool inUse() const {
         const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
@@ -118,6 +127,8 @@ struct Q_QML_EXPORT Base {
         return Chunk::testBit(c->objectBitmap, h - c->realBase());
     }
 
+    inline void markChildren(MarkStack *markStack);
+
     void *operator new(size_t, Managed *m) { return m; }
     void *operator new(size_t, Heap::Base *m) { return m; }
     void operator delete(void *, Heap::Base *) {}
@@ -133,7 +144,7 @@ struct Q_QML_EXPORT Base {
         else if (_livenessStatus == Destroyed)
             fprintf(stderr, "ERROR: use of object '%s' after call to destroy() !!\n",
                     vtable()->className);
-        Q_ASSERT(_livenessStatus = Initialized);
+        Q_ASSERT(_livenessStatus == Initialized);
     }
     void _checkIsDestroyed() {
         if (_livenessStatus == Initialized)
@@ -160,20 +171,12 @@ struct Q_QML_EXPORT Base {
 #endif
 };
 V4_ASSERT_IS_TRIVIAL(Base)
-
-template <typename T>
-struct Pointer {
-    T *operator->() const { return ptr; }
-    operator T *() const { return ptr; }
-
-    Pointer &operator =(T *t) { ptr = t; return *this; }
-
-    template <typename Type>
-    Type *cast() { return static_cast<Type *>(ptr); }
-
-    T *ptr;
-};
-V4_ASSERT_IS_TRIVIAL(Pointer<void>)
+// This class needs to consist only of pointer sized members to allow
+// for a size/offset translation when cross-compiling between 32- and
+// 64-bit.
+Q_STATIC_ASSERT(std::is_standard_layout<Base>::value);
+Q_STATIC_ASSERT(offsetof(Base, vt) == 0);
+Q_STATIC_ASSERT(sizeof(Base) == QT_POINTER_SIZE);
 
 }
 
diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index a829e902fb..7c57b93d9b 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -60,7 +60,11 @@
 #include "qv4alloca_p.h"
 #include "qv4profiling_p.h"
 
-#define MM_DEBUG 0
+//#define MM_STATS
+
+#if !defined(MM_STATS) && !defined(QT_NO_DEBUG)
+#define MM_STATS
+#endif
 
 #if MM_DEBUG
 #define DEBUG qDebug() << "MM:"
@@ -113,14 +117,16 @@ struct MemorySegment {
         pageReservation = PageReservation::reserve(size, OSAllocator::JSGCHeapPages);
         base = reinterpret_cast<Chunk *>((reinterpret_cast<quintptr>(pageReservation.base()) + Chunk::ChunkSize - 1) & ~(Chunk::ChunkSize - 1));
         nChunks = NumChunks;
-        if (base != pageReservation.base())
+        availableBytes = size - (reinterpret_cast<quintptr>(base) - reinterpret_cast<quintptr>(pageReservation.base()));
+        if (availableBytes < SegmentSize)
             --nChunks;
     }
     MemorySegment(MemorySegment &&other) {
         qSwap(pageReservation, other.pageReservation);
         qSwap(base, other.base);
-        qSwap(nChunks, other.nChunks);
         qSwap(allocatedMap, other.allocatedMap);
+        qSwap(availableBytes, other.availableBytes);
+        qSwap(nChunks, other.nChunks);
     }
 
     ~MemorySegment() {
@@ -150,7 +156,7 @@ struct MemorySegment {
     void free(Chunk *chunk, size_t size) {
         DEBUG << "freeing chunk" << chunk;
         size_t index = static_cast<size_t>(chunk - base);
-        size_t end = index + (size - 1)/Chunk::ChunkSize + 1;
+        size_t end = qMin(static_cast<size_t>(NumChunks), index + (size - 1)/Chunk::ChunkSize + 1);
         while (index < end) {
             Q_ASSERT(testBit(index));
             clearBit(index);
@@ -169,11 +175,19 @@ struct MemorySegment {
     PageReservation pageReservation;
     Chunk *base = 0;
     quint64 allocatedMap = 0;
+    size_t availableBytes = 0;
     uint nChunks = 0;
 };
 
 Chunk *MemorySegment::allocate(size_t size)
 {
+    if (!allocatedMap && size >= SegmentSize) {
+        // chunk allocated for one huge allocation
+        Q_ASSERT(availableBytes >= size);
+        pageReservation.commit(base, size);
+        allocatedMap = ~static_cast<quintptr>(0);
+        return base;
+    }
     size_t requiredChunks = (size + sizeof(Chunk) - 1)/sizeof(Chunk);
     uint sequence = 0;
     Chunk *candidate = 0;
@@ -246,12 +260,73 @@ void ChunkAllocator::free(Chunk *chunk, size_t size)
 }
 
 
+void Heap::Base::markChildren(MarkStack *markStack)
+{
+    if (vtable()->markObjects)
+        vtable()->markObjects(this, markStack);
+    if (quint64 m = vtable()->markTable) {
+//            qDebug() << "using mark table:" << hex << m << "for" << h;
+        void **mem = reinterpret_cast<void **>(this);
+        while (m) {
+            MarkFlags mark = static_cast<MarkFlags>(m & 3);
+            switch (mark) {
+            case Mark_NoMark:
+                break;
+            case Mark_Value:
+//                    qDebug() << "marking value at " << mem;
+                reinterpret_cast<Value *>(mem)->mark(markStack);
+                break;
+            case Mark_Pointer: {
+//                    qDebug() << "marking pointer at " << mem;
+                Heap::Base *p = *reinterpret_cast<Heap::Base **>(mem);
+                if (p)
+                    p->mark(markStack);
+                break;
+            }
+            case Mark_ValueArray: {
+                Q_ASSERT(m == Mark_ValueArray);
+//                    qDebug() << "marking Value Array at offset" << hex << (mem - reinterpret_cast<void **>(h));
+                ValueArray<0> *a = reinterpret_cast<ValueArray<0> *>(mem);
+                Value *v = a->values;
+                const Value *end = v + a->alloc;
+                if (a->alloc > 32*1024) {
+                    // drain from time to time to avoid overflows in the js stack
+                    Heap::Base **currentBase = markStack->top;
+                    while (v < end) {
+                        v->mark(markStack);
+                        ++v;
+                        if (markStack->top >= currentBase + 32*1024) {
+                            Heap::Base **oldBase = markStack->base;
+                            markStack->base = currentBase;
+                            markStack->drain();
+                            markStack->base = oldBase;
+                        }
+                    }
+                } else {
+                    while (v < end) {
+                        v->mark(markStack);
+                        ++v;
+                    }
+                }
+                break;
+            }
+            }
+
+            m >>= 2;
+            ++mem;
+        }
+    }
+}
+
+
 void Chunk::sweep()
 {
     //    DEBUG << "sweeping chunk" << this << (*freeList);
     HeapItem *o = realBase();
     for (uint i = 0; i < Chunk::EntriesInBitmap; ++i) {
+#if WRITEBARRIER(none)
         Q_ASSERT((grayBitmap[i] | blackBitmap[i]) == blackBitmap[i]); // check that we don't have gray only objects
+#endif
         quintptr toFree = objectBitmap[i] ^ blackBitmap[i];
         Q_ASSERT((toFree & objectBitmap[i]) == toFree); // check all black objects are marked as being used
         quintptr e = extendsBitmap[i];
@@ -280,7 +355,7 @@ void Chunk::sweep()
             }
         }
         objectBitmap[i] = blackBitmap[i];
-        blackBitmap[i] = 0;
+        grayBitmap[i] = 0;
         extendsBitmap[i] = e;
         o += Chunk::Bits;
     }
@@ -319,13 +394,56 @@ void Chunk::freeAll()
             }
         }
         objectBitmap[i] = 0;
-        blackBitmap[i] = 0;
+        grayBitmap[i] = 0;
         extendsBitmap[i] = e;
         o += Chunk::Bits;
     }
     //    DEBUG << "swept chunk" << this << "freed" << slotsFreed << "slots.";
 }
 
+void Chunk::resetBlackBits()
+{
+    memset(blackBitmap, 0, sizeof(blackBitmap));
+}
+
+#ifdef MM_STATS
+static uint nGrayItems = 0;
+#endif
+
+void Chunk::collectGrayItems(MarkStack *markStack)
+{
+    //    DEBUG << "sweeping chunk" << this << (*freeList);
+    HeapItem *o = realBase();
+    for (uint i = 0; i < Chunk::EntriesInBitmap; ++i) {
+#if WRITEBARRIER(none)
+        Q_ASSERT((grayBitmap[i] | blackBitmap[i]) == blackBitmap[i]); // check that we don't have gray only objects
+#endif
+        quintptr toMark = blackBitmap[i] & grayBitmap[i]; // correct for a Steele type barrier
+        Q_ASSERT((toMark & objectBitmap[i]) == toMark); // check all black objects are marked as being used
+        //        DEBUG << hex << "   index=" << i << toFree;
+        while (toMark) {
+            uint index = qCountTrailingZeroBits(toMark);
+            quintptr bit = (static_cast<quintptr>(1) << index);
+
+            toMark ^= bit; // mask out marked slot
+            //            DEBUG << "       index" << hex << index << toFree;
+
+            HeapItem *itemToFree = o + index;
+            Heap::Base *b = *itemToFree;
+            Q_ASSERT(b->inUse());
+            markStack->push(b);
+#ifdef MM_STATS
+            ++nGrayItems;
+//            qDebug() << "adding gray item" << b << "to mark stack";
+#endif
+        }
+        grayBitmap[i] = 0;
+        o += Chunk::Bits;
+    }
+    //    DEBUG << "swept chunk" << this << "freed" << slotsFreed << "slots.";
+
+}
+
 void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
 {
 //    qDebug() << "sortIntoBins:";
@@ -335,7 +453,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
 #else
     const int start = 1;
 #endif
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
     uint freeSlots = 0;
     uint allocatedSlots = 0;
 #endif
@@ -345,7 +463,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
         if (!i)
             usedSlots |= (static_cast<quintptr>(1) << (HeaderSize/SlotSize)) - 1;
 #endif
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
         allocatedSlots += qPopulationCount(usedSlots);
 //        qDebug() << hex << "   i=" << i << "used=" << usedSlots;
 #endif
@@ -362,7 +480,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
                     break;
                 }
                 usedSlots = (objectBitmap[i]|extendsBitmap[i]);
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
                 allocatedSlots += qPopulationCount(usedSlots);
 //                qDebug() << hex << "   i=" << i << "used=" << usedSlots;
 #endif
@@ -373,7 +491,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
             usedSlots |= (quintptr(1) << index) - 1;
             uint freeEnd = i*Bits + index;
             uint nSlots = freeEnd - freeStart;
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
 //            qDebug() << hex << "   got free slots from" << freeStart << "to" << freeEnd << "n=" << nSlots << "usedSlots=" << usedSlots;
             freeSlots += nSlots;
 #endif
@@ -384,7 +502,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
             bins[bin] = freeItem;
         }
     }
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
     Q_ASSERT(freeSlots + allocatedSlots == (EntriesInBitmap - start) * 8 * sizeof(quintptr));
 #endif
 }
@@ -555,6 +673,19 @@ void BlockAllocator::freeAll()
     }
 }
 
+void BlockAllocator::resetBlackBits()
+{
+    for (auto c : chunks)
+        c->resetBlackBits();
+}
+
+void BlockAllocator::collectGrayItems(MarkStack *markStack)
+{
+    for (auto c : chunks)
+        c->collectGrayItems(markStack);
+
+}
+
 #if MM_DEBUG
 void BlockAllocator::stats() {
     DEBUG << "MM stats:";
@@ -607,7 +738,6 @@ static void freeHugeChunk(ChunkAllocator *chunkAllocator, const HugeItemAllocato
 void HugeItemAllocator::sweep() {
     auto isBlack = [this] (const HugeChunk &c) {
         bool b = c.chunk->first()->isBlack();
-        Chunk::clearBit(c.chunk->blackBitmap, c.chunk->first() - c.chunk->realBase());
         if (!b)
             freeHugeChunk(chunkAllocator, c);
         return !b;
@@ -617,6 +747,24 @@ void HugeItemAllocator::sweep() {
     chunks.erase(newEnd, chunks.end());
 }
 
+void HugeItemAllocator::resetBlackBits()
+{
+    for (auto c : chunks)
+        Chunk::clearBit(c.chunk->blackBitmap, c.chunk->first() - c.chunk->realBase());
+}
+
+void HugeItemAllocator::collectGrayItems(MarkStack *markStack)
+{
+    for (auto c : chunks)
+        // Correct for a Steele type barrier
+        if (Chunk::testBit(c.chunk->blackBitmap, c.chunk->first() - c.chunk->realBase()) &&
+            Chunk::testBit(c.chunk->grayBitmap, c.chunk->first() - c.chunk->realBase())) {
+            HeapItem *i = c.chunk->first();
+            Heap::Base *b = *i;
+            b->mark(markStack);
+        }
+}
+
 void HugeItemAllocator::freeAll()
 {
     for (auto &c : chunks) {
@@ -642,15 +790,17 @@ MemoryManager::MemoryManager(ExecutionEngine *engine)
 #endif
 }
 
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
+static int allocationCount = 0;
 static size_t lastAllocRequestedSlots = 0;
 #endif
 
 Heap::Base *MemoryManager::allocString(std::size_t unmanagedSize)
 {
     const size_t stringSize = align(sizeof(Heap::String));
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
     lastAllocRequestedSlots = stringSize >> Chunk::SlotSizeShift;
+    ++allocationCount;
 #endif
 
     bool didGCRun = false;
@@ -661,7 +811,8 @@ Heap::Base *MemoryManager::allocString(std::size_t unmanagedSize)
 
     unmanagedHeapSize += unmanagedSize;
     if (unmanagedHeapSize > unmanagedHeapSizeGCLimit) {
-        runGC();
+        if (!didGCRun)
+            runGC();
 
         if (3*unmanagedHeapSizeGCLimit <= 4*unmanagedHeapSize)
             // more than 75% full, raise limit
@@ -679,14 +830,16 @@ Heap::Base *MemoryManager::allocString(std::size_t unmanagedSize)
         m = blockAllocator.allocate(stringSize, true);
     }
 
+//    qDebug() << "allocated string" << m;
     memset(m, 0, stringSize);
     return *m;
 }
 
 Heap::Base *MemoryManager::allocData(std::size_t size)
 {
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
     lastAllocRequestedSlots = size >> Chunk::SlotSizeShift;
+    ++allocationCount;
 #endif
 
     bool didRunGC = false;
@@ -703,8 +856,11 @@ Heap::Base *MemoryManager::allocData(std::size_t size)
 
 //    qDebug() << "unmanagedHeapSize:" << unmanagedHeapSize << "limit:" << unmanagedHeapSizeGCLimit << "unmanagedSize:" << unmanagedSize;
 
-    if (size > Chunk::DataSize)
-        return *hugeItemAllocator.allocate(size);
+    if (size > Chunk::DataSize) {
+        HeapItem *h = hugeItemAllocator.allocate(size);
+//        qDebug() << "allocating huge item" << h;
+        return *h;
+    }
 
     HeapItem *m = blockAllocator.allocate(size);
     if (!m) {
@@ -714,51 +870,77 @@ Heap::Base *MemoryManager::allocData(std::size_t size)
     }
 
     memset(m, 0, size);
+//    qDebug() << "allocating data" << m;
     return *m;
 }
 
 Heap::Object *MemoryManager::allocObjectWithMemberData(std::size_t size, uint nMembers)
 {
-    Heap::Object *o = static_cast<Heap::Object *>(allocData(size));
-
-    // ### Could optimize this and allocate both in one go through the block allocator
-    if (nMembers) {
+    Heap::Object *o;
+    if (!nMembers) {
+        o = static_cast<Heap::Object *>(allocData(size));
+    } else {
+        // Allocate both in one go through the block allocator
         std::size_t memberSize = align(sizeof(Heap::MemberData) + (nMembers - 1)*sizeof(Value));
-//        qDebug() << "allocating member data for" << o << nMembers << memberSize;
-        Heap::Base *m;
-        if (memberSize > Chunk::DataSize)
-            m = *hugeItemAllocator.allocate(memberSize);
-        else
-            m = *blockAllocator.allocate(memberSize, true);
-        memset(m, 0, memberSize);
-        o->memberData = static_cast<Heap::MemberData *>(m);
-        o->memberData->setVtable(MemberData::staticVTable());
-        o->memberData->size = static_cast<uint>((memberSize - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
-        o->memberData->init();
+        size_t totalSize = size + memberSize;
+        Heap::MemberData *m;
+        if (totalSize > Chunk::DataSize) {
+            o = static_cast<Heap::Object *>(allocData(size));
+            m = hugeItemAllocator.allocate(memberSize)->as<Heap::MemberData>();
+        } else {
+            HeapItem *mh = reinterpret_cast<HeapItem *>(allocData(totalSize));
+            Heap::Base *b = *mh;
+            o = static_cast<Heap::Object *>(b);
+            mh += (size >> Chunk::SlotSizeShift);
+            m = mh->as<Heap::MemberData>();
+            Chunk *c = mh->chunk();
+            size_t index = mh - c->realBase();
+            Chunk::setBit(c->objectBitmap, index);
+            Chunk::clearBit(c->extendsBitmap, index);
+        }
+        o->memberData.set(engine, m);
+        m->setVtable(MemberData::staticVTable());
+        m->values.alloc = static_cast<uint>((memberSize - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
+        m->values.size = o->memberData->values.alloc;
+        m->init();
 //        qDebug() << "    got" << o->memberData << o->memberData->size;
     }
+//    qDebug() << "allocating object with memberData" << o << o->memberData.operator->();
     return o;
 }
 
-static void drainMarkStack(QV4::ExecutionEngine *engine, Value *markBase)
+static uint markStackSize = 0;
+
+MarkStack::MarkStack(ExecutionEngine *engine)
+    : engine(engine)
+{
+    base = (Heap::Base **)engine->gcStack->base();
+    top = base;
+    limit = base + ExecutionEngine::GCStackLimit/sizeof(Heap::Base)*3/4;
+}
+
+void MarkStack::drain()
 {
-    while (engine->jsStackTop > markBase) {
-        Heap::Base *h = engine->popForGC();
+    while (top > base) {
+        Heap::Base *h = pop();
+        ++markStackSize;
         Q_ASSERT(h); // at this point we should only have Heap::Base objects in this area on the stack. If not, weird things might happen.
-        Q_ASSERT (h->vtable()->markObjects);
-        h->vtable()->markObjects(h, engine);
+        h->markChildren(this);
     }
 }
 
-void MemoryManager::mark()
+void MemoryManager::collectRoots(MarkStack *markStack)
 {
-    Value *markBase = engine->jsStackTop;
+    engine->markObjects(markStack);
+
+//    qDebug() << "   mark stack after engine->mark" << (engine->jsStackTop - markBase);
 
-    engine->markObjects();
+    collectFromJSStack(markStack);
 
-    collectFromJSStack();
+//    qDebug() << "   mark stack after js stack collect" << (engine->jsStackTop - markBase);
+    m_persistentValues->mark(markStack);
 
-    m_persistentValues->mark(engine);
+//    qDebug() << "   mark stack after persistants" << (engine->jsStackTop - markBase);
 
     // Preserve QObject ownership rules within JavaScript: A parent with c++ ownership
     // keeps all of its children alive in JavaScript.
@@ -785,13 +967,21 @@ void MemoryManager::mark()
         }
 
         if (keepAlive)
-            qobjectWrapper->mark(engine);
+            qobjectWrapper->mark(markStack);
 
-        if (engine->jsStackTop >= engine->jsStackLimit)
-            drainMarkStack(engine, markBase);
+        if (markStack->top >= markStack->limit)
+            markStack->drain();
     }
+}
+
+void MemoryManager::mark()
+{
+    markStackSize = 0;
 
-    drainMarkStack(engine, markBase);
+    MarkStack markStack(engine);
+    collectRoots(&markStack);
+
+    markStack.drain();
 }
 
 void MemoryManager::sweep(bool lastSweep)
@@ -848,31 +1038,30 @@ void MemoryManager::sweep(bool lastSweep)
 bool MemoryManager::shouldRunGC() const
 {
     size_t total = blockAllocator.totalSlots();
-    size_t usedSlots = blockAllocator.usedSlotsAfterLastSweep;
-    if (total > MinSlotsGCLimit && usedSlots * GCOverallocation < total * 100)
+    if (total > MinSlotsGCLimit && usedSlotsAfterLastFullSweep * GCOverallocation < total * 100)
         return true;
     return false;
 }
 
 size_t dumpBins(BlockAllocator *b, bool printOutput = true)
 {
-    size_t totalFragmentedSlots = 0;
+    size_t totalSlotMem = 0;
     if (printOutput)
-        qDebug() << "Fragmentation map:";
+        qDebug() << "Slot map:";
     for (uint i = 0; i < BlockAllocator::NumBins; ++i) {
         uint nEntries = 0;
         HeapItem *h = b->freeBins[i];
         while (h) {
             ++nEntries;
-            totalFragmentedSlots += h->freeData.availableSlots;
+            totalSlotMem += h->freeData.availableSlots;
             h = h->freeData.next;
         }
         if (printOutput)
             qDebug() << "    number of entries in slot" << i << ":" << nEntries;
     }
     if (printOutput)
-        qDebug() << "  total mem in bins" << totalFragmentedSlots*Chunk::SlotSize;
-    return totalFragmentedSlots*Chunk::SlotSize;
+        qDebug() << "  total mem in bins" << totalSlotMem*Chunk::SlotSize;
+    return totalSlotMem*Chunk::SlotSize;
 }
 
 void MemoryManager::runGC()
@@ -883,6 +1072,7 @@ void MemoryManager::runGC()
     }
 
     QScopedValueRollback<bool> gcBlocker(gcBlocked, true);
+//    qDebug() << "runGC";
 
     if (!gcStats) {
 //        uint oldUsed = allocator.usedMem();
@@ -897,21 +1087,28 @@ void MemoryManager::runGC()
         const size_t largeItemsBefore = getLargeItemsMem();
 
         qDebug() << "========== GC ==========";
-#ifndef QT_NO_DEBUG
+#ifdef MM_STATS
         qDebug() << "    Triggered by alloc request of" << lastAllocRequestedSlots << "slots.";
+        qDebug() << "    Allocations since last GC" << allocationCount;
+        allocationCount = 0;
 #endif
         qDebug() << "Allocated" << totalMem << "bytes in" << blockAllocator.chunks.size() << "chunks";
         qDebug() << "Fragmented memory before GC" << (totalMem - usedBefore);
         dumpBins(&blockAllocator);
 
+#ifdef MM_STATS
+        nGrayItems = 0;
+#endif
+
         QElapsedTimer t;
         t.start();
         mark();
-        qint64 markTime = t.restart();
+        qint64 markTime = t.nsecsElapsed()/1000;
+        t.restart();
         sweep();
         const size_t usedAfter = getUsedMem();
         const size_t largeItemsAfter = getLargeItemsMem();
-        qint64 sweepTime = t.elapsed();
+        qint64 sweepTime = t.nsecsElapsed()/1000;
 
         if (triggeredByUnmanagedHeap) {
             qDebug() << "triggered by unmanaged heap:";
@@ -920,11 +1117,12 @@ void MemoryManager::runGC()
             qDebug() << "   unmanaged heap limit:" << unmanagedHeapSizeGCLimit;
         }
         size_t memInBins = dumpBins(&blockAllocator);
-        qDebug() << "Marked object in" << markTime << "ms.";
-        qDebug() << "Sweeped object in" << sweepTime << "ms.";
+        qDebug() << "Marked object in" << markTime << "us.";
+        qDebug() << "   " << markStackSize << "objects marked";
+        qDebug() << "Sweeped object in" << sweepTime << "us.";
         qDebug() << "Used memory before GC:" << usedBefore;
-        qDebug() << "Used memory after GC:" << usedAfter;
-        qDebug() << "Freed up bytes:" << (usedBefore - usedAfter);
+        qDebug() << "Used memory after GC :" << usedAfter;
+        qDebug() << "Freed up bytes       :" << (usedBefore - usedAfter);
         size_t lost = blockAllocator.allocatedMem() - memInBins - usedAfter;
         if (lost)
             qDebug() << "!!!!!!!!!!!!!!!!!!!!! LOST MEM:" << lost << "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!";
@@ -940,6 +1138,12 @@ void MemoryManager::runGC()
         // ensure we don't 'loose' any memory
         Q_ASSERT(blockAllocator.allocatedMem() == getUsedMem() + dumpBins(&blockAllocator, false));
     }
+
+    usedSlotsAfterLastFullSweep = blockAllocator.usedSlotsAfterLastSweep;
+
+    // reset all black bits
+    blockAllocator.resetBlackBits();
+    hugeItemAllocator.resetBlackBits();
 }
 
 size_t MemoryManager::getUsedMem() const
@@ -1000,7 +1204,7 @@ void MemoryManager::willAllocate(std::size_t size)
 
 #endif // DETAILED_MM_STATS
 
-void MemoryManager::collectFromJSStack() const
+void MemoryManager::collectFromJSStack(MarkStack *markStack) const
 {
     Value *v = engine->jsStackBase;
     Value *top = engine->jsStackTop;
@@ -1008,7 +1212,7 @@ void MemoryManager::collectFromJSStack() const
         Managed *m = v->managed();
         if (m && m->inUse())
             // Skip pointers to already freed objects, they are bogus as well
-            m->mark(engine);
+            m->mark(markStack);
         ++v;
     }
 }
diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index 00daf8a622..76ffec42de 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -80,27 +80,28 @@ struct StackAllocator {
     StackAllocator(ChunkAllocator *chunkAlloc);
 
     T *allocate() {
-        T *m = nextFree->as<T>();
+        HeapItem *m = nextFree;
         if (Q_UNLIKELY(nextFree == lastInChunk)) {
             nextChunk();
         } else {
             nextFree += requiredSlots;
         }
-#if MM_DEBUG
+#if MM_DEBUG || !defined(QT_NO_DEBUG)
         Chunk *c = m->chunk();
         Chunk::setBit(c->objectBitmap, m - c->realBase());
 #endif
-        return m;
+        return m->as<T>();
     }
     void free() {
-#if MM_DEBUG
-        Chunk::clearBit(item->chunk()->objectBitmap, item - item->chunk()->realBase());
-#endif
         if (Q_UNLIKELY(nextFree == firstInChunk)) {
             prevChunk();
         } else {
             nextFree -= requiredSlots;
         }
+#if MM_DEBUG || !defined(QT_NO_DEBUG)
+        Chunk *c = nextFree->chunk();
+        Chunk::clearBit(c->objectBitmap, nextFree - c->realBase());
+#endif
     }
 
     void nextChunk();
@@ -154,6 +155,8 @@ struct BlockAllocator {
 
     void sweep();
     void freeAll();
+    void resetBlackBits();
+    void collectGrayItems(MarkStack *markStack);
 
     // bump allocations
     HeapItem *nextFree = 0;
@@ -175,6 +178,8 @@ struct HugeItemAllocator {
     HeapItem *allocate(size_t size);
     void sweep();
     void freeAll();
+    void resetBlackBits();
+    void collectGrayItems(MarkStack *markStack);
 
     size_t usedMem() const {
         size_t used = 0;
@@ -206,11 +211,11 @@ public:
     Q_DECL_CONSTEXPR static inline std::size_t align(std::size_t size)
     { return (size + Chunk::SlotSize - 1) & ~(Chunk::SlotSize - 1); }
 
-    QV4::Heap::CallContext *allocSimpleCallContext(QV4::ExecutionEngine *v4)
+    QV4::Heap::SimpleCallContext *allocSimpleCallContext(QV4::ExecutionEngine *v4)
     {
         Heap::CallContext *ctxt = stackAllocator.allocate();
-        memset(ctxt, 0, sizeof(Heap::CallContext));
-        ctxt->setVtable(QV4::CallContext::staticVTable());
+        memset(ctxt, 0, sizeof(Heap::SimpleCallContext));
+        ctxt->setVtable(QV4::SimpleCallContext::staticVTable());
         ctxt->init(v4);
         return ctxt;
 
@@ -245,7 +250,7 @@ public:
         o->setVtable(ObjectType::staticVTable());
         Object *prototype = ObjectType::defaultPrototype(engine);
         o->internalClass = ic;
-        o->prototype = prototype->d();
+        o->prototype.set(engine, prototype->d());
         return static_cast<typename ObjectType::Data *>(o);
     }
 
@@ -272,7 +277,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init();
         return t->d();
     }
@@ -282,7 +287,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1);
         return t->d();
     }
@@ -292,7 +297,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2);
         return t->d();
     }
@@ -302,7 +307,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2, arg3);
         return t->d();
     }
@@ -312,7 +317,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2, arg3, arg4);
         return t->d();
     }
@@ -428,7 +433,6 @@ public:
     // called when a JS object grows itself. Specifically: Heap::String::append
     void changeUnmanagedHeapSizeUsage(qptrdiff delta) { unmanagedHeapSize += delta; }
 
-
 protected:
     /// expects size to be aligned
     Heap::Base *allocString(std::size_t unmanagedSize);
@@ -440,10 +444,11 @@ protected:
 #endif // DETAILED_MM_STATS
 
 private:
-    void collectFromJSStack() const;
+    void collectFromJSStack(MarkStack *markStack) const;
     void mark();
     void sweep(bool lastSweep = false);
     bool shouldRunGC() const;
+    void collectRoots(MarkStack *markStack);
 
 public:
     QV4::ExecutionEngine *engine;
@@ -457,6 +462,7 @@ public:
 
     std::size_t unmanagedHeapSize = 0; // the amount of bytes of heap that is not managed by the memory manager, but which is held onto by managed items.
     std::size_t unmanagedHeapSizeGCLimit;
+    std::size_t usedSlotsAfterLastFullSweep = 0;
 
     bool gcBlocked = false;
     bool aggressiveGC = false;
diff --git a/src/qml/memory/qv4mmdefs_p.h b/src/qml/memory/qv4mmdefs_p.h
index 588ae21ee0..9512722782 100644
--- a/src/qml/memory/qv4mmdefs_p.h
+++ b/src/qml/memory/qv4mmdefs_p.h
@@ -51,6 +51,7 @@
 //
 
 #include <private/qv4global_p.h>
+#include <private/qv4runtimeapi_p.h>
 #include <QtCore/qalgorithms.h>
 #include <qdebug.h>
 
@@ -58,6 +59,8 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
+struct MarkStack;
+
 /*
  * Chunks are the basic structure containing GC managed objects.
  *
@@ -111,22 +114,29 @@ struct Chunk {
     HeapItem *realBase();
     HeapItem *first();
 
+    static Q_ALWAYS_INLINE size_t bitmapIndex(size_t index) {
+        return index >> BitShift;
+    }
+    static Q_ALWAYS_INLINE quintptr bitForIndex(size_t index) {
+        return static_cast<quintptr>(1) << (index & (Bits - 1));
+    }
+
     static void setBit(quintptr *bitmap, size_t index) {
 //        Q_ASSERT(index >= HeaderSize/SlotSize && index < ChunkSize/SlotSize);
-        bitmap += index >> BitShift;
-        quintptr bit = static_cast<quintptr>(1) << (index & (Bits - 1));
+        bitmap += bitmapIndex(index);
+        quintptr bit = bitForIndex(index);
         *bitmap |= bit;
     }
     static void clearBit(quintptr *bitmap, size_t index) {
 //        Q_ASSERT(index >= HeaderSize/SlotSize && index < ChunkSize/SlotSize);
-        bitmap += index >> BitShift;
-        quintptr bit = static_cast<quintptr>(1) << (index & (Bits - 1));
+        bitmap += bitmapIndex(index);
+        quintptr bit = bitForIndex(index);
         *bitmap &= ~bit;
     }
     static bool testBit(quintptr *bitmap, size_t index) {
 //        Q_ASSERT(index >= HeaderSize/SlotSize && index < ChunkSize/SlotSize);
-        bitmap += index >> BitShift;
-        quintptr bit = static_cast<quintptr>(1) << (index & (Bits - 1));
+        bitmap += bitmapIndex(index);
+        quintptr bit = bitForIndex(index);
         return (*bitmap & bit);
     }
     static void setBits(quintptr *bitmap, size_t index, size_t nBits) {
@@ -176,6 +186,8 @@ struct Chunk {
 
     void sweep();
     void freeAll();
+    void resetBlackBits();
+    void collectGrayItems(QV4::MarkStack *markStack);
 
     void sortIntoBins(HeapItem **bins, uint nBins);
 };
@@ -255,6 +267,120 @@ Q_STATIC_ASSERT(sizeof(HeapItem) == Chunk::SlotSize);
 Q_STATIC_ASSERT(QT_POINTER_SIZE*8 == Chunk::Bits);
 Q_STATIC_ASSERT((1 << Chunk::BitShift) == Chunk::Bits);
 
+struct MarkStack {\
+    MarkStack(ExecutionEngine *engine);
+    Heap::Base **top = 0;
+    Heap::Base **base = 0;
+    Heap::Base **limit = 0;
+    ExecutionEngine *engine;
+    void push(Heap::Base *m) {
+        *top = m;
+        ++top;
+    }
+    Heap::Base *pop() {
+        --top;
+        return *top;
+    }
+    void drain();
+
+};
+
+// Base class for the execution engine
+
+#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
+#pragma pack(push, 1)
+#endif
+struct EngineBase {
+    Heap::ExecutionContext *current = 0;
+
+    Value *jsStackTop = 0;
+    quint8 hasException = false;
+    quint8 writeBarrierActive = false;
+    quint16 unused = 0;
+#if QT_POINTER_SIZE == 8
+    quint8 padding[4];
+#endif
+    MemoryManager *memoryManager = 0;
+    Runtime runtime;
+};
+#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
+#pragma pack(pop)
+#endif
+
+Q_STATIC_ASSERT(std::is_standard_layout<EngineBase>::value);
+Q_STATIC_ASSERT(offsetof(EngineBase, current) == 0);
+Q_STATIC_ASSERT(offsetof(EngineBase, jsStackTop) == offsetof(EngineBase, current) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(EngineBase, hasException) == offsetof(EngineBase, jsStackTop) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(EngineBase, memoryManager) == offsetof(EngineBase, hasException) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(EngineBase, runtime) == offsetof(EngineBase, memoryManager) + QT_POINTER_SIZE);
+
+// Some helper classes and macros to automate the generation of our
+// tables used for marking objects
+
+enum MarkFlags {
+    Mark_NoMark = 0,
+    Mark_Value = 1,
+    Mark_Pointer = 2,
+    Mark_ValueArray = 3
+};
+
+template <typename T>
+struct MarkFlagEvaluator {
+    static Q_CONSTEXPR quint64 value = 0;
+};
+template <typename T, size_t o>
+struct MarkFlagEvaluator<Heap::Pointer<T, o>> {
+    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_Pointer) << (2*o / sizeof(quintptr));
+};
+template <size_t o>
+struct MarkFlagEvaluator<ValueArray<o>> {
+    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_ValueArray) << (2*o / sizeof(quintptr));
+};
+template <size_t o>
+struct MarkFlagEvaluator<HeapValue<o>> {
+    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_Value) << (2 *o / sizeof(quintptr));
+};
+
+#define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION(c, gcType, type, name) \
+    HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_##gcType(c, type, name)
+
+#define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_Pointer(c, type, name) Pointer<type, 0> name;
+#define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_NoMark(c, type, name) type name;
+#define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_HeapValue(c, type, name) HeapValue<0> name;
+#define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_ValueArray(c, type, name) type<0> name;
+
+#define HEAP_OBJECT_MEMBER_EXPANSION(c, gcType, type, name) \
+    HEAP_OBJECT_MEMBER_EXPANSION_##gcType(c, type, name)
+
+#define HEAP_OBJECT_MEMBER_EXPANSION_Pointer(c, type, name) \
+    Pointer<type, offsetof(c##OffsetStruct, name) + baseOffset> name;
+#define HEAP_OBJECT_MEMBER_EXPANSION_NoMark(c, type, name) \
+    type name;
+#define HEAP_OBJECT_MEMBER_EXPANSION_HeapValue(c, type, name) \
+    HeapValue<offsetof(c##OffsetStruct, name) + baseOffset> name;
+#define HEAP_OBJECT_MEMBER_EXPANSION_ValueArray(c, type, name) \
+    type<offsetof(c##OffsetStruct, name) + baseOffset> name;
+
+#define HEAP_OBJECT_MARK_EXPANSION(class, gcType, type, name) \
+    MarkFlagEvaluator<decltype(class::name)>::value |
+
+#define DECLARE_HEAP_OBJECT(name, base) \
+struct name##OffsetStruct { \
+    name##Members(name, HEAP_OBJECT_OFFSET_MEMBER_EXPANSION) \
+}; \
+struct name##SizeStruct : base, name##OffsetStruct {}; \
+struct name##Data { \
+    static Q_CONSTEXPR size_t baseOffset = sizeof(name##SizeStruct) - sizeof(name##OffsetStruct); \
+    name##Members(name, HEAP_OBJECT_MEMBER_EXPANSION) \
+}; \
+Q_STATIC_ASSERT(sizeof(name##SizeStruct) == sizeof(name##Data) + name##Data::baseOffset); \
+static Q_CONSTEXPR quint64 name##_markTable = \
+    (name##Members(name##Data, HEAP_OBJECT_MARK_EXPANSION) 0) | QV4::Heap::base::markTable; \
+    \
+struct name : base, name##Data
+
+#define DECLARE_MARK_TABLE(class) static Q_CONSTEXPR quint64 markTable = class##_markTable
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/memory/qv4writebarrier_p.h b/src/qml/memory/qv4writebarrier_p.h
new file mode 100644
index 0000000000..e36ea0749a
--- /dev/null
+++ b/src/qml/memory/qv4writebarrier_p.h
@@ -0,0 +1,203 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4WRITEBARRIER_P_H
+#define QV4WRITEBARRIER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+#include <private/qv4value_p.h>
+
+QT_BEGIN_NAMESPACE
+
+#define WRITEBARRIER_none 1
+
+#define WRITEBARRIER(x) (1/WRITEBARRIER_##x == 1)
+
+namespace QV4 {
+
+namespace WriteBarrier {
+
+enum Type {
+    NoBarrier,
+    Barrier
+};
+
+enum NewValueType {
+    Primitive,
+    Object,
+    Unknown
+};
+
+// ### this needs to be filled with a real memory fence once marking is concurrent
+Q_ALWAYS_INLINE void fence() {}
+
+#if WRITEBARRIER(none)
+
+template <NewValueType type>
+static Q_CONSTEXPR inline bool isRequired() {
+    return false;
+}
+
+inline void write(EngineBase *engine, Heap::Base *base, Value *slot, Value value)
+{
+    Q_UNUSED(engine);
+    Q_UNUSED(base);
+    *slot = value;
+}
+
+inline void write(EngineBase *engine, Heap::Base *base, Value *slot, Heap::Base *value)
+{
+    Q_UNUSED(engine);
+    Q_UNUSED(base);
+    *slot = value;
+}
+
+inline void write(EngineBase *engine, Heap::Base *base, Heap::Base **slot, Heap::Base *value)
+{
+    Q_UNUSED(engine);
+    Q_UNUSED(base);
+    *slot = value;
+}
+
+#endif
+
+}
+
+namespace Heap {
+
+template <typename T, size_t o>
+struct Pointer {
+    static Q_CONSTEXPR size_t offset = o;
+    T operator->() const { return ptr; }
+    operator T () const { return ptr; }
+
+    Heap::Base *base() {
+        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
+        Q_ASSERT(base->inUse());
+        return base;
+    }
+
+    void set(ExecutionEngine *e, T newVal) {
+        WriteBarrier::write(e, base(), reinterpret_cast<Heap::Base **>(&ptr), reinterpret_cast<Heap::Base *>(newVal));
+    }
+
+    template <typename Type>
+    Type *cast() { return static_cast<Type *>(ptr); }
+
+private:
+    T ptr;
+};
+typedef Pointer<char *, 0> V4PointerCheck;
+V4_ASSERT_IS_TRIVIAL(V4PointerCheck)
+
+}
+
+template <size_t offset>
+struct HeapValue : Value {
+    Heap::Base *base() {
+        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
+        Q_ASSERT(base->inUse());
+        return base;
+    }
+
+    void set(ExecutionEngine *e, const Value &newVal) {
+        WriteBarrier::write(e, base(), this, newVal);
+    }
+};
+
+template <size_t offset>
+struct ValueArray {
+    uint size;
+    uint alloc;
+    Value values[1];
+
+    Heap::Base *base() {
+        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
+        Q_ASSERT(base->inUse());
+        return base;
+    }
+
+    void set(ExecutionEngine *e, uint index, Value v) {
+        WriteBarrier::write(e, base(), values + index, v);
+    }
+    void set(ExecutionEngine *e, uint index, Heap::Base *b) {
+        WriteBarrier::write(e, base(), values + index, b);
+    }
+    inline const Value &operator[] (uint index) const {
+        Q_ASSERT(index < alloc);
+        return values[index];
+    }
+    inline const Value *data() const {
+        return values;
+    }
+
+    void insertData(ExecutionEngine *e, uint index, Value v) {
+        for (uint i = size - 1; i > index; --i) {
+            values[i] = values[i - 1];
+        }
+        set(e, index, v);
+    }
+    void removeData(ExecutionEngine *e, uint index, int n = 1) {
+        Q_UNUSED(e);
+        for (uint i = index; i < size - n; ++i) {
+            values[i] = values[i + n];
+        }
+    }
+};
+
+// It's really important that the offset of values in this structure is
+// constant across all architecture,  otherwise JIT cross-compiled code will
+// have wrong offsets between host and target.
+Q_STATIC_ASSERT(offsetof(ValueArray<0>, values) == 8);
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/parser/qqmljsglobal_p.h b/src/qml/parser/qqmljsglobal_p.h
index 933c8f5202..0e195994b4 100644
--- a/src/qml/parser/qqmljsglobal_p.h
+++ b/src/qml/parser/qqmljsglobal_p.h
@@ -67,13 +67,17 @@
 #else // !QT_CREATOR
 #  define QT_QML_BEGIN_NAMESPACE QT_BEGIN_NAMESPACE
 #  define QT_QML_END_NAMESPACE QT_END_NAMESPACE
-#  if defined(QT_BUILD_QMLDEVTOOLS_LIB) || defined(QT_QMLDEVTOOLS_LIB)
-     // QmlDevTools is a static library
-#    define QML_PARSER_EXPORT
-#  elif defined(QT_BUILD_QML_LIB)
-#    define QML_PARSER_EXPORT Q_DECL_EXPORT
+#  ifndef QT_STATIC
+#    if defined(QT_BUILD_QMLDEVTOOLS_LIB) || defined(QT_QMLDEVTOOLS_LIB)
+       // QmlDevTools is a static library
+#      define QML_PARSER_EXPORT
+#    elif defined(QT_BUILD_QML_LIB)
+#      define QML_PARSER_EXPORT Q_DECL_EXPORT
+#    else
+#      define QML_PARSER_EXPORT Q_DECL_IMPORT
+#    endif
 #  else
-#    define QML_PARSER_EXPORT Q_DECL_IMPORT
+#      define QML_PARSER_EXPORT
 #  endif
 #endif // QT_CREATOR
 
diff --git a/src/qml/qml.pro b/src/qml/qml.pro
index 8f9e4b7f83..be3956bb61 100644
--- a/src/qml/qml.pro
+++ b/src/qml/qml.pro
@@ -48,7 +48,9 @@ include(jit/jit.pri)
 include(jsruntime/jsruntime.pri)
 include(qml/qml.pri)
 include(debugger/debugger.pri)
-include(animations/animations.pri)
+qtConfig(animation) {
+    include(animations/animations.pri)
+}
 include(types/types.pri)
 
 MODULE_PLUGIN_TYPES = \
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index a04f47e6a4..75968ffc43 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -1046,14 +1046,18 @@ namespace QV4 {
 
 namespace Heap {
 
-struct QmlIncubatorObject : Object {
+#define QmlIncubatorObjectMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, valuemap) \
+    Member(class, HeapValue, HeapValue, statusChanged) \
+    Member(class, Pointer, QmlContext *, qmlContext) \
+    Member(class, NoMark, QQmlComponentIncubator *, incubator) \
+    Member(class, NoMark, QQmlQPointer<QObject>, parent)
+
+DECLARE_HEAP_OBJECT(QmlIncubatorObject, Object) {
+    DECLARE_MARK_TABLE(QmlIncubatorObject);
+
     void init(QQmlIncubator::IncubationMode = QQmlIncubator::Asynchronous);
     inline void destroy();
-    QQmlComponentIncubator *incubator;
-    QQmlQPointer<QObject> parent;
-    QV4::Value valuemap;
-    QV4::Value statusChanged;
-    Pointer<Heap::QmlContext> qmlContext;
 };
 
 }
@@ -1069,8 +1073,6 @@ struct QmlIncubatorObject : public QV4::Object
     static void method_get_object(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_forceCompletion(const BuiltinFunction *, Scope &scope, CallData *callData);
 
-    static void markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e);
-
     void statusChanged(QQmlIncubator::Status);
     void setInitialState(QObject *);
 };
@@ -1374,8 +1376,8 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
     r->setPrototype(p);
 
     if (!valuemap->isUndefined())
-        r->d()->valuemap = valuemap;
-    r->d()->qmlContext = v4->qmlContext();
+        r->d()->valuemap.set(scope.engine, valuemap);
+    r->d()->qmlContext.set(scope.engine, v4->qmlContext());
     r->d()->parent = parent;
 
     QQmlIncubator *incubator = r->d()->incubator;
@@ -1459,7 +1461,7 @@ void QV4::QmlIncubatorObject::method_set_statusChanged(const BuiltinFunction *,
     if (!o || callData->argc < 1)
         THROW_TYPE_ERROR();
 
-    o->d()->statusChanged = callData->args[0];
+    o->d()->statusChanged.set(scope.engine, callData->args[0]);
 
     RETURN_UNDEFINED();
 }
@@ -1471,10 +1473,10 @@ QQmlComponentExtension::~QQmlComponentExtension()
 void QV4::Heap::QmlIncubatorObject::init(QQmlIncubator::IncubationMode m)
 {
     Object::init();
-    valuemap = QV4::Primitive::undefinedValue();
-    statusChanged = QV4::Primitive::undefinedValue();
+    valuemap.set(internalClass->engine, QV4::Primitive::undefinedValue());
+    statusChanged.set(internalClass->engine, QV4::Primitive::undefinedValue());
     parent.init();
-    qmlContext = nullptr;
+    qmlContext.set(internalClass->engine, nullptr);
     incubator = new QQmlComponentIncubator(this, m);
 }
 
@@ -1497,16 +1499,6 @@ void QV4::QmlIncubatorObject::setInitialState(QObject *o)
     }
 }
 
-void QV4::QmlIncubatorObject::markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e)
-{
-    QmlIncubatorObject::Data *o = static_cast<QmlIncubatorObject::Data *>(that);
-    o->valuemap.mark(e);
-    o->statusChanged.mark(e);
-    if (o->qmlContext)
-        o->qmlContext->mark(e);
-    Object::markObjects(that, e);
-}
-
 void QV4::QmlIncubatorObject::statusChanged(QQmlIncubator::Status s)
 {
     QV4::Scope scope(engine());
diff --git a/src/qml/qml/qqmldata_p.h b/src/qml/qml/qqmldata_p.h
index e271598c2d..2083326cd5 100644
--- a/src/qml/qml/qqmldata_p.h
+++ b/src/qml/qml/qqmldata_p.h
@@ -201,7 +201,9 @@ public:
 
     static QQmlData *get(const QObject *object, bool create = false) {
         QObjectPrivate *priv = QObjectPrivate::get(const_cast<QObject *>(object));
-        if (priv->wasDeleted) {
+        // If QObjectData::isDeletingChildren is set then access to QObjectPrivate::declarativeData has
+        // to be avoided because QObjectPrivate::currentChildBeingDeleted is in use.
+        if (priv->isDeletingChildren || priv->wasDeleted) {
             Q_ASSERT(!create);
             return 0;
         } else if (priv->declarativeData) {
@@ -269,8 +271,8 @@ bool QQmlData::wasDeleted(QObject *object)
     if (!priv || priv->wasDeleted)
         return true;
 
-    return priv->declarativeData &&
-           static_cast<QQmlData *>(priv->declarativeData)->isQueuedForDeletion;
+    QQmlData *ddata = QQmlData::get(object);
+    return ddata && ddata->isQueuedForDeletion;
 }
 
 QQmlNotifierEndpoint *QQmlData::notify(int index)
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index af94ece496..9ff76d7b24 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -82,7 +82,9 @@
 #include <private/qqmllocale_p.h>
 #include <private/qqmlbind_p.h>
 #include <private/qqmlconnections_p.h>
+#if QT_CONFIG(animation)
 #include <private/qqmltimer_p.h>
+#endif
 #include <private/qqmllistmodel_p.h>
 #include <private/qqmlplatform_p.h>
 #include <private/qquickpackage_p.h>
@@ -218,7 +220,9 @@ void QQmlEnginePrivate::registerBaseTypes(const char *uri, int versionMajor, int
     qmlRegisterType<QQmlBind,8>(uri, versionMajor, (versionMinor < 8 ? 8 : versionMinor), "Binding"); //Only available in >=2.8
     qmlRegisterType<QQmlConnections,1>(uri, versionMajor, (versionMinor < 3 ? 3 : versionMinor), "Connections"); //Only available in >=2.3
     qmlRegisterType<QQmlConnections>(uri, versionMajor, versionMinor,"Connections");
+#if QT_CONFIG(animation)
     qmlRegisterType<QQmlTimer>(uri, versionMajor, versionMinor,"Timer");
+#endif
     qmlRegisterType<QQmlInstantiator>(uri, versionMajor, (versionMinor < 1 ? 1 : versionMinor), "Instantiator"); //Only available in >=2.1
     qmlRegisterCustomType<QQmlConnections>(uri, versionMajor, versionMinor,"Connections", new QQmlConnectionsParser);
     qmlRegisterType<QQmlInstanceModel>();
@@ -709,9 +713,7 @@ QQmlEnginePrivate::~QQmlEnginePrivate()
 
 void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
 {
-    QObjectPrivate *p = QObjectPrivate::get(o);
-    if (p->declarativeData) {
-        QQmlData *d = static_cast<QQmlData*>(p->declarativeData);
+    if (QQmlData *d = QQmlData::get(o)) {
         if (d->ownContext && d->context) {
             d->context->destroy();
             d->context = 0;
@@ -791,7 +793,7 @@ void QQmlData::signalEmitted(QAbstractDeclarativeData *, QObject *object, int in
     // marshalled back onto the QObject's thread and handled by QML from there.  This is tested
     // by the qqmlecmascript::threadSignal() autotest.
     if (ddata->notifyList &&
-        QThread::currentThreadId() != QObjectPrivate::get(object)->threadData->threadId) {
+        QThread::currentThreadId() != QObjectPrivate::get(object)->threadData->threadId.load()) {
 
         if (!QObjectPrivate::get(object)->threadData->thread)
             return;
@@ -881,13 +883,10 @@ void QQmlData::markAsDeleted(QObject *o)
 void QQmlData::setQueuedForDeletion(QObject *object)
 {
     if (object) {
-        if (QObjectPrivate *priv = QObjectPrivate::get(object)) {
-            if (!priv->wasDeleted && priv->declarativeData) {
-                QQmlData *ddata = QQmlData::get(object, false);
-                if (ddata->ownContext && ddata->context)
-                    ddata->context->emitDestruction();
-                ddata->isQueuedForDeletion = true;
-            }
+        if (QQmlData *ddata = QQmlData::get(object)) {
+            if (ddata->ownContext && ddata->context)
+                ddata->context->emitDestruction();
+            ddata->isQueuedForDeletion = true;
         }
     }
 }
@@ -1336,17 +1335,11 @@ QQmlContext *QQmlEngine::contextForObject(const QObject *object)
     if(!object)
         return 0;
 
-    QObjectPrivate *priv = QObjectPrivate::get(const_cast<QObject *>(object));
-
-    QQmlData *data =
-        static_cast<QQmlData *>(priv->declarativeData);
-
-    if (!data)
-        return 0;
-    else if (data->outerContext)
+    QQmlData *data = QQmlData::get(object);
+    if (data && data->outerContext)
         return data->outerContext->asQQmlContext();
-    else
-        return 0;
+
+    return 0;
 }
 
 /*!
@@ -1881,6 +1874,7 @@ void QQmlData::setPendingBindingBit(QObject *obj, int coreIndex)
 QQmlData *QQmlData::createQQmlData(QObjectPrivate *priv)
 {
     Q_ASSERT(priv);
+    Q_ASSERT(!priv->isDeletingChildren);
     priv->declarativeData = new QQmlData;
     return static_cast<QQmlData *>(priv->declarativeData);
 }
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index c07d5c740a..ee5b38717b 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -210,7 +210,6 @@ QQmlType *fetchOrCreateTypeForUrl(const QString &urlString, const QHashedStringR
 
 } // namespace
 
-#if QT_CONFIG(library)
 struct RegisteredPlugin {
     QString uri;
     QPluginLoader* loader;
@@ -221,21 +220,23 @@ struct StringRegisteredPluginMap : public QMap<QString, RegisteredPlugin> {
 };
 
 Q_GLOBAL_STATIC(StringRegisteredPluginMap, qmlEnginePluginsWithRegisteredTypes); // stores the uri and the PluginLoaders
+
 void qmlClearEnginePlugins()
 {
     StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
     QMutexLocker lock(&plugins->mutex);
+#if QT_CONFIG(library)
     for (auto &plugin : qAsConst(*plugins)) {
         QPluginLoader* loader = plugin.loader;
         if (loader && !loader->unload())
             qWarning("Unloading %s failed: %s", qPrintable(plugin.uri), qPrintable(loader->errorString()));
         delete loader;
     }
+#endif
     plugins->clear();
 }
 
 typedef QPair<QStaticPlugin, QJsonArray> StaticPluginPair;
-#endif
 
 /*!
     \internal
@@ -332,10 +333,9 @@ public:
                                                       const QString &uri, const QString &url,
                                                       int vmaj, int vmin, QV4::CompiledData::Import::ImportType type,
                                                       QList<QQmlError> *errors, bool lowPrecedence = false);
-#if QT_CONFIG(library)
-   bool populatePluginPairVector(QVector<StaticPluginPair> &result, const QString &uri, const QStringList &versionUris,
+
+    bool populatePluginPairVector(QVector<StaticPluginPair> &result, const QString &uri, const QStringList &versionUris,
                                      const QString &qmldirPath, QList<QQmlError> *errors);
-#endif
 };
 
 /*!
@@ -959,7 +959,6 @@ static QStringList versionUriList(const QString &uri, int vmaj, int vmin)
     return result;
 }
 
-#if QT_CONFIG(library)
 static QVector<QStaticPlugin> makePlugins()
 {
     QVector<QStaticPlugin> plugins;
@@ -1009,7 +1008,6 @@ bool QQmlImportsPrivate::populatePluginPairVector(QVector<StaticPluginPair> &res
     }
     return true;
 }
-#endif
 
 #if defined(QT_SHARED) || !QT_CONFIG(library)
 static inline QString msgCannotLoadPlugin(const QString &uri, const QString &why)
@@ -1030,7 +1028,6 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
                                          const QQmlTypeLoaderQmldirContent *qmldir,
                                          QList<QQmlError> *errors)
 {
-#if QT_CONFIG(library)
     Q_ASSERT(qmldir);
 
     if (qmlImportTrace())
@@ -1143,22 +1140,6 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
 
         database->qmlDirFilesForWhichPluginsHaveBeenLoaded.insert(qmldirFilePath);
     }
-
-#else
-    Q_UNUSED(vmaj);
-    Q_UNUSED(vmin);
-    Q_UNUSED(database);
-    Q_UNUSED(qmldir);
-
-    if (errors) {
-        QQmlError error;
-        error.setDescription(msgCannotLoadPlugin(uri, QQmlImportDatabase::tr("library loading is disabled")));
-        error.setUrl(QUrl::fromLocalFile(qmldirFilePath));
-        errors->prepend(error);
-    }
-
-    return false;
-#endif // library
     return true;
 }
 
@@ -2014,7 +1995,6 @@ bool QQmlImportDatabase::registerPluginTypes(QObject *instance, const QString &b
 bool QQmlImportDatabase::importStaticPlugin(QObject *instance, const QString &basePath,
                                       const QString &uri, const QString &typeNamespace, int vmaj, QList<QQmlError> *errors)
 {
-#if QT_CONFIG(library)
     // Dynamic plugins are differentiated by their filepath. For static plugins we
     // don't have that information so we use their address as key instead.
     const QString uniquePluginID = QString::asprintf("%p", instance);
@@ -2050,15 +2030,6 @@ bool QQmlImportDatabase::importStaticPlugin(QObject *instance, const QString &ba
     }
 
     return true;
-#else
-    Q_UNUSED(instance);
-    Q_UNUSED(basePath);
-    Q_UNUSED(uri);
-    Q_UNUSED(typeNamespace);
-    Q_UNUSED(vmaj);
-    Q_UNUSED(errors);
-    return false;
-#endif
 }
 
 /*!
diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index bd6b9a1599..bb9b69c479 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -1971,7 +1971,9 @@ QString QQmlMetaType::prettyTypeName(const QObject *object)
         const int lastSlash = typeName.lastIndexOf(QLatin1Char('/'));
         if (lastSlash != -1)
             typeName = typeName.mid(lastSlash + 1);
-    } else {
+    }
+
+    if (typeName.isEmpty()) {
         typeName = QString::fromUtf8(object->metaObject()->className());
         int marker = typeName.indexOf(QLatin1String("_QMLTYPE_"));
         if (marker != -1)
@@ -1982,10 +1984,12 @@ QString QQmlMetaType::prettyTypeName(const QObject *object)
             typeName = typeName.leftRef(marker) + QLatin1Char('*');
             type = QQmlMetaType::qmlType(QMetaType::type(typeName.toLatin1()));
             if (type) {
-                typeName = type->qmlTypeName();
-                const int lastSlash = typeName.lastIndexOf(QLatin1Char('/'));
+                QString qmlTypeName = type->qmlTypeName();
+                const int lastSlash = qmlTypeName.lastIndexOf(QLatin1Char('/'));
                 if (lastSlash != -1)
-                    typeName = typeName.mid(lastSlash + 1);
+                    qmlTypeName = qmlTypeName.mid(lastSlash + 1);
+                if (!qmlTypeName.isEmpty())
+                    typeName = qmlTypeName;
             }
         }
     }
diff --git a/src/qml/qml/qqmlnotifier.cpp b/src/qml/qml/qqmlnotifier.cpp
index 185f9687fb..538ca822ee 100644
--- a/src/qml/qml/qqmlnotifier.cpp
+++ b/src/qml/qml/qqmlnotifier.cpp
@@ -122,8 +122,8 @@ void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine
     disconnect();
 
     Q_ASSERT(engine);
-    if (QObjectPrivate::get(source)->threadData->threadId !=
-        QObjectPrivate::get(engine)->threadData->threadId) {
+    if (QObjectPrivate::get(source)->threadData->threadId.load() !=
+        QObjectPrivate::get(engine)->threadData->threadId.load()) {
 
         QString sourceName;
         QDebug(&sourceName) << source;
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 85fbd86dc4..2cbcfbbfb6 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1075,7 +1075,9 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
             {
                 QQmlData *ddata = new (ddataMemory) QQmlData;
                 ddata->ownMemory = false;
-                QObjectPrivate::get(instance)->declarativeData = ddata;
+                QObjectPrivate* p = QObjectPrivate::get(instance);
+                Q_ASSERT(!p->isDeletingChildren);
+                p->declarativeData = ddata;
             }
 
             const int parserStatusCast = type->parserStatusCast();
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index ca522c29af..9b5f7b0a06 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -1627,7 +1627,7 @@ QMetaMethod QQmlPropertyPrivate::findSignalByName(const QMetaObject *mo, const Q
 */
 static inline void flush_vme_signal(const QObject *object, int index, bool indexInSignalRange)
 {
-    QQmlData *data = static_cast<QQmlData *>(QObjectPrivate::get(const_cast<QObject *>(object))->declarativeData);
+    QQmlData *data = QQmlData::get(object);
     if (data && data->propertyCache) {
         QQmlPropertyData *property = indexInSignalRange ? data->propertyCache->signal(index)
                                                         : data->propertyCache->method(index);
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index f4f04e12c0..40bd2e5020 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -64,6 +64,7 @@
 #include <QtCore/qwaitcondition.h>
 #include <QtCore/qloggingcategory.h>
 #include <QtQml/qqmlextensioninterface.h>
+#include <QtCore/qcryptographichash.h>
 
 #include <functional>
 
@@ -80,10 +81,6 @@
 #  define NAME_MAX _POSIX_SYMLINK_MAX
 #endif
 
-// LSB has a broken version of qOffsetOf that can't be used at compile time
-// https://lsbbugs.linuxfoundation.org/show_bug.cgi?id=3462
-#undef qOffsetOf
-#define qOffsetOf(TYPE, MEMBER) __builtin_qOffsetOf (TYPE, MEMBER)
 #endif
 
 // #define DATABLOB_DEBUG
@@ -1249,20 +1246,20 @@ void QQmlTypeLoader::initializeEngine(QQmlExtensionInterface *iface,
 void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QByteArray &data)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlDataBlob::Data d;
-    d.d = &data;
+    QQmlDataBlob::SourceCodeData d;
+    d.inlineSourceCode = QString::fromUtf8(data);
     setData(blob, d);
 }
 
 void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QString &fileName)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlDataBlob::Data d;
-    d.d = &fileName;
+    QQmlDataBlob::SourceCodeData d;
+    d.fileInfo = QFileInfo(fileName);
     setData(blob, d);
 }
 
-void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::Data &d)
+void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeData &d)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
     QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
@@ -1529,7 +1526,8 @@ bool QQmlTypeLoader::Blob::qmldirDataAvailable(QQmlQmldirData *data, QList<QQmlE
                 return false;
             }
 
-            *it = priority;
+            if (it != m_unresolvedImports.end())
+                *it = priority;
             return true;
         }
     }
@@ -2009,6 +2007,16 @@ QQmlTypeData::TypeDataCallback::~TypeDataCallback()
 {
 }
 
+QString QQmlTypeData::TypeReference::qualifiedName() const
+{
+    QString result;
+    if (!prefix.isEmpty()) {
+        result = prefix + QLatin1Char('.');
+    }
+    result.append(type->qmlTypeName());
+    return result;
+}
+
 QQmlTypeData::QQmlTypeData(const QUrl &url, QQmlTypeLoader *manager)
 : QQmlTypeLoader::Blob(url, QmlFile, manager),
    m_typesResolved(false), m_implicitImportLoaded(false)
@@ -2069,7 +2077,7 @@ bool QQmlTypeData::tryLoadFromDiskCache()
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = v4->iselFactory->createUnitForLoading();
     {
         QString error;
-        if (!unit->loadFromDisk(url(), v4->iselFactory.data(), &error)) {
+        if (!unit->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), v4->iselFactory.data(), &error)) {
             qCDebug(DBG_DISK_CACHE) << "Error loading" << url().toString() << "from disk cache:" << error;
             return false;
         }
@@ -2154,6 +2162,23 @@ void QQmlTypeData::createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeName
     aliasCreator.appendAliasPropertiesToMetaObjects();
 }
 
+static bool addTypeReferenceChecksumsToHash(const QList<QQmlTypeData::TypeReference> &typeRefs, QCryptographicHash *hash, QQmlEngine *engine)
+{
+    for (const auto &typeRef: typeRefs) {
+        if (typeRef.typeData) {
+            const auto unit = typeRef.typeData->compilationUnit();
+            hash->addData(unit->data->md5Checksum, sizeof(unit->data->md5Checksum));
+        } else if (typeRef.type) {
+            const auto propertyCache = QQmlEnginePrivate::get(engine)->cache(typeRef.type->metaObject());
+            bool ok = false;
+            hash->addData(propertyCache->checksum(&ok));
+            if (!ok)
+                return false;
+        }
+    }
+    return true;
+}
+
 void QQmlTypeData::done()
 {
     QDeferredCleanup cleanup([this]{
@@ -2234,18 +2259,24 @@ void QQmlTypeData::done()
 
     QQmlEngine *const engine = typeLoader()->engine();
 
+    const auto dependencyHasher = [engine, resolvedTypeCache, this](QCryptographicHash *hash) {
+        if (!resolvedTypeCache.addToHash(hash, engine))
+            return false;
+        return ::addTypeReferenceChecksumsToHash(m_compositeSingletons, hash, engine);
+    };
+
     // verify if any dependencies changed if we're using a cache
-    if (m_document.isNull() && !m_compiledData->verifyChecksum(engine, resolvedTypeCache)) {
+    if (m_document.isNull() && !m_compiledData->verifyChecksum(dependencyHasher)) {
         qCDebug(DBG_DISK_CACHE) << "Checksum mismatch for cached version of" << m_compiledData->url().toString();
         if (!loadFromSource())
             return;
-        m_backupSourceCode.clear();
+        m_backupSourceCode = SourceCodeData();
         m_compiledData = nullptr;
     }
 
     if (!m_document.isNull()) {
         // Compile component
-        compile(typeNameCache, resolvedTypeCache);
+        compile(typeNameCache, resolvedTypeCache, dependencyHasher);
     } else {
         createTypeAndPropertyCaches(typeNameCache, resolvedTypeCache);
     }
@@ -2346,13 +2377,9 @@ bool QQmlTypeData::loadImplicitImport()
     return true;
 }
 
-void QQmlTypeData::dataReceived(const Data &data)
+void QQmlTypeData::dataReceived(const SourceCodeData &data)
 {
-    QString error;
-    m_backupSourceCode = data.readAll(&error, &m_sourceTimeStamp);
-    // if we failed to read the source code, process it _after_ we've tried
-    // to use the disk cache, in order to support scenarios where the source
-    // was removed deliberately.
+    m_backupSourceCode = data;
 
     if (tryLoadFromDiskCache())
         return;
@@ -2360,8 +2387,8 @@ void QQmlTypeData::dataReceived(const Data &data)
     if (isError())
         return;
 
-    if (!error.isEmpty()) {
-        setError(error);
+    if (!m_backupSourceCode.exists()) {
+        setError(QQmlTypeLoader::tr("No such file or directory"));
         return;
     }
 
@@ -2380,12 +2407,19 @@ void QQmlTypeData::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *un
 
 bool QQmlTypeData::loadFromSource()
 {
-    QString code = QString::fromUtf8(m_backupSourceCode);
     m_document.reset(new QmlIR::Document(isDebugging()));
-    m_document->jsModule.sourceTimeStamp = m_sourceTimeStamp;
+    m_document->jsModule.sourceTimeStamp = m_backupSourceCode.sourceTimeStamp();
     QQmlEngine *qmlEngine = typeLoader()->engine();
     QmlIR::IRBuilder compiler(QV8Engine::get(qmlEngine)->illegalNames());
-    if (!compiler.generateFromQml(code, finalUrlString(), m_document.data())) {
+
+    QString sourceError;
+    const QString source = m_backupSourceCode.readAll(&sourceError);
+    if (!sourceError.isEmpty()) {
+        setError(sourceError);
+        return false;
+    }
+
+    if (!compiler.generateFromQml(source, finalUrlString(), m_document.data())) {
         QList<QQmlError> errors;
         errors.reserve(compiler.errors.count());
         for (const QQmlJS::DiagnosticMessage &msg : qAsConst(compiler.errors)) {
@@ -2407,6 +2441,7 @@ void QQmlTypeData::restoreIR(QQmlRefPointer<QV4::CompiledData::CompilationUnit>
     m_document.reset(new QmlIR::Document(isDebugging()));
     QmlIR::IRLoader loader(unit->data, m_document.data());
     loader.load();
+    m_document->jsModule.setFileName(finalUrlString());
     m_document->javaScriptCompilationUnit = unit;
     continueLoadFromIR();
 }
@@ -2503,24 +2538,27 @@ QString QQmlTypeData::stringAt(int index) const
     return m_document->jsGenerator.stringTable.stringForIndex(index);
 }
 
-void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache)
+void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache,
+                           const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
 {
     Q_ASSERT(m_compiledData.isNull());
 
+    const bool typeRecompilation = m_document && m_document->javaScriptCompilationUnit && m_document->javaScriptCompilationUnit->data->flags & QV4::CompiledData::Unit::PendingTypeCompilation;
+
     QQmlEnginePrivate * const enginePrivate = QQmlEnginePrivate::get(typeLoader()->engine());
-    QQmlTypeCompiler compiler(enginePrivate, this, m_document.data(), typeNameCache, resolvedTypeCache);
+    QQmlTypeCompiler compiler(enginePrivate, this, m_document.data(), typeNameCache, resolvedTypeCache, dependencyHasher);
     m_compiledData = compiler.compile();
     if (!m_compiledData) {
         setError(compiler.compilationErrors());
         return;
     }
 
-    const bool trySaveToDisk = (!disableDiskCache() || forceDiskCache()) && !m_document->jsModule.debugMode;
+    const bool trySaveToDisk = (!disableDiskCache() || forceDiskCache()) && !m_document->jsModule.debugMode && !typeRecompilation;
     if (trySaveToDisk) {
         QString errorString;
         if (m_compiledData->saveToDisk(url(), &errorString)) {
             QString error;
-            if (!m_compiledData->loadFromDisk(url(), enginePrivate->v4engine()->iselFactory.data(), &error)) {
+            if (!m_compiledData->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), enginePrivate->v4engine()->iselFactory.data(), &error)) {
                 // ignore error, keep using the in-memory compilation unit.
             }
         } else {
@@ -2580,6 +2618,10 @@ void QQmlTypeData::resolveTypes()
         }
     }
 
+    std::stable_sort(m_compositeSingletons.begin(), m_compositeSingletons.end(), [](const TypeReference &lhs, const TypeReference &rhs){
+        return lhs.qualifiedName() < rhs.qualifiedName();
+    });
+
     for (QV4::CompiledData::TypeReferenceMap::ConstIterator unresolvedRef = m_typeReferences.constBegin(), end = m_typeReferences.constEnd();
          unresolvedRef != end; ++unresolvedRef) {
 
@@ -2873,14 +2915,14 @@ struct EmptyCompilationUnit : public QV4::CompiledData::CompilationUnit
     void linkBackendToEngine(QV4::ExecutionEngine *) override {}
 };
 
-void QQmlScriptBlob::dataReceived(const Data &data)
+void QQmlScriptBlob::dataReceived(const SourceCodeData &data)
 {
     QV4::ExecutionEngine *v4 = QV8Engine::getV4(m_typeLoader->engine());
 
     if (!disableDiskCache() || forceDiskCache()) {
         QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = v4->iselFactory->createUnitForLoading();
         QString error;
-        if (unit->loadFromDisk(url(), v4->iselFactory.data(), &error)) {
+        if (unit->loadFromDisk(url(), data.sourceTimeStamp(), v4->iselFactory.data(), &error)) {
             initializeFromCompilationUnit(unit);
             return;
         } else {
@@ -2891,8 +2933,9 @@ void QQmlScriptBlob::dataReceived(const Data &data)
 
     QmlIR::Document irUnit(isDebugging());
 
+    irUnit.jsModule.sourceTimeStamp = data.sourceTimeStamp();
     QString error;
-    QString source = QString::fromUtf8(data.readAll(&error, &irUnit.jsModule.sourceTimeStamp));
+    QString source = data.readAll(&error);
     if (!error.isEmpty()) {
         setError(error);
         return;
@@ -2917,8 +2960,7 @@ void QQmlScriptBlob::dataReceived(const Data &data)
         irUnit.jsModule.unitFlags |= QV4::CompiledData::Unit::IsSharedLibrary;
 
     QmlIR::QmlUnitGenerator qmlGenerator;
-    QV4::CompiledData::ResolvedTypeReferenceMap emptyDependencies;
-    QV4::CompiledData::Unit *unitData = qmlGenerator.generate(irUnit, m_typeLoader->engine(), emptyDependencies);
+    QV4::CompiledData::Unit *unitData = qmlGenerator.generate(irUnit);
     Q_ASSERT(!unit->data);
     // The js unit owns the data and will free the qml unit.
     unit->data = unitData;
@@ -3056,10 +3098,10 @@ void QQmlQmldirData::setPriority(int priority)
     m_priority = priority;
 }
 
-void QQmlQmldirData::dataReceived(const Data &data)
+void QQmlQmldirData::dataReceived(const SourceCodeData &data)
 {
     QString error;
-    m_content = QString::fromUtf8(data.readAll(&error));
+    m_content = data.readAll(&error);
     if (!error.isEmpty()) {
         setError(error);
         return;
@@ -3071,34 +3113,54 @@ void QQmlQmldirData::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *
     Q_UNIMPLEMENTED();
 }
 
-QByteArray QQmlDataBlob::Data::readAll(QString *error, qint64 *sourceTimeStamp) const
+QString QQmlDataBlob::SourceCodeData::readAll(QString *error) const
 {
-    Q_ASSERT(!d.isNull());
     error->clear();
-    if (d.isT1()) {
-        if (sourceTimeStamp)
-            *sourceTimeStamp = 0;
-        return *d.asT1();
-    }
-    QFile f(*d.asT2());
+    if (!inlineSourceCode.isEmpty())
+        return inlineSourceCode;
+
+    QFile f(fileInfo.absoluteFilePath());
     if (!f.open(QIODevice::ReadOnly)) {
         *error = f.errorString();
-        return QByteArray();
+        return QString();
     }
-    if (sourceTimeStamp) {
-        QDateTime timeStamp = QFileInfo(f).lastModified();
-        // Files from the resource system do not have any time stamps, so fall back to the application
-        // executable.
-        if (!timeStamp.isValid())
-            timeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
-        *sourceTimeStamp = timeStamp.toMSecsSinceEpoch();
+
+    const qint64 fileSize = fileInfo.size();
+
+    if (uchar *mappedData = f.map(0, fileSize)) {
+        QString source = QString::fromUtf8(reinterpret_cast<const char *>(mappedData), fileSize);
+        f.unmap(mappedData);
+        return source;
     }
-    QByteArray data(f.size(), Qt::Uninitialized);
+
+    QByteArray data(fileSize, Qt::Uninitialized);
     if (f.read(data.data(), data.length()) != data.length()) {
         *error = f.errorString();
-        return QByteArray();
+        return QString();
     }
-    return data;
+    return QString::fromUtf8(data);
+}
+
+QDateTime QQmlDataBlob::SourceCodeData::sourceTimeStamp() const
+{
+    if (!inlineSourceCode.isEmpty())
+        return QDateTime();
+
+    QDateTime timeStamp = fileInfo.lastModified();
+    if (timeStamp.isValid())
+        return timeStamp;
+
+    static QDateTime appTimeStamp;
+    if (!appTimeStamp.isValid())
+        appTimeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
+    return appTimeStamp;
+}
+
+bool QQmlDataBlob::SourceCodeData::exists() const
+{
+    if (!inlineSourceCode.isEmpty())
+        return true;
+    return fileInfo.exists();
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 915b1bcc4c..48e7d5cba4 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -54,6 +54,7 @@
 #include <QtQml/qtqmlglobal.h>
 #include <QtCore/qobject.h>
 #include <QtCore/qatomic.h>
+#include <QtCore/qfileinfo.h>
 #if QT_CONFIG(qml_network)
 #include <QtNetwork/qnetworkreply.h>
 #endif
@@ -130,16 +131,16 @@ public:
 
     QList<QQmlError> errors() const;
 
-    class Data {
+    class SourceCodeData {
     public:
-        QByteArray readAll(QString *error, qint64 *sourceTimeStamp = 0) const;
+        QString readAll(QString *error) const;
+        QDateTime sourceTimeStamp() const;
+        bool exists() const;
     private:
         friend class QQmlDataBlob;
         friend class QQmlTypeLoader;
-        inline Data();
-        Data(const Data &);
-        Data &operator=(const Data &);
-        QBiPointer<const QByteArray, const QString> d;
+        QString inlineSourceCode;
+        QFileInfo fileInfo;
     };
 
 protected:
@@ -152,7 +153,7 @@ protected:
     void addDependency(QQmlDataBlob *);
 
     // Callbacks made in load thread
-    virtual void dataReceived(const Data &) = 0;
+    virtual void dataReceived(const SourceCodeData &) = 0;
     virtual void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit*) = 0;
     virtual void done();
 #if QT_CONFIG(qml_network)
@@ -339,7 +340,7 @@ private:
 
     void setData(QQmlDataBlob *, const QByteArray &);
     void setData(QQmlDataBlob *, const QString &fileName);
-    void setData(QQmlDataBlob *, const QQmlDataBlob::Data &);
+    void setData(QQmlDataBlob *, const QQmlDataBlob::SourceCodeData &);
     void setCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit);
 
     template<typename T>
@@ -400,6 +401,7 @@ public:
         int minorVersion;
         QQmlTypeData *typeData;
         QString prefix; // used by CompositeSingleton types
+        QString qualifiedName() const;
         bool needsCreation;
     };
 
@@ -436,7 +438,7 @@ public:
 protected:
     void done() override;
     void completed() override;
-    void dataReceived(const Data &) override;
+    void dataReceived(const SourceCodeData &) override;
     void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit) override;
     void allDependenciesDone() override;
     void downloadProgressChanged(qreal) override;
@@ -454,7 +456,7 @@ private:
             QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache
             ) const;
     void compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
-                 const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache);
+                 const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
     void createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
                                       const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache);
     bool resolveType(const QString &typeName, int &majorVersion, int &minorVersion, TypeReference &ref, int lineNumber = -1, int columnNumber = -1, bool reportErrors = true);
@@ -462,8 +464,7 @@ private:
     void scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace) override;
 
 
-    qint64 m_sourceTimeStamp = 0;
-    QByteArray m_backupSourceCode; // used when cache verification fails.
+    SourceCodeData m_backupSourceCode; // used when cache verification fails.
     QScopedPointer<QmlIR::Document> m_document;
     QV4::CompiledData::TypeReferenceMap m_typeReferences;
 
@@ -547,7 +548,7 @@ public:
     QQmlScriptData *scriptData() const;
 
 protected:
-    void dataReceived(const Data &) override;
+    void dataReceived(const SourceCodeData &) override;
     void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit) override;
     void done() override;
 
@@ -578,7 +579,7 @@ public:
     void setPriority(int);
 
 protected:
-    void dataReceived(const Data &) override;
+    void dataReceived(const SourceCodeData &) override;
     void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit*) override;
 
 private:
@@ -587,11 +588,6 @@ private:
     int m_priority;
 };
 
-QQmlDataBlob::Data::Data()
-{
-}
-
-
 
 QT_END_NAMESPACE
 
diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index 49103ed653..7b98096a7f 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -342,4 +342,44 @@ bool QmlTypeWrapper::isEqualTo(Managed *a, Managed *b)
     return false;
 }
 
+ReturnedValue QmlTypeWrapper::instanceOf(const Object *typeObject, const Value &var)
+{
+    Q_ASSERT(typeObject->as<QV4::QmlTypeWrapper>());
+    const QV4::QmlTypeWrapper *typeWrapper = static_cast<const QV4::QmlTypeWrapper *>(typeObject);
+    QV4::ExecutionEngine *engine = typeObject->internalClass()->engine;
+    QQmlEnginePrivate *qenginepriv = QQmlEnginePrivate::get(engine->qmlEngine());
+
+    // can only compare a QObject* against a QML type
+    const QObjectWrapper *wrapper = var.as<QObjectWrapper>();
+    if (!wrapper)
+        return engine->throwTypeError();
+
+    // in case the wrapper outlived the QObject*
+    const QObject *wrapperObject = wrapper->object();
+    if (!wrapperObject)
+        return engine->throwTypeError();
+
+    const int myTypeId = typeWrapper->d()->type->typeId();
+    QQmlMetaObject myQmlType;
+    if (myTypeId == 0) {
+        // we're a composite type; a composite type cannot be equal to a
+        // non-composite object instance (Rectangle{} is never an instance of
+        // CustomRectangle)
+        QQmlData *theirDData = QQmlData::get(wrapperObject, /*create=*/false);
+        Q_ASSERT(theirDData); // must exist, otherwise how do we have a QObjectWrapper for it?!
+        if (!theirDData->compilationUnit)
+            return Encode(false);
+
+        QQmlTypeData *td = qenginepriv->typeLoader.getType(typeWrapper->d()->type->sourceUrl());
+        CompiledData::CompilationUnit *cu = td->compilationUnit();
+        myQmlType = qenginepriv->metaObjectForType(cu->metaTypeId);
+    } else {
+        myQmlType = qenginepriv->metaObjectForType(myTypeId);
+    }
+
+    const QMetaObject *theirType = wrapperObject->metaObject();
+
+    return QV4::Encode(QQmlMetaObject::canConvert(theirType, myQmlType));
+}
+
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypewrapper_p.h b/src/qml/qml/qqmltypewrapper_p.h
index cfb6cb0ec9..c584458ed4 100644
--- a/src/qml/qml/qqmltypewrapper_p.h
+++ b/src/qml/qml/qqmltypewrapper_p.h
@@ -103,7 +103,7 @@ struct Q_QML_EXPORT QmlTypeWrapper : Object
     static bool put(Managed *m, String *name, const Value &value);
     static PropertyAttributes query(const Managed *, String *name);
     static bool isEqualTo(Managed *that, Managed *o);
-
+    static ReturnedValue instanceOf(const Object *typeObject, const Value &var);
 };
 
 }
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index 490a4e19ab..9f86d1cae9 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -104,8 +104,10 @@ void QQmlVMEVariantQObjectPtr::objectDestroyed(QObject *)
         if (v4) {
             QV4::Scope scope(v4);
             QV4::Scoped<QV4::MemberData> sp(scope, m_target->propertyAndMethodStorage.value());
-            if (sp)
-                *(sp->data() + m_index) = QV4::Primitive::nullValue();
+            if (sp) {
+                QV4::MemberData::Index index{ sp->d(), static_cast<uint>(m_index) };
+                index.set(v4, QV4::Primitive::nullValue());
+            }
         }
 
         m_target->activate(m_target->object, m_target->methodOffset() + m_index, 0);
@@ -329,7 +331,7 @@ QQmlVMEMetaObject::QQmlVMEMetaObject(QObject *obj,
             if (size) {
                 QV4::Heap::MemberData *data = QV4::MemberData::allocate(v4, size);
                 propertyAndMethodStorage.set(v4, data);
-                std::fill(data->data, data->data + data->size, QV4::Encode::undefined());
+                std::fill(data->values.values, data->values.values + data->values.size, QV4::Encode::undefined());
             }
 
             // Need JS wrapper to ensure properties/methods are marked.
@@ -364,77 +366,77 @@ void QQmlVMEMetaObject::writeProperty(int id, int v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = QV4::Primitive::fromInt32(v);
+        md->set(cache->engine, id, QV4::Primitive::fromInt32(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, bool v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = QV4::Primitive::fromBoolean(v);
+        md->set(cache->engine, id, QV4::Primitive::fromBoolean(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, double v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = QV4::Primitive::fromDouble(v);
+        md->set(cache->engine, id, QV4::Primitive::fromDouble(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QString& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newString(v);
+        md->set(cache->engine, id, cache->engine->newString(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QUrl& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QDate& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QDateTime& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QPointF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QSizeF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QRectF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = cache->engine->newVariantObject(QVariant::fromValue(v));
+        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, QObject* v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        *(md->data() + id) = QV4::QObjectWrapper::wrap(cache->engine, v);
+        md->set(cache->engine, id, QV4::Value::fromReturnedValue(QV4::QObjectWrapper::wrap(cache->engine, v)));
 
     QQmlVMEVariantQObjectPtr *guard = getQObjectGuardForProperty(id);
     if (v && !guard) {
@@ -592,7 +594,7 @@ QList<QObject *> *QQmlVMEMetaObject::readPropertyAsList(int id) const
     if (!v || (int)v->d()->data().userType() != qMetaTypeId<QList<QObject *> >()) {
         QVariant variant(qVariantFromValue(QList<QObject*>()));
         v = cache->engine->newVariantObject(variant);
-        *(md->data() + id) = v;
+        md->set(cache->engine, id, v);
     }
     return static_cast<QList<QObject *> *>(v->d()->data().data());
 }
@@ -742,7 +744,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                             Q_ASSERT(fallbackMetaType != QMetaType::UnknownType);
                             if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
                                 QVariant propertyAsVariant;
-                                if (QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>())
+                                if (const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>())
                                     propertyAsVariant = v->d()->data();
                                 QQml_valueTypeProvider()->readValueType(propertyAsVariant, a[0], fallbackMetaType);
                             }
@@ -815,9 +817,9 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                         case QV4::CompiledData::Property::Quaternion:
                             Q_ASSERT(fallbackMetaType != QMetaType::UnknownType);
                             if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
-                                QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
+                                const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
                                 if (!v) {
-                                    *(md->data() + id) = cache->engine->newVariantObject(QVariant());
+                                    md->set(cache->engine, id, cache->engine->newVariantObject(QVariant()));
                                     v = (md->data() + id)->as<QV4::VariantObject>();
                                     QQml_valueTypeProvider()->initValueType(fallbackMetaType, v->d()->data());
                                 }
@@ -1028,7 +1030,7 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
 
     // Importantly, if the current value is a scarce resource, we need to ensure that it
     // gets automatically released by the engine if no other references to it exist.
-    QV4::VariantObject *oldVariant = (md->data() + id)->as<QV4::VariantObject>();
+    const QV4::VariantObject *oldVariant = (md->data() + id)->as<QV4::VariantObject>();
     if (oldVariant)
         oldVariant->removeVmePropertyReference();
 
@@ -1054,7 +1056,7 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
         guard->setGuardedValue(valueObject, this, id);
 
     // Write the value and emit change signal as appropriate.
-    *(md->data() + id) = value;
+    md->set(cache->engine, id, value);
     activate(object, methodOffset() + id, 0);
 }
 
@@ -1067,7 +1069,7 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
 
         // Importantly, if the current value is a scarce resource, we need to ensure that it
         // gets automatically released by the engine if no other references to it exist.
-        QV4::VariantObject *oldv = (md->data() + id)->as<QV4::VariantObject>();
+        const QV4::VariantObject *oldv = (md->data() + id)->as<QV4::VariantObject>();
         if (oldv)
             oldv->removeVmePropertyReference();
 
@@ -1081,7 +1083,7 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
 
         // Write the value and emit change signal as appropriate.
         QVariant currentValue = readPropertyAsVariant(id);
-        *(md->data() + id) = newv;
+        md->set(cache->engine, id, newv);
         if ((currentValue.userType() != value.userType() || currentValue != value))
             activate(object, methodOffset() + id, 0);
     } else {
@@ -1093,14 +1095,14 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
         } else {
             QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
             if (md) {
-                QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
+                const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
                 needActivate = (!v ||
                                  v->d()->data().userType() != value.userType() ||
                                  v->d()->data() != value);
                 if (v)
                     v->removeVmePropertyReference();
-                *(md->data() + id) = cache->engine->newVariantObject(value);
-                v = static_cast<QV4::VariantObject *>(md->data() + id);
+                md->set(cache->engine, id, cache->engine->newVariantObject(value));
+                v = static_cast<const QV4::VariantObject *>(md->data() + id);
                 v->addVmePropertyReference();
             }
         }
@@ -1139,7 +1141,7 @@ void QQmlVMEMetaObject::setVmeMethod(int index, const QV4::Value &function)
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (!md)
         return;
-    *(md->data() + methodIndex + compiledObject->nProperties) = function;
+    md->set(cache->engine, methodIndex + compiledObject->nProperties, function);
 }
 
 QV4::ReturnedValue QQmlVMEMetaObject::vmeProperty(int index) const
@@ -1168,16 +1170,16 @@ void QQmlVMEMetaObject::ensureQObjectWrapper()
     QV4::QObjectWrapper::wrap(v4, object);
 }
 
-void QQmlVMEMetaObject::mark(QV4::ExecutionEngine *e)
+void QQmlVMEMetaObject::mark(QV4::MarkStack *markStack)
 {
     QV4::ExecutionEngine *v4 = cache ? cache->engine : 0;
-    if (v4 != e)
+    if (v4 != markStack->engine)
         return;
 
-    propertyAndMethodStorage.markOnce(e);
+    propertyAndMethodStorage.markOnce(markStack);
 
     if (QQmlVMEMetaObject *parent = parentVMEMetaObject())
-        parent->mark(e);
+        parent->mark(markStack);
 }
 
 bool QQmlVMEMetaObject::aliasTarget(int index, QObject **target, int *coreIndex, int *valueTypeIndex) const
diff --git a/src/qml/qml/qqmlvmemetaobject_p.h b/src/qml/qml/qqmlvmemetaobject_p.h
index bb6fede7c8..031a9a9ddd 100644
--- a/src/qml/qml/qqmlvmemetaobject_p.h
+++ b/src/qml/qml/qqmlvmemetaobject_p.h
@@ -203,7 +203,7 @@ public:
 
     void ensureQObjectWrapper();
 
-    void mark(QV4::ExecutionEngine *e);
+    void mark(QV4::MarkStack *markStack);
 
     void connectAlias(int aliasId);
 
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index d0d9f080da..b18904fc73 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1597,10 +1597,12 @@ struct QQmlXMLHttpRequestWrapper : Object {
     QQmlXMLHttpRequest *request;
 };
 
-struct QQmlXMLHttpRequestCtor : FunctionObject {
-    void init(ExecutionEngine *engine);
+#define QQmlXMLHttpRequestCtorMembers(class, Member) \
+    Member(class, Pointer, Object *, proto)
 
-    Pointer<Object> proto;
+DECLARE_HEAP_OBJECT(QQmlXMLHttpRequestCtor, FunctionObject) {
+    DECLARE_MARK_TABLE(QQmlXMLHttpRequestCtor);
+    void init(ExecutionEngine *engine);
 };
 
 }
@@ -1614,12 +1616,7 @@ struct QQmlXMLHttpRequestWrapper : public Object
 struct QQmlXMLHttpRequestCtor : public FunctionObject
 {
     V4_OBJECT2(QQmlXMLHttpRequestCtor, FunctionObject)
-    static void markObjects(Heap::Base *that, ExecutionEngine *e) {
-        QQmlXMLHttpRequestCtor::Data *c = static_cast<QQmlXMLHttpRequestCtor::Data *>(that);
-        if (c->proto)
-            c->proto->mark(e);
-        FunctionObject::markObjects(that, e);
-    }
+
     static void construct(const Managed *that, Scope &scope, QV4::CallData *)
     {
         Scoped<QQmlXMLHttpRequestCtor> ctor(scope, that->as<QQmlXMLHttpRequestCtor>());
@@ -1686,7 +1683,7 @@ void QQmlXMLHttpRequestCtor::setupProto()
     ExecutionEngine *v4 = engine();
     Scope scope(v4);
     ScopedObject p(scope, v4->newObject());
-    d()->proto = p->d();
+    d()->proto.set(scope.engine, p->d());
 
     // Methods
     p->defineDefaultProperty(QStringLiteral("open"), method_open);
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index d359a0f62f..8cc0b32168 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -1885,7 +1885,7 @@ void GlobalExtensions::method_qsTr(const BuiltinFunction *, Scope &scope, CallDa
         ExecutionContext *parentCtx = scope.engine->currentContext;
         // The first non-empty source URL in the call stack determines the translation context.
         while (!!parentCtx && context.isEmpty()) {
-            if (QV4::CompiledData::CompilationUnit *unit = parentCtx->d()->compilationUnit) {
+            if (CompiledData::CompilationUnit *unit = static_cast<CompiledData::CompilationUnit*>(parentCtx->d()->compilationUnit)) {
                 QString fileName = unit->fileName();
                 QUrl url(unit->fileName());
                 if (url.isValid() && url.isRelative()) {
diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index a5878dcffd..f26e5f6cdb 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -837,10 +837,9 @@ void QQDMIncubationTask::statusChanged(Status status)
     } else if (isDoneIncubating(status)) {
         Q_ASSERT(incubating);
         // The model was deleted from under our feet, cleanup ourselves
-        if (incubating->object) {
-            delete incubating->object;
-
-            incubating->object = 0;
+        delete incubating->object;
+        incubating->object = 0;
+        if (incubating->contextData) {
             incubating->contextData->destroy();
             incubating->contextData = 0;
         }
@@ -1965,9 +1964,8 @@ void QQmlDelegateModelItem::destroyObject()
     Q_ASSERT(object);
     Q_ASSERT(contextData);
 
-    QObjectPrivate *p = QObjectPrivate::get(object);
-    Q_ASSERT(p->declarativeData);
-    QQmlData *data = static_cast<QQmlData*>(p->declarativeData);
+    QQmlData *data = QQmlData::get(object);
+    Q_ASSERT(data);
     if (data->ownContext && data->context)
         data->context->clearContext();
     object->deleteLater();
@@ -1984,10 +1982,8 @@ void QQmlDelegateModelItem::destroyObject()
 
 QQmlDelegateModelItem *QQmlDelegateModelItem::dataForObject(QObject *object)
 {
-    QObjectPrivate *p = QObjectPrivate::get(object);
-    QQmlContextData *context = p->declarativeData
-            ? static_cast<QQmlData *>(p->declarativeData)->context
-            : 0;
+    QQmlData *d = QQmlData::get(object);
+    QQmlContextData *context = d ? d->context : 0;
     for (context = context ? context->parent : 0; context; context = context->parent) {
         if (QQmlDelegateModelItem *cacheItem = qobject_cast<QQmlDelegateModelItem *>(
                 context->contextObject)) {
diff --git a/src/qml/types/types.pri b/src/qml/types/types.pri
index d2e5020738..e85ab5982b 100644
--- a/src/qml/types/types.pri
+++ b/src/qml/types/types.pri
@@ -7,7 +7,6 @@ SOURCES += \
     $$PWD/qqmlmodelsmodule.cpp \
     $$PWD/qqmlmodelindexvaluetype.cpp \
     $$PWD/qqmlobjectmodel.cpp \
-    $$PWD/qqmltimer.cpp \
     $$PWD/qquickpackage.cpp \
     $$PWD/qquickworkerscript.cpp \
     $$PWD/qqmlinstantiator.cpp
@@ -23,8 +22,15 @@ HEADERS += \
     $$PWD/qqmlmodelsmodule_p.h \
     $$PWD/qqmlmodelindexvaluetype_p.h \
     $$PWD/qqmlobjectmodel_p.h \
-    $$PWD/qqmltimer_p.h \
     $$PWD/qquickpackage_p.h \
     $$PWD/qquickworkerscript_p.h \
     $$PWD/qqmlinstantiator_p.h \
     $$PWD/qqmlinstantiator_p_p.h
+
+qtConfig(animation) {
+    SOURCES += \
+        $$PWD/qqmltimer.cpp
+
+    HEADERS += \
+    $$PWD/qqmltimer_p.h
+}
diff --git a/src/quick/configure.json b/src/quick/configure.json
index 4ed11e8318..047fa8c948 100644
--- a/src/quick/configure.json
+++ b/src/quick/configure.json
@@ -51,6 +51,7 @@
         "quick-canvas": {
             "label": "Canvas item",
             "purpose": "Provides the Qt Quick Canvas Item",
+            "condition": "features.quick-path",
             "output": [
                 "privateFeature"
             ]
@@ -97,6 +98,14 @@
                 "privateFeature"
             ]
         },
+        "quick-particles": {
+            "label": "Particle support",
+            "purpose": "Provides a particle system for Qt Quick",
+            "condition": "features.quick-shadereffect && features.quick-sprite && features.opengl",
+            "output": [
+                "privateFeature"
+            ]
+        },
         "quick-path": {
             "label": "Path support",
             "purpose": "Provides Path elements in Qt Quick",
diff --git a/src/quick/items/context2d/qquickcanvasitem.cpp b/src/quick/items/context2d/qquickcanvasitem.cpp
index 1167f408f5..dab35f2a54 100644
--- a/src/quick/items/context2d/qquickcanvasitem.cpp
+++ b/src/quick/items/context2d/qquickcanvasitem.cpp
@@ -44,8 +44,10 @@
 #include <private/qquickcontext2d_p.h>
 #include <private/qquickcontext2dtexture_p.h>
 #include <private/qsgadaptationlayer_p.h>
+#include <qsgtextureprovider.h>
 #include <QtQuick/private/qquickpixmapcache_p.h>
 #include <QtGui/QGuiApplication>
+#include <qsgtextureprovider.h>
 
 #include <qqmlinfo.h>
 #include <private/qqmlengine_p.h>
@@ -1102,14 +1104,17 @@ bool QQuickCanvasItem::isImageLoaded(const QUrl& url) const
 QImage QQuickCanvasItem::toImage(const QRectF& rect) const
 {
     Q_D(const QQuickCanvasItem);
-    if (d->context) {
-        if (rect.isEmpty())
-            return d->context->toImage(canvasWindow());
-        else
-            return d->context->toImage(rect);
-    }
 
-    return QImage();
+    if (!d->context)
+        return QImage();
+
+    const QRectF &rectSource = rect.isEmpty() ? canvasWindow() : rect;
+    const qreal dpr = window() ? window()->effectiveDevicePixelRatio() : qreal(1);
+    const QRectF rectScaled(rectSource.topLeft() * dpr, rectSource.size() * dpr);
+
+    QImage image = d->context->toImage(rectScaled);
+    image.setDevicePixelRatio(dpr);
+    return image;
 }
 
 static const char* mimeToType(const QString &mime)
diff --git a/src/quick/items/context2d/qquickcontext2d.cpp b/src/quick/items/context2d/qquickcontext2d.cpp
index b9b701313e..1a6f530bfa 100644
--- a/src/quick/items/context2d/qquickcontext2d.cpp
+++ b/src/quick/items/context2d/qquickcontext2d.cpp
@@ -42,13 +42,16 @@
 #include "qquickcanvasitem_p.h"
 #include <private/qquickcontext2dtexture_p.h>
 #include <private/qquickitem_p.h>
+#if QT_CONFIG(quick_shadereffect)
 #include <QtQuick/private/qquickshadereffectsource_p.h>
+#endif
 #include <qsgrendererinterface.h>
 
 #include <QtQuick/private/qsgcontext_p.h>
 #include <private/qquicksvgparser_p.h>
+#if QT_CONFIG(quick_path)
 #include <private/qquickpath_p.h>
-
+#endif
 #include <private/qquickimage_p_p.h>
 
 #include <qqmlinfo.h>
@@ -126,8 +129,6 @@ QT_BEGIN_NAMESPACE
 
 Q_CORE_EXPORT double qstrtod(const char *s00, char const **se, bool *ok);
 
-#define DEGREES(t) ((t) * 180.0 / M_PI)
-
 #define CHECK_CONTEXT(r)     if (!r || !r->d()->context || !r->d()->context->bufferValid()) \
                                 THROW_GENERIC_ERROR("Not a Context2D object");
 
@@ -567,9 +568,10 @@ struct QQuickJSContext2D : public QV4::Object
     static void method_set_shadowOffsetY(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
 
     // should these two be on the proto?
+#if QT_CONFIG(quick_path)
     static void method_get_path(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
     static void method_set_path(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
+#endif
     static void method_get_font(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
     static void method_set_font(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
     static void method_get_textAlign(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
@@ -925,9 +927,9 @@ struct QQuickJSContext2DImageData : public QV4::Object
     static void method_get_height(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
     static void method_get_data(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
 
-    static void markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *engine) {
-        static_cast<QQuickJSContext2DImageData::Data *>(that)->pixelData.mark(engine);
-        QV4::Object::markObjects(that, engine);
+    static void markObjects(QV4::Heap::Base *that, QV4::MarkStack *markStack) {
+        static_cast<QQuickJSContext2DImageData::Data *>(that)->pixelData.mark(markStack);
+        QV4::Object::markObjects(that, markStack);
     }
 };
 
@@ -958,7 +960,7 @@ static QV4::ReturnedValue qt_create_image_data(qreal w, qreal h, QV4::ExecutionE
         *pixelData->d()->image = QImage(w, h, QImage::Format_ARGB32);
         pixelData->d()->image->fill(0x00000000);
     } else {
-        Q_ASSERT(image.width() == qRound(w) && image.height() == qRound(h));
+        Q_ASSERT(image.width()== qRound(w * image.devicePixelRatio()) && image.height() == qRound(h * image.devicePixelRatio()));
         *pixelData->d()->image = image.format() == QImage::Format_ARGB32 ? image : image.convertToFormat(QImage::Format_ARGB32);
     }
 
@@ -1639,7 +1641,7 @@ void QQuickJSContext2DPrototype::method_createConicalGradient(const QV4::Builtin
     if (callData->argc >= 3) {
         qreal x = callData->args[0].toNumber();
         qreal y = callData->args[1].toNumber();
-        qreal angle = DEGREES(callData->args[2].toNumber());
+        qreal angle = qRadiansToDegrees(callData->args[2].toNumber());
         if (!qt_is_finite(x) || !qt_is_finite(y)) {
             THROW_DOM(DOMEXCEPTION_NOT_SUPPORTED_ERR, "createConicalGradient(): Incorrect arguments");
         }
@@ -2032,6 +2034,7 @@ void QQuickJSContext2D::method_set_shadowOffsetY(const QV4::BuiltinFunction *, Q
     RETURN_UNDEFINED();
 }
 
+#if QT_CONFIG(quick_path)
 void QQuickJSContext2D::method_get_path(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
 {
     QV4::Scoped<QQuickJSContext2D> r(scope, callData->thisObject);
@@ -2058,6 +2061,7 @@ void QQuickJSContext2D::method_set_path(const QV4::BuiltinFunction *, QV4::Scope
     r->d()->context->m_v4path.set(scope.engine, value);
     RETURN_UNDEFINED();
 }
+#endif // QT_CONFIG(quick_path)
 
 //rects
 /*!
@@ -3364,7 +3368,7 @@ void QQuickContext2D::rotate(qreal angle)
         return;
 
     QTransform newTransform =state.matrix;
-    newTransform.rotate(DEGREES(angle));
+    newTransform.rotate(qRadiansToDegrees(angle));
 
     if (!newTransform.isInvertible()) {
         state.invertibleCTM = false;
@@ -3373,7 +3377,7 @@ void QQuickContext2D::rotate(qreal angle)
 
     state.matrix = newTransform;
     buffer()->updateMatrix(state.matrix);
-    m_path = QTransform().rotate(-DEGREES(angle)).map(m_path);
+    m_path = QTransform().rotate(-qRadiansToDegrees(angle)).map(m_path);
 }
 
 void QQuickContext2D::shear(qreal h, qreal v)
@@ -3770,8 +3774,8 @@ void QQuickContext2D::arc(qreal xc, qreal yc, qreal radius, qreal sar, qreal ear
     antiClockWise = !antiClockWise;
     //end hack
 
-    float sa = DEGREES(sar);
-    float ea = DEGREES(ear);
+    float sa = qRadiansToDegrees(sar);
+    float ea = qRadiansToDegrees(ear);
 
     double span = 0;
 
@@ -4208,7 +4212,9 @@ QQuickContext2DEngineData::QQuickContext2DEngineData(QV4::ExecutionEngine *v4)
     proto->defineAccessorProperty(QStringLiteral("fillStyle"), QQuickJSContext2D::method_get_fillStyle, QQuickJSContext2D::method_set_fillStyle);
     proto->defineAccessorProperty(QStringLiteral("shadowColor"), QQuickJSContext2D::method_get_shadowColor, QQuickJSContext2D::method_set_shadowColor);
     proto->defineAccessorProperty(QStringLiteral("textBaseline"), QQuickJSContext2D::method_get_textBaseline, QQuickJSContext2D::method_set_textBaseline);
+#if QT_CONFIG(quick_path)
     proto->defineAccessorProperty(QStringLiteral("path"), QQuickJSContext2D::method_get_path, QQuickJSContext2D::method_set_path);
+#endif
     proto->defineAccessorProperty(QStringLiteral("lineJoin"), QQuickJSContext2D::method_get_lineJoin, QQuickJSContext2D::method_set_lineJoin);
     proto->defineAccessorProperty(QStringLiteral("lineWidth"), QQuickJSContext2D::method_get_lineWidth, QQuickJSContext2D::method_set_lineWidth);
     proto->defineAccessorProperty(QStringLiteral("textAlign"), QQuickJSContext2D::method_get_textAlign, QQuickJSContext2D::method_set_textAlign);
diff --git a/src/quick/items/qquickdrag_p.h b/src/quick/items/qquickdrag_p.h
index 357f72b3e7..17e9d8c690 100644
--- a/src/quick/items/qquickdrag_p.h
+++ b/src/quick/items/qquickdrag_p.h
@@ -248,7 +248,7 @@ class QQuickDragAttached : public QObject
     Q_PROPERTY(QObject *source READ source WRITE setSource NOTIFY sourceChanged RESET resetSource)
     Q_PROPERTY(QObject *target READ target NOTIFY targetChanged)
     Q_PROPERTY(QPointF hotSpot READ hotSpot WRITE setHotSpot NOTIFY hotSpotChanged)
-    Q_PROPERTY(QUrl imageSource READ imageSource WRITE setImageSource NOTIFY imageSourceChanged REVISION 8)
+    Q_PROPERTY(QUrl imageSource READ imageSource WRITE setImageSource NOTIFY imageSourceChanged)
     Q_PROPERTY(QStringList keys READ keys WRITE setKeys NOTIFY keysChanged)
     Q_PROPERTY(QVariantMap mimeData READ mimeData WRITE setMimeData NOTIFY mimeDataChanged)
     Q_PROPERTY(Qt::DropActions supportedActions READ supportedActions WRITE setSupportedActions NOTIFY supportedActionsChanged)
diff --git a/src/quick/items/qquickevents.cpp b/src/quick/items/qquickevents.cpp
index 2671b9c9a2..19dd81b6fc 100644
--- a/src/quick/items/qquickevents.cpp
+++ b/src/quick/items/qquickevents.cpp
@@ -195,8 +195,8 @@ Item {
 */
 
 /*!
-    \qmlproperty int QtQuick::MouseEvent::x
-    \qmlproperty int QtQuick::MouseEvent::y
+    \qmlproperty real QtQuick::MouseEvent::x
+    \qmlproperty real QtQuick::MouseEvent::y
 
     These properties hold the coordinates of the position supplied by the mouse event.
 */
@@ -342,8 +342,8 @@ Item {
 */
 
 /*!
-    \qmlproperty int QtQuick::WheelEvent::x
-    \qmlproperty int QtQuick::WheelEvent::y
+    \qmlproperty real QtQuick::WheelEvent::x
+    \qmlproperty real QtQuick::WheelEvent::y
 
     These properties hold the coordinates of the position supplied by the wheel event.
 */
@@ -1225,9 +1225,24 @@ QTouchEvent *QQuickPointerTouchEvent::touchEventForItem(QQuickItem *item, bool i
         auto p = m_touchPoints.at(i);
         if (p->isAccepted())
             continue;
+        // include points where item is the grabber
         bool isGrabber = p->exclusiveGrabber() == item;
+        // include newly pressed points inside the bounds
         bool isPressInside = p->state() == QQuickEventPoint::Pressed && item->contains(item->mapFromScene(p->scenePos()));
-        if (!(isGrabber || isPressInside || isFiltering))
+
+        // filtering: (childMouseEventFilter) include points that are grabbed by children of the target item
+        bool grabberIsChild = false;
+        auto parent = p->grabberItem();
+        while (isFiltering && parent) {
+            if (parent == item) {
+                grabberIsChild = true;
+                break;
+            }
+            parent = parent->parentItem();
+        }
+        bool filterRelevant = isFiltering && grabberIsChild;
+
+        if (!(isGrabber || isPressInside || filterRelevant))
             continue;
 
         const QTouchEvent::TouchPoint *tp = touchPointById(p->pointId());
diff --git a/src/quick/items/qquickflickable.cpp b/src/quick/items/qquickflickable.cpp
index 6306a48d48..40719c6324 100644
--- a/src/quick/items/qquickflickable.cpp
+++ b/src/quick/items/qquickflickable.cpp
@@ -255,6 +255,7 @@ QQuickFlickablePrivate::QQuickFlickablePrivate()
     , flickBoost(1.0), fixupMode(Normal), vTime(0), visibleArea(0)
     , flickableDirection(QQuickFlickable::AutoFlickDirection)
     , boundsBehavior(QQuickFlickable::DragAndOvershootBounds)
+    , boundsMovement(QQuickFlickable::FollowBoundsBehavior)
     , rebound(0)
 {
 }
@@ -643,8 +644,10 @@ is finished.
 
     \section1 Limitations
 
-    \note Due to an implementation detail, items placed inside a Flickable cannot anchor to it by
-    \c id. Use \c parent instead.
+    \note Due to an implementation detail, items placed inside a Flickable
+    cannot anchor to the Flickable. Instead, use \l {Item::}{parent}, which
+    refers to the Flickable's \l contentItem. The size of the content item is
+    determined by \l contentWidth and \l contentHeight.
 */
 
 /*!
@@ -1575,16 +1578,18 @@ void QQuickFlickablePrivate::replayDelayedPress()
 void QQuickFlickablePrivate::setViewportX(qreal x)
 {
     Q_Q(QQuickFlickable);
-    if (pixelAligned)
-        x = -Round(-x);
-
-    contentItem->setX(x);
-    if (contentItem->x() != x)
-        return; // reentered
+    qreal effectiveX = pixelAligned ? -Round(-x) : x;
 
     const qreal maxX = q->maxXExtent();
     const qreal minX = q->minXExtent();
 
+    if (boundsMovement == int(QQuickFlickable::StopAtBounds))
+        effectiveX = qBound(maxX, effectiveX, minX);
+
+    contentItem->setX(effectiveX);
+    if (contentItem->x() != effectiveX)
+        return; // reentered
+
     qreal overshoot = 0.0;
     if (x <= maxX)
         overshoot = maxX - x;
@@ -1600,16 +1605,18 @@ void QQuickFlickablePrivate::setViewportX(qreal x)
 void QQuickFlickablePrivate::setViewportY(qreal y)
 {
     Q_Q(QQuickFlickable);
-    if (pixelAligned)
-        y = -Round(-y);
-
-    contentItem->setY(y);
-    if (contentItem->y() != y)
-        return; // reentered
+    qreal effectiveY = pixelAligned ? -Round(-y) : y;
 
     const qreal maxY = q->maxYExtent();
     const qreal minY = q->minYExtent();
 
+    if (boundsMovement == int(QQuickFlickable::StopAtBounds))
+        effectiveY = qBound(maxY, effectiveY, minY);
+
+    contentItem->setY(effectiveY);
+    if (contentItem->y() != effectiveY)
+        return; // reentered
+
     qreal overshoot = 0.0;
     if (y <= maxY)
         overshoot = maxY - y;
@@ -1869,8 +1876,9 @@ QQmlListProperty<QQuickItem> QQuickFlickable::flickableChildren()
     beyond the Flickable's boundaries, or overshoot the
     Flickable's boundaries when flicked.
 
-    This enables the feeling that the edges of the view are soft,
-    rather than a hard physical boundary.
+    When the \l boundsMovement is \c Flickable.FollowBoundsBehavior, a value
+    other than \c Flickable.StopAtBounds will give a feeling that the edges of
+    the view are soft, rather than a hard physical boundary.
 
     The \c boundsBehavior can be one of:
 
@@ -1886,7 +1894,7 @@ QQmlListProperty<QQuickItem> QQuickFlickable::flickableChildren()
     boundary when flicked.
     \endlist
 
-    \sa horizontalOvershoot, verticalOvershoot
+    \sa horizontalOvershoot, verticalOvershoot, boundsMovement
 */
 QQuickFlickable::BoundsBehavior QQuickFlickable::boundsBehavior() const
 {
@@ -2303,7 +2311,8 @@ bool QQuickFlickable::filterMouseEvent(QQuickItem *receiver, QMouseEvent *event)
 
     bool receiverDisabled = receiver && !receiver->isEnabled();
     bool stealThisEvent = d->stealMouse;
-    if ((stealThisEvent || contains(localPos)) && (!receiver || !receiver->keepMouseGrab() || receiverDisabled)) {
+    bool receiverKeepsGrab = receiver && (receiver->keepMouseGrab() || receiver->keepTouchGrab());
+    if ((stealThisEvent || contains(localPos)) && (!receiver || !receiverKeepsGrab || receiverDisabled)) {
         QScopedPointer<QMouseEvent> mouseEvent(QQuickWindowPrivate::cloneMouseEvent(event, &localPos));
         mouseEvent->setAccepted(false);
 
@@ -2323,7 +2332,7 @@ bool QQuickFlickable::filterMouseEvent(QQuickItem *receiver, QMouseEvent *event)
         default:
             break;
         }
-        if ((receiver && stealThisEvent && !receiver->keepMouseGrab() && receiver != this) || receiverDisabled) {
+        if ((receiver && stealThisEvent && !receiverKeepsGrab && receiver != this) || receiverDisabled) {
             d->clearDelayedPress();
             grabMouse();
         } else if (d->delayedPressEvent) {
@@ -2339,7 +2348,7 @@ bool QQuickFlickable::filterMouseEvent(QQuickItem *receiver, QMouseEvent *event)
         d->lastPosTime = -1;
         returnToBounds();
     }
-    if (event->type() == QEvent::MouseButtonRelease || (receiver && receiver->keepMouseGrab() && !receiverDisabled)) {
+    if (event->type() == QEvent::MouseButtonRelease || (receiverKeepsGrab && !receiverDisabled)) {
         // mouse released, or another item has claimed the grab
         d->lastPosTime = -1;
         d->clearDelayedPress();
@@ -2696,7 +2705,11 @@ void QQuickFlickablePrivate::updateVelocity()
     The value is negative when the content is dragged or flicked beyond the beginning,
     and positive when beyond the end; \c 0.0 otherwise.
 
-    \sa verticalOvershoot, boundsBehavior
+    Whether the values are reported for dragging and/or flicking is determined by
+    \l boundsBehavior. The overshoot distance is reported even when \l boundsMovement
+    is \c Flickable.StopAtBounds.
+
+    \sa verticalOvershoot, boundsBehavior, boundsMovement
 */
 qreal QQuickFlickable::horizontalOvershoot() const
 {
@@ -2713,7 +2726,11 @@ qreal QQuickFlickable::horizontalOvershoot() const
     The value is negative when the content is dragged or flicked beyond the beginning,
     and positive when beyond the end; \c 0.0 otherwise.
 
-    \sa horizontalOvershoot, boundsBehavior
+    Whether the values are reported for dragging and/or flicking is determined by
+    \l boundsBehavior. The overshoot distance is reported even when \l boundsMovement
+    is \c Flickable.StopAtBounds.
+
+    \sa horizontalOvershoot, boundsBehavior, boundsMovement
 */
 qreal QQuickFlickable::verticalOvershoot() const
 {
@@ -2721,4 +2738,66 @@ qreal QQuickFlickable::verticalOvershoot() const
     return d->vData.overshoot;
 }
 
+/*!
+    \qmlproperty enumeration QtQuick::Flickable::boundsMovement
+    \since 5.10
+
+    This property holds whether the flickable will give a feeling that the edges of the
+    view are soft, rather than a hard physical boundary.
+
+    The \c boundsMovement can be one of:
+
+    \list
+    \li Flickable.StopAtBounds - this allows implementing custom edge effects where the
+    contents do not follow drags or flicks beyond the bounds of the flickable. The values
+    of \l horizontalOvershoot and \l verticalOvershoot can be utilized to implement custom
+    edge effects.
+    \li Flickable.FollowBoundsBehavior (default) - whether the contents follow drags or
+    flicks beyond the bounds of the flickable is determined by \l boundsBehavior.
+    \endlist
+
+    The following example keeps the contents within bounds and instead applies a flip
+    effect when flicked over horizontal bounds:
+    \code
+    Flickable {
+        id: flickable
+        boundsMovement: Flickable.StopAtBounds
+        boundsBehavior: Flickable.DragAndOvershootBounds
+        transform: Rotation {
+            axis { x: 0; y: 1; z: 0 }
+            origin.x: flickable.width / 2
+            origin.y: flickable.height / 2
+            angle: Math.min(30, Math.max(-30, flickable.horizontalOvershoot))
+        }
+    }
+    \endcode
+
+    The following example keeps the contents within bounds and instead applies an opacity
+    effect when dragged over vertical bounds:
+    \code
+    Flickable {
+        boundsMovement: Flickable.StopAtBounds
+        boundsBehavior: Flickable.DragOverBounds
+        opacity: Math.max(0.5, 1.0 - Math.abs(verticalOvershoot) / height)
+    }
+    \endcode
+
+    \sa boundsBehavior, verticalOvershoot, horizontalOvershoot
+*/
+QQuickFlickable::BoundsMovement QQuickFlickable::boundsMovement() const
+{
+    Q_D(const QQuickFlickable);
+    return d->boundsMovement;
+}
+
+void QQuickFlickable::setBoundsMovement(BoundsMovement movement)
+{
+    Q_D(QQuickFlickable);
+    if (d->boundsMovement == movement)
+        return;
+
+    d->boundsMovement = movement;
+    emit boundsMovementChanged();
+}
+
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickflickable_p.h b/src/quick/items/qquickflickable_p.h
index 52cade1472..7558ee7df8 100644
--- a/src/quick/items/qquickflickable_p.h
+++ b/src/quick/items/qquickflickable_p.h
@@ -80,6 +80,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickFlickable : public QQuickItem
     Q_PROPERTY(qreal verticalVelocity READ verticalVelocity NOTIFY verticalVelocityChanged)
 
     Q_PROPERTY(BoundsBehavior boundsBehavior READ boundsBehavior WRITE setBoundsBehavior NOTIFY boundsBehaviorChanged)
+    Q_PROPERTY(BoundsMovement boundsMovement READ boundsMovement WRITE setBoundsMovement NOTIFY boundsMovementChanged REVISION 10)
     Q_PROPERTY(QQuickTransition *rebound READ rebound WRITE setRebound NOTIFY reboundChanged)
     Q_PROPERTY(qreal maximumFlickVelocity READ maximumFlickVelocity WRITE setMaximumFlickVelocity NOTIFY maximumFlickVelocityChanged)
     Q_PROPERTY(qreal flickDeceleration READ flickDeceleration WRITE setFlickDeceleration NOTIFY flickDecelerationChanged)
@@ -132,6 +133,15 @@ public:
     BoundsBehavior boundsBehavior() const;
     void setBoundsBehavior(BoundsBehavior);
 
+    enum BoundsMovement {
+        // StopAtBounds = 0x0,
+        FollowBoundsBehavior = 0x1
+    };
+    Q_ENUM(BoundsMovement)
+
+    BoundsMovement boundsMovement() const;
+    void setBoundsMovement(BoundsMovement movement);
+
     QQuickTransition *rebound() const;
     void setRebound(QQuickTransition *transition);
 
@@ -237,6 +247,7 @@ Q_SIGNALS:
     void flickableDirectionChanged();
     void interactiveChanged();
     void boundsBehaviorChanged();
+    Q_REVISION(10) void boundsMovementChanged();
     void reboundChanged();
     void maximumFlickVelocityChanged();
     void flickDecelerationChanged();
diff --git a/src/quick/items/qquickflickable_p_p.h b/src/quick/items/qquickflickable_p_p.h
index 1ceff22dfc..8609a15fcd 100644
--- a/src/quick/items/qquickflickable_p_p.h
+++ b/src/quick/items/qquickflickable_p_p.h
@@ -247,6 +247,7 @@ public:
     QQuickFlickableVisibleArea *visibleArea;
     QQuickFlickable::FlickableDirection flickableDirection;
     QQuickFlickable::BoundsBehavior boundsBehavior;
+    QQuickFlickable::BoundsMovement boundsMovement;
     QQuickTransition *rebound;
 
     void viewportAxisMoved(AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
diff --git a/src/quick/items/qquickimage.cpp b/src/quick/items/qquickimage.cpp
index f3d7dc4b56..bf982117e8 100644
--- a/src/quick/items/qquickimage.cpp
+++ b/src/quick/items/qquickimage.cpp
@@ -559,7 +559,8 @@ void QQuickImage::updatePaintedGeometry()
 void QQuickImage::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
 {
     QQuickImageBase::geometryChanged(newGeometry, oldGeometry);
-    updatePaintedGeometry();
+    if (newGeometry.size() != oldGeometry.size())
+        updatePaintedGeometry();
 }
 
 QRectF QQuickImage::boundingRect() const
diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index 1edc54aca2..bfc4a59851 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -6780,8 +6780,27 @@ bool QQuickItem::heightValid() const
 }
 
 /*!
-    \internal
-  */
+    \since 5.10
+
+    Returns the size of the item.
+
+    \sa setSize, width, height
+ */
+
+QSizeF QQuickItem::size() const
+{
+    Q_D(const QQuickItem);
+    return QSizeF(d->width, d->height);
+}
+
+
+/*!
+    \since 5.10
+
+    Sets the size of the item to \a size.
+
+    \sa size, setWidth, setHeight
+ */
 void QQuickItem::setSize(const QSizeF &size)
 {
     Q_D(QQuickItem);
@@ -8456,19 +8475,19 @@ struct QQuickItemWrapper : public QObjectWrapper {
 
 struct QQuickItemWrapper : public QV4::QObjectWrapper {
     V4_OBJECT2(QQuickItemWrapper, QV4::QObjectWrapper)
-    static void markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e);
+    static void markObjects(QV4::Heap::Base *that, QV4::MarkStack *markStack);
 };
 
 DEFINE_OBJECT_VTABLE(QQuickItemWrapper);
 
-void QQuickItemWrapper::markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e)
+void QQuickItemWrapper::markObjects(QV4::Heap::Base *that, QV4::MarkStack *markStack)
 {
     QObjectWrapper::Data *This = static_cast<QObjectWrapper::Data *>(that);
     if (QQuickItem *item = static_cast<QQuickItem*>(This->object())) {
         for (QQuickItem *child : qAsConst(QQuickItemPrivate::get(item)->childItems))
-            QV4::QObjectWrapper::markWrapper(child, e);
+            QV4::QObjectWrapper::markWrapper(child, markStack);
     }
-    QV4::QObjectWrapper::markObjects(that, e);
+    QV4::QObjectWrapper::markObjects(that, markStack);
 }
 
 quint64 QQuickItemPrivate::_q_createJSWrapper(QV4::ExecutionEngine *engine)
diff --git a/src/quick/items/qquickitem.h b/src/quick/items/qquickitem.h
index 279d052db9..1d174ca979 100644
--- a/src/quick/items/qquickitem.h
+++ b/src/quick/items/qquickitem.h
@@ -237,6 +237,7 @@ public:
     void setImplicitHeight(qreal);
     qreal implicitHeight() const;
 
+    QSizeF size() const;
     void setSize(const QSizeF &size);
 
     TransformOrigin transformOrigin() const;
diff --git a/src/quick/items/qquickitemanimation.cpp b/src/quick/items/qquickitemanimation.cpp
index 9873622f41..874130b137 100644
--- a/src/quick/items/qquickitemanimation.cpp
+++ b/src/quick/items/qquickitemanimation.cpp
@@ -327,7 +327,7 @@ QAbstractAnimationJob* QQuickParentAnimation::transition(QQuickStateActions &act
                     }
 
                     if (scale != 0)
-                        rotation = qAtan2(transform.m12()/scale, transform.m11()/scale) * 180/M_PI;
+                        rotation = qRadiansToDegrees(qAtan2(transform.m12() / scale, transform.m11() / scale));
                     else {
                         qmlWarning(this) << QQuickParentAnimation::tr("Unable to preserve appearance under scale of 0");
                         ok = false;
diff --git a/src/quick/items/qquickitemsmodule.cpp b/src/quick/items/qquickitemsmodule.cpp
index eeffe1ee48..13f23c918a 100644
--- a/src/quick/items/qquickitemsmodule.cpp
+++ b/src/quick/items/qquickitemsmodule.cpp
@@ -273,7 +273,7 @@ static void qt_quickitems_defineModule(const char *uri, int major, int minor)
     qmlRegisterType<QQuickAnchorSet>();
     qmlRegisterType<QQuickAnchorAnimation>(uri, major, minor,"AnchorAnimation");
     qmlRegisterType<QQuickParentAnimation>(uri, major, minor,"ParentAnimation");
-#if QT_CONFIG(quick_canvas)
+#if QT_CONFIG(quick_path)
     qmlRegisterType<QQuickPathAnimation>("QtQuick",2,0,"PathAnimation");
     qmlRegisterType<QQuickPathInterpolator>("QtQuick",2,0,"PathInterpolator");
 #endif
@@ -389,6 +389,8 @@ static void qt_quickitems_defineModule(const char *uri, int major, int minor)
 #if QT_CONFIG(quick_shadereffect)
     qmlRegisterType<QQuickShaderEffectSource, 2>(uri, 2, 9, "ShaderEffectSource");
 #endif
+
+    qmlRegisterType<QQuickFlickable, 10>(uri, 2, 10, "Flickable");
 }
 
 static void initResources()
diff --git a/src/quick/items/qquickpainteditem_p.h b/src/quick/items/qquickpainteditem_p.h
index 742e786335..3e160ed55a 100644
--- a/src/quick/items/qquickpainteditem_p.h
+++ b/src/quick/items/qquickpainteditem_p.h
@@ -51,7 +51,9 @@
 // We mean it.
 //
 
+#include "qquickpainteditem.h"
 #include "qquickitem_p.h"
+#include "qquickpainteditem.h"
 #include <QtGui/qcolor.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/src/quick/items/qquickpositioners.cpp b/src/quick/items/qquickpositioners.cpp
index 70fc5fa65f..05882d0464 100644
--- a/src/quick/items/qquickpositioners.cpp
+++ b/src/quick/items/qquickpositioners.cpp
@@ -48,19 +48,8 @@
 
 QT_BEGIN_NAMESPACE
 
-// The default item change types that positioners are interested in.
-static const QQuickItemPrivate::ChangeTypes explicitSizeItemChangeTypes =
-    QQuickItemPrivate::Geometry
-    | QQuickItemPrivate::SiblingOrder
-    | QQuickItemPrivate::Visibility
-    | QQuickItemPrivate::Destroyed;
-
-// The item change types for positioners that are only interested in the implicit
-// size of the items they manage. These are used if useImplicitSize is true.
-// useImplicitSize should be set in the constructor, before any items are added.
-static const QQuickItemPrivate::ChangeTypes implicitSizeItemChangeTypes =
-    QQuickItemPrivate::ImplicitWidth
-    | QQuickItemPrivate::ImplicitHeight
+static const QQuickItemPrivate::ChangeTypes watchedChanges
+    = QQuickItemPrivate::Geometry
     | QQuickItemPrivate::SiblingOrder
     | QQuickItemPrivate::Visibility
     | QQuickItemPrivate::Destroyed;
@@ -68,15 +57,13 @@ static const QQuickItemPrivate::ChangeTypes implicitSizeItemChangeTypes =
 void QQuickBasePositionerPrivate::watchChanges(QQuickItem *other)
 {
     QQuickItemPrivate *otherPrivate = QQuickItemPrivate::get(other);
-    otherPrivate->addItemChangeListener(this, useImplicitSize
-        ? implicitSizeItemChangeTypes : explicitSizeItemChangeTypes);
+    otherPrivate->addItemChangeListener(this, watchedChanges);
 }
 
 void QQuickBasePositionerPrivate::unwatchChanges(QQuickItem* other)
 {
     QQuickItemPrivate *otherPrivate = QQuickItemPrivate::get(other);
-    otherPrivate->removeItemChangeListener(this, useImplicitSize
-        ? implicitSizeItemChangeTypes : explicitSizeItemChangeTypes);
+    otherPrivate->removeItemChangeListener(this, watchedChanges);
 }
 
 
@@ -336,7 +323,7 @@ void QQuickBasePositioner::prePositioning()
         if (wIdx < 0) {
             d->watchChanges(child);
             posItem.isNew = true;
-            if (!childPrivate->explicitVisible || !d->itemWidth(child) || !d->itemHeight(child)) {
+            if (!childPrivate->explicitVisible || !child->width() || !child->height()) {
                 posItem.isVisible = false;
                 posItem.index = -1;
                 unpositionedItems.append(posItem);
@@ -358,7 +345,7 @@ void QQuickBasePositioner::prePositioning()
             PositionedItem *item = &oldItems[wIdx];
             // Items are only omitted from positioning if they are explicitly hidden
             // i.e. their positioning is not affected if an ancestor is hidden.
-            if (!childPrivate->explicitVisible || !d->itemWidth(child) || !d->itemHeight(child)) {
+            if (!childPrivate->explicitVisible || !child->width() || !child->height()) {
                 item->isVisible = false;
                 item->index = -1;
                 unpositionedItems.append(*item);
@@ -957,7 +944,6 @@ QQuickColumn::QQuickColumn(QQuickItem *parent)
 void QQuickColumn::doPositioning(QSizeF *contentSize)
 {
     //Precondition: All items in the positioned list have a valid item pointer and should be positioned
-    QQuickBasePositionerPrivate *d = static_cast<QQuickBasePositionerPrivate*>(QQuickBasePositionerPrivate::get(this));
     qreal voffset = topPadding();
     const qreal padding = leftPadding() + rightPadding();
     contentSize->setWidth(qMax(contentSize->width(), padding));
@@ -966,9 +952,9 @@ void QQuickColumn::doPositioning(QSizeF *contentSize)
         PositionedItem &child = positionedItems[ii];
         positionItem(child.itemX() + leftPadding() - child.leftPadding, voffset, &child);
         child.updatePadding(leftPadding(), topPadding(), rightPadding(), bottomPadding());
-        contentSize->setWidth(qMax(contentSize->width(), d->itemWidth(child.item) + padding));
+        contentSize->setWidth(qMax(contentSize->width(), child.item->width() + padding));
 
-        voffset += d->itemHeight(child.item);
+        voffset += child.item->height();
         voffset += spacing();
     }
 
@@ -1236,9 +1222,9 @@ void QQuickRow::doPositioning(QSizeF *contentSize)
             hoffsets << hoffset;
         }
 
-        contentSize->setHeight(qMax(contentSize->height(), d->itemHeight(child.item) + padding));
+        contentSize->setHeight(qMax(contentSize->height(), child.item->height() + padding));
 
-        hoffset += d->itemWidth(child.item);
+        hoffset += child.item->width();
         hoffset += spacing();
     }
 
@@ -1259,7 +1245,7 @@ void QQuickRow::doPositioning(QSizeF *contentSize)
     int acc = 0;
     for (int ii = 0; ii < positionedItems.count(); ++ii) {
         PositionedItem &child = positionedItems[ii];
-        hoffset = end - hoffsets[acc++] - d->itemWidth(child.item);
+        hoffset = end - hoffsets[acc++] - child.item->width();
         positionItem(hoffset, child.itemY() + topPadding() - child.topPadding, &child);
         child.updatePadding(leftPadding(), topPadding(), rightPadding(), bottomPadding());
     }
@@ -1760,12 +1746,10 @@ void QQuickGrid::doPositioning(QSizeF *contentSize)
                     break;
 
                 const PositionedItem &child = positionedItems.at(childIndex++);
-                const qreal childWidth = d->itemWidth(child.item);
-                const qreal childHeight = d->itemHeight(child.item);
-                if (childWidth > maxColWidth[j])
-                    maxColWidth[j] = childWidth;
-                if (childHeight > maxRowHeight[i])
-                    maxRowHeight[i] = childHeight;
+                if (child.item->width() > maxColWidth[j])
+                    maxColWidth[j] = child.item->width();
+                if (child.item->height() > maxRowHeight[i])
+                    maxRowHeight[i] = child.item->height();
             }
         }
     } else {
@@ -1780,12 +1764,10 @@ void QQuickGrid::doPositioning(QSizeF *contentSize)
                     break;
 
                 const PositionedItem &child = positionedItems.at(childIndex++);
-                const qreal childWidth = d->itemWidth(child.item);
-                const qreal childHeight = d->itemHeight(child.item);
-                if (childWidth > maxColWidth[j])
-                    maxColWidth[j] = childWidth;
-                if (childHeight > maxRowHeight[i])
-                    maxRowHeight[i] = childHeight;
+                if (child.item->width() > maxColWidth[j])
+                    maxColWidth[j] = child.item->width();
+                if (child.item->height() > maxRowHeight[i])
+                    maxRowHeight[i] = child.item->height();
             }
         }
     }
@@ -1827,22 +1809,20 @@ void QQuickGrid::doPositioning(QSizeF *contentSize)
     for (int i = 0; i < positionedItems.count(); ++i) {
         PositionedItem &child = positionedItems[i];
         qreal childXOffset = xoffset;
-        const qreal childWidth = d->itemWidth(child.item);
-        const qreal childHeight = d->itemHeight(child.item);
 
         if (effectiveHAlign() == AlignRight)
-            childXOffset += maxColWidth[curCol] - childWidth;
+            childXOffset += maxColWidth[curCol] - child.item->width();
         else if (hItemAlign() == AlignHCenter)
-            childXOffset += (maxColWidth[curCol] - childWidth)/2.0;
+            childXOffset += (maxColWidth[curCol] - child.item->width())/2.0;
 
         if (!d->isLeftToRight())
             childXOffset -= maxColWidth[curCol];
 
         qreal alignYOffset = yoffset;
         if (m_vItemAlign == AlignVCenter)
-            alignYOffset += (maxRowHeight[curRow] - childHeight)/2.0;
+            alignYOffset += (maxRowHeight[curRow] - child.item->height())/2.0;
         else if (m_vItemAlign == AlignBottom)
-            alignYOffset += maxRowHeight[curRow] - childHeight;
+            alignYOffset += maxRowHeight[curRow] - child.item->height();
 
         positionItem(childXOffset, alignYOffset, &child);
         child.updatePadding(leftPadding(), topPadding(), rightPadding(), bottomPadding());
@@ -2160,17 +2140,15 @@ void QQuickFlow::doPositioning(QSizeF *contentSize)
 
     for (int i = 0; i < positionedItems.count(); ++i) {
         PositionedItem &child = positionedItems[i];
-        const qreal childWidth = d->itemWidth(child.item);
-        const qreal childHeight = d->itemHeight(child.item);
 
         if (d->flow == LeftToRight)  {
-            if (widthValid() && hoffset != hoffset1 && hoffset + childWidth + hoffset2 > width()) {
+            if (widthValid() && hoffset != hoffset1 && hoffset + child.item->width() + hoffset2 > width()) {
                 hoffset = hoffset1;
                 voffset += linemax + spacing();
                 linemax = 0;
             }
         } else {
-            if (heightValid() && voffset != voffset1 && voffset + childHeight + bottomPadding() > height()) {
+            if (heightValid() && voffset != voffset1 && voffset + child.item->height() + bottomPadding() > height()) {
                 voffset = voffset1;
                 hoffset += linemax + spacing();
                 linemax = 0;
@@ -2187,17 +2165,17 @@ void QQuickFlow::doPositioning(QSizeF *contentSize)
             child.bottomPadding = bottomPadding();
         }
 
-        contentSize->setWidth(qMax(contentSize->width(), hoffset + childWidth + hoffset2));
-        contentSize->setHeight(qMax(contentSize->height(), voffset + childHeight + bottomPadding()));
+        contentSize->setWidth(qMax(contentSize->width(), hoffset + child.item->width() + hoffset2));
+        contentSize->setHeight(qMax(contentSize->height(), voffset + child.item->height() + bottomPadding()));
 
         if (d->flow == LeftToRight)  {
-            hoffset += childWidth;
+            hoffset += child.item->width();
             hoffset += spacing();
-            linemax = qMax(linemax, childHeight);
+            linemax = qMax(linemax, child.item->height());
         } else {
-            voffset += childHeight;
+            voffset += child.item->height();
             voffset += spacing();
-            linemax = qMax(linemax, childWidth);
+            linemax = qMax(linemax, child.item->width());
         }
     }
 
@@ -2212,7 +2190,7 @@ void QQuickFlow::doPositioning(QSizeF *contentSize)
     int acc = 0;
     for (int i = 0; i < positionedItems.count(); ++i) {
         PositionedItem &child = positionedItems[i];
-        hoffset = end - hoffsets[acc++] - d->itemWidth(child.item);
+        hoffset = end - hoffsets[acc++] - child.item->width();
         positionItemX(hoffset, &child);
         child.leftPadding = leftPadding();
         child.rightPadding = rightPadding();
@@ -2236,18 +2214,4 @@ void QQuickFlow::reportConflictingAnchors()
         qmlWarning(this) << "Cannot specify anchors for items inside Flow." << " Flow will not function.";
 }
 
-QQuickImplicitRow::QQuickImplicitRow(QQuickItem *parent)
-    : QQuickRow(parent)
-{
-    QQuickBasePositionerPrivate *d = QQuickBasePositioner::get(this);
-    d->useImplicitSize = true;
-}
-
-QQuickImplicitGrid::QQuickImplicitGrid(QQuickItem *parent)
-    : QQuickGrid(parent)
-{
-    QQuickBasePositionerPrivate *d = QQuickBasePositioner::get(this);
-    d->useImplicitSize = true;
-}
-
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickpositioners_p.h b/src/quick/items/qquickpositioners_p.h
index cfe163b4c1..9ae7029d69 100644
--- a/src/quick/items/qquickpositioners_p.h
+++ b/src/quick/items/qquickpositioners_p.h
@@ -67,7 +67,7 @@ QT_BEGIN_NAMESPACE
 
 class QQuickBasePositionerPrivate;
 
-class Q_QUICK_PRIVATE_EXPORT QQuickPositionerAttached : public QObject
+class QQuickPositionerAttached : public QObject
 {
     Q_OBJECT
 
@@ -132,11 +132,6 @@ public:
 
     static QQuickPositionerAttached *qmlAttachedProperties(QObject *obj);
 
-    static QQuickBasePositionerPrivate* get(QQuickBasePositioner *positioner)
-    {
-        return positioner->d_func();
-    }
-
     void updateAttachedProperties(QQuickPositionerAttached *specificProperty = 0, QQuickItem *specificPropertyOwner = 0) const;
 
     qreal padding() const;
@@ -187,7 +182,7 @@ protected:
     virtual void doPositioning(QSizeF *contentSize)=0;
     virtual void reportConflictingAnchors()=0;
 
-    class Q_QUICK_PRIVATE_EXPORT PositionedItem
+    class PositionedItem
     {
     public :
         PositionedItem(QQuickItem *i);
@@ -232,7 +227,7 @@ private:
     Q_DECLARE_PRIVATE(QQuickBasePositioner)
 };
 
-class Q_QUICK_PRIVATE_EXPORT QQuickColumn : public QQuickBasePositioner
+class Q_AUTOTEST_EXPORT QQuickColumn : public QQuickBasePositioner
 {
     Q_OBJECT
 public:
@@ -246,7 +241,7 @@ private:
 };
 
 class QQuickRowPrivate;
-class Q_QUICK_PRIVATE_EXPORT QQuickRow: public QQuickBasePositioner
+class Q_AUTOTEST_EXPORT QQuickRow: public QQuickBasePositioner
 {
     Q_OBJECT
     Q_PROPERTY(Qt::LayoutDirection layoutDirection READ layoutDirection WRITE setLayoutDirection NOTIFY layoutDirectionChanged)
@@ -271,7 +266,7 @@ private:
 };
 
 class QQuickGridPrivate;
-class Q_QUICK_PRIVATE_EXPORT QQuickGrid : public QQuickBasePositioner
+class Q_AUTOTEST_EXPORT QQuickGrid : public QQuickBasePositioner
 {
     Q_OBJECT
     Q_PROPERTY(int rows READ rows WRITE setRows NOTIFY rowsChanged)
@@ -358,7 +353,7 @@ private:
 };
 
 class QQuickFlowPrivate;
-class Q_QUICK_PRIVATE_EXPORT QQuickFlow: public QQuickBasePositioner
+class Q_AUTOTEST_EXPORT QQuickFlow: public QQuickBasePositioner
 {
     Q_OBJECT
     Q_PROPERTY(Flow flow READ flow WRITE setFlow NOTIFY flowChanged)
@@ -391,22 +386,6 @@ private:
     Q_DECLARE_PRIVATE(QQuickFlow)
 };
 
-class Q_QUICK_PRIVATE_EXPORT QQuickImplicitRow : public QQuickRow
-{
-    Q_OBJECT
-
-public:
-    QQuickImplicitRow(QQuickItem *parent = nullptr);
-};
-
-class Q_QUICK_PRIVATE_EXPORT QQuickImplicitGrid : public QQuickGrid
-{
-    Q_OBJECT
-
-public:
-    QQuickImplicitGrid(QQuickItem *parent = nullptr);
-};
-
 
 QT_END_NAMESPACE
 
@@ -414,8 +393,6 @@ QML_DECLARE_TYPE(QQuickColumn)
 QML_DECLARE_TYPE(QQuickRow)
 QML_DECLARE_TYPE(QQuickGrid)
 QML_DECLARE_TYPE(QQuickFlow)
-QML_DECLARE_TYPE(QQuickImplicitRow)
-QML_DECLARE_TYPE(QQuickImplicitGrid)
 
 QML_DECLARE_TYPE(QQuickBasePositioner)
 QML_DECLARE_TYPEINFO(QQuickBasePositioner, QML_HAS_ATTACHED_PROPERTIES)
diff --git a/src/quick/items/qquickpositioners_p_p.h b/src/quick/items/qquickpositioners_p_p.h
index 1a7051615c..0be4c56df6 100644
--- a/src/quick/items/qquickpositioners_p_p.h
+++ b/src/quick/items/qquickpositioners_p_p.h
@@ -89,14 +89,10 @@ public:
     QLazilyAllocated<ExtraData> extra;
 
     QQuickBasePositionerPrivate()
-        : spacing(0)
-        , type(QQuickBasePositioner::None)
-        , transitioner(0)
-        , positioningDirty(false)
-        , doingPositioning(false)
-        , anchorConflict(false)
-        , useImplicitSize(false)
-        , layoutDirection(Qt::LeftToRight)
+        : spacing(0), type(QQuickBasePositioner::None)
+        , transitioner(0), positioningDirty(false)
+        , doingPositioning(false), anchorConflict(false), layoutDirection(Qt::LeftToRight)
+
     {
     }
 
@@ -123,7 +119,6 @@ public:
     bool positioningDirty : 1;
     bool doingPositioning : 1;
     bool anchorConflict : 1;
-    bool useImplicitSize : 1;
 
     Qt::LayoutDirection layoutDirection;
 
@@ -179,34 +174,6 @@ public:
     {
     }
 
-    void itemImplicitWidthChanged(QQuickItem *) override
-    {
-        Q_ASSERT(useImplicitSize);
-        setPositioningDirty();
-    }
-
-    void itemImplicitHeightChanged(QQuickItem *) override
-    {
-        Q_ASSERT(useImplicitSize);
-        setPositioningDirty();
-    }
-
-    qreal itemWidth(QQuickItem *item) const
-    {
-        if (Q_LIKELY(!useImplicitSize))
-            return item->width();
-
-        return item->implicitWidth();
-    }
-
-    qreal itemHeight(QQuickItem *item) const
-    {
-        if (Q_LIKELY(!useImplicitSize))
-            return item->height();
-
-        return item->implicitHeight();
-    }
-
     inline qreal padding() const { return extra.isAllocated() ? extra->padding : 0.0; }
     void setTopPadding(qreal value, bool reset = false);
     void setLeftPadding(qreal value, bool reset = false);
diff --git a/src/quick/items/qquickrendercontrol.cpp b/src/quick/items/qquickrendercontrol.cpp
index 03d96aea1f..e2a20f9e7e 100644
--- a/src/quick/items/qquickrendercontrol.cpp
+++ b/src/quick/items/qquickrendercontrol.cpp
@@ -385,6 +385,9 @@ QImage QQuickRenderControl::grab()
         cd->syncSceneGraph();
         render();
         grabContent = qt_gl_read_framebuffer(d->window->size() * d->window->effectiveDevicePixelRatio(), false, false);
+        if (QQuickRenderControl::renderWindowFor(d->window)) {
+            grabContent.setDevicePixelRatio(d->window->effectiveDevicePixelRatio());
+        }
 #endif
     } else if (d->window->rendererInterface()->graphicsApi() == QSGRendererInterface::Software) {
         QQuickWindowPrivate *cd = QQuickWindowPrivate::get(d->window);
diff --git a/src/quick/items/qquickshadereffect.cpp b/src/quick/items/qquickshadereffect.cpp
index 436d7b33ce..d317c1d19b 100644
--- a/src/quick/items/qquickshadereffect.cpp
+++ b/src/quick/items/qquickshadereffect.cpp
@@ -873,9 +873,11 @@ void QQuickShaderEffectPrivate::updatePolish()
     q->m_impl->maybeUpdateShaders();
 }
 
+#if QT_CONFIG(opengl)
 bool QQuickShaderEffect::isOpenGLShaderEffect() const
 {
     return m_glImpl != Q_NULLPTR;
 }
+#endif
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickshadereffect_p.h b/src/quick/items/qquickshadereffect_p.h
index d269dc5e50..30bd018098 100644
--- a/src/quick/items/qquickshadereffect_p.h
+++ b/src/quick/items/qquickshadereffect_p.h
@@ -117,7 +117,9 @@ public:
     bool isComponentComplete() const;
     QString parseLog();
 
+#if QT_CONFIG(opengl)
     bool isOpenGLShaderEffect() const;
+#endif
 
 Q_SIGNALS:
     void fragmentShaderChanged();
diff --git a/src/quick/items/qquickstateoperations.cpp b/src/quick/items/qquickstateoperations.cpp
index b40a9e2843..a4ce13a199 100644
--- a/src/quick/items/qquickstateoperations.cpp
+++ b/src/quick/items/qquickstateoperations.cpp
@@ -101,7 +101,7 @@ void QQuickParentChangePrivate::doChange(QQuickItem *targetParent, QQuickItem *s
             }
 
             if (scale != 0)
-                rotation = qAtan2(transform.m12()/scale, transform.m11()/scale) * 180/M_PI;
+                rotation = qRadiansToDegrees(qAtan2(transform.m12() / scale, transform.m11() / scale));
             else {
                 qmlWarning(q) << QQuickParentChange::tr("Unable to preserve appearance under scale of 0");
                 ok = false;
diff --git a/src/quick/items/qquicktextcontrol.cpp b/src/quick/items/qquicktextcontrol.cpp
index 555fd233b3..2dce3e9ec8 100644
--- a/src/quick/items/qquicktextcontrol.cpp
+++ b/src/quick/items/qquicktextcontrol.cpp
@@ -769,52 +769,8 @@ void QQuickTextControl::processEvent(QEvent *e, const QMatrix &matrix)
         case QEvent::ShortcutOverride:
             if (d->interactionFlags & Qt::TextEditable) {
                 QKeyEvent* ke = static_cast<QKeyEvent *>(e);
-                if (ke->modifiers() == Qt::NoModifier
-                    || ke->modifiers() == Qt::ShiftModifier
-                    || ke->modifiers() == Qt::KeypadModifier) {
-                    if (ke->key() < Qt::Key_Escape) {
-                        ke->accept();
-                    } else {
-                        switch (ke->key()) {
-                            case Qt::Key_Return:
-                            case Qt::Key_Enter:
-                            case Qt::Key_Delete:
-                            case Qt::Key_Home:
-                            case Qt::Key_End:
-                            case Qt::Key_Backspace:
-                            case Qt::Key_Left:
-                            case Qt::Key_Right:
-                            case Qt::Key_Up:
-                            case Qt::Key_Down:
-                            case Qt::Key_Tab:
-                            ke->accept();
-                        default:
-                            break;
-                        }
-                    }
-#if QT_CONFIG(shortcut)
-                } else if (ke == QKeySequence::Copy
-                           || ke == QKeySequence::Paste
-                           || ke == QKeySequence::Cut
-                           || ke == QKeySequence::Redo
-                           || ke == QKeySequence::Undo
-                           || ke == QKeySequence::MoveToNextWord
-                           || ke == QKeySequence::MoveToPreviousWord
-                           || ke == QKeySequence::MoveToStartOfDocument
-                           || ke == QKeySequence::MoveToEndOfDocument
-                           || ke == QKeySequence::SelectNextWord
-                           || ke == QKeySequence::SelectPreviousWord
-                           || ke == QKeySequence::SelectStartOfLine
-                           || ke == QKeySequence::SelectEndOfLine
-                           || ke == QKeySequence::SelectStartOfBlock
-                           || ke == QKeySequence::SelectEndOfBlock
-                           || ke == QKeySequence::SelectStartOfDocument
-                           || ke == QKeySequence::SelectEndOfDocument
-                           || ke == QKeySequence::SelectAll
-                          ) {
+                if (isCommonTextEditShortcut(ke))
                     ke->accept();
-#endif
-                }
             }
             break;
         default:
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 0105e84cd6..888b0cde85 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -748,6 +748,7 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
 
     QQuickItem *oldGrabber = q->mouseGrabberItem();
     qCDebug(DBG_MOUSE_TARGET) << "grabber" << oldGrabber << "->" << grabber;
+    bool fromTouch = false;
 
     if (grabber && touchMouseId != -1 && touchMouseDevice) {
         // update the touch item for mouse touch id to the new grabber
@@ -758,6 +759,7 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
             for (auto handler : point->passiveGrabbers())
                 point->cancelPassiveGrab(handler);
         }
+        fromTouch = true;
     } else {
         QQuickPointerEvent *event = QQuickPointerDevice::genericMouseDevice()->pointerEvent();
         Q_ASSERT(event->pointCount() == 1);
@@ -771,8 +773,11 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
     if (oldGrabber) {
         QEvent e(QEvent::UngrabMouse);
         QSet<QQuickItem *> hasFiltered;
-        if (!sendFilteredMouseEvent(oldGrabber->parentItem(), oldGrabber, &e, &hasFiltered))
+        if (!sendFilteredMouseEvent(oldGrabber->parentItem(), oldGrabber, &e, &hasFiltered)) {
             oldGrabber->mouseUngrabEvent();
+            if (fromTouch)
+                oldGrabber->touchUngrabEvent();
+        }
     }
 }
 
@@ -2503,7 +2508,6 @@ void QQuickWindowPrivate::deliverDragEvent(QQuickDragGrabber *grabber, QEvent *e
         } else for (; grabItem != grabber->end(); grabItem = grabber->release(grabItem)) {
             QDragMoveEvent *moveEvent = static_cast<QDragMoveEvent *>(event);
             if (deliverDragEvent(grabber, **grabItem, moveEvent)) {
-                moveEvent->setAccepted(true);
                 for (++grabItem; grabItem != grabber->end();) {
                     QPointF p = (**grabItem)->mapFromScene(moveEvent->pos());
                     if ((**grabItem)->contains(p)) {
@@ -2578,7 +2582,10 @@ bool QQuickWindowPrivate::deliverDragEvent(QQuickDragGrabber *grabber, QQuickIte
                     event->keyboardModifiers(),
                     event->type());
             QQuickDropEventEx::copyActions(&translatedEvent, *event);
+            translatedEvent.setAccepted(event->isAccepted());
             QCoreApplication::sendEvent(item, &translatedEvent);
+            event->setAccepted(translatedEvent.isAccepted());
+            event->setDropAction(translatedEvent.dropAction());
             if (event->type() == QEvent::DragEnter) {
                 if (translatedEvent.isAccepted()) {
                     grabber->grab(item);
@@ -2726,18 +2733,23 @@ bool QQuickWindowPrivate::sendFilteredPointerEvent(QQuickPointerEvent *event, QQ
                     break;
                 }
 
+                bool touchMouseUnset = (touchMouseId == -1);
                 // Only deliver mouse event if it is the touchMouseId or it could become the touchMouseId
-                if (touchMouseId == -1 || touchMouseId == tp.id()) {
+                if (touchMouseUnset || touchMouseId == tp.id()) {
                     // convert filteringParentTouchEvent (which is already transformed wrt local position, velocity, etc.)
                     // into a synthetic mouse event, and let childMouseEventFilter() have another chance with that
                     QScopedPointer<QMouseEvent> mouseEvent(touchToMouseEvent(t, tp, filteringParentTouchEvent.data(), item, false));
+                    // If a filtering item calls QQuickWindow::mouseGrabberItem(), it should
+                    // report the touchpoint's grabber.  Whenever we send a synthetic mouse event,
+                    // touchMouseId and touchMouseDevice must be set, even if it's only temporarily and isn't grabbed.
+                    touchMouseId = tp.id();
+                    touchMouseDevice = event->device();
                     if (filteringParent->childMouseEventFilter(item, mouseEvent.data())) {
                         qCDebug(DBG_TOUCH) << "touch event intercepted as synth mouse event by childMouseEventFilter of " << filteringParent;
                         if (t != QEvent::MouseButtonRelease) {
                             qCDebug(DBG_TOUCH_TARGET) << "TP (mouse)" << hex << tp.id() << "->" << filteringParent;
-                            touchMouseId = tp.id();
-                            touchMouseDevice = event->device();
                             touchMouseDevice->pointerEvent()->pointById(tp.id())->setGrabberItem(filteringParent);
+                            touchMouseUnset = false; // We want to leave touchMouseId and touchMouseDevice set
                             filteringParent->grabMouse();
                             auto pointerEventPoint = pte->pointById(tp.id());
                             for (auto handler : pointerEventPoint->passiveGrabbers()) {
@@ -2748,9 +2760,15 @@ bool QQuickWindowPrivate::sendFilteredPointerEvent(QQuickPointerEvent *event, QQ
                         }
                         ret = true;
                     }
+                    if (touchMouseUnset) {
+                        // Now that we're done sending a synth mouse event, and it wasn't grabbed,
+                        // the touchpoint is no longer acting as a synthetic mouse.  Restore previous state.
+                        touchMouseId = -1;
+                        touchMouseDevice = nullptr;
+                    }
                     // Only one touchpoint can be treated as a synthetic mouse, so after childMouseEventFilter
                     // has been called once, we're done with this loop over the touchpoints.
-                    break;
+                     break;
                 }
             }
         }
@@ -3542,6 +3560,11 @@ void QQuickWindow::setRenderTarget(QOpenGLFramebufferObject *fbo)
     The specified FBO must be created in the context of the window
     or one that shares with it.
 
+    \note \a fboId can also be set to 0. In this case rendering will target the
+    default framebuffer of whichever surface is current when the scenegraph
+    renders. \a size must still be valid, specifying the dimensions of the
+    surface.
+
     \note
     This function only has an effect when using the default OpenGL scene
     graph adaptation.
@@ -3648,6 +3671,7 @@ QImage QQuickWindow::grabWindow()
 
             bool alpha = format().alphaBufferSize() > 0 && color().alpha() < 255;
             QImage image = qt_gl_read_framebuffer(size() * effectiveDevicePixelRatio(), alpha, alpha);
+            image.setDevicePixelRatio(effectiveDevicePixelRatio());
             d->cleanupNodesOnShutdown();
             d->context->invalidate();
             context.doneCurrent();
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
index 6856d34616..b3b8274a73 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
@@ -101,7 +101,7 @@ void QSGSoftwareRenderLoop::windowDestroyed(QQuickWindow *window)
     }
 }
 
-void QSGSoftwareRenderLoop::renderWindow(QQuickWindow *window)
+void QSGSoftwareRenderLoop::renderWindow(QQuickWindow *window, bool isNewExpose)
 {
     QQuickWindowPrivate *cd = QQuickWindowPrivate::get(window);
     if (!m_windows.contains(window))
@@ -174,7 +174,10 @@ void QSGSoftwareRenderLoop::renderWindow(QQuickWindow *window)
 
     if (alsoSwap && window->isVisible()) {
         //Flush backingstore to window
-        m_backingStores[window]->flush(softwareRenderer->flushRegion());
+        if (!isNewExpose)
+            m_backingStores[window]->flush(softwareRenderer->flushRegion());
+        else
+            m_backingStores[window]->flush(QRegion(QRect(QPoint(0,0), window->size())));
         cd->fireFrameSwapped();
     }
 
@@ -206,7 +209,7 @@ void QSGSoftwareRenderLoop::exposureChanged(QQuickWindow *window)
 {
     if (window->isExposed()) {
         m_windows[window].updatePending = true;
-        renderWindow(window);
+        renderWindow(window, true);
     }
 }
 
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop_p.h b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop_p.h
index 02dcf4eefa..c724d18298 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop_p.h
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop_p.h
@@ -69,7 +69,7 @@ public:
 
     void windowDestroyed(QQuickWindow *window) override;
 
-    void renderWindow(QQuickWindow *window);
+    void renderWindow(QQuickWindow *window, bool isNewExpose = false);
     void exposureChanged(QQuickWindow *window) override;
     QImage grab(QQuickWindow *window) override;
 
diff --git a/src/quick/scenegraph/coreapi/qsgmaterial.cpp b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
index 8d666d3d0b..07dc87a643 100644
--- a/src/quick/scenegraph/coreapi/qsgmaterial.cpp
+++ b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
@@ -419,6 +419,10 @@ void QSGMaterialShader::compile()
     \value DirtyMatrix Used to indicate that the matrix has changed and must be updated.
 
     \value DirtyOpacity Used to indicate that the opacity has changed and must be updated.
+
+    \value DirtyCachedMaterialData Used to indicate that the cached material data have changed and must be updated.
+
+    \value DirtyAll Used to indicate that everything needs to be updated.
  */
 
 
diff --git a/src/quick/scenegraph/coreapi/qsgnode.cpp b/src/quick/scenegraph/coreapi/qsgnode.cpp
index 7ef75d4b4c..7ac3914023 100644
--- a/src/quick/scenegraph/coreapi/qsgnode.cpp
+++ b/src/quick/scenegraph/coreapi/qsgnode.cpp
@@ -112,6 +112,7 @@ static void qt_print_node_count()
     \value DirtyGeometry The geometry of a QSGGeometryNode has changed.
     \value DirtyMaterial The material of a QSGGeometryNode has changed.
     \value DirtyOpacity The opacity of a QSGOpacityNode has changed.
+    \value DirtySubtreeBlocked The subtree has been blocked.
 
     \sa QSGNode::markDirty()
  */
@@ -146,6 +147,7 @@ static void qt_print_node_count()
     \value TransformNodeType The type of QSGTransformNode
     \value ClipNodeType The type of QSGClipNode
     \value OpacityNodeType The type of QSGOpacityNode
+    \value RenderNodeType The type of QSGRenderNode
 
     \sa type()
  */
diff --git a/src/quick/scenegraph/coreapi/qsgrenderer.cpp b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
index 9207fdbc55..bb2671f6c3 100644
--- a/src/quick/scenegraph/coreapi/qsgrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
@@ -134,6 +134,7 @@ QSGRenderer::QSGRenderer(QSGRenderContext *context)
     , m_bindable(0)
     , m_changed_emitted(false)
     , m_is_rendering(false)
+    , m_is_preprocessing(false)
 {
 }
 
@@ -287,6 +288,8 @@ void QSGRenderer::nodeChanged(QSGNode *node, QSGNode::DirtyState state)
 
 void QSGRenderer::preprocess()
 {
+    m_is_preprocessing = true;
+
     QSGRootNode *root = rootNode();
     Q_ASSERT(root);
 
@@ -298,6 +301,11 @@ void QSGRenderer::preprocess()
     for (QSet<QSGNode *>::const_iterator it = items.constBegin();
          it != items.constEnd(); ++it) {
         QSGNode *n = *it;
+
+        // If we are currently preprocessing, check this node hasn't been
+        // deleted or something. we don't want a use-after-free!
+        if (m_nodes_dont_preprocess.contains(n)) // skip
+            continue;
         if (!nodeUpdater()->isNodeBlocked(n, root)) {
             n->preprocess();
         }
@@ -315,8 +323,13 @@ void QSGRenderer::preprocess()
         updatePassTime = frameTimer.nsecsElapsed();
     Q_QUICK_SG_PROFILE_RECORD(QQuickProfiler::SceneGraphRendererFrame,
                               QQuickProfiler::SceneGraphRendererUpdate);
+
+    m_is_preprocessing = false;
+    m_nodes_dont_preprocess.clear();
 }
 
+
+
 void QSGRenderer::addNodesToPreprocess(QSGNode *node)
 {
     for (QSGNode *c = node->firstChild(); c; c = c->nextSibling())
@@ -329,8 +342,13 @@ void QSGRenderer::removeNodesToPreprocess(QSGNode *node)
 {
     for (QSGNode *c = node->firstChild(); c; c = c->nextSibling())
         removeNodesToPreprocess(c);
-    if (node->flags() & QSGNode::UsePreprocess)
+    if (node->flags() & QSGNode::UsePreprocess) {
         m_nodes_to_preprocess.remove(node);
+
+        // If preprocessing *now*, mark the node as gone.
+        if (m_is_preprocessing)
+            m_nodes_dont_preprocess.insert(node);
+    }
 }
 
 
diff --git a/src/quick/scenegraph/coreapi/qsgrenderer_p.h b/src/quick/scenegraph/coreapi/qsgrenderer_p.h
index 4589685765..1ea2775e6f 100644
--- a/src/quick/scenegraph/coreapi/qsgrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgrenderer_p.h
@@ -118,11 +118,13 @@ private:
     QSGNodeUpdater *m_node_updater;
 
     QSet<QSGNode *> m_nodes_to_preprocess;
+    QSet<QSGNode *> m_nodes_dont_preprocess;
 
     const QSGBindable *m_bindable;
 
     uint m_changed_emitted : 1;
     uint m_is_rendering : 1;
+    uint m_is_preprocessing : 1;
 };
 
 class Q_QUICK_PRIVATE_EXPORT QSGBindable
diff --git a/src/quick/scenegraph/qsgadaptationlayer.cpp b/src/quick/scenegraph/qsgadaptationlayer.cpp
index 412023564f..f90706affe 100644
--- a/src/quick/scenegraph/qsgadaptationlayer.cpp
+++ b/src/quick/scenegraph/qsgadaptationlayer.cpp
@@ -40,7 +40,6 @@
 #include "qsgadaptationlayer_p.h"
 
 #include <qmath.h>
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #include <QtQuick/private/qsgdistancefieldglyphnode_p.h>
 #include <QtQuick/private/qsgcontext_p.h>
 #include <private/qrawfont_p.h>
@@ -57,9 +56,8 @@ static QElapsedTimer qsg_render_timer;
 
 QSGDistanceFieldGlyphCache::Texture QSGDistanceFieldGlyphCache::s_emptyTexture;
 
-QSGDistanceFieldGlyphCache::QSGDistanceFieldGlyphCache(QSGDistanceFieldGlyphCacheManager *man, QOpenGLContext *c, const QRawFont &font)
-    : m_manager(man)
-    , m_pendingGlyphs(64)
+QSGDistanceFieldGlyphCache::QSGDistanceFieldGlyphCache(QOpenGLContext *c, const QRawFont &font)
+    : m_pendingGlyphs(64)
 {
     Q_ASSERT(font.isValid());
 
diff --git a/src/quick/scenegraph/qsgadaptationlayer_p.h b/src/quick/scenegraph/qsgadaptationlayer_p.h
index a8e35b1ac1..ba146b884f 100644
--- a/src/quick/scenegraph/qsgadaptationlayer_p.h
+++ b/src/quick/scenegraph/qsgadaptationlayer_p.h
@@ -73,7 +73,6 @@ QT_BEGIN_NAMESPACE
 class QSGNode;
 class QImage;
 class TextureReference;
-class QSGDistanceFieldGlyphCacheManager;
 class QSGDistanceFieldGlyphNode;
 class QOpenGLContext;
 class QSGInternalImageNode;
@@ -409,7 +408,7 @@ public:
 class Q_QUICK_PRIVATE_EXPORT QSGDistanceFieldGlyphCache
 {
 public:
-    QSGDistanceFieldGlyphCache(QSGDistanceFieldGlyphCacheManager *man, QOpenGLContext *c, const QRawFont &font);
+    QSGDistanceFieldGlyphCache(QOpenGLContext *c, const QRawFont &font);
     virtual ~QSGDistanceFieldGlyphCache();
 
     struct Metrics {
@@ -443,8 +442,6 @@ public:
         bool operator == (const Texture &other) const { return textureId == other.textureId; }
     };
 
-    const QSGDistanceFieldGlyphCacheManager *manager() const { return m_manager; }
-
     const QRawFont &referenceFont() const { return m_referenceFont; }
 
     qreal fontScale(qreal pixelSize) const
@@ -514,8 +511,6 @@ protected:
     inline bool isCoreProfile() const { return m_coreProfile; }
 
 private:
-    QSGDistanceFieldGlyphCacheManager *m_manager;
-
     QRawFont m_referenceFont;
     int m_glyphCount;
 
diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index d52f69c7a3..ff2379ecb5 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -333,7 +333,6 @@ QSGRendererInterface *QSGContext::rendererInterface(QSGRenderContext *renderCont
 
 QSGRenderContext::QSGRenderContext(QSGContext *context)
     : m_sg(context)
-    , m_distanceFieldCacheManager(0)
 {
 }
 
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index 2f5d5790ee..bd10453131 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -78,7 +78,6 @@ class QSGMaterial;
 class QSGRenderLoop;
 class QSGLayer;
 class QQuickTextureFactory;
-class QSGDistanceFieldGlyphCacheManager;
 class QSGContext;
 class QQuickPaintedItem;
 class QSGRendererInterface;
@@ -194,7 +193,7 @@ protected:
     QMutex m_mutex;
     QHash<QQuickTextureFactory *, QSGTexture *> m_textures;
     QSet<QSGTexture *> m_texturesToDelete;
-    QSGDistanceFieldGlyphCacheManager *m_distanceFieldCacheManager;
+    QHash<QRawFont, QSGDistanceFieldGlyphCache*> m_glyphCaches;
 
     QSet<QFontEngine *> m_fontEnginesToClean;
 };
diff --git a/src/quick/scenegraph/qsgdefaultcontext.cpp b/src/quick/scenegraph/qsgdefaultcontext.cpp
index d31a7025e5..be5fec9dab 100644
--- a/src/quick/scenegraph/qsgdefaultcontext.cpp
+++ b/src/quick/scenegraph/qsgdefaultcontext.cpp
@@ -39,7 +39,6 @@
 
 #include "qsgdefaultcontext_p.h"
 
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #include <QtQuick/private/qsgdefaultinternalrectanglenode_p.h>
 #include <QtQuick/private/qsgdefaultinternalimagenode_p.h>
 #include <QtQuick/private/qsgdefaultpainternode_p.h>
diff --git a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
index f0a336e229..ba25172d2f 100644
--- a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
+++ b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
@@ -42,7 +42,6 @@
 #include <QtGui/private/qdistancefield_p.h>
 #include <QtGui/private/qopenglcontext_p.h>
 #include <QtQml/private/qqmlglobal_p.h>
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #include <qopenglfunctions.h>
 #include <qopenglframebufferobject.h>
 #include <qmath.h>
@@ -60,8 +59,8 @@ DEFINE_BOOL_CONFIG_OPTION(qsgPreferFullSizeGlyphCacheTextures, QSG_PREFER_FULLSI
 #  define QSG_DEFAULT_DISTANCEFIELD_GLYPH_CACHE_PADDING 2
 #endif
 
-QSGDefaultDistanceFieldGlyphCache::QSGDefaultDistanceFieldGlyphCache(QSGDistanceFieldGlyphCacheManager *man, QOpenGLContext *c, const QRawFont &font)
-    : QSGDistanceFieldGlyphCache(man, c, font)
+QSGDefaultDistanceFieldGlyphCache::QSGDefaultDistanceFieldGlyphCache(QOpenGLContext *c, const QRawFont &font)
+    : QSGDistanceFieldGlyphCache(c, font)
     , m_maxTextureSize(0)
     , m_maxTextureCount(3)
     , m_blitProgram(0)
diff --git a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
index 57dc4a5d07..fe365495c2 100644
--- a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
+++ b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache_p.h
@@ -69,7 +69,7 @@ class QOpenGLFunctions_3_2_Core;
 class Q_QUICK_PRIVATE_EXPORT QSGDefaultDistanceFieldGlyphCache : public QSGDistanceFieldGlyphCache
 {
 public:
-    QSGDefaultDistanceFieldGlyphCache(QSGDistanceFieldGlyphCacheManager *man, QOpenGLContext *c, const QRawFont &font);
+    QSGDefaultDistanceFieldGlyphCache(QOpenGLContext *c, const QRawFont &font);
     virtual ~QSGDefaultDistanceFieldGlyphCache();
 
     void requestGlyphs(const QSet<glyph_t> &glyphs) override;
diff --git a/src/quick/scenegraph/qsgdefaultglyphnode.cpp b/src/quick/scenegraph/qsgdefaultglyphnode.cpp
index b856d99bc1..0d42102f36 100644
--- a/src/quick/scenegraph/qsgdefaultglyphnode.cpp
+++ b/src/quick/scenegraph/qsgdefaultglyphnode.cpp
@@ -42,11 +42,33 @@
 
 QT_BEGIN_NAMESPACE
 
+QSGDefaultGlyphNode::QSGDefaultGlyphNode()
+    : m_glyphNodeType(RootGlyphNode)
+    , m_dirtyGeometry(false)
+{
+    setFlag(UsePreprocess);
+}
+
+QSGDefaultGlyphNode::~QSGDefaultGlyphNode()
+{
+    if (m_glyphNodeType == SubGlyphNode)
+        return;
+
+    qDeleteAll(m_nodesToDelete);
+    m_nodesToDelete.clear();
+}
+
 void QSGDefaultGlyphNode::setMaterialColor(const QColor &color)
 {
     static_cast<QSGTextMaskMaterial *>(m_material)->setColor(color);
 }
 
+void QSGDefaultGlyphNode::setGlyphs(const QPointF &position, const QGlyphRun &glyphs)
+{
+    QSGBasicGlyphNode::setGlyphs(position, glyphs);
+    m_dirtyGeometry = true;
+}
+
 void QSGDefaultGlyphNode::update()
 {
     QRawFont font = m_glyphs.rawFont();
@@ -84,4 +106,110 @@ void QSGDefaultGlyphNode::update()
     markDirty(DirtyGeometry);
 }
 
+void QSGDefaultGlyphNode::preprocess()
+{
+    qDeleteAll(m_nodesToDelete);
+    m_nodesToDelete.clear();
+
+    if (m_dirtyGeometry)
+        updateGeometry();
+}
+
+void QSGDefaultGlyphNode::updateGeometry()
+{
+    // Remove previously created sub glyph nodes
+    // We assume all the children are sub glyph nodes
+    QSGNode *subnode = firstChild();
+    while (subnode) {
+        // We can't delete the node now as it might be in the preprocess list
+        // It will be deleted in the next preprocess
+        m_nodesToDelete.append(subnode);
+        subnode = subnode->nextSibling();
+    }
+    removeAllChildNodes();
+
+    GlyphInfo glyphInfo;
+
+    const QVector<quint32> indexes = m_glyphs.glyphIndexes();
+    const QVector<QPointF> positions = m_glyphs.positions();
+
+    const int maxGlyphs = (USHRT_MAX + 1) / 4; // 16384
+    const int maxVertices = maxGlyphs * 4; // 65536
+    const int maxIndexes = maxGlyphs * 6; // 98304
+
+    for (int i = 0; i < indexes.size(); ++i) {
+        const int glyphIndex = indexes.at(i);
+        const QPointF position = positions.at(i);
+
+        // As we use UNSIGNED_SHORT indexing in the geometry, we overload the
+        // "glyphsInOtherNodes" concept as overflow for if there are more than
+        // 65536 (16384 * 4) vertices to render which would otherwise exceed
+        // the maximum index size. This will cause sub-nodes to be recursively
+        // created to handle any number of glyphs.
+        if (i >= maxGlyphs) {
+            glyphInfo.indexes.append(glyphIndex);
+            glyphInfo.positions.append(position);
+            continue;
+        }
+    }
+
+    if (!glyphInfo.indexes.isEmpty()) {
+        QGlyphRun subNodeGlyphRun(m_glyphs);
+        subNodeGlyphRun.setGlyphIndexes(glyphInfo.indexes);
+        subNodeGlyphRun.setPositions(glyphInfo.positions);
+
+        QSGDefaultGlyphNode *subNode = new QSGDefaultGlyphNode();
+        subNode->setGlyphNodeType(SubGlyphNode);
+        subNode->setColor(m_color);
+        subNode->setStyle(m_style);
+        subNode->setStyleColor(m_styleColor);
+        subNode->setGlyphs(m_position, subNodeGlyphRun);
+        subNode->update();
+        subNode->updateGeometry(); // we have to explicitly call this now as preprocess won't be called before it's rendered
+        appendChildNode(subNode);
+
+        QSGGeometry *g = geometry();
+
+        QSGGeometry::TexturedPoint2D *vertexData = g->vertexDataAsTexturedPoint2D();
+        quint16 *indexData = g->indexDataAsUShort();
+
+        QVector<QSGGeometry::TexturedPoint2D> tempVertexData(maxVertices);
+        QVector<quint16> tempIndexData(maxIndexes);
+
+        for (int i = 0; i < maxGlyphs; i++) {
+            tempVertexData[i * 4 + 0] = vertexData[i * 4 + 0];
+            tempVertexData[i * 4 + 1] = vertexData[i * 4 + 1];
+            tempVertexData[i * 4 + 2] = vertexData[i * 4 + 2];
+            tempVertexData[i * 4 + 3] = vertexData[i * 4 + 3];
+
+            tempIndexData[i * 6 + 0] = indexData[i * 6 + 0];
+            tempIndexData[i * 6 + 1] = indexData[i * 6 + 1];
+            tempIndexData[i * 6 + 2] = indexData[i * 6 + 2];
+            tempIndexData[i * 6 + 3] = indexData[i * 6 + 3];
+            tempIndexData[i * 6 + 4] = indexData[i * 6 + 4];
+            tempIndexData[i * 6 + 5] = indexData[i * 6 + 5];
+        }
+
+        g->allocate(maxVertices, maxIndexes);
+        vertexData = g->vertexDataAsTexturedPoint2D();
+        indexData = g->indexDataAsUShort();
+
+        for (int i = 0; i < maxGlyphs; i++) {
+            vertexData[i * 4 + 0] = tempVertexData[i * 4 + 0];
+            vertexData[i * 4 + 1] = tempVertexData[i * 4 + 1];
+            vertexData[i * 4 + 2] = tempVertexData[i * 4 + 2];
+            vertexData[i * 4 + 3] = tempVertexData[i * 4 + 3];
+
+            indexData[i * 6 + 0] = tempIndexData[i * 6 + 0];
+            indexData[i * 6 + 1] = tempIndexData[i * 6 + 1];
+            indexData[i * 6 + 2] = tempIndexData[i * 6 + 2];
+            indexData[i * 6 + 3] = tempIndexData[i * 6 + 3];
+            indexData[i * 6 + 4] = tempIndexData[i * 6 + 4];
+            indexData[i * 6 + 5] = tempIndexData[i * 6 + 5];
+        }
+    }
+
+    m_dirtyGeometry = false;
+}
+
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgdefaultglyphnode_p.h b/src/quick/scenegraph/qsgdefaultglyphnode_p.h
index 0eb7a4e4bd..37a89c70b9 100644
--- a/src/quick/scenegraph/qsgdefaultglyphnode_p.h
+++ b/src/quick/scenegraph/qsgdefaultglyphnode_p.h
@@ -59,8 +59,31 @@ QT_BEGIN_NAMESPACE
 class QSGDefaultGlyphNode : public QSGBasicGlyphNode
 {
 public:
+    QSGDefaultGlyphNode();
+    ~QSGDefaultGlyphNode();
     void setMaterialColor(const QColor &color) override;
+    void setGlyphs(const QPointF &position, const QGlyphRun &glyphs) override;
     void update() override;
+    void preprocess() override;
+    void updateGeometry();
+
+private:
+    enum DefaultGlyphNodeType {
+        RootGlyphNode,
+        SubGlyphNode
+    };
+
+    void setGlyphNodeType(DefaultGlyphNodeType type) { m_glyphNodeType = type; }
+
+    DefaultGlyphNodeType m_glyphNodeType;
+    QLinkedList<QSGNode *> m_nodesToDelete;
+
+    struct GlyphInfo {
+        QVector<quint32> indexes;
+        QVector<QPointF> positions;
+    };
+
+    uint m_dirtyGeometry: 1;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgdefaultrendercontext.cpp b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
index 2c5b4ff5c8..7542068a53 100644
--- a/src/quick/scenegraph/qsgdefaultrendercontext.cpp
+++ b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
@@ -45,7 +45,6 @@
 #include <QtQuick/private/qsgrenderer_p.h>
 #include <QtQuick/private/qsgatlastexture_p.h>
 #include <QtQuick/private/qsgdefaultdistancefieldglyphcache_p.h>
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -159,8 +158,8 @@ void QSGDefaultRenderContext::invalidate()
     delete m_depthStencilManager;
     m_depthStencilManager = 0;
 
-    delete m_distanceFieldCacheManager;
-    m_distanceFieldCacheManager = 0;
+    qDeleteAll(m_glyphCaches);
+    m_glyphCaches.clear();
 
     if (m_gl->property(QSG_RENDERCONTEXT_PROPERTY) == QVariant::fromValue(this))
         m_gl->setProperty(QSG_RENDERCONTEXT_PROPERTY, QVariant());
@@ -294,13 +293,10 @@ QT_END_NAMESPACE
 
 QSGDistanceFieldGlyphCache *QSGDefaultRenderContext::distanceFieldGlyphCache(const QRawFont &font)
 {
-    if (!m_distanceFieldCacheManager)
-        m_distanceFieldCacheManager = new QSGDistanceFieldGlyphCacheManager;
-
-    QSGDistanceFieldGlyphCache *cache = m_distanceFieldCacheManager->cache(font);
+    QSGDistanceFieldGlyphCache *cache = m_glyphCaches.value(font, 0);
     if (!cache) {
-        cache = new QSGDefaultDistanceFieldGlyphCache(m_distanceFieldCacheManager, openglContext(), font);
-        m_distanceFieldCacheManager->insertCache(font, cache);
+        cache = new QSGDefaultDistanceFieldGlyphCache(openglContext(), font);
+        m_glyphCaches.insert(font, cache);
     }
 
     return cache;
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp b/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
index 456a197ba1..32eda2d142 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
@@ -39,7 +39,6 @@
 
 #include "qsgdistancefieldglyphnode_p.h"
 #include "qsgdistancefieldglyphnode_p_p.h"
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #include <QtQuick/private/qsgcontext_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -76,9 +75,6 @@ QSGDistanceFieldGlyphNode::~QSGDistanceFieldGlyphNode()
         m_glyph_cache->unregisterGlyphNode(this);
         m_glyph_cache->unregisterOwnerElement(ownerElement());
     }
-
-    while (m_nodesToDelete.count())
-        delete m_nodesToDelete.takeLast();
 }
 
 void QSGDistanceFieldGlyphNode::setColor(const QColor &color)
@@ -158,9 +154,6 @@ void QSGDistanceFieldGlyphNode::preprocess()
 {
     Q_ASSERT(m_glyph_cache);
 
-    while (m_nodesToDelete.count())
-        delete m_nodesToDelete.takeLast();
-
     m_glyph_cache->processPendingGlyphs();
     m_glyph_cache->update();
 
@@ -188,13 +181,12 @@ void QSGDistanceFieldGlyphNode::updateGeometry()
     // Remove previously created sub glyph nodes
     // We assume all the children are sub glyph nodes
     QSGNode *subnode = firstChild();
+    QSGNode *nextNode = 0;
     while (subnode) {
-        // We can't delete the node now as it might be in the preprocess list
-        // It will be deleted in the next preprocess
-        m_nodesToDelete.append(subnode);
-        subnode = subnode->nextSibling();
+        nextNode = subnode->nextSibling();
+        delete subnode;
+        subnode = nextNode;
     }
-    removeAllChildNodes();
 
     QSGGeometry *g = geometry();
 
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
index fc66f2f2cc..a67c659c99 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.cpp
@@ -38,7 +38,6 @@
 ****************************************************************************/
 
 #include "qsgdistancefieldglyphnode_p_p.h"
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #include <QtQuick/private/qsgtexture_p.h>
 #include <QtGui/qopenglfunctions.h>
 #include <QtGui/qsurface.h>
@@ -58,7 +57,7 @@ public:
 protected:
     void initialize() override;
 
-    void updateAlphaRange(ThresholdFunc thresholdFunc, AntialiasingSpreadFunc spreadFunc);
+    void updateAlphaRange();
     void updateColor(const QVector4D &c);
     void updateTextureScale(const QVector2D &ts);
 
@@ -98,7 +97,31 @@ QSGDistanceFieldTextMaterialShader::QSGDistanceFieldTextMaterialShader()
     setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/distancefieldtext.frag"));
 }
 
-void QSGDistanceFieldTextMaterialShader::updateAlphaRange(ThresholdFunc thresholdFunc, AntialiasingSpreadFunc spreadFunc)
+static float qt_sg_envFloat(const char *name, float defaultValue)
+{
+    if (Q_LIKELY(!qEnvironmentVariableIsSet(name)))
+        return defaultValue;
+    bool ok = false;
+    const float value = qgetenv(name).toFloat(&ok);
+    return ok ? value : defaultValue;
+}
+
+static float thresholdFunc(float glyphScale)
+{
+    static const float base = qt_sg_envFloat("QT_DF_BASE", 0.5f);
+    static const float baseDev = qt_sg_envFloat("QT_DF_BASEDEVIATION", 0.065f);
+    static const float devScaleMin = qt_sg_envFloat("QT_DF_SCALEFORMAXDEV", 0.15f);
+    static const float devScaleMax = qt_sg_envFloat("QT_DF_SCALEFORNODEV", 0.3f);
+    return base - ((qBound(devScaleMin, glyphScale, devScaleMax) - devScaleMin) / (devScaleMax - devScaleMin) * -baseDev + baseDev);
+}
+
+static float spreadFunc(float glyphScale)
+{
+    static const float range = qt_sg_envFloat("QT_DF_RANGE", 0.06f);
+    return range / glyphScale;
+}
+
+void QSGDistanceFieldTextMaterialShader::updateAlphaRange()
 {
     float combinedScale = m_fontScale * m_matrixScale;
     float base = thresholdFunc(combinedScale);
@@ -169,8 +192,7 @@ void QSGDistanceFieldTextMaterialShader::updateState(const RenderState &state, Q
         updateRange = true;
     }
     if (updateRange) {
-        updateAlphaRange(material->glyphCache()->manager()->thresholdFunc(),
-                         material->glyphCache()->manager()->antialiasingSpreadFunc());
+        updateAlphaRange();
     }
 
     Q_ASSERT(material->glyphCache());
@@ -334,7 +356,7 @@ public:
 protected:
     void initialize() override;
 
-    void updateOutlineAlphaRange(ThresholdFunc thresholdFunc, AntialiasingSpreadFunc spreadFunc, int dfRadius);
+    void updateOutlineAlphaRange(int dfRadius);
 
     int m_outlineAlphaMax0_id;
     int m_outlineAlphaMax1_id;
@@ -355,9 +377,7 @@ void DistanceFieldOutlineTextMaterialShader::initialize()
     m_outlineAlphaMax1_id = program()->uniformLocation("outlineAlphaMax1");
 }
 
-void DistanceFieldOutlineTextMaterialShader::updateOutlineAlphaRange(ThresholdFunc thresholdFunc,
-                                                                     AntialiasingSpreadFunc spreadFunc,
-                                                                     int dfRadius)
+void DistanceFieldOutlineTextMaterialShader::updateOutlineAlphaRange(int dfRadius)
 {
     float combinedScale = m_fontScale * m_matrixScale;
     float base = thresholdFunc(combinedScale);
@@ -381,9 +401,7 @@ void DistanceFieldOutlineTextMaterialShader::updateState(const RenderState &stat
     if (oldMaterial == 0
             || material->fontScale() != oldMaterial->fontScale()
             || state.isMatrixDirty())
-        updateOutlineAlphaRange(material->glyphCache()->manager()->thresholdFunc(),
-                                material->glyphCache()->manager()->antialiasingSpreadFunc(),
-                                material->glyphCache()->distanceFieldRadius());
+        updateOutlineAlphaRange(material->glyphCache()->distanceFieldRadius());
 }
 
 
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
index c0c6bda718..7008f20925 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
@@ -59,7 +59,6 @@
 QT_BEGIN_NAMESPACE
 
 class QSGRenderContext;
-class QSGDistanceFieldGlyphCacheManager;
 class QSGDistanceFieldTextMaterial;
 class QSGDistanceFieldGlyphNode: public QSGGlyphNode, public QSGDistanceFieldGlyphConsumer
 {
@@ -107,7 +106,6 @@ private:
     AntialiasingMode m_antialiasingMode;
     QRectF m_boundingRect;
     const QSGDistanceFieldGlyphCache::Texture *m_texture;
-    QLinkedList<QSGNode *> m_nodesToDelete;
 
     struct GlyphInfo {
         QVector<quint32> indexes;
diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index bb581c5e36..293a706c2e 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -423,6 +423,7 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     if (data.grabOnly) {
         bool alpha = window->format().alphaBufferSize() > 0 && window->color().alpha() != 255;
         grabContent = qt_gl_read_framebuffer(window->size() * window->effectiveDevicePixelRatio(), alpha, alpha);
+        grabContent.setDevicePixelRatio(window->effectiveDevicePixelRatio());
         data.grabOnly = false;
     }
 
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index 17a2c62a4e..560fddd580 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -432,6 +432,7 @@ bool QSGRenderThread::event(QEvent *e)
             qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- grabbing result";
             bool alpha = ce->window->format().alphaBufferSize() > 0 && ce->window->color().alpha() != 255;
             *ce->image = qt_gl_read_framebuffer(windowSize * ce->window->effectiveDevicePixelRatio(), alpha, alpha);
+            ce->image->setDevicePixelRatio(ce->window->effectiveDevicePixelRatio());
         }
         qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- waking gui to handle result";
         waitCondition.wakeOne();
diff --git a/src/quick/scenegraph/qsgwindowsrenderloop.cpp b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
index e944ddbc4f..eff6763a16 100644
--- a/src/quick/scenegraph/qsgwindowsrenderloop.cpp
+++ b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
@@ -325,6 +325,7 @@ QImage QSGWindowsRenderLoop::grab(QQuickWindow *window)
 
     bool alpha = window->format().alphaBufferSize() > 0 && window->color().alpha() != 255;
     QImage image = qt_gl_read_framebuffer(window->size() * window->effectiveDevicePixelRatio(), alpha, alpha);
+    image.setDevicePixelRatio(window->effectiveDevicePixelRatio());
     return image;
 }
 
diff --git a/src/quick/scenegraph/scenegraph.pri b/src/quick/scenegraph/scenegraph.pri
index 38c3b8dd85..c6db3df158 100644
--- a/src/quick/scenegraph/scenegraph.pri
+++ b/src/quick/scenegraph/scenegraph.pri
@@ -45,7 +45,6 @@ HEADERS += \
     $$PWD/util/qsgtexture.h \
     $$PWD/util/qsgtexture_p.h \
     $$PWD/util/qsgtextureprovider.h \
-    $$PWD/util/qsgdistancefieldutil_p.h \
     $$PWD/util/qsgflatcolormaterial.h \
     $$PWD/util/qsgsimplematerial.h \
     $$PWD/util/qsgtexturematerial.h \
@@ -62,7 +61,6 @@ SOURCES += \
     $$PWD/util/qsgsimpletexturenode.cpp \
     $$PWD/util/qsgtexture.cpp \
     $$PWD/util/qsgtextureprovider.cpp \
-    $$PWD/util/qsgdistancefieldutil.cpp \
     $$PWD/util/qsgflatcolormaterial.cpp \
     $$PWD/util/qsgsimplematerial.cpp \
     $$PWD/util/qsgtexturematerial.cpp \
diff --git a/src/quick/scenegraph/util/qsgdistancefieldutil.cpp b/src/quick/scenegraph/util/qsgdistancefieldutil.cpp
deleted file mode 100644
index 9ca9cdb107..0000000000
--- a/src/quick/scenegraph/util/qsgdistancefieldutil.cpp
+++ /dev/null
@@ -1,95 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQuick module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qsgdistancefieldutil_p.h"
-
-#include <private/qsgadaptationlayer_p.h>
-#if QT_CONFIG(opengl)
-# include <QtGui/private/qopenglengineshadersource_p.h>
-#endif
-#include <QtQuick/private/qsgcontext_p.h>
-
-QT_BEGIN_NAMESPACE
-
-static float qt_sg_envFloat(const char *name, float defaultValue)
-{
-    if (Q_LIKELY(!qEnvironmentVariableIsSet(name)))
-        return defaultValue;
-    bool ok = false;
-    const float value = qgetenv(name).toFloat(&ok);
-    return ok ? value : defaultValue;
-}
-
-static float defaultThresholdFunc(float glyphScale)
-{
-    static const float base = qt_sg_envFloat("QT_DF_BASE", 0.5f);
-    static const float baseDev = qt_sg_envFloat("QT_DF_BASEDEVIATION", 0.065f);
-    static const float devScaleMin = qt_sg_envFloat("QT_DF_SCALEFORMAXDEV", 0.15f);
-    static const float devScaleMax = qt_sg_envFloat("QT_DF_SCALEFORNODEV", 0.3f);
-    return base - ((qBound(devScaleMin, glyphScale, devScaleMax) - devScaleMin) / (devScaleMax - devScaleMin) * -baseDev + baseDev);
-}
-
-static float defaultAntialiasingSpreadFunc(float glyphScale)
-{
-    static const float range = qt_sg_envFloat("QT_DF_RANGE", 0.06f);
-    return range / glyphScale;
-}
-
-QSGDistanceFieldGlyphCacheManager::QSGDistanceFieldGlyphCacheManager()
-    : m_threshold_func(defaultThresholdFunc)
-    , m_antialiasingSpread_func(defaultAntialiasingSpreadFunc)
-{
-}
-
-QSGDistanceFieldGlyphCacheManager::~QSGDistanceFieldGlyphCacheManager()
-{
-    qDeleteAll(m_caches);
-}
-
-QSGDistanceFieldGlyphCache *QSGDistanceFieldGlyphCacheManager::cache(const QRawFont &font)
-{
-    return m_caches.value(font, 0);
-}
-
-void QSGDistanceFieldGlyphCacheManager::insertCache(const QRawFont &font, QSGDistanceFieldGlyphCache *cache)
-{
-    m_caches.insert(font, cache);
-}
-
-QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/util/qsgdistancefieldutil_p.h b/src/quick/scenegraph/util/qsgdistancefieldutil_p.h
deleted file mode 100644
index ad366cb4d4..0000000000
--- a/src/quick/scenegraph/util/qsgdistancefieldutil_p.h
+++ /dev/null
@@ -1,91 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQuick module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QSGDISTANCEFIELDUTIL_H
-#define QSGDISTANCEFIELDUTIL_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <qrawfont.h>
-#include <private/qfontengine_p.h>
-#include <private/qsgadaptationlayer_p.h>
-
-QT_BEGIN_NAMESPACE
-
-typedef float (*ThresholdFunc)(float glyphScale);
-typedef float (*AntialiasingSpreadFunc)(float glyphScale);
-
-class QOpenGLShaderProgram;
-class QSGDistanceFieldGlyphCache;
-class QSGContext;
-
-class Q_QUICK_PRIVATE_EXPORT QSGDistanceFieldGlyphCacheManager
-{
-public:
-    QSGDistanceFieldGlyphCacheManager();
-    ~QSGDistanceFieldGlyphCacheManager();
-
-    QSGDistanceFieldGlyphCache *cache(const QRawFont &font);
-    void insertCache(const QRawFont &font, QSGDistanceFieldGlyphCache *cache);
-
-    ThresholdFunc thresholdFunc() const { return m_threshold_func; }
-    void setThresholdFunc(ThresholdFunc func) { m_threshold_func = func; }
-
-    AntialiasingSpreadFunc antialiasingSpreadFunc() const { return m_antialiasingSpread_func; }
-    void setAntialiasingSpreadFunc(AntialiasingSpreadFunc func) { m_antialiasingSpread_func = func; }
-
-private:
-    QHash<QRawFont, QSGDistanceFieldGlyphCache *> m_caches;
-
-    ThresholdFunc m_threshold_func;
-    AntialiasingSpreadFunc m_antialiasingSpread_func;
-};
-
-QT_END_NAMESPACE
-
-#endif // QSGDISTANCEFIELDUTIL_H
diff --git a/src/quick/scenegraph/util/qsgengine.cpp b/src/quick/scenegraph/util/qsgengine.cpp
index 09e4cdf5a7..259e45c978 100644
--- a/src/quick/scenegraph/util/qsgengine.cpp
+++ b/src/quick/scenegraph/util/qsgengine.cpp
@@ -84,6 +84,8 @@ QT_BEGIN_NAMESPACE
     will delete the GL texture when the texture object is deleted.
 
     \value TextureCanUseAtlas The image can be uploaded into a texture atlas.
+
+    \value TextureIsOpaque The texture object is opaque.
  */
 
 QSGEnginePrivate::QSGEnginePrivate()
diff --git a/src/quick/scenegraph/util/qsgsimplematerial.cpp b/src/quick/scenegraph/util/qsgsimplematerial.cpp
index 7214a255df..f29c58ad9e 100644
--- a/src/quick/scenegraph/util/qsgsimplematerial.cpp
+++ b/src/quick/scenegraph/util/qsgsimplematerial.cpp
@@ -194,19 +194,15 @@
 /*!
     \fn const char *QSGSimpleMaterialShader::uniformMatrixName() const
 
-    Reimplement this function to give a different name to the uniform for
-    item transformation. The default value is \c qt_Matrix.
-
+    Returns the name for the transform matrix uniform of this item.
+    The default value is \c qt_Matrix.
  */
 
 /*!
     \fn const char *QSGSimpleMaterialShader::uniformOpacityName() const
 
-    Reimplement this function to give a different name to the uniform for
-    item opacity. The default value is \c qt_Opacity.
-
-    If the shader program does not implement the item opacity, the
-    implemented function should return a null pointer.
+    Returns the name for the opacity uniform of this item.
+    The default value is \c qt_Opacity.
  */
 
 /*!
diff --git a/src/quick/scenegraph/util/qsgsimplematerial.h b/src/quick/scenegraph/util/qsgsimplematerial.h
index 0e7219d7bd..b5b8815b4a 100644
--- a/src/quick/scenegraph/util/qsgsimplematerial.h
+++ b/src/quick/scenegraph/util/qsgsimplematerial.h
@@ -71,6 +71,7 @@ public:
         resolveUniforms();
     }
 
+    // ### Qt 6: make both virtual and fix docs
     const char *uniformMatrixName() const { return "qt_Matrix"; }
     const char *uniformOpacityName() const { return "qt_Opacity"; }
 
diff --git a/src/quick/scenegraph/util/qsgtexture.cpp b/src/quick/scenegraph/util/qsgtexture.cpp
index bc59c49162..591b679ec4 100644
--- a/src/quick/scenegraph/util/qsgtexture.cpp
+++ b/src/quick/scenegraph/util/qsgtexture.cpp
@@ -256,6 +256,8 @@ static void qt_debug_remove_texture(QSGTexture* texture)
 
     Specifies how the texture should treat texture coordinates.
 
+    \note Texture wrapping needs to be handled explicitly for atlas textures.
+
     \value Repeat Only the factional part of the texture coordiante is
     used, causing values above 1 and below 0 to repeat.
 
diff --git a/src/quick/util/qquickanimatorjob.cpp b/src/quick/util/qquickanimatorjob.cpp
index 4aacb09c97..89007cff1f 100644
--- a/src/quick/util/qquickanimatorjob.cpp
+++ b/src/quick/util/qquickanimatorjob.cpp
@@ -345,12 +345,13 @@ void QQuickTransformAnimatorJob::postSync()
     }
 
     QQuickItemPrivate *d = QQuickItemPrivate::get(m_target);
+#if QT_CONFIG(quick_shadereffect)
     if (d->extra.isAllocated()
             && d->extra->layer
             && d->extra->layer->enabled()) {
         d = QQuickItemPrivate::get(d->extra->layer->m_effectSource);
     }
-
+#endif
     m_helper->node = d->itemNode();
 }
 
diff --git a/src/quick/util/qquickimageprovider.cpp b/src/quick/util/qquickimageprovider.cpp
index a026abe762..c4a98c69f9 100644
--- a/src/quick/util/qquickimageprovider.cpp
+++ b/src/quick/util/qquickimageprovider.cpp
@@ -183,7 +183,12 @@ QString QQuickImageResponse::errorString() const
 
     It may be reimplemented to cancel a request in the provider side, however, it is not mandatory.
 
-    A cancelled QQuickImageResponse still needs to emit finished().
+    A cancelled QQuickImageResponse still needs to emit finished() so that the
+    engine may clean up the QQuickImageResponse.
+
+    \note finished() should not be emitted until the response is complete,
+    regardless of whether or not cancel() was called. If it is called prematurely,
+    the engine may destroy the response while it is still active, leading to a crash.
 */
 void QQuickImageResponse::cancel()
 {
@@ -192,7 +197,12 @@ void QQuickImageResponse::cancel()
 /*!
     \fn void QQuickImageResponse::finished()
 
-    Signals that the job execution has finished (be it successfully, because an error happened or because it was cancelled).
+    Signals that the job execution has finished (be it successfully, because an
+    error happened or because it was cancelled).
+
+    \note Emission of this signal must be the final action the response performs:
+    once the signal is received, the response will subsequently be destroyed by
+    the engine.
  */
 
 /*!
@@ -603,7 +613,6 @@ void QQuickImageProviderOptions::setPreserveAspectRatioFit(bool preserveAspectRa
     d->preserveAspectRatioFit = preserveAspectRatioFit;
 }
 
-
 QQuickImageProviderWithOptions::QQuickImageProviderWithOptions(ImageType type, Flags flags)
  : QQuickAsyncImageProvider()
 {
@@ -660,5 +669,49 @@ QQuickImageResponse *QQuickImageProviderWithOptions::requestImageResponse(const
     return requestImageResponse(id, requestedSize);
 }
 
+/*!
+    Returns the recommended scaled image size for loading and storage. This is
+    calculated according to the native pixel size of the image \a originalSize,
+    the requested sourceSize \a requestedSize, the image file format \a format,
+    and \a options. If the calculation otherwise concludes that scaled loading
+    is not recommended, an invalid size is returned.
+*/
+QSize QQuickImageProviderWithOptions::loadSize(const QSize &originalSize, const QSize &requestedSize, const QByteArray &format, const QQuickImageProviderOptions &options)
+{
+    QSize res;
+    if ((requestedSize.width() <= 0 && requestedSize.height() <= 0) || originalSize.isEmpty())
+        return res;
+
+    const bool preserveAspectCropOrFit = options.preserveAspectRatioCrop() || options.preserveAspectRatioFit();
+    const bool force_scale = (format == "svg" || format == "svgz");
+
+    qreal ratio = 0.0;
+    if (requestedSize.width() && (preserveAspectCropOrFit || force_scale || requestedSize.width() < originalSize.width())) {
+        ratio = qreal(requestedSize.width()) / originalSize.width();
+    }
+    if (requestedSize.height() && (preserveAspectCropOrFit || force_scale || requestedSize.height() < originalSize.height())) {
+        qreal hr = qreal(requestedSize.height()) / originalSize.height();
+        if (ratio == 0.0)
+            ratio = hr;
+        else if (!preserveAspectCropOrFit && (hr < ratio))
+            ratio = hr;
+        else if (preserveAspectCropOrFit && (hr > ratio))
+            ratio = hr;
+    }
+    if (ratio > 0.0) {
+        res.setHeight(qRound(originalSize.height() * ratio));
+        res.setWidth(qRound(originalSize.width() * ratio));
+    }
+    return res;
+}
+
+QQuickImageProviderWithOptions *QQuickImageProviderWithOptions::checkedCast(QQuickImageProvider *provider)
+{
+    if (provider && provider->d && provider->d->isProviderWithOptions)
+        return static_cast<QQuickImageProviderWithOptions *>(provider);
+
+    return nullptr;
+}
+
 QT_END_NAMESPACE
 
diff --git a/src/quick/util/qquickimageprovider.h b/src/quick/util/qquickimageprovider.h
index c77ff95f32..681de4b6c2 100644
--- a/src/quick/util/qquickimageprovider.h
+++ b/src/quick/util/qquickimageprovider.h
@@ -88,7 +88,6 @@ Q_SIGNALS:
 class Q_QUICK_EXPORT QQuickImageProvider : public QQmlImageProviderBase
 {
     friend class QQuickImageProviderWithOptions; // ### Qt 6 Remove
-    friend class QQuickPixmapReader; // ### Qt 6 Remove
 public:
     QQuickImageProvider(ImageType type, Flags flags = Flags());
     virtual ~QQuickImageProvider();
diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index 395b89c784..7d88935402 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -141,6 +141,7 @@ public:
     QUrl url;
 
     bool loading;
+    QQuickImageProviderOptions providerOptions;
     int redirectCount;
 
     class Event : public QEvent {
@@ -204,7 +205,7 @@ protected:
 private:
     friend class QQuickPixmapReaderThreadObject;
     void processJobs();
-    void processJob(QQuickPixmapReply *, const QUrl &, const QString &, const QQuickImageProviderOptions &, QQuickImageProvider::ImageType, QQuickImageProvider *);
+    void processJob(QQuickPixmapReply *, const QUrl &, const QString &, QQuickImageProvider::ImageType, QQuickImageProvider *);
 #if QT_CONFIG(qml_network)
     void networkRequestDone(QNetworkReply *);
 #endif
@@ -386,37 +387,15 @@ static bool readImage(const QUrl& url, QIODevice *dev, QImage *image, QString *e
                       const QSize &requestSize, const QQuickImageProviderOptions &providerOptions,
                       QQuickImageProviderOptions::AutoTransform *appliedTransform = nullptr)
 {
-    const bool preserveAspectCropOrFit = providerOptions.preserveAspectRatioCrop() || providerOptions.preserveAspectRatioFit();
-
     QImageReader imgio(dev);
     if (providerOptions.autoTransform() != QQuickImageProviderOptions::UsePluginDefaultTransform)
         imgio.setAutoTransform(providerOptions.autoTransform() == QQuickImageProviderOptions::ApplyTransform);
     else if (appliedTransform)
         *appliedTransform = imgio.autoTransform() ? QQuickImageProviderOptions::ApplyTransform : QQuickImageProviderOptions::DoNotApplyTransform;
 
-    const bool force_scale = imgio.format() == "svg" || imgio.format() == "svgz";
-
-    if (requestSize.width() > 0 || requestSize.height() > 0) {
-        QSize s = imgio.size();
-        qreal ratio = 0.0;
-        if (requestSize.width() && (preserveAspectCropOrFit || force_scale || requestSize.width() < s.width())) {
-            ratio = qreal(requestSize.width())/s.width();
-        }
-        if (requestSize.height() && (preserveAspectCropOrFit || force_scale || requestSize.height() < s.height())) {
-            qreal hr = qreal(requestSize.height())/s.height();
-            if (ratio == 0.0)
-                ratio = hr;
-            else if (!preserveAspectCropOrFit && (hr < ratio))
-                ratio = hr;
-            else if (preserveAspectCropOrFit && (hr > ratio))
-                ratio = hr;
-        }
-        if (ratio > 0.0) {
-            s.setHeight(qRound(s.height() * ratio));
-            s.setWidth(qRound(s.width() * ratio));
-            imgio.setScaledSize(s);
-        }
-    }
+    QSize scSize = QQuickImageProviderWithOptions::loadSize(imgio.size(), requestSize, imgio.format(), providerOptions);
+    if (scSize.isValid())
+        imgio.setScaledSize(scSize);
 
     if (impsize)
         *impsize = imgio.size();
@@ -664,7 +643,7 @@ void QQuickPixmapReader::processJobs()
                     PIXMAP_PROFILE(pixmapStateChanged<QQuickProfiler::PixmapLoadingStarted>(url));
 
                     locker.unlock();
-                    processJob(job, url, localFile, job->data->providerOptions, imageType, provider);
+                    processJob(job, url, localFile, imageType, provider);
                     locker.relock();
                 }
             }
@@ -676,7 +655,6 @@ void QQuickPixmapReader::processJobs()
 }
 
 void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &url, const QString &localFile,
-                                    const QQuickImageProviderOptions &providerOptions,
                                     QQuickImageProvider::ImageType imageType, QQuickImageProvider *provider)
 {
     // fetch
@@ -693,8 +671,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             return;
         }
 
-        QQuickImageProviderWithOptions *providerV2 = provider->d->isProviderWithOptions ? static_cast<QQuickImageProviderWithOptions *>(provider)
-                                                                                        : nullptr;
+        QQuickImageProviderWithOptions *providerV2 = QQuickImageProviderWithOptions::checkedCast(provider);
 
         switch (imageType) {
             case QQuickImageProvider::Invalid:
@@ -707,7 +684,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             {
                 QImage image;
                 if (providerV2) {
-                    image = providerV2->requestImage(imageId(url), &readSize, runningJob->requestSize, providerOptions);
+                    image = providerV2->requestImage(imageId(url), &readSize, runningJob->requestSize, runningJob->providerOptions);
                 } else {
                     image = provider->requestImage(imageId(url), &readSize, runningJob->requestSize);
                 }
@@ -728,7 +705,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             {
                 QPixmap pixmap;
                 if (providerV2) {
-                    pixmap = providerV2->requestPixmap(imageId(url), &readSize, runningJob->requestSize, providerOptions);
+                    pixmap = providerV2->requestPixmap(imageId(url), &readSize, runningJob->requestSize, runningJob->providerOptions);
                 } else {
                     pixmap = provider->requestPixmap(imageId(url), &readSize, runningJob->requestSize);
                 }
@@ -749,7 +726,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             {
                 QQuickTextureFactory *t;
                 if (providerV2) {
-                    t = providerV2->requestTexture(imageId(url), &readSize, runningJob->requestSize, providerOptions);
+                    t = providerV2->requestTexture(imageId(url), &readSize, runningJob->requestSize, runningJob->providerOptions);
                 } else {
                     t = provider->requestTexture(imageId(url), &readSize, runningJob->requestSize);
                 }
@@ -772,7 +749,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             {
                 QQuickImageResponse *response;
                 if (providerV2) {
-                    response = providerV2->requestImageResponse(imageId(url), runningJob->requestSize, providerOptions);
+                    response = providerV2->requestImageResponse(imageId(url), runningJob->requestSize, runningJob->providerOptions);
                 } else {
                     QQuickAsyncImageProvider *asyncProvider = static_cast<QQuickAsyncImageProvider*>(provider);
                     response = asyncProvider->requestImageResponse(imageId(url), runningJob->requestSize);
@@ -794,7 +771,7 @@ void QQuickPixmapReader::processJob(QQuickPixmapReply *runningJob, const QUrl &u
             QFile f(localFile);
             QSize readSize;
             if (f.open(QIODevice::ReadOnly)) {
-                if (!readImage(url, &f, &image, &errorStr, &readSize, runningJob->requestSize, providerOptions))
+                if (!readImage(url, &f, &image, &errorStr, &readSize, runningJob->requestSize, runningJob->providerOptions))
                     errorCode = QQuickPixmapReply::Loading;
             } else {
                 errorStr = QQuickPixmap::tr("Cannot open: %1").arg(url.toString());
@@ -1075,7 +1052,7 @@ void QQuickPixmap::purgeCache()
 }
 
 QQuickPixmapReply::QQuickPixmapReply(QQuickPixmapData *d)
-: data(d), engineForReader(0), requestSize(d->requestSize), url(d->url), loading(false), redirectCount(0)
+: data(d), engineForReader(0), requestSize(d->requestSize), url(d->url), loading(false), providerOptions(d->providerOptions), redirectCount(0)
 {
     if (finishedIndex == -1) {
         finishedIndex = QMetaMethod::fromSignal(&QQuickPixmapReply::finished).methodIndex();
@@ -1196,6 +1173,7 @@ static QQuickPixmapData* createPixmapDataSync(QQuickPixmap *declarativePixmap, Q
 
         QQuickImageProvider::ImageType imageType = QQuickImageProvider::Invalid;
         QQuickImageProvider *provider = static_cast<QQuickImageProvider *>(engine->imageProvider(imageProviderId(url)));
+        QQuickImageProviderWithOptions *providerV2 = QQuickImageProviderWithOptions::checkedCast(provider);
         if (provider)
             imageType = provider->imageType();
 
@@ -1205,7 +1183,8 @@ static QQuickPixmapData* createPixmapDataSync(QQuickPixmap *declarativePixmap, Q
                     QQuickPixmap::tr("Invalid image provider: %1").arg(url.toString()));
             case QQuickImageProvider::Texture:
             {
-                QQuickTextureFactory *texture = provider->requestTexture(imageId(url), &readSize, requestSize);
+                QQuickTextureFactory *texture = providerV2 ? providerV2->requestTexture(imageId(url), &readSize, requestSize, providerOptions)
+                                                           : provider->requestTexture(imageId(url), &readSize, requestSize);
                 if (texture) {
                     *ok = true;
                     return new QQuickPixmapData(declarativePixmap, url, texture, readSize, requestSize, providerOptions, QQuickImageProviderOptions::UsePluginDefaultTransform);
@@ -1215,7 +1194,8 @@ static QQuickPixmapData* createPixmapDataSync(QQuickPixmap *declarativePixmap, Q
 
             case QQuickImageProvider::Image:
             {
-                QImage image = provider->requestImage(imageId(url), &readSize, requestSize);
+                QImage image = providerV2 ? providerV2->requestImage(imageId(url), &readSize, requestSize, providerOptions)
+                                          : provider->requestImage(imageId(url), &readSize, requestSize);
                 if (!image.isNull()) {
                     *ok = true;
                     return new QQuickPixmapData(declarativePixmap, url, QQuickTextureFactory::textureFactoryForImage(image), readSize, requestSize, providerOptions, QQuickImageProviderOptions::UsePluginDefaultTransform);
@@ -1224,7 +1204,8 @@ static QQuickPixmapData* createPixmapDataSync(QQuickPixmap *declarativePixmap, Q
             }
             case QQuickImageProvider::Pixmap:
             {
-                QPixmap pixmap = provider->requestPixmap(imageId(url), &readSize, requestSize);
+                QPixmap pixmap = providerV2 ? providerV2->requestPixmap(imageId(url), &readSize, requestSize, providerOptions)
+                                            : provider->requestPixmap(imageId(url), &readSize, requestSize);
                 if (!pixmap.isNull()) {
                     *ok = true;
                     return new QQuickPixmapData(declarativePixmap, url, QQuickTextureFactory::textureFactoryForImage(pixmap.toImage()), readSize, requestSize, providerOptions, QQuickImageProviderOptions::UsePluginDefaultTransform);
diff --git a/src/quick/util/qquickpixmapcache_p.h b/src/quick/util/qquickpixmapcache_p.h
index 93d5a1cf56..91fb1ed3bb 100644
--- a/src/quick/util/qquickpixmapcache_p.h
+++ b/src/quick/util/qquickpixmapcache_p.h
@@ -204,6 +204,9 @@ public:
     virtual QPixmap requestPixmap(const QString &id, QSize *size, const QSize& requestedSize, const QQuickImageProviderOptions &options);
     virtual QQuickTextureFactory *requestTexture(const QString &id, QSize *size, const QSize &requestedSize, const QQuickImageProviderOptions &options);
     virtual QQuickImageResponse *requestImageResponse(const QString &id, const QSize &requestedSize, const QQuickImageProviderOptions &options);
+
+    static QSize loadSize(const QSize &originalSize, const QSize &requestedSize, const QByteArray &format, const QQuickImageProviderOptions &options);
+    static QQuickImageProviderWithOptions *checkedCast(QQuickImageProvider *provider);
 };
 
 QT_END_NAMESPACE
diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index 4ed41a0c6c..a2ea0f7af2 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -76,10 +76,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#if QT_CONFIG(opengl)
-extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha);
-#endif
-
 class QQuickWidgetRenderControl : public QQuickRenderControl
 {
 public:
@@ -157,6 +153,16 @@ void QQuickWidgetPrivate::invalidateRenderControl()
 #endif
 
     renderControl->invalidate();
+
+    // Many things can happen inside the above invalidate() call, including a
+    // change of current context. Restore if needed since some code will rely
+    // on the fact that this function makes and leaves the context current.
+#if QT_CONFIG(opengl)
+    if (!useSoftwareRenderer && context) {
+        if (QOpenGLContext::currentContext() != context)
+            context->makeCurrent(offscreenSurface);
+    }
+#endif
 }
 
 void QQuickWidgetPrivate::handleWindowChange()
@@ -353,10 +359,9 @@ QImage QQuickWidgetPrivate::grabFramebuffer()
     return renderControl->grab();
 }
 
-QObject *QQuickWidgetPrivate::focusObject()
-{
-    return offscreenWindow ? offscreenWindow->focusObject() : 0;
-}
+// Intentionally not overriding the QQuickWindow's focusObject.
+// Key events should go to our key event handlers, and then to the
+// QQuickWindow, not any in-scene item.
 
 /*!
     \module QtQuickWidgets
@@ -1140,7 +1145,7 @@ QSize QQuickWidget::initialSize() const
 
 /*!
   Returns the view's root \l {QQuickItem} {item}. Can be null
-  when setContents/setSource has not been called, if they were called with
+  when setSource() has not been called, if it was called with
   broken QtQuick code or while the QtQuick contents are being created.
  */
 QQuickItem *QQuickWidget::rootObject() const
diff --git a/src/quickwidgets/qquickwidget_p.h b/src/quickwidgets/qquickwidget_p.h
index 559321cd51..6892e6e0b4 100644
--- a/src/quickwidgets/qquickwidget_p.h
+++ b/src/quickwidgets/qquickwidget_p.h
@@ -99,8 +99,6 @@ public:
     void destroyContext();
     void handleContextCreationFailure(const QSurfaceFormat &format, bool isEs);
 
-    QObject *focusObject() Q_DECL_OVERRIDE;
-
 #if QT_CONFIG(opengl)
     GLuint textureId() const Q_DECL_OVERRIDE;
     QImage grabFramebuffer() Q_DECL_OVERRIDE;
diff --git a/src/src.pro b/src/src.pro
index 4e2de8da14..3bb399acd4 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -10,7 +10,7 @@ qtHaveModule(gui):qtConfig(animation) {
         quick \
         qmltest
 
-    qtConfig(quick-sprite):qtConfig(opengl(es1|es2)?): \
+    qtConfig(quick-particles): \
         SUBDIRS += particles
     qtHaveModule(widgets): SUBDIRS += quickwidgets
 }
diff --git a/tests/auto/auto.pro b/tests/auto/auto.pro
index 1e80f1bf65..f9c1fcce91 100644
--- a/tests/auto/auto.pro
+++ b/tests/auto/auto.pro
@@ -18,4 +18,7 @@ qtHaveModule(gui):qtConfig(opengl(es1|es2)?) {
 # console applications not supported
 uikit: SUBDIRS -= qmltest
 
+# Restricted sub-set for now
+boot2qt: SUBDIRS = qml
+
 installed_cmake.depends = cmake
diff --git a/tests/auto/particles/qquickparticlesystem/data/crashaffectors.qml b/tests/auto/particles/qquickparticlesystem/data/crashaffectors.qml
new file mode 100644
index 0000000000..de105916a7
--- /dev/null
+++ b/tests/auto/particles/qquickparticlesystem/data/crashaffectors.qml
@@ -0,0 +1,43 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 reMarkable A/S
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.6
+import QtQuick.Particles 2.0
+
+ParticleSystem {
+    running: false
+    Affector { Component.onCompleted: destroy() }
+    Emitter {
+        Timer { interval: 1; running: true; onTriggered: parent.lifeSpan = 1 }
+    }
+}
diff --git a/tests/auto/particles/qquickparticlesystem/tst_qquickparticlesystem.cpp b/tests/auto/particles/qquickparticlesystem/tst_qquickparticlesystem.cpp
index 5c82b946e5..5f9db12144 100644
--- a/tests/auto/particles/qquickparticlesystem/tst_qquickparticlesystem.cpp
+++ b/tests/auto/particles/qquickparticlesystem/tst_qquickparticlesystem.cpp
@@ -42,6 +42,7 @@ public:
 private slots:
     void initTestCase();
     void test_basic();
+    void test_affectorscrash();
 };
 
 void tst_qquickparticlesystem::initTestCase()
@@ -78,6 +79,12 @@ void tst_qquickparticlesystem::test_basic()
     delete view;
     QVERIFY(extremelyFuzzyCompare(stillAlive, 500, 5));//Small simulation variance is permissible.
 }
+void tst_qquickparticlesystem::test_affectorscrash()
+{
+    QScopedPointer<QQuickView> view (createView(testFileUrl("crashaffectors.qml"), 600));
+
+    // This should have crashed by now
+}
 
 QTEST_MAIN(tst_qquickparticlesystem);
 
diff --git a/tests/auto/qml/debugger/qdebugmessageservice/tst_qdebugmessageservice.cpp b/tests/auto/qml/debugger/qdebugmessageservice/tst_qdebugmessageservice.cpp
index 8be82c30f9..f193d3928a 100644
--- a/tests/auto/qml/debugger/qdebugmessageservice/tst_qdebugmessageservice.cpp
+++ b/tests/auto/qml/debugger/qdebugmessageservice/tst_qdebugmessageservice.cpp
@@ -135,7 +135,7 @@ void QQmlDebugMsgClient::messageReceived(const QByteArray &data)
         QVERIFY(ds.atEnd());
 
         QVERIFY(type >= QtDebugMsg);
-        QVERIFY(type <= QtFatalMsg);
+        QVERIFY(type <= QtInfoMsg);
         QVERIFY(timestamp > 0);
 
         LogEntry entry((QtMsgType)type, QString::fromUtf8(message));
diff --git a/tests/auto/qml/debugger/qqmldebugjs/qqmldebugjs/tst_qqmldebugjs.cpp b/tests/auto/qml/debugger/qqmldebugjs/qqmldebugjs/tst_qqmldebugjs.cpp
index 31b8d63ec2..d248cf9708 100644
--- a/tests/auto/qml/debugger/qqmldebugjs/qqmldebugjs/tst_qqmldebugjs.cpp
+++ b/tests/auto/qml/debugger/qqmldebugjs/qqmldebugjs/tst_qqmldebugjs.cpp
@@ -257,7 +257,7 @@ public:
         stringify = jsEngine.evaluate(QLatin1String("JSON.stringify"));
     }
 
-    void connect();
+    void connect(bool redundantRefs = false, bool namesAsObjects = false);
     void interrupt();
 
     void continueDebugging(StepAction stepAction);
@@ -304,9 +304,13 @@ public:
 
 };
 
-void QJSDebugClient::connect()
+void QJSDebugClient::connect(bool redundantRefs, bool namesAsObjects)
 {
-    sendMessage(packMessage(CONNECT));
+    QJSValue jsonVal = parser.call(QJSValueList() << QLatin1String("{}"));
+    jsonVal.setProperty("redundantRefs", QJSValue(redundantRefs));
+    jsonVal.setProperty("namesAsObjects", QJSValue(namesAsObjects));
+    sendMessage(packMessage(CONNECT,
+                            stringify.call(QJSValueList() << jsonVal).toString().toUtf8()));
 }
 
 void QJSDebugClient::interrupt()
@@ -870,8 +874,10 @@ void tst_QQmlDebugJS::interrupt()
     //void connect()
 
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     init(qmlscene);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
 
     client->interrupt();
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(interruptRequested())));
@@ -882,8 +888,10 @@ void tst_QQmlDebugJS::getVersion()
     //void version()
 
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     init(qmlscene);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(connected())));
 
     client->version();
@@ -894,9 +902,11 @@ void tst_QQmlDebugJS::getVersionWhenAttaching()
 {
     //void version()
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     init(qmlscene, QLatin1String(TIMER_QMLFILE), false);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
 
     client->version();
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(result())));
@@ -907,8 +917,10 @@ void tst_QQmlDebugJS::disconnect()
     //void disconnect()
 
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     init(qmlscene);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
 
     client->disconnect();
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(result())));
@@ -918,12 +930,14 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnCompleted()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     init(qmlscene, ONCOMPLETED_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     QString jsonString(client->response);
@@ -939,12 +953,14 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnComponentCreated()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     init(qmlscene, CREATECOMPONENT_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     QString jsonString(client->response);
@@ -959,10 +975,12 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnComponentCreated()
 void tst_QQmlDebugJS::setBreakpointInScriptOnTimerCallback()
 {
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     int sourceLine = 35;
     init(qmlscene, TIMER_QMLFILE);
 
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     //We can set the breakpoint after connect() here because the timer is repeating and if we miss
     //its first iteration we can still catch the second one.
     client->setBreakpoint(QLatin1String(TIMER_QMLFILE), sourceLine, -1, true);
@@ -981,12 +999,14 @@ void tst_QQmlDebugJS::setBreakpointInScriptInDifferentFile()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 31;
     init(qmlscene, LOADJSFILE_QMLFILE);
 
     client->setBreakpoint(QLatin1String(TEST_JSFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     QString jsonString(client->response);
@@ -1002,13 +1022,15 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnComment()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     int actualLine = 36;
     init(qmlscene, BREAKPOINTRELOCATION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(BREAKPOINTRELOCATION_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QEXPECT_FAIL("", "Relocation of breakpoints is disabled right now", Abort);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped()), 1));
 
@@ -1025,13 +1047,15 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnEmptyLine()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 35;
     int actualLine = 36;
     init(qmlscene, BREAKPOINTRELOCATION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(BREAKPOINTRELOCATION_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QEXPECT_FAIL("", "Relocation of breakpoints is disabled right now", Abort);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped()), 1));
 
@@ -1048,12 +1072,14 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnOptimizedBinding()
 {
     //void setBreakpoint(QString type, QString target, int line = -1, int column = -1, bool enabled = false, QString condition = QString(), int ignoreCount = -1)
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 39;
     init(qmlscene, BREAKPOINTRELOCATION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(BREAKPOINTRELOCATION_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     QString jsonString(client->response);
@@ -1068,11 +1094,13 @@ void tst_QQmlDebugJS::setBreakpointInScriptOnOptimizedBinding()
 void tst_QQmlDebugJS::setBreakpointInScriptWithCondition()
 {
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     int out = 10;
     int sourceLine = 37;
     init(qmlscene, CONDITION_QMLFILE);
 
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     //The breakpoint is in a timer loop so we can set it after connect().
     client->setBreakpoint(QLatin1String(CONDITION_QMLFILE), sourceLine, 1, true, QLatin1String("a > 10"));
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
@@ -1105,12 +1133,14 @@ void tst_QQmlDebugJS::setBreakpointInScriptWithCondition()
 void tst_QQmlDebugJS::setBreakpointInScriptThatQuits()
 {
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     init(qmlscene, QUIT_QMLFILE);
 
     int sourceLine = 36;
 
     client->setBreakpoint(QLatin1String(QUIT_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     QString jsonString(client->response);
@@ -1147,12 +1177,14 @@ void tst_QQmlDebugJS::clearBreakpoint()
 {
     //void clearBreakpoint(int breakpoint);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine1 = 37;
     int sourceLine2 = 38;
     init(qmlscene, CHANGEBREAKPOINT_QMLFILE);
 
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     //The breakpoints are in a timer loop so we can set them after connect().
     //Furthermore the breakpoints should be hit in the right order because setting of breakpoints
     //can only occur in the QML event loop. (see QCOMPARE for sourceLine2 below)
@@ -1195,10 +1227,12 @@ void tst_QQmlDebugJS::setExceptionBreak()
 {
     //void setExceptionBreak(QString type, bool enabled = false);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     init(qmlscene, EXCEPTION_QMLFILE);
     client->setExceptionBreak(QJSDebugClient::All,true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 }
 
@@ -1206,12 +1240,14 @@ void tst_QQmlDebugJS::stepNext()
 {
     //void continueDebugging(StepAction stepAction, int stepCount = 1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 37;
     init(qmlscene, STEPACTION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(STEPACTION_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->continueDebugging(QJSDebugClient::Next);
@@ -1230,13 +1266,15 @@ void tst_QQmlDebugJS::stepIn()
 {
     //void continueDebugging(StepAction stepAction, int stepCount = 1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 41;
     int actualLine = 37;
     init(qmlscene, STEPACTION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(STEPACTION_QMLFILE), sourceLine, 1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->continueDebugging(QJSDebugClient::In);
@@ -1255,13 +1293,15 @@ void tst_QQmlDebugJS::stepOut()
 {
     //void continueDebugging(StepAction stepAction, int stepCount = 1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 37;
     int actualLine = 41;
     init(qmlscene, STEPACTION_QMLFILE);
 
     client->setBreakpoint(QLatin1String(STEPACTION_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->continueDebugging(QJSDebugClient::Out);
@@ -1280,6 +1320,8 @@ void tst_QQmlDebugJS::continueDebugging()
 {
     //void continueDebugging(StepAction stepAction, int stepCount = 1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine1 = 41;
     int sourceLine2 = 38;
@@ -1287,7 +1329,7 @@ void tst_QQmlDebugJS::continueDebugging()
 
     client->setBreakpoint(QLatin1String(STEPACTION_QMLFILE), sourceLine1, -1, true);
     client->setBreakpoint(QLatin1String(STEPACTION_QMLFILE), sourceLine2, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->continueDebugging(QJSDebugClient::Continue);
@@ -1306,12 +1348,14 @@ void tst_QQmlDebugJS::backtrace()
 {
     //void backtrace(int fromFrame = -1, int toFrame = -1, bool bottom = false);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     init(qmlscene, ONCOMPLETED_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->backtrace();
@@ -1322,12 +1366,14 @@ void tst_QQmlDebugJS::getFrameDetails()
 {
     //void frame(int number = -1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     init(qmlscene, ONCOMPLETED_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->frame();
@@ -1338,12 +1384,14 @@ void tst_QQmlDebugJS::getScopeDetails()
 {
     //void scope(int number = -1, int frameNumber = -1);
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
 
     int sourceLine = 34;
     init(qmlscene, ONCOMPLETED_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->scope();
@@ -1374,11 +1422,13 @@ void tst_QQmlDebugJS::evaluateInLocalScope()
     //void evaluate(QString expr, bool global = false, bool disableBreak = false, int frame = -1, const QVariantMap &addContext = QVariantMap());
 
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     int sourceLine = 34;
     init(qmlscene, ONCOMPLETED_QMLFILE);
 
     client->setBreakpoint(QLatin1String(ONCOMPLETED_QMLFILE), sourceLine, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->frame();
@@ -1461,10 +1511,12 @@ void tst_QQmlDebugJS::getScripts()
     //void scripts(int types = -1, QList<int> ids = QList<int>(), bool includeSource = false, QVariant filter = QVariant());
 
     QFETCH(bool, qmlscene);
+    QFETCH(bool, redundantRefs);
+    QFETCH(bool, namesAsObjects);
     init(qmlscene);
 
     client->setBreakpoint(QString(TEST_QMLFILE), 35, -1, true);
-    client->connect();
+    client->connect(redundantRefs, namesAsObjects);
     QVERIFY(QQmlDebugTest::waitForSignal(client, SIGNAL(stopped())));
 
     client->scripts();
@@ -1482,8 +1534,16 @@ void tst_QQmlDebugJS::getScripts()
 void tst_QQmlDebugJS::targetData()
 {
     QTest::addColumn<bool>("qmlscene");
-    QTest::newRow("custom") << false;
-    QTest::newRow("qmlscene") << true;
+    QTest::addColumn<bool>("redundantRefs");
+    QTest::addColumn<bool>("namesAsObjects");
+    QTest::newRow("custom / redundant / objects")   << false << true  << true;
+    QTest::newRow("qmlscene / redundant / objects") << true  << true  << true;
+    QTest::newRow("custom / redundant / strings")   << false << true  << false;
+    QTest::newRow("qmlscene / redundant / strings") << true  << true  << false;
+    QTest::newRow("custom / sparse / objects")      << false << false << true;
+    QTest::newRow("qmlscene / sparse / objects")    << true  << false << true;
+    QTest::newRow("custom / sparse / strings")      << false << false << false;
+    QTest::newRow("qmlscene / sparse / strings")    << true  << false << false;
 }
 
 QTEST_MAIN(tst_QQmlDebugJS)
diff --git a/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp b/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
index 8c30a82317..d9a4777115 100644
--- a/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
+++ b/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
@@ -180,14 +180,9 @@ void tst_QQmlEngineDebugService::recursiveObjectTest(
 {
     const QMetaObject *meta = o->metaObject();
 
-    QQmlType *type = QQmlMetaType::qmlType(meta);
-    QString className = type ? QString(type->qmlTypeName())
-                             : QString(meta->className());
-    className = className.mid(className.lastIndexOf(QLatin1Char('/'))+1);
-
     QCOMPARE(oref.debugId, QQmlDebugService::idForObject(o));
     QCOMPARE(oref.name, o->objectName());
-    QCOMPARE(oref.className, className);
+    QCOMPARE(oref.className, QQmlMetaType::prettyTypeName(o));
     QCOMPARE(oref.contextDebugId, QQmlDebugService::idForObject(
                  qmlContext(o)));
 
@@ -201,6 +196,7 @@ void tst_QQmlEngineDebugService::recursiveObjectTest(
 
         QmlDebugObjectReference cref;
         foreach (const QmlDebugObjectReference &ref, oref.children) {
+            QVERIFY(!ref.className.isEmpty());
             if (ref.debugId == debugId) {
                 cref = ref;
                 break;
@@ -369,6 +365,7 @@ void tst_QQmlEngineDebugService::setMethodBody()
 {
     bool success;
     QmlDebugObjectReference obj = findRootObject(2);
+    QVERIFY(!obj.className.isEmpty());
 
     QObject *root = m_components.at(2);
     // Without args
@@ -410,6 +407,7 @@ void tst_QQmlEngineDebugService::setMethodBody()
 void tst_QQmlEngineDebugService::watch_property()
 {
     QmlDebugObjectReference obj = findRootObject();
+    QVERIFY(!obj.className.isEmpty());
     QmlDebugPropertyReference prop = findProperty(obj.properties, "width");
 
     bool success;
@@ -454,6 +452,7 @@ void tst_QQmlEngineDebugService::watch_property()
 void tst_QQmlEngineDebugService::watch_object()
 {
     QmlDebugObjectReference obj = findRootObject();
+    QVERIFY(!obj.className.isEmpty());
 
     bool success;
 
@@ -519,6 +518,7 @@ void tst_QQmlEngineDebugService::watch_expression()
     int origWidth = m_rootItem->property("width").toInt();
 
     QmlDebugObjectReference obj = findRootObject();
+    QVERIFY(!obj.className.isEmpty());
 
     bool success;
 
@@ -654,6 +654,7 @@ void tst_QQmlEngineDebugService::queryObject()
     bool success;
 
     QmlDebugObjectReference rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
 
     QQmlEngineDebugClient *unconnected = new QQmlEngineDebugClient(0);
     recursive ? unconnected->queryObjectRecursive(rootObject, &success) : unconnected->queryObject(rootObject, &success);
@@ -665,6 +666,7 @@ void tst_QQmlEngineDebugService::queryObject()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     QmlDebugObjectReference obj = m_dbg->object();
+    QVERIFY(!obj.className.isEmpty());
 
     // check source as defined in main()
     QmlDebugFileReference source = obj.source;
@@ -676,12 +678,15 @@ void tst_QQmlEngineDebugService::queryObject()
     recursiveObjectTest(m_rootItem, obj, recursive);
 
     if (recursive) {
-        foreach (const QmlDebugObjectReference &child, obj.children)
+        foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             QVERIFY(child.properties.count() > 0);
+        }
 
         QmlDebugObjectReference rect;
         QmlDebugObjectReference text;
         foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             if (child.className == "Rectangle")
                 rect = child;
             else if (child.className == "Text")
@@ -695,8 +700,10 @@ void tst_QQmlEngineDebugService::queryObject()
 
         QCOMPARE(findProperty(text.properties, "color").value, qVariantFromValue(QColor("blue")));
     } else {
-        foreach (const QmlDebugObjectReference &child, obj.children)
+        foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             QCOMPARE(child.properties.count(), 0);
+        }
     }
 }
 
@@ -715,6 +722,7 @@ void tst_QQmlEngineDebugService::queryObjectsForLocation()
     bool success;
 
     QmlDebugObjectReference rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
 
     const QString fileName = QFileInfo(rootObject.source.url.toString()).fileName();
     int lineNumber = rootObject.source.lineNumber;
@@ -737,6 +745,7 @@ void tst_QQmlEngineDebugService::queryObjectsForLocation()
 
     QCOMPARE(m_dbg->objects().count(), 1);
     QmlDebugObjectReference obj = m_dbg->objects().first();
+    QVERIFY(!obj.className.isEmpty());
 
     // check source as defined in main()
     QmlDebugFileReference source = obj.source;
@@ -748,12 +757,15 @@ void tst_QQmlEngineDebugService::queryObjectsForLocation()
     recursiveObjectTest(m_rootItem, obj, recursive);
 
     if (recursive) {
-        foreach (const QmlDebugObjectReference &child, obj.children)
+        foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             QVERIFY(child.properties.count() > 0);
+        }
 
         QmlDebugObjectReference rect;
         QmlDebugObjectReference text;
         foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             if (child.className == "Rectangle")
                 rect = child;
             else if (child.className == "Text")
@@ -767,8 +779,10 @@ void tst_QQmlEngineDebugService::queryObjectsForLocation()
 
         QCOMPARE(findProperty(text.properties, "color").value, qVariantFromValue(QColor("blue")));
     } else {
-        foreach (const QmlDebugObjectReference &child, obj.children)
+        foreach (const QmlDebugObjectReference &child, obj.children) {
+            QVERIFY(!child.className.isEmpty());
             QCOMPARE(child.properties.count(), 0);
+        }
     }
 }
 
@@ -783,6 +797,7 @@ void tst_QQmlEngineDebugService::queryObjectsForLocation_data()
 void tst_QQmlEngineDebugService::regression_QTCREATORBUG_7451()
 {
     QmlDebugObjectReference rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     int contextId = rootObject.contextDebugId;
     QQmlContext *context = qobject_cast<QQmlContext *>(QQmlDebugService::objectForId(contextId));
     QQmlComponent component(context->engine());
@@ -809,6 +824,7 @@ void tst_QQmlEngineDebugService::regression_QTCREATORBUG_7451()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     foreach (QmlDebugObjectReference child, rootObject.children) {
+        QVERIFY(!child.className.isEmpty());
         success = false;
         lineNumber = child.source.lineNumber;
         columnNumber = child.source.columnNumber;
@@ -831,6 +847,7 @@ void tst_QQmlEngineDebugService::regression_QTCREATORBUG_7451()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     foreach (QmlDebugObjectReference child, rootObject.children) {
+        QVERIFY(!child.className.isEmpty());
         success = false;
         lineNumber = child.source.lineNumber;
         columnNumber = child.source.columnNumber;
@@ -846,6 +863,7 @@ void tst_QQmlEngineDebugService::queryObjectWithNonStreamableTypes()
     bool success;
 
     QmlDebugObjectReference rootObject = findRootObject(4, true);
+    QVERIFY(!rootObject.className.isEmpty());
 
     QQmlEngineDebugClient *unconnected = new QQmlEngineDebugClient(0);
     unconnected->queryObject(rootObject, &success);
@@ -857,6 +875,7 @@ void tst_QQmlEngineDebugService::queryObjectWithNonStreamableTypes()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     QmlDebugObjectReference obj = m_dbg->object();
+    QVERIFY(!obj.className.isEmpty());
 
     QCOMPARE(findProperty(obj.properties, "modelIndex").value, QVariant());
 }
@@ -950,6 +969,7 @@ void tst_QQmlEngineDebugService::queryExpressionResultBC_data()
 void tst_QQmlEngineDebugService::setBindingForObject()
 {
     QmlDebugObjectReference rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     QVERIFY(rootObject.debugId != -1);
     QmlDebugPropertyReference widthPropertyRef = findProperty(rootObject.properties, "width");
 
@@ -967,6 +987,7 @@ void tst_QQmlEngineDebugService::setBindingForObject()
     QCOMPARE(m_dbg->valid(), true);
 
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     widthPropertyRef =  findProperty(rootObject.properties, "width");
 
     QCOMPARE(widthPropertyRef.value, QVariant(15));
@@ -982,6 +1003,7 @@ void tst_QQmlEngineDebugService::setBindingForObject()
     QCOMPARE(m_dbg->valid(), true);
 
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     widthPropertyRef =  findProperty(rootObject.properties, "width");
 
     QCOMPARE(widthPropertyRef.value, QVariant(20));
@@ -992,13 +1014,14 @@ void tst_QQmlEngineDebugService::setBindingForObject()
     // set handler
     //
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     QCOMPARE(rootObject.children.size(), 5); // Rectangle, Text, MouseArea, Component.onCompleted, NonScriptPropertyElement
     QmlDebugObjectReference mouseAreaObject = rootObject.children.at(2);
+    QVERIFY(!mouseAreaObject.className.isEmpty());
     m_dbg->queryObjectRecursive(mouseAreaObject, &success);
     QVERIFY(success);
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
     mouseAreaObject = m_dbg->object();
-
     QCOMPARE(mouseAreaObject.className, QString("MouseArea"));
 
     QmlDebugPropertyReference onEnteredRef = findProperty(mouseAreaObject.properties, "onEntered");
@@ -1015,11 +1038,14 @@ void tst_QQmlEngineDebugService::setBindingForObject()
     QCOMPARE(m_dbg->valid(), true);
 
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     mouseAreaObject = rootObject.children.at(2);
+    QVERIFY(!mouseAreaObject.className.isEmpty());
     m_dbg->queryObjectRecursive(mouseAreaObject, &success);
     QVERIFY(success);
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
     mouseAreaObject = m_dbg->object();
+    QVERIFY(!mouseAreaObject.className.isEmpty());
     onEnteredRef = findProperty(mouseAreaObject.properties, "onEntered");
     QCOMPARE(onEnteredRef.name, QString("onEntered"));
     QCOMPARE(onEnteredRef.value, QVariant("function() { [code] }"));
@@ -1028,6 +1054,7 @@ void tst_QQmlEngineDebugService::setBindingForObject()
 void tst_QQmlEngineDebugService::resetBindingForObject()
 {
     QmlDebugObjectReference rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     QVERIFY(rootObject.debugId != -1);
     QmlDebugPropertyReference widthPropertyRef = findProperty(rootObject.properties, "width");
 
@@ -1048,6 +1075,7 @@ void tst_QQmlEngineDebugService::resetBindingForObject()
     QCOMPARE(m_dbg->valid(), true);
 
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     widthPropertyRef =  findProperty(rootObject.properties, "width");
 
     QCOMPARE(widthPropertyRef.value, QVariant(0));
@@ -1063,6 +1091,7 @@ void tst_QQmlEngineDebugService::resetBindingForObject()
     QCOMPARE(m_dbg->valid(), true);
 
     rootObject = findRootObject();
+    QVERIFY(!rootObject.className.isEmpty());
     QmlDebugPropertyReference boldPropertyRef =  findProperty(rootObject.properties, "font.bold");
 
     QCOMPARE(boldPropertyRef.value.toBool(), false);
@@ -1076,7 +1105,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     const int sourceIndex = 3;
 
     QmlDebugObjectReference obj = findRootObject(sourceIndex);
-
+    QVERIFY(!obj.className.isEmpty());
     QVERIFY(obj.debugId != -1);
     QVERIFY(obj.children.count() >= 2);
     bool success;
@@ -1092,6 +1121,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(),200);
 
 
@@ -1102,6 +1132,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
 
 
     obj = findRootObject(sourceIndex, true);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(),100);
 
 
@@ -1111,6 +1142,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(state.children.count() > 0);
 
     QmlDebugObjectReference propertyChange = state.children[0];
+    QVERIFY(!propertyChange.className.isEmpty());
     QVERIFY(propertyChange.debugId != -1);
 
     m_dbg->setBindingForObject(propertyChange.debugId, "width",QVariant(300),true,
@@ -1120,6 +1152,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
 
     // check properties changed in state
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(),100);
 
 
@@ -1128,6 +1161,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(),300);
 
     // check changing properties of base state from within a state
@@ -1141,6 +1175,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(),300);
 
     m_dbg->queryExpressionResult(obj.debugId,QString("state=\"\""), &success);
@@ -1148,6 +1183,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(), 400);
 
     //  reset binding while in a state
@@ -1156,6 +1192,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(), 300);
 
     m_dbg->resetBindingForObject(propertyChange.debugId, "width", &success);
@@ -1164,6 +1201,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QCOMPARE(m_dbg->valid(), true);
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(), 400);
 
     // re-add binding
@@ -1174,6 +1212,7 @@ void tst_QQmlEngineDebugService::setBindingInStates()
     QCOMPARE(m_dbg->valid(), true);
 
     obj = findRootObject(sourceIndex);
+    QVERIFY(!obj.className.isEmpty());
     QCOMPARE(findProperty(obj.properties,"width").value.toInt(), 300);
 }
 
@@ -1182,7 +1221,7 @@ void tst_QQmlEngineDebugService::queryObjectTree()
     const int sourceIndex = 3;
 
     QmlDebugObjectReference obj = findRootObject(sourceIndex, true);
-
+    QVERIFY(!obj.className.isEmpty());
     QVERIFY(obj.debugId != -1);
     QVERIFY(obj.children.count() >= 2);
 
@@ -1192,16 +1231,16 @@ void tst_QQmlEngineDebugService::queryObjectTree()
     QVERIFY(state.children.count() > 0);
 
     QmlDebugObjectReference propertyChange = state.children[0];
+    QVERIFY(!propertyChange.className.isEmpty());
     QVERIFY(propertyChange.debugId != -1);
 
     QmlDebugPropertyReference propertyChangeTarget = findProperty(propertyChange.properties,"target");
     QCOMPARE(propertyChangeTarget.objectDebugId, propertyChange.debugId);
 
     QmlDebugObjectReference targetReference = qvariant_cast<QmlDebugObjectReference>(propertyChangeTarget.value);
+    QVERIFY(!targetReference.className.isEmpty());
     QVERIFY(targetReference.debugId != -1);
 
-
-
     // check transition
     QmlDebugObjectReference transition = obj.children[0];
     QCOMPARE(transition.className, QString("Transition"));
@@ -1210,12 +1249,14 @@ void tst_QQmlEngineDebugService::queryObjectTree()
     QVERIFY(transition.children.count() > 0);
 
     QmlDebugObjectReference animation = transition.children[0];
+    QVERIFY(!animation.className.isEmpty());
     QVERIFY(animation.debugId != -1);
 
     QmlDebugPropertyReference animationTarget = findProperty(animation.properties,"target");
     QCOMPARE(animationTarget.objectDebugId, animation.debugId);
 
     targetReference = qvariant_cast<QmlDebugObjectReference>(animationTarget.value);
+    QVERIFY(!targetReference.className.isEmpty());
     QVERIFY(targetReference.debugId != -1);
 
     QCOMPARE(findProperty(animation.properties,"property").value.toString(), QString("width"));
diff --git a/tests/auto/qml/debugger/qv4debugger/tst_qv4debugger.cpp b/tests/auto/qml/debugger/qv4debugger/tst_qv4debugger.cpp
index 6793596174..584bd10151 100644
--- a/tests/auto/qml/debugger/qv4debugger/tst_qv4debugger.cpp
+++ b/tests/auto/qml/debugger/qv4debugger/tst_qv4debugger.cpp
@@ -120,7 +120,6 @@ public:
     typedef QV4DataCollector::Refs Refs;
     typedef QV4DataCollector::Ref Ref;
     struct NamedRefs {
-        QJsonArray refs;
         QJsonObject scope;
 
         int size() const {
@@ -131,15 +130,6 @@ public:
             return scope.contains(name);
         }
 
-        QJsonObject resolveRef(int ref) const {
-            foreach (const QJsonValue &val, refs) {
-                QJsonObject obj = val.toObject();
-                if (obj.value(QLatin1String("handle")).toInt() == ref)
-                    return obj;
-            }
-            return QJsonObject();
-        }
-
 #define DUMP_JSON(x) {\
     QJsonDocument doc(x);\
     qDebug() << #x << "=" << doc.toJson(QJsonDocument::Indented);\
@@ -176,6 +166,7 @@ public:
         , m_captureContextInfo(false)
         , m_thrownValue(-1)
         , collector(engine)
+        , m_resumeSpeed(QV4Debugger::FullThrottle)
         , m_debugger(0)
     {
     }
@@ -208,13 +199,12 @@ public slots:
                                   request.expression, &collector);
             debugger->runInEngine(&job);
             m_expressionResults << job.returnValue();
-            m_expressionRefs << job.refs();
         }
 
         if (m_captureContextInfo)
             captureContextInfo(debugger);
 
-        debugger->resume(QV4Debugger::FullThrottle);
+        debugger->resume(m_resumeSpeed);
     }
 
 public:
@@ -234,24 +224,17 @@ public:
             ScopeJob job(&collector, i, 0);
             debugger->runInEngine(&job);
             NamedRefs &refs = m_capturedScope.last();
-            refs.refs = job.refs();
             QJsonObject object = job.returnValue();
             object = object.value(QLatin1String("object")).toObject();
-            int ref = object.value(QLatin1String("ref")).toInt();
-            object = refs.resolveRef(ref);
+            if (object.contains("ref") && !object.contains("properties")) {
+                QVERIFY(collector.redundantRefs());
+                object = collector.lookupRef(object.value("ref").toInt(), true);
+                QVERIFY(object.contains("properties"));
+            }
             foreach (const QJsonValue &value, object.value(QLatin1String("properties")).toArray()) {
                 QJsonObject property = value.toObject();
                 QString name = property.value(QLatin1String("name")).toString();
                 property.remove(QLatin1String("name"));
-                if (property.contains(QLatin1String("ref"))) {
-                    int childRef = property.value(QLatin1String("ref")).toInt();
-                    if (childRef >= 0 && refs.refs.size() > childRef) {
-                        property.remove(QLatin1String("ref"));
-                        property.insert(QLatin1String("properties"),
-                                        refs.resolveRef(childRef).value(
-                                            QLatin1String("properties")).toArray());
-                    }
-                }
                 refs.scope.insert(name, property);
             }
         }
@@ -280,8 +263,8 @@ public:
         int context;
     };
     QVector<ExpressionRequest> m_expressionRequests;
+    QV4Debugger::Speed m_resumeSpeed;
     QList<QJsonObject> m_expressionResults;
-    QList<QJsonArray> m_expressionRefs;
     QV4Debugger *m_debugger;
 
     // Utility methods:
@@ -313,9 +296,13 @@ private slots:
     void conditionalBreakPointInQml();
 
     // context access:
+    void readArguments_data() { redundancy_data(); }
     void readArguments();
+    void readLocals_data() { redundancy_data(); }
     void readLocals();
+    void readObject_data() { redundancy_data(); }
     void readObject();
+    void readContextInAllFrames_data() { redundancy_data(); }
     void readContextInAllFrames();
 
     // exceptions:
@@ -323,8 +310,13 @@ private slots:
     void breakInCatch();
     void breakInWith();
 
+    void evaluateExpression_data() { redundancy_data(); }
     void evaluateExpression();
+    void stepToEndOfScript_data() { redundancy_data(); }
+    void stepToEndOfScript();
 
+    void lastLineOfConditional_data();
+    void lastLineOfConditional();
 private:
     QV4Debugger *debugger() const
     {
@@ -338,6 +330,8 @@ private:
         waitForSignal(m_engine, SIGNAL(evaluateFinished()), /*timeout*/0);
     }
 
+    void redundancy_data();
+
     TestEngine *m_engine;
     QV4::ExecutionEngine *m_v4;
     TestAgent *m_debuggerAgent;
@@ -532,6 +526,9 @@ void tst_qv4debugger::conditionalBreakPointInQml()
 
 void tst_qv4debugger::readArguments()
 {
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
     m_debuggerAgent->m_captureContextInfo = true;
     QString script =
             "function f(a, b, c, d) {\n"
@@ -555,6 +552,9 @@ void tst_qv4debugger::readArguments()
 
 void tst_qv4debugger::readLocals()
 {
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
     m_debuggerAgent->m_captureContextInfo = true;
     QString script =
             "function f(a, b) {\n"
@@ -578,6 +578,9 @@ void tst_qv4debugger::readLocals()
 
 void tst_qv4debugger::readObject()
 {
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
     m_debuggerAgent->m_captureContextInfo = true;
     QString script =
             "function f(a) {\n"
@@ -594,6 +597,12 @@ void tst_qv4debugger::readObject()
     QVERIFY(frame0.contains("b"));
     QCOMPARE(frame0.type("b"), QStringLiteral("object"));
     QJsonObject b = frame0.rawValue("b");
+    QVERIFY(b.contains(QStringLiteral("ref")));
+    QVERIFY(b.contains(QStringLiteral("value")));
+    QVERIFY(!b.contains(QStringLiteral("properties")));
+    QVERIFY(b.value("value").isDouble());
+    QCOMPARE(b.value("value").toInt(), 2);
+    b = m_debuggerAgent->collector.lookupRef(b.value("ref").toInt(), true);
     QVERIFY(b.contains(QStringLiteral("properties")));
     QVERIFY(b.value("properties").isArray());
     QJsonArray b_props = b.value("properties").toArray();
@@ -609,7 +618,8 @@ void tst_qv4debugger::readObject()
     QCOMPARE(b_tail.value("name").toString(), QStringLiteral("tail"));
     QVERIFY(b_tail.contains("ref"));
 
-    QJsonObject b_tail_value = m_debuggerAgent->collector.lookupRef(b_tail.value("ref").toInt());
+    QJsonObject b_tail_value = m_debuggerAgent->collector.lookupRef(b_tail.value("ref").toInt(),
+                                                                    true);
     QCOMPARE(b_tail_value.value("type").toString(), QStringLiteral("object"));
     QVERIFY(b_tail_value.contains("properties"));
     QJsonArray b_tail_props = b_tail_value.value("properties").toArray();
@@ -626,6 +636,9 @@ void tst_qv4debugger::readObject()
 
 void tst_qv4debugger::readContextInAllFrames()
 {
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
     m_debuggerAgent->m_captureContextInfo = true;
     QString script =
             "function fact(n) {\n"
@@ -673,7 +686,8 @@ void tst_qv4debugger::pauseOnThrow()
     QCOMPARE(m_debuggerAgent->m_pauseReason, QV4Debugger::Throwing);
     QCOMPARE(m_debuggerAgent->m_stackTrace.size(), 2);
     QVERIFY(m_debuggerAgent->m_thrownValue >= qint64(0));
-    QJsonObject exception = m_debuggerAgent->collector.lookupRef(m_debuggerAgent->m_thrownValue);
+    QJsonObject exception = m_debuggerAgent->collector.lookupRef(m_debuggerAgent->m_thrownValue,
+                                                                 true);
 //    DUMP_JSON(exception);
     QCOMPARE(exception.value("type").toString(), QStringLiteral("string"));
     QCOMPARE(exception.value("value").toString(), QStringLiteral("hard"));
@@ -717,6 +731,9 @@ void tst_qv4debugger::breakInWith()
 
 void tst_qv4debugger::evaluateExpression()
 {
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
     QString script =
             "function testFunction() {\n"
             "    var x = 10\n"
@@ -745,19 +762,119 @@ void tst_qv4debugger::evaluateExpression()
 
     evaluateJavaScript(script, "evaluateExpression");
 
-    QCOMPARE(m_debuggerAgent->m_expressionRefs.count(), 4);
-    QCOMPARE(m_debuggerAgent->m_expressionRefs[0].size(), 1);
-    QJsonObject result0 = m_debuggerAgent->m_expressionRefs[0].first().toObject();
+    QCOMPARE(m_debuggerAgent->m_expressionResults.count(), 4);
+    QJsonObject result0 = m_debuggerAgent->m_expressionResults[0];
     QCOMPARE(result0.value("type").toString(), QStringLiteral("number"));
     QCOMPARE(result0.value("value").toInt(), 10);
     for (int i = 1; i < 4; ++i) {
-        QCOMPARE(m_debuggerAgent->m_expressionRefs[i].size(), 1);
-        QJsonObject result1 = m_debuggerAgent->m_expressionRefs[1].first().toObject();
+        QJsonObject result1 = m_debuggerAgent->m_expressionResults[i];
         QCOMPARE(result1.value("type").toString(), QStringLiteral("number"));
         QCOMPARE(result1.value("value").toInt(), 20);
     }
 }
 
+void tst_qv4debugger::stepToEndOfScript()
+{
+    QFETCH(bool, redundantRefs);
+    m_debuggerAgent->collector.setRedundantRefs(redundantRefs);
+
+    QString script =
+            "var ret = 0;\n"
+            "ret += 4;\n"
+            "ret += 1;\n"
+            "ret += 5;\n";
+
+    debugger()->addBreakPoint("toEnd", 1);
+    m_debuggerAgent->m_resumeSpeed = QV4Debugger::StepOver;
+    evaluateJavaScript(script, "toEnd");
+    QVERIFY(m_debuggerAgent->m_wasPaused);
+    QCOMPARE(m_debuggerAgent->m_pauseReason, QV4Debugger::Step);
+    QCOMPARE(m_debuggerAgent->m_statesWhenPaused.count(), 5);
+    for (int i = 0; i < 4; ++i) {
+        QV4Debugger::ExecutionState state = m_debuggerAgent->m_statesWhenPaused.at(i);
+        QCOMPARE(state.fileName, QString("toEnd"));
+        QCOMPARE(state.lineNumber, i + 1);
+    }
+
+    QV4Debugger::ExecutionState state = m_debuggerAgent->m_statesWhenPaused.at(4);
+    QCOMPARE(state.fileName, QString("toEnd"));
+    QCOMPARE(state.lineNumber, -4); // A return instruction without proper line number.
+}
+
+void tst_qv4debugger::lastLineOfConditional_data()
+{
+    QTest::addColumn<QString>("head");
+    QTest::addColumn<QString>("tail");
+    QTest::addColumn<int>("breakPoint");
+    QTest::addColumn<int>("lastLine");
+
+    QTest::newRow("for {block}")       << "for (var i = 0; i < 10; ++i) {\n"   << "}" << 4 << 7;
+    QTest::newRow("for..in {block}")   << "for (var i in [0, 1, 2, 3, 4]) {\n" << "}" << 4 << 7;
+    QTest::newRow("while {block}")     << "while (ret < 10) {\n"               << "}" << 4 << 7;
+    QTest::newRow("do..while {block}") << "do {\n"           << "} while (ret < 10);" << 4 << 7;
+
+    QTest::newRow("if true {block}")       << "if (true) {\n"  << "}"
+                                           << 4 << 7;
+    QTest::newRow("if false {block}")      << "if (false) {\n" << "}"
+                                           << 2 << 8;
+    QTest::newRow("if true else {block}")  << "if (true) {\n"  << "} else {\n    ret += 8;\n}"
+                                           << 4 << 7;
+    QTest::newRow("if false else {block}") << "if (false) {\n" << "} else {\n    ret += 8;\n}"
+                                           << 8 << 9;
+
+    QTest::newRow("for statement")       << "for (var i = 0; i < 10; ++i)\n"   << "" << 4 << 2;
+    QTest::newRow("for..in statement")   << "for (var i in [0, 1, 2, 3, 4])\n" << "" << 4 << 2;
+    QTest::newRow("while statement")     << "while (ret < 10)\n"               << "" << 4 << 2;
+    QTest::newRow("do..while statement") << "do\n"            << "while (ret < 10);" << 4 << 7;
+
+    // For two nested if statements without blocks, we need to map the jump from the inner to the
+    // outer one on the outer "if". There is just no better place.
+    QTest::newRow("if true statement")       << "if (true)\n"  << ""                    << 4 << 2;
+    QTest::newRow("if false statement")      << "if (false)\n" << ""                    << 2 << 8;
+
+    // Also two nested ifs without blocks.
+    QTest::newRow("if true else statement")  << "if (true)\n"  << "else\n    ret += 8;" << 4 << 2;
+    QTest::newRow("if false else statement") << "if (false)\n" << "else\n    ret += 8;" << 8 << 9;
+}
+
+void tst_qv4debugger::lastLineOfConditional()
+{
+    QFETCH(QString, head);
+    QFETCH(QString, tail);
+    QFETCH(int, breakPoint);
+    QFETCH(int, lastLine);
+
+    QString script =
+            "var ret = 2;\n"
+            + head +
+            "    if (ret == 2)\n"
+            "        ret += 4;\n" // breakpoint, then step over
+            "    else\n"
+            "        ret += 1;\n"
+            + tail + "\n" +
+            "ret -= 5;";
+
+    debugger()->addBreakPoint("trueBranch", breakPoint);
+    m_debuggerAgent->m_resumeSpeed = QV4Debugger::StepOver;
+    evaluateJavaScript(script, "trueBranch");
+    QVERIFY(m_debuggerAgent->m_wasPaused);
+    QCOMPARE(m_debuggerAgent->m_pauseReason, QV4Debugger::Step);
+    QVERIFY(m_debuggerAgent->m_statesWhenPaused.count() > 1);
+    QV4Debugger::ExecutionState firstState = m_debuggerAgent->m_statesWhenPaused.first();
+    QCOMPARE(firstState.fileName, QString("trueBranch"));
+    QCOMPARE(firstState.lineNumber, breakPoint);
+    QV4Debugger::ExecutionState secondState = m_debuggerAgent->m_statesWhenPaused.at(1);
+    QCOMPARE(secondState.fileName, QString("trueBranch"));
+    QCOMPARE(secondState.lineNumber, lastLine);
+}
+
+void tst_qv4debugger::redundancy_data()
+{
+    QTest::addColumn<bool>("redundantRefs");
+    QTest::addRow("redundant") << true;
+    QTest::addRow("sparse")    << false;
+}
+
 QTEST_MAIN(tst_qv4debugger)
 
 #include "tst_qv4debugger.moc"
diff --git a/tests/auto/qml/debugger/shared/qqmlenginedebugclient.cpp b/tests/auto/qml/debugger/shared/qqmlenginedebugclient.cpp
index 3e27951d78..c0252a0290 100644
--- a/tests/auto/qml/debugger/shared/qqmlenginedebugclient.cpp
+++ b/tests/auto/qml/debugger/shared/qqmlenginedebugclient.cpp
@@ -386,6 +386,7 @@ void QQmlEngineDebugClient::decode(QPacket &ds,
         {
             QmlDebugObjectReference obj;
             obj.debugId = prop.value.toInt();
+            obj.className = prop.valueTypeName;
             prop.value = qVariantFromValue(obj);
             break;
         }
diff --git a/tests/manual/v4/TestExpectations b/tests/auto/qml/ecmascripttests/TestExpectations
index 27498de473..27498de473 100644
--- a/tests/manual/v4/TestExpectations
+++ b/tests/auto/qml/ecmascripttests/TestExpectations
diff --git a/tests/auto/qml/ecmascripttests/ecmascripttests.pro b/tests/auto/qml/ecmascripttests/ecmascripttests.pro
new file mode 100644
index 0000000000..6d3ee12307
--- /dev/null
+++ b/tests/auto/qml/ecmascripttests/ecmascripttests.pro
@@ -0,0 +1,20 @@
+CONFIG += testcase
+TARGET = tst_ecmascripttests
+QT += testlib
+macos:CONFIG -= app_bundle
+SOURCES += tst_ecmascripttests.cpp
+DEFINES += SRCDIR=\\\"$$PWD\\\"
+
+TESTSCRIPT=$$PWD/test262.py
+isEmpty(V4CMD): V4CMD = qmljs
+
+checkjittarget.target = check-jit
+checkjittarget.commands = python $$TESTSCRIPT --command=$$V4CMD --parallel --with-test-expectations --update-expectations
+checkjittarget.depends = all
+QMAKE_EXTRA_TARGETS += checkjittarget
+
+checkmothtarget.target = check-interpreter
+checkmothtarget.commands = python $$TESTSCRIPT --command=\"$$V4CMD --interpret\" --parallel --with-test-expectations
+checkmothtarget.depends = all
+QMAKE_EXTRA_TARGETS += checkmothtarget
+
diff --git a/tests/auto/qml/ecmascripttests/test262 b/tests/auto/qml/ecmascripttests/test262
new file mode 160000
+Subproject d60c4ed97e69639bc5bc1db43a98828debf80c8
diff --git a/tests/manual/v4/test262.py b/tests/auto/qml/ecmascripttests/test262.py
index 3b5bfa119a..99f029cffd 100755
--- a/tests/manual/v4/test262.py
+++ b/tests/auto/qml/ecmascripttests/test262.py
@@ -555,6 +555,7 @@ class TestSuite(object):
     print
     if update_expectations:
         self.expectations.update(progress)
+    return progress.failed == 0
 
   def Print(self, tests):
     cases = self.EnumerateTests(tests)
@@ -567,6 +568,7 @@ def Main():
   # Uncomment the next line for more logging info.
   #logging.basicConfig(level=logging.DEBUG)
   os.environ["TZ"] = "PST8PDT"
+  os.environ["LANG"] = "en_US.UTF-8"
   parser = BuildOptions()
   (options, args) = parser.parse_args()
   ValidateOptions(options)
@@ -578,18 +580,21 @@ def Main():
   test_suite.Validate()
   if options.cat:
     test_suite.Print(args)
+    return 0
   else:
-    test_suite.Run(options.command, args,
-                   options.summary or options.full_summary,
-                   options.full_summary,
-                   options.parallel,
-                   options.update_expectations)
+    if test_suite.Run(options.command, args,
+                      options.summary or options.full_summary,
+                      options.full_summary,
+                      options.parallel,
+                      options.update_expectations):
+      return 0
+    else:
+      return 1
 
 
 if __name__ == '__main__':
   try:
-    Main()
-    sys.exit(0)
+    sys.exit(Main())
   except Test262Error, e:
     print "Error: %s" % e.message
     sys.exit(1)
diff --git a/tests/auto/qml/ecmascripttests/tst_ecmascripttests.cpp b/tests/auto/qml/ecmascripttests/tst_ecmascripttests.cpp
new file mode 100644
index 0000000000..5d7009e7c8
--- /dev/null
+++ b/tests/auto/qml/ecmascripttests/tst_ecmascripttests.cpp
@@ -0,0 +1,77 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include <QtTest/QtTest>
+#include <QProcess>
+#include <QLibraryInfo>
+
+class tst_EcmaScriptTests : public QObject
+{
+    Q_OBJECT
+private slots:
+    void runTests_data();
+    void runTests();
+};
+
+void tst_EcmaScriptTests::runTests_data()
+{
+    QTest::addColumn<QString>("qmljsParameter");
+
+    QTest::newRow("jit") << QStringLiteral("--jit");
+    // Not passing yet: QTest::newRow("interpreter") << QStringLiteral("--interpret");
+}
+
+void tst_EcmaScriptTests::runTests()
+{
+#if defined(Q_OS_LINUX) && defined(Q_PROCESSOR_X86_64)
+    QFETCH(QString, qmljsParameter);
+
+    QProcess process;
+    process.setProcessChannelMode(QProcess::ForwardedChannels);
+    process.setWorkingDirectory(QLatin1String(SRCDIR));
+    process.setProgram("python");
+    process.setArguments(QStringList() << "test262.py" << "--command=" + QLibraryInfo::location(QLibraryInfo::BinariesPath) + "/qmljs " + qmljsParameter << "--parallel" << "--with-test-expectations");
+
+    qDebug() << "Going to run" << process.program() << process.arguments() << "in" << process.workingDirectory();
+
+    process.start();
+    QVERIFY(process.waitForStarted());
+    const int timeoutInMSecs = 20 * 60 * 1000;
+    QVERIFY2(process.waitForFinished(timeoutInMSecs), "Tests did not terminate in time -- see output above for details");
+    QVERIFY2(process.exitStatus() == QProcess::NormalExit, "Running the test harness failed -- see output above for details");
+    QVERIFY2(process.exitCode() == 0, "Tests failed -- see output above for details");
+#else
+    QSKIP("Currently the ecmascript tests are only run on Linux/x86-64");
+#endif
+}
+
+QTEST_GUILESS_MAIN(tst_EcmaScriptTests)
+
+#include "tst_ecmascripttests.moc"
+
diff --git a/tests/auto/qml/qml.pro b/tests/auto/qml/qml.pro
index 7d182b7255..59566ad927 100644
--- a/tests/auto/qml/qml.pro
+++ b/tests/auto/qml/qml.pro
@@ -7,6 +7,9 @@ PUBLICTESTS += \
     parserstress \
     qjsvalueiterator \
     qjsonbinding \
+
+!boot2qt {
+PUBLICTESTS += \
     qmlmin \
     qqmlcomponent \
     qqmlconsole \
@@ -25,15 +28,22 @@ PUBLICTESTS += \
     qquickfolderlistmodel \
     qqmlapplicationengine \
     qqmlsettings \
-    qqmlstatemachine
+    qqmlstatemachine \
+    qmldiskcache
+}
 
 PRIVATETESTS += \
-    animation \
     qqmlcpputils \
+    qqmldirparser \
+    v4misc \
+    qmlcachegen
+
+!boot2qt {
+PRIVATETESTS += \
+    animation \
     qqmlecmascript \
     qqmlcontext \
     qqmlexpression \
-    qqmldirparser \
     qqmlglobal \
     qqmllanguage \
     qqmlopenmetaobject \
@@ -57,12 +67,12 @@ PRIVATETESTS += \
     qqmltimer \
     qqmlinstantiator \
     qqmlenginecleanup \
-    v4misc \
     qqmltranslation \
     qqmlimport \
     qqmlobjectmodel \
-    qmldiskcache \
-    qv4mm
+    qv4mm \
+    ecmascripttests
+}
 
 qtHaveModule(widgets) {
     PUBLICTESTS += \
@@ -70,14 +80,17 @@ qtHaveModule(widgets) {
         qjsvalue
 }
 
-SUBDIRS += $$PUBLICTESTS \
-    qqmlextensionplugin
+SUBDIRS += $$PUBLICTESTS
 SUBDIRS += $$METATYPETESTS
-qtConfig(process) {
+qtConfig(process):!boot2qt {
     !contains(QT_CONFIG, no-qml-debug): SUBDIRS += debugger
     SUBDIRS += qmllint qmlplugindump
 }
 
+qtConfig(library) {
+    SUBDIRS += qqmlextensionplugin
+}
+
 qtConfig(private_tests): \
     SUBDIRS += $$PRIVATETESTS
 
diff --git a/tests/auto/qml/qmlcachegen/qmlcachegen.pro b/tests/auto/qml/qmlcachegen/qmlcachegen.pro
new file mode 100644
index 0000000000..8d8b37be15
--- /dev/null
+++ b/tests/auto/qml/qmlcachegen/qmlcachegen.pro
@@ -0,0 +1,7 @@
+CONFIG += testcase
+TARGET = tst_qmlcachegen
+macos:CONFIG -= app_bundle
+
+SOURCES += tst_qmlcachegen.cpp
+
+QT += core-private qml-private testlib
diff --git a/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
new file mode 100644
index 0000000000..b7e616a050
--- /dev/null
+++ b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
@@ -0,0 +1,163 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qtest.h>
+
+#include <QQmlComponent>
+#include <QQmlEngine>
+#include <QProcess>
+#include <QLibraryInfo>
+#include <QSysInfo>
+
+class tst_qmlcachegen: public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void initTestCase();
+
+    void loadGeneratedFile();
+    void translationExpressionSupport();
+};
+
+// A wrapper around QQmlComponent to ensure the temporary reference counts
+// on the type data as a result of the main thread <> loader thread communication
+// are dropped. Regular Synchronous loading will leave us with an event posted
+// to the gui thread and an extra refcount that will only be dropped after the
+// event delivery. A plain sendPostedEvents() however is insufficient because
+// we can't be sure that the event is posted after the constructor finished.
+class CleanlyLoadingComponent : public QQmlComponent
+{
+public:
+    CleanlyLoadingComponent(QQmlEngine *engine, const QUrl &url)
+        : QQmlComponent(engine, url, QQmlComponent::Asynchronous)
+    { waitForLoad(); }
+    CleanlyLoadingComponent(QQmlEngine *engine, const QString &fileName)
+        : QQmlComponent(engine, fileName, QQmlComponent::Asynchronous)
+    { waitForLoad(); }
+
+    void waitForLoad()
+    {
+        QTRY_VERIFY(status() == QQmlComponent::Ready || status() == QQmlComponent::Error);
+    }
+};
+
+static bool generateCache(const QString &qmlFileName)
+{
+    QProcess proc;
+    proc.setProcessChannelMode(QProcess::ForwardedChannels);
+    proc.setProgram(QLibraryInfo::location(QLibraryInfo::BinariesPath) + QDir::separator() + QLatin1String("qmlcachegen"));
+    proc.setArguments(QStringList() << (QLatin1String("--target-architecture=") + QSysInfo::buildCpuArchitecture()) << (QLatin1String("--target-abi=") + QSysInfo::buildAbi()) << qmlFileName);
+    proc.start();
+    if (!proc.waitForFinished())
+        return false;
+    if (proc.exitStatus() != QProcess::NormalExit)
+        return false;
+    return proc.exitCode() == 0;
+}
+
+void tst_qmlcachegen::initTestCase()
+{
+    qputenv("QML_FORCE_DISK_CACHE", "1");
+}
+
+void tst_qmlcachegen::loadGeneratedFile()
+{
+    QTemporaryDir tempDir;
+    QVERIFY(tempDir.isValid());
+
+    const auto writeTempFile = [&tempDir](const QString &fileName, const char *contents) {
+        QFile f(tempDir.path() + '/' + fileName);
+        const bool ok = f.open(QIODevice::WriteOnly | QIODevice::Truncate);
+        Q_ASSERT(ok);
+        f.write(contents);
+        return f.fileName();
+    };
+
+    const QString testFilePath = writeTempFile("test.qml", "import QtQml 2.0\n"
+                                                           "QtObject {\n"
+                                                           "    property int value: Math.min(100, 42);\n"
+                                                           "}");
+
+    QVERIFY(generateCache(testFilePath));
+
+    const QString cacheFilePath = testFilePath + QLatin1Char('c');
+    QVERIFY(QFile::exists(cacheFilePath));
+    QVERIFY(QFile::remove(testFilePath));
+
+    QQmlEngine engine;
+    CleanlyLoadingComponent component(&engine, QUrl::fromLocalFile(testFilePath));
+    QScopedPointer<QObject> obj(component.create());
+    QVERIFY(!obj.isNull());
+    QCOMPARE(obj->property("value").toInt(), 42);
+}
+
+void tst_qmlcachegen::translationExpressionSupport()
+{
+    QTemporaryDir tempDir;
+    QVERIFY(tempDir.isValid());
+
+    const auto writeTempFile = [&tempDir](const QString &fileName, const char *contents) {
+        QFile f(tempDir.path() + '/' + fileName);
+        const bool ok = f.open(QIODevice::WriteOnly | QIODevice::Truncate);
+        Q_ASSERT(ok);
+        f.write(contents);
+        return f.fileName();
+    };
+
+    const QString testFilePath = writeTempFile("test.qml", "import QtQml.Models 2.2\n"
+                                                           "import QtQml 2.2\n"
+                                                           "QtObject {\n"
+                                                           "    property ListModel model: ListModel {\n"
+                                                           "        ListElement {\n"
+                                                           "            text: qsTr(\"All\")\n"
+                                                           "        }\n"
+                                                           "        ListElement {\n"
+                                                           "            text: QT_TR_NOOP(\"Ok\")\n"
+                                                           "        }\n"
+                                                           "    }\n"
+                                                           "    property string text: model.get(0).text + \" \" + model.get(1).text\n"
+                                                           "}");
+
+
+    QVERIFY(generateCache(testFilePath));
+
+    const QString cacheFilePath = testFilePath + QLatin1Char('c');
+    QVERIFY(QFile::exists(cacheFilePath));
+    QVERIFY(QFile::remove(testFilePath));
+
+    QQmlEngine engine;
+    CleanlyLoadingComponent component(&engine, QUrl::fromLocalFile(testFilePath));
+    QScopedPointer<QObject> obj(component.create());
+    QVERIFY(!obj.isNull());
+    QCOMPARE(obj->property("text").toString(), QString("All Ok"));
+}
+
+QTEST_GUILESS_MAIN(tst_qmlcachegen)
+
+#include "tst_qmlcachegen.moc"
diff --git a/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp b/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
index b265607fd1..3402aeebc1 100644
--- a/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
+++ b/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
@@ -58,6 +58,7 @@ private slots:
     void localAliases();
     void cacheResources();
     void stableOrderOfDependentCompositeTypes();
+    void singletonDependency();
 };
 
 // A wrapper around QQmlComponent to ensure the temporary reference counts
@@ -174,7 +175,7 @@ struct TestCompiler
     {
         QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
         QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = v4->iselFactory->createUnitForLoading();
-        return unit->loadFromDisk(QUrl::fromLocalFile(testFilePath), v4->iselFactory.data(), &lastErrorString);
+        return unit->loadFromDisk(QUrl::fromLocalFile(testFilePath), QFileInfo(testFilePath).lastModified(), v4->iselFactory.data(), &lastErrorString);
     }
 
     void closeMapping()
@@ -737,6 +738,58 @@ void tst_qmldiskcache::stableOrderOfDependentCompositeTypes()
     }
 }
 
+void tst_qmldiskcache::singletonDependency()
+{
+    QScopedPointer<QQmlEngine> engine(new QQmlEngine);
+
+    QTemporaryDir tempDir;
+    QVERIFY(tempDir.isValid());
+
+    const auto writeTempFile = [&tempDir](const QString &fileName, const char *contents) {
+        QFile f(tempDir.path() + '/' + fileName);
+        const bool ok = f.open(QIODevice::WriteOnly | QIODevice::Truncate);
+        Q_ASSERT(ok);
+        f.write(contents);
+        return f.fileName();
+    };
+
+    writeTempFile("MySingleton.qml", "import QtQml 2.0\npragma Singleton\nQtObject { property int value: 42 }");
+    writeTempFile("qmldir", "singleton MySingleton 1.0 MySingleton.qml");
+    const QString testFilePath = writeTempFile("main.qml", "import QtQml 2.0\nimport \".\"\nQtObject {\n"
+                                                           "    property int value: MySingleton.value\n"
+                                                           "}");
+
+    {
+        CleanlyLoadingComponent component(engine.data(), QUrl::fromLocalFile(testFilePath));
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        QCOMPARE(obj->property("value").toInt(), 42);
+    }
+
+    const QString testFileCachePath = testFilePath + QLatin1Char('c');
+    QVERIFY(QFile::exists(testFileCachePath));
+    QDateTime initialCacheTimeStamp = QFileInfo(testFileCachePath).lastModified();
+
+    engine.reset(new QQmlEngine);
+    waitForFileSystem();
+
+    writeTempFile("MySingleton.qml", "import QtQml 2.0\npragma Singleton\nQtObject { property int value: 100 }");
+    waitForFileSystem();
+
+    {
+        CleanlyLoadingComponent component(engine.data(), QUrl::fromLocalFile(testFilePath));
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        QCOMPARE(obj->property("value").toInt(), 100);
+    }
+
+    {
+        QVERIFY(QFile::exists(testFileCachePath));
+        QDateTime newCacheTimeStamp = QFileInfo(testFileCachePath).lastModified();
+        QVERIFY2(newCacheTimeStamp > initialCacheTimeStamp, qPrintable(newCacheTimeStamp.toString()));
+    }
+}
+
 QTEST_MAIN(tst_qmldiskcache)
 
 #include "tst_qmldiskcache.moc"
diff --git a/tests/auto/qml/qmlmin/tst_qmlmin.cpp b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
index 3ed0aa7446..171c2bda8a 100644
--- a/tests/auto/qml/qmlmin/tst_qmlmin.cpp
+++ b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
@@ -29,7 +29,9 @@
 #include <qtest.h>
 #include <QLibraryInfo>
 #include <QDir>
+#if QT_CONFIG(process)
 #include <QProcess>
+#endif
 #include <QDebug>
 #include <QQmlError>
 #include <cstdlib>
@@ -42,7 +44,7 @@ public:
 
 private slots:
     void initTestCase();
-#if !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
+#if QT_CONFIG(process) && !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
     void qmlMinify_data();
     void qmlMinify();
 #endif
@@ -82,6 +84,7 @@ void tst_qmlmin::initTestCase()
     excludedDirs << "doc/src/snippets/qtquick1/qtbinding";
     excludedDirs << "doc/src/snippets/qtquick1/imports";
     excludedDirs << "tests/manual/v4";
+    excludedDirs << "tests/auto/qml/ecmascripttests";
     excludedDirs << "tests/auto/qml/qmllint";
 
     // Add invalid files (i.e. files with syntax errors)
@@ -166,7 +169,7 @@ Examples are any .qml files under the examples/ directory that start
 with a lower case letter.
 */
 
-#if !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
+#if QT_CONFIG(process) && !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
 void tst_qmlmin::qmlMinify_data()
 {
     QTest::addColumn<QString>("file");
@@ -183,7 +186,7 @@ void tst_qmlmin::qmlMinify_data()
 }
 #endif
 
-#if !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
+#if QT_CONFIG(process) && !defined(QTEST_CROSS_COMPILED) // sources not available when cross compiled
 void tst_qmlmin::qmlMinify()
 {
     QFETCH(QString, file);
diff --git a/tests/auto/qml/qmlplugindump/tst_qmlplugindump.cpp b/tests/auto/qml/qmlplugindump/tst_qmlplugindump.cpp
index 838966e2a0..68e11e3551 100644
--- a/tests/auto/qml/qmlplugindump/tst_qmlplugindump.cpp
+++ b/tests/auto/qml/qmlplugindump/tst_qmlplugindump.cpp
@@ -105,12 +105,12 @@ void tst_qmlplugindump::singleton()
     args << QLatin1String("tests.dumper.CompositeSingleton") << QLatin1String("1.0")
          << QLatin1String(".");
     dumper.start(qmlplugindumpPath, args);
-    dumper.waitForFinished();
+    QVERIFY2(dumper.waitForStarted(), qPrintable(dumper.errorString()));
+    QVERIFY2(dumper.waitForFinished(), qPrintable(dumper.errorString()));
 
     const QString &result = dumper.readAllStandardOutput();
-    qDebug() << "result: " << result;
-    QVERIFY(result.contains(QLatin1String("exports: [\"Singleton 1.0\"]")));
-    QVERIFY(result.contains(QLatin1String("exportMetaObjectRevisions: [0]")));
+    QVERIFY2(result.contains(QLatin1String("exports: [\"Singleton 1.0\"]")), qPrintable(result));
+    QVERIFY2(result.contains(QLatin1String("exportMetaObjectRevisions: [0]")), qPrintable(result));
 }
 
 QTEST_MAIN(tst_qmlplugindump)
diff --git a/tests/auto/qml/qqmlapplicationengine/tst_qqmlapplicationengine.cpp b/tests/auto/qml/qqmlapplicationengine/tst_qqmlapplicationengine.cpp
index 74add85cb0..f7748b2da9 100644
--- a/tests/auto/qml/qqmlapplicationengine/tst_qqmlapplicationengine.cpp
+++ b/tests/auto/qml/qqmlapplicationengine/tst_qqmlapplicationengine.cpp
@@ -29,7 +29,9 @@
 #include "../../shared/util.h"
 #include <QQmlApplicationEngine>
 #include <QSignalSpy>
+#if QT_CONFIG(process)
 #include <QProcess>
+#endif
 #include <QDebug>
 
 class tst_qqmlapplicationengine : public QQmlDataTest
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 91ceed7697..6c9cb331a2 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -8170,6 +8170,8 @@ void tst_qqmlecmascript::stringify_qtbug_50592()
     QCOMPARE(obj->property("source").toString(), QString::fromLatin1("http://example.org/some_nonexistant_image.png"));
 }
 
+// Tests for the JS-only instanceof. Tests for the QML extensions for
+// instanceof belong in tst_qqmllanguage!
 void tst_qqmlecmascript::instanceof_data()
 {
     QTest::addColumn<QString>("setupCode");
diff --git a/tests/auto/qml/qqmllanguage/data/instanceOf/CustomMouseArea.qml b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomMouseArea.qml
new file mode 100644
index 0000000000..f6ec5848c1
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomMouseArea.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.6
+
+MouseArea {
+
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangle.qml b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangle.qml
new file mode 100644
index 0000000000..b3fa43a671
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangle.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.6
+
+Rectangle {
+}
diff --git a/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangleWithProp.qml b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangleWithProp.qml
new file mode 100644
index 0000000000..cf566b9315
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceOf/CustomRectangleWithProp.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.6
+
+Rectangle {
+    property int somethingCustom: 0
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/instanceOf/qmldir b/tests/auto/qml/qqmllanguage/data/instanceOf/qmldir
new file mode 100644
index 0000000000..144c93d8e3
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceOf/qmldir
@@ -0,0 +1,2 @@
+CustomRectangle 1.0 CustomRectangle.qml
+CustomMouseArea 1.0 CustomMouseArea.qml
diff --git a/tests/auto/qml/qqmllanguage/data/instanceof_qtqml.qml b/tests/auto/qml/qqmllanguage/data/instanceof_qtqml.qml
new file mode 100644
index 0000000000..d74b172cf8
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceof_qtqml.qml
@@ -0,0 +1,13 @@
+import QtQml 2.0
+
+QtObject {
+    id: qtobjectInstance
+
+    property Timer aTimer: Timer {
+        id: timerInstance
+    }
+
+    property Connections aConnections: Connections {
+        id: connectionsInstance
+    }
+}
diff --git a/tests/auto/qml/qqmllanguage/data/instanceof_qtqml_qualified.qml b/tests/auto/qml/qqmllanguage/data/instanceof_qtqml_qualified.qml
new file mode 100644
index 0000000000..a8e303363e
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceof_qtqml_qualified.qml
@@ -0,0 +1,13 @@
+import QtQml 2.0 as QmlImport
+
+QmlImport.QtObject {
+    id: qtobjectInstance
+
+    property QmlImport.Timer aTimer: QmlImport.Timer {
+        id: timerInstance
+    }
+
+    property QmlImport.Connections aConnections: QmlImport.Connections {
+        id: connectionsInstance
+    }
+}
diff --git a/tests/auto/qml/qqmllanguage/data/instanceof_qtquick.qml b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick.qml
new file mode 100644
index 0000000000..9c1808d515
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick.qml
@@ -0,0 +1,14 @@
+import QtQuick 2.0
+
+Item {
+    id: itemInstance
+
+    Rectangle {
+        id: rectangleInstance
+    }
+
+    MouseArea {
+        id: mouseAreaInstance
+    }
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite.qml b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite.qml
new file mode 100644
index 0000000000..78fc112805
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite.qml
@@ -0,0 +1,26 @@
+import QtQuick 2.0
+import "instanceOf"
+
+Item {
+    id: itemInstance
+
+    Rectangle {
+        id: rectangleInstance
+    }
+
+    MouseArea {
+        id: mouseAreaInstance
+    }
+
+    CustomRectangle {
+        id: customRectangleInstance
+    }
+    CustomRectangleWithProp {
+        id: customRectangleWithPropInstance
+    }
+    CustomMouseArea {
+        id: customMouseAreaInstance
+    }
+}
+
+
diff --git a/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite_qualified.qml b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite_qualified.qml
new file mode 100644
index 0000000000..97361b7334
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/instanceof_qtquick_composite_qualified.qml
@@ -0,0 +1,27 @@
+import QtQuick 2.0 as QuickImport
+import "instanceOf" as CustomImport
+
+QuickImport.Item {
+    id: itemInstance
+
+    QuickImport.Rectangle {
+        id: rectangleInstance
+    }
+
+    QuickImport.MouseArea {
+        id: mouseAreaInstance
+    }
+
+    CustomImport.CustomRectangle {
+        id: customRectangleInstance
+    }
+    CustomImport.CustomRectangleWithProp {
+        id: customRectangleWithPropInstance
+    }
+    CustomImport.CustomMouseArea {
+        id: customMouseAreaInstance
+    }
+}
+
+
+
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 750c32cc3c..e67fa18309 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -263,6 +263,9 @@ private slots:
     void qmlTypeCanBeResolvedByName_data();
     void qmlTypeCanBeResolvedByName();
 
+    void instanceof_data();
+    void instanceof();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -309,7 +312,7 @@ private:
     if (!errorfile) { \
         if (qgetenv("DEBUG") != "" && !component.errors().isEmpty()) \
             qWarning() << "Unexpected Errors:" << component.errors(); \
-        QVERIFY(!component.isError()); \
+        QVERIFY2(!component.isError(), qPrintable(component.errorString())); \
         QVERIFY(component.errors().isEmpty()); \
     } else { \
         DETERMINE_ERRORS(errorfile,expected,actual);\
@@ -4338,6 +4341,200 @@ void tst_qqmllanguage::qmlTypeCanBeResolvedByName()
     QVERIFY(!o.isNull());
 }
 
+// Tests for the QML-only extensions of instanceof. Tests for the regular JS
+// instanceof belong in tst_qqmlecmascript!
+void tst_qqmllanguage::instanceof_data()
+{
+    QTest::addColumn<QUrl>("documentToTestIn");
+    QTest::addColumn<QVariant>("expectedValue");
+
+    // so the way this works is that the name of the test tag defines the test
+    // to run.
+    //
+    // the expectedValue is either a boolean true or false for whether the two
+    // operands are indeed an instanceof each other, or a string for the
+    // expected error message.
+
+    // assert that basic types don't convert to QObject
+    QTest::newRow("1 instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+    QTest::newRow("true instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+    QTest::newRow("\"foobar\" instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+
+    // assert that Managed don't either
+    QTest::newRow("new String(\"foobar\") instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+    QTest::newRow("new Object() instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+    QTest::newRow("new Date() instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant("TypeError: Type error");
+
+    // test that simple QtQml comparisons work
+    QTest::newRow("qtobjectInstance instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(true);
+    QTest::newRow("qtobjectInstance instanceof Timer")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(false);
+    QTest::newRow("timerInstance instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(true);
+    QTest::newRow("timerInstance instanceof Timer")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(true);
+    QTest::newRow("connectionsInstance instanceof QtObject")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(true);
+    QTest::newRow("connectionsInstance instanceof Timer")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(false);
+    QTest::newRow("connectionsInstance instanceof Connections")
+        << testFileUrl("instanceof_qtqml.qml")
+        << QVariant(true);
+
+    // make sure they still work when imported with a qualifier
+    QTest::newRow("qtobjectInstance instanceof QmlImport.QtObject")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("qtobjectInstance instanceof QmlImport.Timer")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(false);
+    QTest::newRow("timerInstance instanceof QmlImport.QtObject")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("timerInstance instanceof QmlImport.Timer")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("connectionsInstance instanceof QmlImport.QtObject")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("connectionsInstance instanceof QmlImport.Timer")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(false);
+    QTest::newRow("connectionsInstance instanceof QmlImport.Connections")
+        << testFileUrl("instanceof_qtqml_qualified.qml")
+        << QVariant(true);
+
+    // test that Quick C++ types work ok
+    QTest::newRow("itemInstance instanceof QtObject")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(true);
+    QTest::newRow("itemInstance instanceof Timer")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(false);
+    QTest::newRow("itemInstance instanceof Rectangle")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(false);
+    QTest::newRow("rectangleInstance instanceof Item")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(true);
+    QTest::newRow("rectangleInstance instanceof Rectangle")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(true);
+    QTest::newRow("rectangleInstance instanceof MouseArea")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(false);
+    QTest::newRow("mouseAreaInstance instanceof Item")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(true);
+    QTest::newRow("mouseAreaInstance instanceof Rectangle")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(false);
+    QTest::newRow("mouseAreaInstance instanceof MouseArea")
+        << testFileUrl("instanceof_qtquick.qml")
+        << QVariant(true);
+
+    // test that unqualified quick composite types work ok
+    QTest::newRow("rectangleInstance instanceof CustomRectangle")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(false);
+    QTest::newRow("customRectangleInstance instanceof Rectangle")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleInstance instanceof Item")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleWithPropInstance instanceof CustomRectangleWithProp")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleWithPropInstance instanceof CustomRectangle")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(false); // ### XXX: QTBUG-58477
+    QTest::newRow("customRectangleWithPropInstance instanceof Rectangle")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleInstance instanceof MouseArea")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(false);
+    QTest::newRow("customMouseAreaInstance instanceof MouseArea")
+        << testFileUrl("instanceof_qtquick_composite.qml")
+        << QVariant(true);
+
+    // test that they still work when qualified
+    QTest::newRow("rectangleInstance instanceof CustomImport.CustomRectangle")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(false);
+    QTest::newRow("customRectangleInstance instanceof QuickImport.Rectangle")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleInstance instanceof QuickImport.Item")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleWithPropInstance instanceof CustomImport.CustomRectangleWithProp")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleWithPropInstance instanceof CustomImport.CustomRectangle")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(false); // ### XXX: QTBUG-58477
+    QTest::newRow("customRectangleWithPropInstance instanceof QuickImport.Rectangle")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(true);
+    QTest::newRow("customRectangleInstance instanceof QuickImport.MouseArea")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(false);
+    QTest::newRow("customMouseAreaInstance instanceof QuickImport.MouseArea")
+        << testFileUrl("instanceof_qtquick_composite_qualified.qml")
+        << QVariant(true);
+}
+
+void tst_qqmllanguage::instanceof()
+{
+    QFETCH(QUrl, documentToTestIn);
+    QFETCH(QVariant, expectedValue);
+
+    QQmlEngine engine;
+    QQmlComponent component(&engine, documentToTestIn);
+    VERIFY_ERRORS(0);
+
+    QScopedPointer<QObject> o(component.create());
+    QVERIFY(o != 0);
+
+    QQmlExpression expr(engine.contextForObject(o.data()), 0, QString::fromLatin1(QTest::currentDataTag()));
+    QVariant ret = expr.evaluate();
+
+    if (expectedValue.type() == QVariant::Bool) {
+        // no error expected
+        QVERIFY2(!expr.hasError(), qPrintable(expr.error().description()));
+        bool returnValue = ret.toBool();
+
+        if (QTest::currentDataTag() == QLatin1String("customRectangleWithPropInstance instanceof CustomRectangle") ||
+            QTest::currentDataTag() == QLatin1String("customRectangleWithPropInstance instanceof CustomImport.CustomRectangle"))
+            QEXPECT_FAIL("", "QTBUG-58477: QML type rules are a little lax", Continue);
+        QCOMPARE(returnValue, expectedValue.toBool());
+    } else {
+        QVERIFY(expr.hasError());
+        QCOMPARE(expr.error().description(), expectedValue.toString());
+    }
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"
diff --git a/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp b/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
index 9fbd719d7b..30e517c8f9 100644
--- a/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
+++ b/tests/auto/qml/qqmlmetatype/tst_qqmlmetatype.cpp
@@ -52,6 +52,7 @@ private slots:
     void qmlPropertyValueInterceptorCast();
     void qmlType();
     void invalidQmlTypeName();
+    void prettyTypeName();
     void registrationType();
     void compositeType();
     void externalEnums();
@@ -72,6 +73,16 @@ public:
 };
 QML_DECLARE_TYPE(TestType);
 
+class TestType2 : public QObject
+{
+    Q_OBJECT
+};
+
+class TestType3 : public QObject
+{
+    Q_OBJECT
+};
+
 class ExternalEnums : public QObject
 {
     Q_OBJECT
@@ -214,13 +225,28 @@ void tst_qqmlmetatype::invalidQmlTypeName()
 {
     QStringList currFailures = QQmlMetaType::typeRegistrationFailures();
     QCOMPARE(qmlRegisterType<TestType>("TestNamespace", 1, 0, "Test$Type"), -1); // should fail due to invalid QML type name.
+    QCOMPARE(qmlRegisterType<TestType>("Test", 1, 0, "EndingInSlash/"), -1);
     QStringList nowFailures = QQmlMetaType::typeRegistrationFailures();
 
     foreach (const QString &f, currFailures)
         nowFailures.removeOne(f);
 
-    QCOMPARE(nowFailures.size(), 1);
+    QCOMPARE(nowFailures.size(), 2);
     QCOMPARE(nowFailures.at(0), QStringLiteral("Invalid QML element name \"Test$Type\""));
+    QCOMPARE(nowFailures.at(1), QStringLiteral("Invalid QML element name \"EndingInSlash/\""));
+}
+
+void tst_qqmlmetatype::prettyTypeName()
+{
+    TestType2 obj2;
+    QCOMPARE(QQmlMetaType::prettyTypeName(&obj2), QString("TestType2"));
+    QVERIFY(qmlRegisterType<TestType2>("Test", 1, 0, "") >= 0);
+    QCOMPARE(QQmlMetaType::prettyTypeName(&obj2), QString("TestType2"));
+
+    TestType3 obj3;
+    QCOMPARE(QQmlMetaType::prettyTypeName(&obj3), QString("TestType3"));
+    QVERIFY(qmlRegisterType<TestType3>("Test", 1, 0, "OtherName") >= 0);
+    QCOMPARE(QQmlMetaType::prettyTypeName(&obj3), QString("OtherName"));
 }
 
 void tst_qqmlmetatype::isList()
diff --git a/tests/auto/qml/v4misc/tst_v4misc.cpp b/tests/auto/qml/v4misc/tst_v4misc.cpp
index 88b6ae92a8..55a1f65608 100644
--- a/tests/auto/qml/v4misc/tst_v4misc.cpp
+++ b/tests/auto/qml/v4misc/tst_v4misc.cpp
@@ -26,6 +26,7 @@
 **
 ****************************************************************************/
 
+#include <qhashfunctions.h>
 #include <qtest.h>
 
 #define V4_AUTOTEST
@@ -46,17 +47,12 @@ private slots:
     void moveMapping_2();
 };
 
-QT_BEGIN_NAMESPACE
-// Avoid QHash randomization so that the temp numbering is stable.
-extern Q_CORE_EXPORT QBasicAtomicInt qt_qhash_seed; // from qhash.cpp
-QT_END_NAMESPACE
-
 using namespace QT_PREPEND_NAMESPACE(QV4::IR);
 
 void tst_v4misc::initTestCase()
 {
-    qt_qhash_seed.store(0);
-    QCOMPARE(qt_qhash_seed.load(), 0);
+    qSetGlobalQHashSeed(0);
+    QCOMPARE(qGlobalQHashSeed(), 0);
 }
 
 // split between two ranges
diff --git a/tests/auto/qmltest/BLACKLIST b/tests/auto/qmltest/BLACKLIST
index c38347b42a..e0a4ce1743 100644
--- a/tests/auto/qmltest/BLACKLIST
+++ b/tests/auto/qmltest/BLACKLIST
@@ -9,3 +9,8 @@ linux
 linux
 [ListView::test_listInteractiveCurrentIndexEnforce]
 linux
+macos-10.12
+[TextEdit::test_textentry]
+macos-10.12
+[TextEdit::test_textentry_char]
+macos-10.12
diff --git a/tests/auto/qmltest/selftests/tst_selftests.qml b/tests/auto/qmltest/selftests/tst_selftests.qml
index 439ea7a70d..5555876014 100644
--- a/tests/auto/qmltest/selftests/tst_selftests.qml
+++ b/tests/auto/qmltest/selftests/tst_selftests.qml
@@ -167,6 +167,16 @@ TestCase {
             caught = true
         }
         verify(caught)
+
+        caught = false;
+        try {
+            testCase.verify(true, "foo", "bar")
+        } catch (e) {
+            compare(e.message, "QtQuickTest::fail")
+            compare(functions.failmsg, "More than two arguments given to verify(). Did you mean tryVerify() or tryCompare()?")
+            caught = true
+        }
+        verify(caught)
     }
 
     function test_compare() {
diff --git a/tests/auto/quick/examples/tst_examples.cpp b/tests/auto/quick/examples/tst_examples.cpp
index d5c9aaeb90..b6742b9efe 100644
--- a/tests/auto/quick/examples/tst_examples.cpp
+++ b/tests/auto/quick/examples/tst_examples.cpp
@@ -29,7 +29,6 @@
 #include <qtest.h>
 #include <QLibraryInfo>
 #include <QDir>
-#include <QProcess>
 #include <QDebug>
 #include <QtQuick/QQuickItem>
 #include <QtQuick/QQuickView>
diff --git a/tests/auto/quick/nokeywords/tst_nokeywords.cpp b/tests/auto/quick/nokeywords/tst_nokeywords.cpp
index ad77743ddd..e6655589a3 100644
--- a/tests/auto/quick/nokeywords/tst_nokeywords.cpp
+++ b/tests/auto/quick/nokeywords/tst_nokeywords.cpp
@@ -55,7 +55,6 @@
 #include <QtQuick/private/qsgdefaultinternalrectanglenode_p.h>
 #include <QtQuick/private/qsgdepthstencilbuffer_p.h>
 #include <QtQuick/private/qsgdistancefieldglyphnode_p.h>
-#include <QtQuick/private/qsgdistancefieldutil_p.h>
 #endif
 #include <QtQuick/private/qsggeometry_p.h>
 #include <QtQuick/private/qsgnode_p.h>
diff --git a/tests/auto/quick/qquickapplication/BLACKLIST b/tests/auto/quick/qquickapplication/BLACKLIST
new file mode 100644
index 0000000000..81592db56f
--- /dev/null
+++ b/tests/auto/quick/qquickapplication/BLACKLIST
@@ -0,0 +1,2 @@
+[active]
+osx-10.11
diff --git a/tests/auto/quick/qquickflickable/BLACKLIST b/tests/auto/quick/qquickflickable/BLACKLIST
index 647bf819a5..f35397f119 100644
--- a/tests/auto/quick/qquickflickable/BLACKLIST
+++ b/tests/auto/quick/qquickflickable/BLACKLIST
@@ -17,3 +17,5 @@ osx
 osx-10.10
 [flickVelocity]
 osx-10.10
+[nestedSliderUsingTouch:keepNeither]
+ubuntu-16.04
diff --git a/tests/auto/quick/qquickflickable/data/nestedSlider.qml b/tests/auto/quick/qquickflickable/data/nestedSlider.qml
new file mode 100644
index 0000000000..2fd0cbfcc8
--- /dev/null
+++ b/tests/auto/quick/qquickflickable/data/nestedSlider.qml
@@ -0,0 +1,36 @@
+import QtQuick 2.0
+import Test 1.0
+
+Flickable {
+    width: 240
+    height: 320
+    contentWidth: width * 1.5
+    contentHeight: height * 1.5
+    contentY: height * 0.25
+
+    Rectangle {
+        id: slider
+        width: 50
+        height: 200
+        color: "lightgray"
+        border.color: drag.active ? "green" : "black"
+        anchors.centerIn: parent
+        radius: 4
+
+        TouchDragArea {
+            id: drag
+            objectName: "drag"
+            anchors.fill: parent
+        }
+
+        Rectangle {
+            width: parent.width - 2
+            height: 20
+            radius: 5
+            color: "darkgray"
+            border.color: "black"
+            x: 1
+            y: Math.min(slider.height - height, Math.max(0, drag.pos.y - height / 2))
+        }
+    }
+}
diff --git a/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp b/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
index 9ead271bfe..ef6e444580 100644
--- a/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
+++ b/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
@@ -46,12 +46,107 @@
 using namespace QQuickViewTestUtil;
 using namespace QQuickVisualTestUtil;
 
+// an abstract Slider which only handles touch events
+class TouchDragArea : public QQuickItem
+{
+    Q_OBJECT
+    Q_PROPERTY(QPointF pos READ pos NOTIFY posChanged)
+    Q_PROPERTY(bool active READ active NOTIFY activeChanged)
+    Q_PROPERTY(bool keepMouseGrab READ keepMouseGrab WRITE setKeepMouseGrab NOTIFY keepMouseGrabChanged)
+    Q_PROPERTY(bool keepTouchGrab READ keepTouchGrab WRITE setKeepTouchGrab NOTIFY keepTouchGrabChanged)
+
+public:
+    TouchDragArea(QQuickItem *parent = 0)
+        : QQuickItem(parent)
+        , touchEvents(0)
+        , touchUpdates(0)
+        , touchReleases(0)
+        , ungrabs(0)
+        , m_active(false)
+    { }
+
+    QPointF pos() const { return m_pos; }
+
+    bool active() const  { return m_active; }
+
+    void setKeepMouseGrab(bool keepMouseGrab)
+    {
+        QQuickItem::setKeepMouseGrab(keepMouseGrab);
+        emit keepMouseGrabChanged();
+    }
+
+    void setKeepTouchGrab(bool keepTouchGrab)
+    {
+        QQuickItem::setKeepTouchGrab(keepTouchGrab);
+        emit keepTouchGrabChanged();
+    }
+
+    int touchEvents;
+    int touchUpdates;
+    int touchReleases;
+    int ungrabs;
+    QVector<Qt::TouchPointState> touchPointStates;
+
+protected:
+    void touchEvent(QTouchEvent *ev) override
+    {
+        QCOMPARE(ev->touchPoints().count(), 1);
+        auto touchpoint = ev->touchPoints().first();
+        switch (touchpoint.state()) {
+        case Qt::TouchPointPressed:
+            QVERIFY(!m_active);
+            m_active = true;
+            emit activeChanged();
+            grabTouchPoints(QVector<int>() << touchpoint.id());
+            break;
+        case Qt::TouchPointMoved:
+            ++touchUpdates;
+            break;
+        case Qt::TouchPointReleased:
+            QVERIFY(m_active);
+            m_active = false;
+            ++touchReleases;
+            emit activeChanged();
+        case Qt::TouchPointStationary:
+            break;
+        }
+        touchPointStates << touchpoint.state();
+        ++touchEvents;
+        m_pos = touchpoint.pos();
+        emit posChanged();
+    }
+
+    void touchUngrabEvent() override
+    {
+        ++ungrabs;
+        QVERIFY(m_active);
+        emit ungrabbed();
+        m_active = false;
+        emit activeChanged();
+    }
+
+signals:
+    void ungrabbed();
+    void posChanged();
+    void keepMouseGrabChanged();
+    void keepTouchGrabChanged();
+    void activeChanged();
+
+private:
+    QPointF m_pos;
+    bool m_active;
+};
+
 class tst_qquickflickable : public QQmlDataTest
 {
     Q_OBJECT
 public:
+    tst_qquickflickable()
+      : touchDevice(QTest::createTouchDevice())
+    {}
 
 private slots:
+    void initTestCase() override;
     void create();
     void horizontalViewportSize();
     void verticalViewportSize();
@@ -89,6 +184,8 @@ private slots:
     void stopAtBounds();
     void stopAtBounds_data();
     void nestedMouseAreaUsingTouch();
+    void nestedSliderUsingTouch();
+    void nestedSliderUsingTouch_data();
     void pressDelayWithLoader();
     void movementFromProgrammaticFlick();
     void cleanup();
@@ -101,9 +198,16 @@ private slots:
     void overshoot_reentrant();
 
 private:
-    void flickWithTouch(QQuickWindow *window, QTouchDevice *touchDevice, const QPoint &from, const QPoint &to);
+    void flickWithTouch(QQuickWindow *window, const QPoint &from, const QPoint &to);
+    QTouchDevice *touchDevice;
 };
 
+void tst_qquickflickable::initTestCase()
+{
+    QQmlDataTest::initTestCase();
+    qmlRegisterType<TouchDragArea>("Test",1,0,"TouchDragArea");
+}
+
 void tst_qquickflickable::cleanup()
 {
     QVERIFY(QGuiApplication::topLevelWindows().isEmpty());
@@ -1530,12 +1634,6 @@ void tst_qquickflickable::clickAndDragWhenTransformed()
 
 void tst_qquickflickable::flickTwiceUsingTouches()
 {
-    QTouchDevice *touchDevice = new QTouchDevice;
-    touchDevice->setName("Fake Touchscreen");
-    touchDevice->setType(QTouchDevice::TouchScreen);
-    touchDevice->setCapabilities(QTouchDevice::Position);
-    QWindowSystemInterface::registerTouchDevice(touchDevice);
-
     QScopedPointer<QQuickView> window(new QQuickView);
     window->setSource(testFileUrl("longList.qml"));
     QTRY_COMPARE(window->status(), QQuickView::Ready);
@@ -1548,7 +1646,7 @@ void tst_qquickflickable::flickTwiceUsingTouches()
     QVERIFY(flickable != 0);
 
     QCOMPARE(flickable->contentY(), 0.0f);
-    flickWithTouch(window.data(), touchDevice, QPoint(100, 400), QPoint(100, 240));
+    flickWithTouch(window.data(), QPoint(100, 400), QPoint(100, 240));
 
     qreal contentYAfterFirstFlick = flickable->contentY();
     qDebug() << "contentYAfterFirstFlick " << contentYAfterFirstFlick;
@@ -1556,7 +1654,7 @@ void tst_qquickflickable::flickTwiceUsingTouches()
     // Wait until view stops moving
     QTRY_VERIFY(!flickable->isMoving());
 
-    flickWithTouch(window.data(), touchDevice, QPoint(100, 400), QPoint(100, 240));
+    flickWithTouch(window.data(), QPoint(100, 400), QPoint(100, 240));
 
     // In the original bug, that second flick would cause Flickable to halt immediately
     qreal contentYAfterSecondFlick = flickable->contentY();
@@ -1564,7 +1662,7 @@ void tst_qquickflickable::flickTwiceUsingTouches()
     QTRY_VERIFY(contentYAfterSecondFlick > (contentYAfterFirstFlick + 80.0f));
 }
 
-void tst_qquickflickable::flickWithTouch(QQuickWindow *window, QTouchDevice *touchDevice, const QPoint &from, const QPoint &to)
+void tst_qquickflickable::flickWithTouch(QQuickWindow *window, const QPoint &from, const QPoint &to)
 {
     QTest::touchEvent(window, touchDevice).press(0, from, window);
     QQuickTouchUtils::flush(window);
@@ -1869,12 +1967,6 @@ void tst_qquickflickable::stopAtBounds()
 
 void tst_qquickflickable::nestedMouseAreaUsingTouch()
 {
-    QTouchDevice *touchDevice = new QTouchDevice;
-    touchDevice->setName("Fake Touchscreen");
-    touchDevice->setType(QTouchDevice::TouchScreen);
-    touchDevice->setCapabilities(QTouchDevice::Position);
-    QWindowSystemInterface::registerTouchDevice(touchDevice);
-
     QScopedPointer<QQuickView> window(new QQuickView);
     window->setSource(testFileUrl("nestedmousearea.qml"));
     QTRY_COMPARE(window->status(), QQuickView::Ready);
@@ -1887,7 +1979,7 @@ void tst_qquickflickable::nestedMouseAreaUsingTouch()
     QVERIFY(flickable != 0);
 
     QCOMPARE(flickable->contentY(), 50.0f);
-    flickWithTouch(window.data(), touchDevice, QPoint(100, 300), QPoint(100, 200));
+    flickWithTouch(window.data(), QPoint(100, 300), QPoint(100, 200));
 
     // flickable should not have moved
     QCOMPARE(flickable->contentY(), 50.0);
@@ -1897,6 +1989,65 @@ void tst_qquickflickable::nestedMouseAreaUsingTouch()
     QVERIFY(nested->y() < 100.0);
 }
 
+void tst_qquickflickable::nestedSliderUsingTouch_data()
+{
+    QTest::addColumn<bool>("keepMouseGrab");
+    QTest::addColumn<bool>("keepTouchGrab");
+    QTest::addColumn<int>("updates");
+    QTest::addColumn<int>("releases");
+    QTest::addColumn<int>("ungrabs");
+
+    QTest::newRow("keepBoth") << true << true << 8 << 1 << 0;
+    QTest::newRow("keepMouse") << true << false << 8 << 1 << 0;
+    QTest::newRow("keepTouch") << false << true << 8 << 1 << 0;
+    QTest::newRow("keepNeither") << false << false << 6 << 0 << 1;
+}
+
+void tst_qquickflickable::nestedSliderUsingTouch()
+{
+    QFETCH(bool, keepMouseGrab);
+    QFETCH(bool, keepTouchGrab);
+    QFETCH(int, updates);
+    QFETCH(int, releases);
+    QFETCH(int, ungrabs);
+
+    QQuickView *window = new QQuickView;
+    QScopedPointer<QQuickView> windowPtr(window);
+    windowPtr->setSource(testFileUrl("nestedSlider.qml"));
+    QTRY_COMPARE(window->status(), QQuickView::Ready);
+    QQuickViewTestUtil::centerOnScreen(window);
+    QQuickViewTestUtil::moveMouseAway(window);
+    window->show();
+    QVERIFY(QTest::qWaitForWindowActive(window));
+    QVERIFY(window->rootObject() != 0);
+
+    QQuickFlickable *flickable = qobject_cast<QQuickFlickable*>(window->rootObject());
+    QVERIFY(flickable);
+
+    TouchDragArea *tda = flickable->findChild<TouchDragArea*>("drag");
+    QVERIFY(tda);
+
+    // Drag down and a little to the right: flickable will steal the grab only if tda allows it
+    const int dragThreshold = qApp->styleHints()->startDragDistance();
+    tda->setKeepMouseGrab(keepMouseGrab);
+    tda->setKeepTouchGrab(keepTouchGrab);
+    QPoint p0 = tda->mapToScene(QPoint(20, 20)).toPoint();
+    QTest::touchEvent(window, touchDevice).press(0, p0, window);
+    QQuickTouchUtils::flush(window);
+    for (int i = 0; i < 8; ++i) {
+        p0 += QPoint(dragThreshold / 6, dragThreshold / 4);
+        QTest::touchEvent(window, touchDevice).move(0, p0, window);
+        QQuickTouchUtils::flush(window);
+    }
+    QCOMPARE(tda->active(), !ungrabs);
+    QTest::touchEvent(window, touchDevice).release(0, p0, window);
+    QQuickTouchUtils::flush(window);
+    QTRY_COMPARE(tda->touchPointStates.first(), Qt::TouchPointPressed);
+    QTRY_COMPARE(tda->touchUpdates, updates);
+    QTRY_COMPARE(tda->touchReleases, releases);
+    QTRY_COMPARE(tda->ungrabs, ungrabs);
+}
+
 // QTBUG-31328
 void tst_qquickflickable::pressDelayWithLoader()
 {
@@ -2065,6 +2216,7 @@ Q_DECLARE_METATYPE(QQuickFlickable::BoundsBehavior)
 void tst_qquickflickable::overshoot()
 {
     QFETCH(QQuickFlickable::BoundsBehavior, boundsBehavior);
+    QFETCH(int, boundsMovement);
 
     QScopedPointer<QQuickView> window(new QQuickView);
     window->setSource(testFileUrl("overshoot.qml"));
@@ -2081,6 +2233,7 @@ void tst_qquickflickable::overshoot()
     QCOMPARE(flickable->contentHeight(), 400.0);
 
     flickable->setBoundsBehavior(boundsBehavior);
+    flickable->setBoundsMovement(QQuickFlickable::BoundsMovement(boundsMovement));
 
     // drag past the beginning
     QTest::mousePress(window.data(), Qt::LeftButton, 0, QPoint(10, 10));
@@ -2089,23 +2242,30 @@ void tst_qquickflickable::overshoot()
     QTest::mouseMove(window.data(), QPoint(40, 40));
     QTest::mouseRelease(window.data(), Qt::LeftButton, 0, QPoint(50, 50));
 
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) && (boundsBehavior & QQuickFlickable::DragOverBounds)) {
+        QVERIFY(flickable->property("minContentX").toReal() < 0.0);
+        QVERIFY(flickable->property("minContentY").toReal() < 0.0);
+    } else {
+        QCOMPARE(flickable->property("minContentX").toReal(), 0.0);
+        QCOMPARE(flickable->property("minContentY").toReal(), 0.0);
+    }
     if (boundsBehavior & QQuickFlickable::DragOverBounds) {
-        QVERIFY(flickable->property("minVerticalOvershoot").toReal() < 0.0);
         QVERIFY(flickable->property("minHorizontalOvershoot").toReal() < 0.0);
-        QCOMPARE(flickable->property("minContentY").toReal(),
-                 flickable->property("minVerticalOvershoot").toReal());
-        QCOMPARE(flickable->property("minContentX").toReal(),
-                 flickable->property("minHorizontalOvershoot").toReal());
+        QVERIFY(flickable->property("minVerticalOvershoot").toReal() < 0.0);
     } else {
-        QCOMPARE(flickable->property("minContentY").toReal(), 0.0);
-        QCOMPARE(flickable->property("minContentX").toReal(), 0.0);
-        QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
         QCOMPARE(flickable->property("minHorizontalOvershoot").toReal(), 0.0);
+        QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
+    }
+    if (bool(boundsMovement == QQuickFlickable::FollowBoundsBehavior) == bool(boundsBehavior & QQuickFlickable::DragOverBounds)) {
+        QCOMPARE(flickable->property("minContentX").toReal(),
+                 flickable->property("minHorizontalOvershoot").toReal());
+        QCOMPARE(flickable->property("minContentY").toReal(),
+                 flickable->property("minVerticalOvershoot").toReal());
     }
-    QCOMPARE(flickable->property("maxContentY").toReal(), 0.0);
     QCOMPARE(flickable->property("maxContentX").toReal(), 0.0);
-    QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("maxContentY").toReal(), 0.0);
     QCOMPARE(flickable->property("maxHorizontalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
 
     flickable->setContentX(20.0);
     flickable->setContentY(20.0);
@@ -2115,23 +2275,30 @@ void tst_qquickflickable::overshoot()
     flick(window.data(), QPoint(10, 10), QPoint(50, 50), 100);
     QTRY_VERIFY(!flickable->property("flicking").toBool());
 
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) && (boundsBehavior & QQuickFlickable::OvershootBounds)) {
+        QVERIFY(flickable->property("minContentX").toReal() < 0.0);
+        QVERIFY(flickable->property("minContentY").toReal() < 0.0);
+    } else {
+        QCOMPARE(flickable->property("minContentX").toReal(), 0.0);
+        QCOMPARE(flickable->property("minContentY").toReal(), 0.0);
+    }
     if (boundsBehavior & QQuickFlickable::OvershootBounds) {
-        QVERIFY(flickable->property("minVerticalOvershoot").toReal() < 0.0);
         QVERIFY(flickable->property("minHorizontalOvershoot").toReal() < 0.0);
-        QCOMPARE(flickable->property("minContentY").toReal(),
-                 flickable->property("minVerticalOvershoot").toReal());
-        QCOMPARE(flickable->property("minContentX").toReal(),
-                 flickable->property("minHorizontalOvershoot").toReal());
+        QVERIFY(flickable->property("minVerticalOvershoot").toReal() < 0.0);
     } else {
-        QCOMPARE(flickable->property("minContentY").toReal(), 0.0);
-        QCOMPARE(flickable->property("minContentX").toReal(), 0.0);
-        QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
         QCOMPARE(flickable->property("minHorizontalOvershoot").toReal(), 0.0);
+        QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
+    }
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) == (boundsBehavior & QQuickFlickable::OvershootBounds)) {
+        QCOMPARE(flickable->property("minContentX").toReal(),
+                 flickable->property("minHorizontalOvershoot").toReal());
+        QCOMPARE(flickable->property("minContentY").toReal(),
+                 flickable->property("minVerticalOvershoot").toReal());
     }
-    QCOMPARE(flickable->property("maxContentY").toReal(), 20.0);
     QCOMPARE(flickable->property("maxContentX").toReal(), 20.0);
-    QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("maxContentY").toReal(), 20.0);
     QCOMPARE(flickable->property("maxHorizontalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
 
     flickable->setContentX(200.0);
     flickable->setContentY(200.0);
@@ -2144,23 +2311,30 @@ void tst_qquickflickable::overshoot()
     QTest::mouseMove(window.data(), QPoint(20, 20));
     QTest::mouseRelease(window.data(), Qt::LeftButton, 0, QPoint(10, 10));
 
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) && (boundsBehavior & QQuickFlickable::DragOverBounds)) {
+        QVERIFY(flickable->property("maxContentX").toReal() > 200.0);
+        QVERIFY(flickable->property("maxContentX").toReal() > 200.0);
+    } else {
+        QCOMPARE(flickable->property("maxContentX").toReal(), 200.0);
+        QCOMPARE(flickable->property("maxContentY").toReal(), 200.0);
+    }
     if (boundsBehavior & QQuickFlickable::DragOverBounds) {
-        QVERIFY(flickable->property("maxVerticalOvershoot").toReal() > 0.0);
         QVERIFY(flickable->property("maxHorizontalOvershoot").toReal() > 0.0);
-        QCOMPARE(flickable->property("maxContentY").toReal() - 200.0,
-                 flickable->property("maxVerticalOvershoot").toReal());
-        QCOMPARE(flickable->property("maxContentX").toReal() - 200.0,
-                 flickable->property("maxHorizontalOvershoot").toReal());
+        QVERIFY(flickable->property("maxVerticalOvershoot").toReal() > 0.0);
     } else {
-        QCOMPARE(flickable->property("maxContentY").toReal(), 200.0);
-        QCOMPARE(flickable->property("maxContentX").toReal(), 200.0);
-        QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
         QCOMPARE(flickable->property("maxHorizontalOvershoot").toReal(), 0.0);
+        QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
+    }
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) == (boundsBehavior & QQuickFlickable::DragOverBounds)) {
+        QCOMPARE(flickable->property("maxContentX").toReal() - 200.0,
+                 flickable->property("maxHorizontalOvershoot").toReal());
+        QCOMPARE(flickable->property("maxContentY").toReal() - 200.0,
+                 flickable->property("maxVerticalOvershoot").toReal());
     }
-    QCOMPARE(flickable->property("minContentY").toReal(), 200.0);
     QCOMPARE(flickable->property("minContentX").toReal(), 200.0);
-    QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("minContentY").toReal(), 200.0);
     QCOMPARE(flickable->property("minHorizontalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
 
     flickable->setContentX(180.0);
     flickable->setContentY(180.0);
@@ -2170,37 +2344,59 @@ void tst_qquickflickable::overshoot()
     flick(window.data(), QPoint(50, 50), QPoint(10, 10), 100);
     QTRY_VERIFY(!flickable->property("flicking").toBool());
 
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) && (boundsBehavior & QQuickFlickable::OvershootBounds)) {
+        QVERIFY(flickable->property("maxContentX").toReal() > 200.0);
+        QVERIFY(flickable->property("maxContentY").toReal() > 200.0);
+    } else {
+        QCOMPARE(flickable->property("maxContentX").toReal(), 200.0);
+        QCOMPARE(flickable->property("maxContentY").toReal(), 200.0);
+    }
     if (boundsBehavior & QQuickFlickable::OvershootBounds) {
-        QVERIFY(flickable->property("maxVerticalOvershoot").toReal() > 0.0);
         QVERIFY(flickable->property("maxHorizontalOvershoot").toReal() > 0.0);
-        QCOMPARE(flickable->property("maxContentY").toReal() - 200.0,
-                 flickable->property("maxVerticalOvershoot").toReal());
-        QCOMPARE(flickable->property("maxContentX").toReal() - 200.0,
-                 flickable->property("maxHorizontalOvershoot").toReal());
+        QVERIFY(flickable->property("maxVerticalOvershoot").toReal() > 0.0);
     } else {
-        QCOMPARE(flickable->property("maxContentY").toReal(), 200.0);
-        QCOMPARE(flickable->property("maxContentX").toReal(), 200.0);
-        QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
         QCOMPARE(flickable->property("maxHorizontalOvershoot").toReal(), 0.0);
+        QCOMPARE(flickable->property("maxVerticalOvershoot").toReal(), 0.0);
+    }
+    if ((boundsMovement == QQuickFlickable::FollowBoundsBehavior) == (boundsBehavior & QQuickFlickable::OvershootBounds)) {
+        QCOMPARE(flickable->property("maxContentX").toReal() - 200.0,
+                 flickable->property("maxHorizontalOvershoot").toReal());
+        QCOMPARE(flickable->property("maxContentY").toReal() - 200.0,
+                 flickable->property("maxVerticalOvershoot").toReal());
     }
-    QCOMPARE(flickable->property("minContentY").toReal(), 180.0);
     QCOMPARE(flickable->property("minContentX").toReal(), 180.0);
-    QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("minContentY").toReal(), 180.0);
     QCOMPARE(flickable->property("minHorizontalOvershoot").toReal(), 0.0);
+    QCOMPARE(flickable->property("minVerticalOvershoot").toReal(), 0.0);
 }
 
 void tst_qquickflickable::overshoot_data()
 {
     QTest::addColumn<QQuickFlickable::BoundsBehavior>("boundsBehavior");
-
-    QTest::newRow("StopAtBounds")
-            << QQuickFlickable::BoundsBehavior(QQuickFlickable::StopAtBounds);
-    QTest::newRow("DragOverBounds")
-            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragOverBounds);
-    QTest::newRow("OvershootBounds")
-            << QQuickFlickable::BoundsBehavior(QQuickFlickable::OvershootBounds);
-    QTest::newRow("DragAndOvershootBounds")
-            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragAndOvershootBounds);
+    QTest::addColumn<int>("boundsMovement");
+
+    QTest::newRow("StopAtBounds,FollowBoundsBehavior")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::StopAtBounds)
+            << int(QQuickFlickable::FollowBoundsBehavior);
+    QTest::newRow("DragOverBounds,FollowBoundsBehavior")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragOverBounds)
+            << int(QQuickFlickable::FollowBoundsBehavior);
+    QTest::newRow("OvershootBounds,FollowBoundsBehavior")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::OvershootBounds)
+            << int(QQuickFlickable::FollowBoundsBehavior);
+    QTest::newRow("DragAndOvershootBounds,FollowBoundsBehavior")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragAndOvershootBounds)
+            << int(QQuickFlickable::FollowBoundsBehavior);
+
+    QTest::newRow("DragOverBounds,StopAtBounds")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragOverBounds)
+            << int(QQuickFlickable::StopAtBounds);
+    QTest::newRow("OvershootBounds,StopAtBounds")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::OvershootBounds)
+            << int(QQuickFlickable::StopAtBounds);
+    QTest::newRow("DragAndOvershootBounds,StopAtBounds")
+            << QQuickFlickable::BoundsBehavior(QQuickFlickable::DragAndOvershootBounds)
+            << int(QQuickFlickable::StopAtBounds);
 }
 
 void tst_qquickflickable::overshoot_reentrant()
diff --git a/tests/auto/quick/qquickimage/tst_qquickimage.cpp b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
index 2681f1a966..36d99ad48d 100644
--- a/tests/auto/quick/qquickimage/tst_qquickimage.cpp
+++ b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
@@ -375,7 +375,7 @@ void tst_qquickimage::mirror()
         }
 
         QImage img = expected.toImage();
-        QCOMPARE(screenshots[fillMode], img);
+        QCOMPARE(screenshots[fillMode].convertToFormat(img.format()), img);
     }
 }
 
diff --git a/tests/auto/quick/qquickmultipointtoucharea/BLACKLIST b/tests/auto/quick/qquickmultipointtoucharea/BLACKLIST
index 1777af9e0c..cab6e2f7bf 100644
--- a/tests/auto/quick/qquickmultipointtoucharea/BLACKLIST
+++ b/tests/auto/quick/qquickmultipointtoucharea/BLACKLIST
@@ -1,2 +1,4 @@
-[inFlickable]
-*
+[nonOverlapping]
+ubuntu-16.04
+[nested]
+ubuntu-16.04
diff --git a/tests/auto/quick/qquickmultipointtoucharea/tst_qquickmultipointtoucharea.cpp b/tests/auto/quick/qquickmultipointtoucharea/tst_qquickmultipointtoucharea.cpp
index 2872556a94..87acd67f6a 100644
--- a/tests/auto/quick/qquickmultipointtoucharea/tst_qquickmultipointtoucharea.cpp
+++ b/tests/auto/quick/qquickmultipointtoucharea/tst_qquickmultipointtoucharea.cpp
@@ -800,7 +800,7 @@ void tst_QQuickMultiPointTouchArea::inFlickable2()
 
     QVERIFY(flickable->contentY() < 0);
     QVERIFY(flickable->isMoving());
-    QCOMPARE(point11->pressed(), true);
+    QCOMPARE(point11->pressed(), false);
 
     QTest::touchEvent(window.data(), device).release(0, p1);
     QQuickTouchUtils::flush(window.data());
diff --git a/tests/auto/quick/qquickpositioners/data/implicitGridOneItem.qml b/tests/auto/quick/qquickpositioners/data/implicitGridOneItem.qml
deleted file mode 100644
index 8da9fc270d..0000000000
--- a/tests/auto/quick/qquickpositioners/data/implicitGridOneItem.qml
+++ /dev/null
@@ -1,12 +0,0 @@
-import QtQuick 2.9
-import PositionerTest 1.0
-
-ImplicitGrid {
-    columns: 2
-    rows: 1
-
-    Text {
-        text: "Text"
-        width: parent.width
-    }
-}
diff --git a/tests/auto/quick/qquickpositioners/data/implicitRowOneItem.qml b/tests/auto/quick/qquickpositioners/data/implicitRowOneItem.qml
deleted file mode 100644
index 25a287cf31..0000000000
--- a/tests/auto/quick/qquickpositioners/data/implicitRowOneItem.qml
+++ /dev/null
@@ -1,9 +0,0 @@
-import QtQuick 2.9
-import PositionerTest 1.0
-
-ImplicitRow {
-   Text {
-       text: "Text"
-       width: parent.width
-   }
-}
diff --git a/tests/auto/quick/qquickpositioners/tst_qquickpositioners.cpp b/tests/auto/quick/qquickpositioners/tst_qquickpositioners.cpp
index 4c4afb7a7b..1b3939401a 100644
--- a/tests/auto/quick/qquickpositioners/tst_qquickpositioners.cpp
+++ b/tests/auto/quick/qquickpositioners/tst_qquickpositioners.cpp
@@ -98,8 +98,6 @@ private slots:
     void test_attachedproperties();
     void test_attachedproperties_data();
     void test_attachedproperties_dynamic();
-    void test_useImplicitSize_oneItem_data();
-    void test_useImplicitSize_oneItem();
 
     void populateTransitions_row();
     void populateTransitions_row_data();
@@ -306,8 +304,6 @@ void tst_qquickpositioners::moveTransitions_flow_data()
 
 tst_qquickpositioners::tst_qquickpositioners()
 {
-    qmlRegisterType<QQuickImplicitRow>("PositionerTest", 1, 0, "ImplicitRow");
-    qmlRegisterType<QQuickImplicitGrid>("PositionerTest", 1, 0, "ImplicitGrid");
 }
 
 void tst_qquickpositioners::test_horizontal()
@@ -4008,46 +4004,6 @@ void tst_qquickpositioners::test_attachedproperties_dynamic()
 
 }
 
-void tst_qquickpositioners::test_useImplicitSize_oneItem_data()
-{
-    QTest::addColumn<QString>("positionerType");
-
-    QTest::newRow("Grid") << "Grid";
-    QTest::newRow("Row") << "Row";
-}
-
-void tst_qquickpositioners::test_useImplicitSize_oneItem()
-{
-    QFETCH(QString, positionerType);
-
-    QQuickView view;
-    view.setSource(testFileUrl(QString::fromLatin1("implicit%1OneItem.qml").arg(positionerType)));
-    QCOMPARE(view.status(), QQuickView::Ready);
-    view.show();
-    QVERIFY(QTest::qWaitForWindowExposed(&view));
-
-    QQuickItem *positioner = view.rootObject();
-    QVERIFY(positioner);
-    const qreal oldPositionerImplicitWidth = positioner->implicitWidth();
-
-    QQuickText *text = qobject_cast<QQuickText*>(positioner->childItems().first());
-    QVERIFY(text);
-    const qreal oldTextImplicitWidth = text->implicitWidth();
-    QCOMPARE(positioner->implicitWidth(), text->implicitWidth());
-
-    // Ensure that the implicit size of the positioner changes when the implicit size
-    // of one of its children changes.
-    text->setText(QLatin1String("Even More Text"));
-    const qreal textImplicitWidthIncrease = text->implicitWidth() - oldTextImplicitWidth;
-    QVERIFY(textImplicitWidthIncrease > 0);
-    QTRY_COMPARE(positioner->implicitWidth(), oldPositionerImplicitWidth + textImplicitWidthIncrease);
-
-    // Ensure that the implicit size of the positioner does not change when the
-    // explicit size of one of its children changes.
-    text->setWidth(10);
-    QTRY_COMPARE(positioner->implicitWidth(), oldPositionerImplicitWidth + textImplicitWidthIncrease);
-}
-
 QQuickView *tst_qquickpositioners::createView(const QString &filename, bool wait)
 {
     QQuickView *window = new QQuickView(0);
diff --git a/tests/auto/quick/qquickwindow/BLACKLIST b/tests/auto/quick/qquickwindow/BLACKLIST
new file mode 100644
index 0000000000..157808fdbf
--- /dev/null
+++ b/tests/auto/quick/qquickwindow/BLACKLIST
@@ -0,0 +1,4 @@
+[requestActivate]
+osx-10.11
+[attachedProperty]
+osx-10.11
diff --git a/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp b/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
index 578f737c4d..4fea13eb49 100644
--- a/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
+++ b/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
@@ -28,6 +28,7 @@
 
 #include <qtest.h>
 #include <QDebug>
+#include <QMimeData>
 #include <QTouchEvent>
 #include <QtQuick/QQuickItem>
 #include <QtQuick/QQuickView>
@@ -385,6 +386,8 @@ private slots:
 
     void grabContentItemToImage();
 
+    void testDragEventPropertyPropagation();
+
 private:
     QTouchDevice *touchDevice;
     QTouchDevice *touchDeviceWithVelocity;
@@ -2617,6 +2620,261 @@ void tst_qquickwindow::grabContentItemToImage()
     QTRY_COMPARE(created->property("success").toInt(), 1);
 }
 
+class TestDropTarget : public QQuickItem
+{
+    Q_OBJECT
+public:
+    TestDropTarget(QQuickItem *parent = 0)
+        : QQuickItem(parent)
+        , enterDropAction(Qt::CopyAction)
+        , moveDropAction(Qt::CopyAction)
+        , dropDropAction(Qt::CopyAction)
+        , enterAccept(true)
+        , moveAccept(true)
+        , dropAccept(true)
+    {
+        setFlags(ItemAcceptsDrops);
+    }
+
+    void reset()
+    {
+        enterDropAction = Qt::CopyAction;
+        moveDropAction = Qt::CopyAction;
+        dropDropAction = Qt::CopyAction;
+        enterAccept = true;
+        moveAccept = true;
+        dropAccept = true;
+    }
+
+    void dragEnterEvent(QDragEnterEvent *event)
+    {
+        event->setAccepted(enterAccept);
+        event->setDropAction(enterDropAction);
+    }
+
+    void dragMoveEvent(QDragMoveEvent *event)
+    {
+        event->setAccepted(moveAccept);
+        event->setDropAction(moveDropAction);
+    }
+
+    void dropEvent(QDropEvent *event)
+    {
+        event->setAccepted(dropAccept);
+        event->setDropAction(dropDropAction);
+    }
+
+    Qt::DropAction enterDropAction;
+    Qt::DropAction moveDropAction;
+    Qt::DropAction dropDropAction;
+    bool enterAccept;
+    bool moveAccept;
+    bool dropAccept;
+};
+
+class DragEventTester {
+public:
+    DragEventTester()
+        : pos(60, 60)
+        , actions(Qt::CopyAction | Qt::MoveAction | Qt::LinkAction)
+        , buttons(Qt::LeftButton)
+        , modifiers(Qt::NoModifier)
+    {
+    }
+
+    ~DragEventTester() {
+        qDeleteAll(events);
+        events.clear();
+        enterEvent = 0;
+        moveEvent = 0;
+        dropEvent = 0;
+        leaveEvent = 0;
+    }
+
+    void addEnterEvent()
+    {
+        enterEvent = new QDragEnterEvent(pos, actions, &data, buttons, modifiers);
+        events.append(enterEvent);
+    }
+
+    void addMoveEvent()
+    {
+        moveEvent = new QDragMoveEvent(pos, actions, &data, buttons, modifiers, QEvent::DragMove);
+        events.append(moveEvent);
+    }
+
+    void addDropEvent()
+    {
+        dropEvent = new QDropEvent(pos, actions, &data, buttons, modifiers, QEvent::Drop);
+        events.append(dropEvent);
+    }
+
+    void addLeaveEvent()
+    {
+        leaveEvent = new QDragLeaveEvent();
+        events.append(leaveEvent);
+    }
+
+    void sendDragEventSequence(QQuickWindow *window) const {
+        for (int i = 0; i < events.size(); ++i) {
+            QCoreApplication::sendEvent(window, events[i]);
+        }
+    }
+
+    // Used for building events.
+    QMimeData data;
+    QPoint pos;
+    Qt::DropActions actions;
+    Qt::MouseButtons buttons;
+    Qt::KeyboardModifiers modifiers;
+
+    // Owns events.
+    QList<QEvent *> events;
+
+    // Non-owner pointers for easy acccess.
+    QDragEnterEvent *enterEvent;
+    QDragMoveEvent *moveEvent;
+    QDropEvent *dropEvent;
+    QDragLeaveEvent *leaveEvent;
+};
+
+void tst_qquickwindow::testDragEventPropertyPropagation()
+{
+    QQuickWindow window;
+    TestDropTarget dropTarget(window.contentItem());
+
+    // Setting the size is important because the QQuickWindow checks if the drag happened inside
+    // the drop target.
+    dropTarget.setSize(QSizeF(100, 100));
+
+    // Test enter events property propagation.
+    // For enter events, only isAccepted gets propagated.
+    {
+        DragEventTester builder;
+        dropTarget.enterAccept = false;
+        dropTarget.enterDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragEnterEvent* enterEvent = builder.enterEvent;
+        QCOMPARE(enterEvent->isAccepted(), dropTarget.enterAccept);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.enterAccept = false;
+        dropTarget.enterDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragEnterEvent* enterEvent = builder.enterEvent;
+        QCOMPARE(enterEvent->isAccepted(), dropTarget.enterAccept);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.enterAccept = true;
+        dropTarget.enterDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragEnterEvent* enterEvent = builder.enterEvent;
+        QCOMPARE(enterEvent->isAccepted(), dropTarget.enterAccept);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.enterAccept = true;
+        dropTarget.enterDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragEnterEvent* enterEvent = builder.enterEvent;
+        QCOMPARE(enterEvent->isAccepted(), dropTarget.enterAccept);
+    }
+
+    // Test move events property propagation.
+    // For move events, both isAccepted and dropAction get propagated.
+    dropTarget.reset();
+    {
+        DragEventTester builder;
+        dropTarget.moveAccept = false;
+        dropTarget.moveDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragMoveEvent* moveEvent = builder.moveEvent;
+        QCOMPARE(moveEvent->isAccepted(), dropTarget.moveAccept);
+        QCOMPARE(moveEvent->dropAction(), dropTarget.moveDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.moveAccept = false;
+        dropTarget.moveDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragMoveEvent* moveEvent = builder.moveEvent;
+        QCOMPARE(moveEvent->isAccepted(), dropTarget.moveAccept);
+        QCOMPARE(moveEvent->dropAction(), dropTarget.moveDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.moveAccept = true;
+        dropTarget.moveDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragMoveEvent* moveEvent = builder.moveEvent;
+        QCOMPARE(moveEvent->isAccepted(), dropTarget.moveAccept);
+        QCOMPARE(moveEvent->dropAction(), dropTarget.moveDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.moveAccept = true;
+        dropTarget.moveDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addLeaveEvent();
+        builder.sendDragEventSequence(&window);
+        QDragMoveEvent* moveEvent = builder.moveEvent;
+        QCOMPARE(moveEvent->isAccepted(), dropTarget.moveAccept);
+        QCOMPARE(moveEvent->dropAction(), dropTarget.moveDropAction);
+    }
+
+    // Test drop events property propagation.
+    // For drop events, both isAccepted and dropAction get propagated.
+    dropTarget.reset();
+    {
+        DragEventTester builder;
+        dropTarget.dropAccept = false;
+        dropTarget.dropDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addDropEvent();
+        builder.sendDragEventSequence(&window);
+        QDropEvent* dropEvent = builder.dropEvent;
+        QCOMPARE(dropEvent->isAccepted(), dropTarget.dropAccept);
+        QCOMPARE(dropEvent->dropAction(), dropTarget.dropDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.dropAccept = false;
+        dropTarget.dropDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addDropEvent();
+        builder.sendDragEventSequence(&window);
+        QDropEvent* dropEvent = builder.dropEvent;
+        QCOMPARE(dropEvent->isAccepted(), dropTarget.dropAccept);
+        QCOMPARE(dropEvent->dropAction(), dropTarget.dropDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.dropAccept = true;
+        dropTarget.dropDropAction = Qt::IgnoreAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addDropEvent();
+        builder.sendDragEventSequence(&window);
+        QDropEvent* dropEvent = builder.dropEvent;
+        QCOMPARE(dropEvent->isAccepted(), dropTarget.dropAccept);
+        QCOMPARE(dropEvent->dropAction(), dropTarget.dropDropAction);
+    }
+    {
+        DragEventTester builder;
+        dropTarget.dropAccept = true;
+        dropTarget.dropDropAction = Qt::CopyAction;
+        builder.addEnterEvent(); builder.addMoveEvent(); builder.addDropEvent();
+        builder.sendDragEventSequence(&window);
+        QDropEvent* dropEvent = builder.dropEvent;
+        QCOMPARE(dropEvent->isAccepted(), dropTarget.dropAccept);
+        QCOMPARE(dropEvent->dropAction(), dropTarget.dropDropAction);
+    }
+}
+
 QTEST_MAIN(tst_qquickwindow)
 
 #include "tst_qquickwindow.moc"
diff --git a/tests/auto/quick/touchmouse/tst_touchmouse.cpp b/tests/auto/quick/touchmouse/tst_touchmouse.cpp
index b02d60d0c5..6e7fce6189 100644
--- a/tests/auto/quick/touchmouse/tst_touchmouse.cpp
+++ b/tests/auto/quick/touchmouse/tst_touchmouse.cpp
@@ -71,7 +71,7 @@ Q_SIGNALS:
 
 public:
     EventItem(QQuickItem *parent = 0)
-        : QQuickItem(parent), acceptMouse(false), acceptTouch(false), filterTouch(false), point0(-1)
+        : QQuickItem(parent), touchUngrabCount(0), acceptMouse(false), acceptTouch(false), filterTouch(false), point0(-1)
     {
         setAcceptedMouseButtons(Qt::LeftButton);
     }
@@ -111,11 +111,17 @@ public:
         eventList.append(Event(QEvent::UngrabMouse, QPoint(0,0), QPoint(0,0)));
     }
 
+    void touchUngrabEvent()
+    {
+        ++touchUngrabCount;
+    }
+
     bool event(QEvent *event) {
         return QQuickItem::event(event);
     }
 
     QList<Event> eventList;
+    int touchUngrabCount;
     bool acceptMouse;
     bool acceptTouch;
     bool filterTouch; // when used as event filter
@@ -158,6 +164,7 @@ private slots:
     void mouseOverTouch();
 
     void buttonOnFlickable();
+    void touchButtonOnFlickable();
     void buttonOnDelayedPressFlickable_data();
     void buttonOnDelayedPressFlickable();
     void buttonOnTouch();
@@ -568,9 +575,10 @@ void tst_TouchMouse::buttonOnFlickable()
     QCOMPARE(pointerEvent->point(0)->exclusiveGrabber(), eventItem1);
     QCOMPARE(window->mouseGrabberItem(), eventItem1);
 
-    p1 += QPoint(0, -10);
-    QPoint p2 = p1 + QPoint(0, -10);
-    QPoint p3 = p2 + QPoint(0, -10);
+    int dragDelta = -qApp->styleHints()->startDragDistance();
+    p1 += QPoint(0, dragDelta);
+    QPoint p2 = p1 + QPoint(0, dragDelta);
+    QPoint p3 = p2 + QPoint(0, dragDelta);
     QQuickTouchUtils::flush(window.data());
     QTest::touchEvent(window.data(), device).move(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
@@ -593,6 +601,66 @@ void tst_TouchMouse::buttonOnFlickable()
     QQuickTouchUtils::flush(window.data());
 }
 
+void tst_TouchMouse::touchButtonOnFlickable()
+{
+    // flickable - height 500 / 1000
+    //   - eventItem1 y: 100, height 100
+    //   - eventItem2 y: 300, height 100
+
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("buttononflickable.qml"));
+    window->show();
+    QQuickViewTestUtil::centerOnScreen(window.data());
+    QVERIFY(QTest::qWaitForWindowActive(window.data()));
+    QVERIFY(window->rootObject() != 0);
+
+    QQuickFlickable *flickable = window->rootObject()->findChild<QQuickFlickable*>("flickable");
+    QVERIFY(flickable);
+
+    EventItem *eventItem2 = window->rootObject()->findChild<EventItem*>("eventItem2");
+    QVERIFY(eventItem2);
+    QCOMPARE(eventItem2->eventList.size(), 0);
+    eventItem2->acceptTouch = true;
+
+    // press via touch, then drag: check that flickable moves and that the button gets ungrabbed
+    QCOMPARE(eventItem2->eventList.size(), 0);
+    QPoint p1 = QPoint(10, 310);
+    QTest::touchEvent(window.data(), device).press(0, p1, window.data());
+    QQuickTouchUtils::flush(window.data());
+    QCOMPARE(eventItem2->eventList.size(), 1);
+    QCOMPARE(eventItem2->eventList.at(0).type, QEvent::TouchBegin);
+
+    QQuickWindowPrivate *windowPriv = QQuickWindowPrivate::get(window.data());
+    QVERIFY(windowPriv->touchMouseId == -1);
+    auto pointerEvent = QQuickPointerDevice::touchDevices().at(0)->pointerEvent();
+    QCOMPARE(pointerEvent->point(0)->grabberItem(), eventItem2);
+    QCOMPARE(window->mouseGrabberItem(), nullptr);
+
+    int dragDelta = qApp->styleHints()->startDragDistance() * -0.7;
+    p1 += QPoint(0, dragDelta);
+    QPoint p2 = p1 + QPoint(0, dragDelta);
+    QPoint p3 = p2 + QPoint(0, dragDelta);
+
+    QQuickTouchUtils::flush(window.data());
+    QTest::touchEvent(window.data(), device).move(0, p1, window.data());
+    QQuickTouchUtils::flush(window.data());
+    QTest::touchEvent(window.data(), device).move(0, p2, window.data());
+    QQuickTouchUtils::flush(window.data());
+    QTest::touchEvent(window.data(), device).move(0, p3, window.data());
+    QQuickTouchUtils::flush(window.data());
+
+    QVERIFY(eventItem2->eventList.size() > 2);
+    QCOMPARE(eventItem2->eventList.at(1).type, QEvent::TouchUpdate);
+    QCOMPARE(eventItem2->touchUngrabCount, 1);
+    QCOMPARE(window->mouseGrabberItem(), flickable);
+    QVERIFY(windowPriv->touchMouseId != -1);
+    QCOMPARE(pointerEvent->point(0)->grabberItem(), flickable);
+    QVERIFY(flickable->isMovingVertically());
+
+    QTest::touchEvent(window.data(), device).release(0, p3, window.data());
+    QQuickTouchUtils::flush(window.data());
+}
+
 void tst_TouchMouse::buttonOnDelayedPressFlickable_data()
 {
     QTest::addColumn<bool>("scrollBeforeDelayIsOver");
diff --git a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
index 5e8f762e23..bd051ec990 100644
--- a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
+++ b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
@@ -58,6 +58,7 @@ private slots:
     void grabBeforeShow();
     void reparentToNewWindow();
     void nullEngine();
+    void keyEvents();
 };
 
 
@@ -337,6 +338,33 @@ void tst_qquickwidget::nullEngine()
     QVERIFY(widget.engine());
 }
 
+class KeyHandlingWidget : public QQuickWidget
+{
+public:
+    void keyPressEvent(QKeyEvent *e) override {
+        if (e->key() == Qt::Key_A)
+            ok = true;
+    }
+
+    bool ok = false;
+};
+
+void tst_qquickwidget::keyEvents()
+{
+    // A QQuickWidget should behave like a normal widget when it comes to event handling.
+    // Verify that key events actually reach the widget. (QTBUG-45757)
+    KeyHandlingWidget widget;
+    widget.setSource(testFileUrl("rectangle.qml"));
+    widget.show();
+    QVERIFY(QTest::qWaitForWindowExposed(widget.window(), 5000));
+
+    // Note: send the event to the QWindow, not the QWidget, in order
+    // to simulate the full event processing chain.
+    QTest::keyClick(widget.window()->windowHandle(), Qt::Key_A);
+
+    QTRY_VERIFY(widget.ok);
+}
+
 QTEST_MAIN(tst_qquickwidget)
 
 #include "tst_qquickwidget.moc"
diff --git a/tests/auto/toolsupport/tst_toolsupport.cpp b/tests/auto/toolsupport/tst_toolsupport.cpp
index 9a11a67e65..6ee1db805a 100644
--- a/tests/auto/toolsupport/tst_toolsupport.cpp
+++ b/tests/auto/toolsupport/tst_toolsupport.cpp
@@ -101,7 +101,7 @@ void tst_toolsupport::offsets_data()
             = QTest::newRow("CompiledData::CompilationUnit::data")
             << pmm_to_offsetof(&QV4::CompiledData::CompilationUnit::data);
 
-        data << 8 << 16;
+        data << 12 << 24;
     }
 
     {
@@ -109,7 +109,7 @@ void tst_toolsupport::offsets_data()
             = QTest::newRow("CompiledData::CompilationUnit::runtimeStrings")
             << pmm_to_offsetof(&QV4::CompiledData::CompilationUnit::runtimeStrings);
 
-        data << 16 << 32;
+        data << 0 << 0;
     }
 
     {
diff --git a/tests/benchmarks/qml/holistic/testtypes.h b/tests/benchmarks/qml/holistic/testtypes.h
index 0736982373..a752a8585b 100644
--- a/tests/benchmarks/qml/holistic/testtypes.h
+++ b/tests/benchmarks/qml/holistic/testtypes.h
@@ -43,6 +43,7 @@
 #include <QtQml/qjsvalue.h>
 #include <QtQml/qqmlscriptstring.h>
 #include <QtQml/qqmlcomponent.h>
+#include <QtCore/qregexp.h>
 
 class MyQmlAttachedObject : public QObject
 {
diff --git a/tests/manual/scenegraph_lancelot/scenegrabber/main.cpp b/tests/manual/scenegraph_lancelot/scenegrabber/main.cpp
index 886cfc6599..6da0799bbc 100644
--- a/tests/manual/scenegraph_lancelot/scenegrabber/main.cpp
+++ b/tests/manual/scenegraph_lancelot/scenegrabber/main.cpp
@@ -29,6 +29,7 @@
 #include <QtCore/QTimer>
 #include <QtCore/QDebug>
 #include <QtCore/QFileInfo>
+#include <QtCore/QHashFunctions>
 #include <QtGui/QGuiApplication>
 #include <QtGui/QImage>
 
@@ -134,11 +135,9 @@ private:
 };
 
 
-Q_CORE_EXPORT extern QBasicAtomicInt qt_qhash_seed;
-
 int main(int argc, char *argv[])
 {
-    qt_qhash_seed = 0;
+    qSetGlobalQHashSeed(0);
 
     QGuiApplication a(argc, argv);
 
diff --git a/tests/manual/v4/test262 b/tests/manual/v4/test262
deleted file mode 160000
-Subproject 9741ac4655808ac46c127e3d1d8ba3d27ada618
diff --git a/tests/manual/v4/tests.pro b/tests/manual/v4/tests.pro
deleted file mode 100644
index ce4a34f7a0..0000000000
--- a/tests/manual/v4/tests.pro
+++ /dev/null
@@ -1,15 +0,0 @@
-TEMPLATE = aux
-
-TESTSCRIPT=$$PWD/test262.py
-isEmpty(V4CMD): V4CMD = qmljs
-
-checktarget.target = check
-checktarget.commands = python $$TESTSCRIPT --command=$$V4CMD --parallel --with-test-expectations --update-expectations
-checktarget.depends = all
-QMAKE_EXTRA_TARGETS += checktarget
-
-checkmothtarget.target = check-interpreter
-checkmothtarget.commands = python $$TESTSCRIPT --command=\"$$V4CMD --interpret\" --parallel --with-test-expectations
-checkmothtarget.depends = all
-QMAKE_EXTRA_TARGETS += checkmothtarget
-
diff --git a/tools/qml/main.cpp b/tools/qml/main.cpp
index 1699d3d81b..3b20fba5d4 100644
--- a/tools/qml/main.cpp
+++ b/tools/qml/main.cpp
@@ -55,7 +55,9 @@
 #include <QLibraryInfo>
 #include <qqml.h>
 #include <qqmldebug.h>
+#if QT_CONFIG(animation)
 #include <private/qabstractanimation_p.h>
+#endif
 
 #include <cstdio>
 #include <cstring>
@@ -476,10 +478,12 @@ int main(int argc, char *argv[])
             break;
         else if (arg == QLatin1String("-verbose"))
             verboseMode = true;
+#if QT_CONFIG(animation)
         else if (arg == QLatin1String("-slow-animations"))
             QUnifiedTimer::instance()->setSlowModeEnabled(true);
         else if (arg == QLatin1String("-fixed-animations"))
             QUnifiedTimer::instance()->setConsistentTiming(true);
+#endif
         else if (arg == QLatin1String("-I")) {
             if (i+1 == argList.count())
                 continue;//Invalid usage, but just ignore it
@@ -567,7 +571,7 @@ int main(int argc, char *argv[])
         loadDummyDataFiles(e, dummyDir);
 
     for (const QString &path : qAsConst(files)) {
-        QUrl url = QUrl::fromUserInput(path, QDir::currentPath());
+        QUrl url = QUrl::fromUserInput(path, QDir::currentPath(), QUrl::AssumeLocalFile);
         if (verboseMode)
             printf("qml: loading %s\n", qPrintable(url.toString()));
         QByteArray strippedFile;
diff --git a/tools/qmlcachegen/qmlcache.prf b/tools/qmlcachegen/qmlcache.prf
index fed9f0d2f3..4470db0d09 100644
--- a/tools/qmlcachegen/qmlcache.prf
+++ b/tools/qmlcachegen/qmlcache.prf
@@ -1,12 +1,55 @@
-qtPrepareTool(QML_CACHEGEN, qmlcachegen)
+static {
+    message("QML cache generation ahead of time is not supported in static builds")
+    return()
+}
+
+qtPrepareTool(QML_CACHEGEN, qmlcachegen, _ARCH_CHECK)
+
+isEmpty(TARGETPATH): error("Must set TARGETPATH (QML import name) for ahead-of-time QML cache generation")
 
 !isEmpty(QT_TARGET_ARCH):QML_CACHEGEN_ARCH=$$QT_TARGET_ARCH
 else:QML_CACHEGEN_ARCH=$$QT_ARCH
 
-qmlcachegen.input = QML_FILES
-qmlcachegen.output = ${QMAKE_FILE_IN}c
-qmlcachegen.commands = $$QML_CACHEGEN --target-architecture=$$QML_CACHEGEN_ARCH ${QMAKE_FILE_IN}
+!isEmpty(QT_TARGET_BUILDABI):QML_CACHEGEN_ABI=$$QT_TARGET_BUILDABI
+else:QML_CACHEGEN_ABI=$$QT_BUILDABI
+
+QML_CACHEGEN_ARGS=--target-architecture=$$QML_CACHEGEN_ARCH --target-abi=$$QML_CACHEGEN_ABI
+
+!system($$QML_CACHEGEN_ARCH_CHECK $$QML_CACHEGEN_ARGS --check-if-supported) {
+    message("QML cache generation requested but target architecture $$QML_CACHEGEN_ARCH is not supported.")
+    return()
+}
+
+load(qt_build_paths)
+
+prefix_build: QMLCACHE_DESTDIR = $$MODULE_BASE_OUTDIR/qml/$$TARGETPATH
+else: QMLCACHE_DESTDIR = $$[QT_INSTALL_QML]/$$TARGETPATH
+
+CACHEGEN_FILES=
+qmlcacheinst.files =
+for(qmlf, QML_FILES) {
+    contains(qmlf,.*\\.js$)|contains(qmlf,.*\\.qml$) {
+        CACHEGEN_FILES += $$absolute_path($$qmlf, $$_PRO_FILE_PWD_)
+        qmlcacheinst.files += $$QMLCACHE_DESTDIR/$$relative_path($$qmlf, $$_PRO_FILE_PWD_)c
+    }
+}
+
+defineReplace(qmlCacheOutputFileName) {
+    return($$relative_path($$QMLCACHE_DESTDIR/$$relative_path($$1, $$_PRO_FILE_PWD_)c, $$OUT_PWD))
+}
+
+qmlcacheinst.base = $$QMLCACHE_DESTDIR
+qmlcacheinst.path = $$[QT_INSTALL_QML]/$$TARGETPATH
+qmlcacheinst.CONFIG = no_check_exist
+
+qmlcachegen.input = CACHEGEN_FILES
+qmlcachegen.output = ${QMAKE_FUNC_FILE_IN_qmlCacheOutputFileName}
+qmlcachegen.CONFIG = no_link target_predeps
+qmlcachegen.commands = $$QML_CACHEGEN $$QML_CACHEGEN_ARGS -o ${QMAKE_FILE_OUT} ${QMAKE_FILE_IN}
 qmlcachegen.name = Generate QML Cache ${QMAKE_FILE_IN}
-qmlcachegen.variable_out = AUX_QML_FILES
+qmlcachegen.variable_out = GENERATED_FILES
 
-QMAKE_EXTRA_COMPILERS += qmlcachegen
+!debug_and_release|!build_all|CONFIG(release, debug|release) {
+    QMAKE_EXTRA_COMPILERS += qmlcachegen
+    INSTALLS += qmlcacheinst
+}
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index 977c5b6ff1..b201176d5e 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -32,13 +32,14 @@
 #include <QFile>
 #include <QFileInfo>
 #include <QDateTime>
+#include <QHashFunctions>
 
 #include <private/qqmlirbuilder_p.h>
 #include <private/qv4isel_moth_p.h>
 #include <private/qqmljsparser_p.h>
+#include <private/qv4jssimplifier_p.h>
 
 QT_BEGIN_NAMESPACE
-extern Q_CORE_EXPORT QBasicAtomicInt qt_qhash_seed;
 
 namespace QV4 { namespace JIT {
 Q_QML_EXPORT QV4::EvalISelFactory *createISelForArchitecture(const QString &architecture);
@@ -80,9 +81,43 @@ QString diagnosticErrorMessage(const QString &fileName, const QQmlJS::Diagnostic
     return message;
 }
 
-static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *iselFactory, Error *error)
+// Ensure that ListElement objects keep all property assignments in their string form
+static void annotateListElements(QmlIR::Document *document)
+{
+    QStringList listElementNames;
+
+    foreach (const QV4::CompiledData::Import *import, document->imports) {
+        const QString uri = document->stringAt(import->uriIndex);
+        if (uri != QStringLiteral("QtQml.Models") && uri != QStringLiteral("QtQuick"))
+            continue;
+
+         QString listElementName = QStringLiteral("ListElement");
+         const QString qualifier = document->stringAt(import->qualifierIndex);
+         if (!qualifier.isEmpty()) {
+             listElementName.prepend(QLatin1Char('.'));
+             listElementName.prepend(qualifier);
+         }
+         listElementNames.append(listElementName);
+    }
+
+    if (listElementNames.isEmpty())
+        return;
+
+    foreach (QmlIR::Object *object, document->objects) {
+        if (!listElementNames.contains(document->stringAt(object->inheritedTypeNameIndex)))
+            continue;
+        for (QmlIR::Binding *binding = object->firstBinding(); binding; binding = binding->next) {
+            if (binding->type != QV4::CompiledData::Binding::Type_Script)
+                continue;
+            binding->stringIndex = document->registerString(object->bindingAsString(document, binding->value.compiledScriptIndex));
+        }
+    }
+}
+
+static bool compileQmlFile(const QString &inputFileName, const QString &outputFileName, QV4::EvalISelFactory *iselFactory, const QString &targetABI, Error *error)
 {
     QmlIR::Document irDocument(/*debugMode*/false);
+    irDocument.jsModule.targetABI = targetABI;
 
     QString sourceCode;
     {
@@ -96,7 +131,6 @@ static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *i
             error->message = QLatin1String("Error reading from ") + inputFileName + QLatin1Char(':') + f.errorString();
             return false;
         }
-        irDocument.jsModule.sourceTimeStamp = QFileInfo(f).lastModified().toMSecsSinceEpoch();
     }
 
     {
@@ -112,8 +146,10 @@ static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *i
         }
     }
 
+    annotateListElements(&irDocument);
+
     {
-        QmlIR::JSCodeGen v4CodeGen(inputFileName, irDocument.code, &irDocument.jsModule, &irDocument.jsParserEngine, irDocument.program, /*import cache*/0, &irDocument.jsGenerator.stringTable);
+        QmlIR::JSCodeGen v4CodeGen(/*empty input file name*/QString(), irDocument.code, &irDocument.jsModule, &irDocument.jsParserEngine, irDocument.program, /*import cache*/0, &irDocument.jsGenerator.stringTable);
         for (QmlIR::Object *object: qAsConst(irDocument.objects)) {
             if (object->functionsAndExpressions->count == 0)
                 continue;
@@ -139,21 +175,22 @@ static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *i
 
         QmlIR::QmlUnitGenerator generator;
 
-        // ### translation binding simplification
+        {
+            QQmlJavaScriptBindingExpressionSimplificationPass pass(irDocument.objects, &irDocument.jsModule, &irDocument.jsGenerator);
+            pass.reduceTranslationBindings();
+        }
 
         QV4::ExecutableAllocator allocator;
         QScopedPointer<QV4::EvalInstructionSelection> isel(iselFactory->create(/*engine*/nullptr, &allocator, &irDocument.jsModule, &irDocument.jsGenerator));
         // Disable lookups in non-standalone (aka QML) mode
         isel->setUseFastLookups(false);
         irDocument.javaScriptCompilationUnit = isel->compile(/*generate unit*/false);
-        // ###
-        QV4::CompiledData::ResolvedTypeReferenceMap dummyDependencies;
-        QV4::CompiledData::Unit *unit = generator.generate(irDocument, /*engine*/nullptr, dummyDependencies);
+        QV4::CompiledData::Unit *unit = generator.generate(irDocument);
         unit->flags |= QV4::CompiledData::Unit::StaticData;
         unit->flags |= QV4::CompiledData::Unit::PendingTypeCompilation;
         irDocument.javaScriptCompilationUnit->data = unit;
 
-        if (!irDocument.javaScriptCompilationUnit->saveToDisk(inputFileName, &error->message))
+        if (!irDocument.javaScriptCompilationUnit->saveToDisk(outputFileName, &error->message))
             return false;
 
         free(unit);
@@ -161,9 +198,10 @@ static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *i
     return true;
 }
 
-static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *iselFactory, Error *error)
+static bool compileJSFile(const QString &inputFileName, const QString &outputFileName, QV4::EvalISelFactory *iselFactory, const QString &targetABI, Error *error)
 {
     QmlIR::Document irDocument(/*debugMode*/false);
+    irDocument.jsModule.targetABI = targetABI;
 
     QString sourceCode;
     {
@@ -177,7 +215,6 @@ static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *is
             error->message = QLatin1String("Error reading from ") + inputFileName + QLatin1Char(':') + f.errorString();
             return false;
         }
-        irDocument.jsModule.sourceTimeStamp = QFileInfo(f).lastModified().toMSecsSinceEpoch();
     }
 
     QQmlJS::Engine *engine = &irDocument.jsParserEngine;
@@ -217,7 +254,7 @@ static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *is
 
     {
         QmlIR::JSCodeGen v4CodeGen(inputFileName, irDocument.code, &irDocument.jsModule, &irDocument.jsParserEngine, irDocument.program, /*import cache*/0, &irDocument.jsGenerator.stringTable);
-        v4CodeGen.generateFromProgram(inputFileName, sourceCode, program, &irDocument.jsModule, QQmlJS::Codegen::GlobalCode);
+        v4CodeGen.generateFromProgram(/*empty input file name*/QString(), sourceCode, program, &irDocument.jsModule, QQmlJS::Codegen::GlobalCode);
         QList<QQmlJS::DiagnosticMessage> jsErrors = v4CodeGen.errors();
         if (!jsErrors.isEmpty()) {
             for (const QQmlJS::DiagnosticMessage &e: qAsConst(jsErrors)) {
@@ -231,19 +268,16 @@ static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *is
 
         QmlIR::QmlUnitGenerator generator;
 
-        // ### translation binding simplification
-
-        QScopedPointer<QV4::EvalInstructionSelection> isel(iselFactory->create(/*engine*/nullptr, /*executable allocator*/nullptr, &irDocument.jsModule, &irDocument.jsGenerator));
+        QV4::ExecutableAllocator allocator;
+        QScopedPointer<QV4::EvalInstructionSelection> isel(iselFactory->create(/*engine*/nullptr, &allocator, &irDocument.jsModule, &irDocument.jsGenerator));
         // Disable lookups in non-standalone (aka QML) mode
         isel->setUseFastLookups(false);
         irDocument.javaScriptCompilationUnit = isel->compile(/*generate unit*/false);
-        // ###
-        QV4::CompiledData::ResolvedTypeReferenceMap dummyDependencies;
-        QV4::CompiledData::Unit *unit = generator.generate(irDocument, /*engine*/nullptr, dummyDependencies);
+        QV4::CompiledData::Unit *unit = generator.generate(irDocument);
         unit->flags |= QV4::CompiledData::Unit::StaticData;
         irDocument.javaScriptCompilationUnit->data = unit;
 
-        if (!irDocument.javaScriptCompilationUnit->saveToDisk(inputFileName, &error->message)) {
+        if (!irDocument.javaScriptCompilationUnit->saveToDisk(outputFileName, &error->message)) {
             engine->setDirectives(oldDirs);
             return false;
         }
@@ -257,7 +291,7 @@ static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *is
 int main(int argc, char **argv)
 {
     // Produce reliably the same output for the same input by disabling QHash's random seeding.
-    qt_qhash_seed.testAndSetRelaxed(-1, 0);
+    qSetGlobalQHashSeed(0);
 
     QCoreApplication app(argc, argv);
     QCoreApplication::setApplicationName(QStringLiteral("qmlcachegen"));
@@ -270,37 +304,65 @@ int main(int argc, char **argv)
     QCommandLineOption targetArchitectureOption(QStringLiteral("target-architecture"), QCoreApplication::translate("main", "Target architecture"), QCoreApplication::translate("main", "architecture"));
     parser.addOption(targetArchitectureOption);
 
+    QCommandLineOption targetABIOption(QStringLiteral("target-abi"), QCoreApplication::translate("main", "Target architecture binary interface"), QCoreApplication::translate("main", "abi"));
+    parser.addOption(targetABIOption);
+
+    QCommandLineOption outputFileOption(QStringLiteral("o"), QCoreApplication::translate("main", "Output file name"), QCoreApplication::translate("main", "file name"));
+    parser.addOption(outputFileOption);
+
+    QCommandLineOption checkIfSupportedOption(QStringLiteral("check-if-supported"), QCoreApplication::translate("main", "Check if cache generate is supported on the specified target architecture"));
+    parser.addOption(checkIfSupportedOption);
+
     parser.addPositionalArgument(QStringLiteral("[qml file]"),
             QStringLiteral("QML source file to generate cache for."));
 
     parser.process(app);
 
-    const QStringList sources = parser.positionalArguments();
-    if (sources.isEmpty()){
+    if (!parser.isSet(targetArchitectureOption)) {
+        fprintf(stderr, "Target architecture not specified. Please specify with --target-architecture=<arch>\n");
         parser.showHelp();
-    } else if (sources.count() > 1) {
-        fprintf(stderr, "%s\n", qPrintable(QStringLiteral("Too many input files specified: '") + sources.join(QStringLiteral("' '")) + QLatin1Char('\'')));
         return EXIT_FAILURE;
     }
-    const QString inputFile = sources.first();
 
     QScopedPointer<QV4::EvalISelFactory> isel;
     const QString targetArchitecture = parser.value(targetArchitectureOption);
 
     isel.reset(QV4::JIT::createISelForArchitecture(targetArchitecture));
 
+    if (parser.isSet(checkIfSupportedOption)) {
+        if (isel.isNull())
+            return EXIT_FAILURE;
+        else
+            return EXIT_SUCCESS;
+    }
+
+    const QStringList sources = parser.positionalArguments();
+    if (sources.isEmpty()){
+        parser.showHelp();
+    } else if (sources.count() > 1) {
+        fprintf(stderr, "%s\n", qPrintable(QStringLiteral("Too many input files specified: '") + sources.join(QStringLiteral("' '")) + QLatin1Char('\'')));
+        return EXIT_FAILURE;
+    }
+    const QString inputFile = sources.first();
+
     if (!isel)
         isel.reset(new QV4::Moth::ISelFactory);
 
     Error error;
 
+    QString outputFileName = inputFile + QLatin1Char('c');
+    if (parser.isSet(outputFileOption))
+        outputFileName = parser.value(outputFileOption);
+
+    const QString targetABI = parser.value(targetABIOption);
+
     if (inputFile.endsWith(QLatin1String(".qml"))) {
-        if (!compileQmlFile(inputFile, isel.data(), &error)) {
+        if (!compileQmlFile(inputFile, outputFileName, isel.data(), targetABI, &error)) {
             error.augment(QLatin1String("Error compiling qml file: ")).print();
             return EXIT_FAILURE;
         }
     } else if (inputFile.endsWith(QLatin1String(".js"))) {
-        if (!compileJSFile(inputFile, isel.data(), &error)) {
+        if (!compileJSFile(inputFile, outputFileName, isel.data(), targetABI, &error)) {
             error.augment(QLatin1String("Error compiling qml file: ")).print();
             return EXIT_FAILURE;
         }
diff --git a/tools/qmlcachegen/qmlcachegen.pro b/tools/qmlcachegen/qmlcachegen.pro
index 81783d0396..25afc2860d 100644
--- a/tools/qmlcachegen/qmlcachegen.pro
+++ b/tools/qmlcachegen/qmlcachegen.pro
@@ -6,19 +6,9 @@ DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
 SOURCES = qmlcachegen.cpp
 TARGET = qmlcachegen
 
-BUILD_INTEGRATION = qmlcache.prf
-!force_independent {
-    qmake_integration.input = BUILD_INTEGRATION
-    qmake_integration.output = $$[QT_HOST_DATA]/mkspecs/features/${QMAKE_FILE_BASE}.prf
-    qmake_integration.commands = $$QMAKE_COPY ${QMAKE_FILE_IN} ${QMAKE_FILE_OUT}
-    qmake_integration.name = COPY ${QMAKE_FILE_IN} ${QMAKE_FILE_OUT}
-    qmake_integration.CONFIG = no_clean no_link
-    !contains(TEMPLATE, vc.*): qmake_integration.variable_out = GENERATED_FILES
-    QMAKE_EXTRA_COMPILERS += qmake_integration
-}
-
-qmake_integration_installs.files = $$BUILD_INTEGRATION
-qmake_integration_installs.path = $$[QT_HOST_DATA]/mkspecs/features
-INSTALLS += qmake_integration_installs
+build_integration.files = qmlcache.prf
+build_integration.path = $$[QT_HOST_DATA]/mkspecs/features
+prefix_build: INSTALLS += build_integration
+else: COPIES += build_integration
 
 load(qt_tool)
diff --git a/tools/qmljs/qmljs.cpp b/tools/qmljs/qmljs.cpp
index 081e0660d5..182547490d 100644
--- a/tools/qmljs/qmljs.cpp
+++ b/tools/qmljs/qmljs.cpp
@@ -157,7 +157,7 @@ int main(int argc, char *argv[])
                 if (cache && QFile::exists(fn + QLatin1Char('c'))) {
                     QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = iSelFactory->createUnitForLoading();
                     QString error;
-                    if (unit->loadFromDisk(QUrl::fromLocalFile(fn), iSelFactory, &error)) {
+                    if (unit->loadFromDisk(QUrl::fromLocalFile(fn), QFileInfo(fn).lastModified(), iSelFactory, &error)) {
                         script.reset(new QV4::Script(&vm, nullptr, unit));
                     } else {
                         std::cout << "Error loading" << qPrintable(fn) << "from disk cache:" << qPrintable(error) << std::endl;
diff --git a/tools/qmlprofiler/qmlprofilerdata.cpp b/tools/qmlprofiler/qmlprofilerdata.cpp
index 668cb3ce2d..bcda0bb7fe 100644
--- a/tools/qmlprofiler/qmlprofilerdata.cpp
+++ b/tools/qmlprofiler/qmlprofilerdata.cpp
@@ -33,6 +33,7 @@
 #include <QHash>
 #include <QFile>
 #include <QXmlStreamReader>
+#include <QRegularExpression>
 
 #include <limits>
 
@@ -231,10 +232,10 @@ void QmlProfilerData::addQmlEvent(QQmlProfilerDefinitions::RangeType type,
     if (!data.isEmpty()) {
         details = data.join(QLatin1Char(' ')).replace(
                     QLatin1Char('\n'), QLatin1Char(' ')).simplified();
-        QRegExp rewrite(QStringLiteral("\\(function \\$(\\w+)\\(\\) \\{ (return |)(.+) \\}\\)"));
-        bool match = rewrite.exactMatch(details);
-        if (match) {
-            details = rewrite.cap(1) +QLatin1String(": ") + rewrite.cap(3);
+        QRegularExpression rewrite(QStringLiteral("^\\(function \\$(\\w+)\\(\\) \\{ (return |)(.+) \\}\\)$"));
+        QRegularExpressionMatch match = rewrite.match(details);
+        if (match.hasMatch()) {
+            details = match.captured(1) +QLatin1String(": ") + match.captured(3);
         }
         if (details.startsWith(QLatin1String("file://")))
             details = details.mid(details.lastIndexOf(QLatin1Char('/')) + 1);
diff --git a/tools/qmlscene/main.cpp b/tools/qmlscene/main.cpp
index 1e8d91a95b..6ce676456c 100644
--- a/tools/qmlscene/main.cpp
+++ b/tools/qmlscene/main.cpp
@@ -33,6 +33,7 @@
 #include <QtCore/qpointer.h>
 #include <QtCore/qscopedpointer.h>
 #include <QtCore/qtextstream.h>
+#include <QtCore/qregularexpression.h>
 
 #include <QtGui/QGuiApplication>
 #include <QtGui/QOpenGLFunctions>
@@ -132,6 +133,17 @@ void RenderStatistics::printTotalStats()
 
 struct Options
 {
+    enum QmlApplicationType
+    {
+        QmlApplicationTypeGui,
+        QmlApplicationTypeWidget,
+#ifdef QT_WIDGETS_LIB
+        DefaultQmlApplicationType = QmlApplicationTypeWidget
+#else
+        DefaultQmlApplicationType = QmlApplicationTypeGui
+#endif
+    };
+
     Options()
         : originalQml(false)
         , originalQmlRaster(false)
@@ -145,6 +157,7 @@ struct Options
         , resizeViewToRootItem(false)
         , multisample(false)
         , verbose(false)
+        , applicationType(DefaultQmlApplicationType)
     {
         // QtWebEngine needs a shared context in order for the GPU thread to
         // upload textures.
@@ -166,6 +179,7 @@ struct Options
     bool verbose;
     QVector<Qt::ApplicationAttribute> applicationAttributes;
     QString translationFile;
+    QmlApplicationType applicationType;
 };
 
 #if defined(QMLSCENE_BUNDLE)
@@ -258,8 +272,8 @@ static bool checkVersion(const QUrl &url)
         return false;
     }
 
-    QRegExp quick1("^\\s*import +QtQuick +1\\.\\w*");
-    QRegExp qt47("^\\s*import +Qt +4\\.7");
+    QRegularExpression quick1("^\\s*import +QtQuick +1\\.\\w*");
+    QRegularExpression qt47("^\\s*import +Qt +4\\.7");
 
     QTextStream stream(&f);
     bool codeFound= false;
@@ -269,10 +283,11 @@ static bool checkVersion(const QUrl &url)
             codeFound = true;
         } else {
             QString import;
-            if (quick1.indexIn(line) >= 0)
-                import = quick1.cap(0).trimmed();
-            else if (qt47.indexIn(line) >= 0)
-                import = qt47.cap(0).trimmed();
+            QRegularExpressionMatch match = quick1.match(line);
+            if (match.hasMatch())
+                import = match.captured(0).trimmed();
+            else if ((match = qt47.match(line)).hasMatch())
+                import = match.captured(0).trimmed();
 
             if (!import.isNull()) {
                 fprintf(stderr, "qmlscene: '%s' is no longer supported.\n"
@@ -290,15 +305,17 @@ static bool checkVersion(const QUrl &url)
 static void displayFileDialog(Options *options)
 {
 #if defined(QT_WIDGETS_LIB) && QT_CONFIG(filedialog)
-    QString fileName = QFileDialog::getOpenFileName(0, "Open QML file", QString(), "QML Files (*.qml)");
-    if (!fileName.isEmpty()) {
-        QFileInfo fi(fileName);
-        options->url = QUrl::fromLocalFile(fi.canonicalFilePath());
+    if (options->applicationType == Options::QmlApplicationTypeWidget) {
+        QString fileName = QFileDialog::getOpenFileName(0, "Open QML file", QString(), "QML Files (*.qml)");
+        if (!fileName.isEmpty()) {
+            QFileInfo fi(fileName);
+            options->url = QUrl::fromLocalFile(fi.canonicalFilePath());
+        }
+        return;
     }
-#else
+#endif // QT_WIDGETS_LIB && QT_CONFIG(filedialog)
     Q_UNUSED(options);
     puts("No filename specified...");
-#endif
 }
 
 #if QT_CONFIG(translation)
@@ -354,6 +371,9 @@ static void usage()
     puts("  --scaling..........................Enable High DPI scaling (AA_EnableHighDpiScaling)");
     puts("  --no-scaling.......................Disable High DPI scaling (AA_DisableHighDpiScaling)");
     puts("  --verbose..........................Print version and graphical diagnostics for the run-time");
+#ifdef QT_WIDGETS_LIB
+    puts("  --apptype [gui|widgets] ...........Select which application class to use. Default is widgets.");
+#endif
     puts("  -I <path> ........................ Add <path> to the list of import paths");
     puts("  -P <path> ........................ Add <path> to the list of plugin paths");
     puts("  -translation <translationfile> ... Set the language to run in");
@@ -443,30 +463,38 @@ int main(int argc, char ** argv)
     // Parse arguments for application attributes to be applied before Q[Gui]Application creation.
     for (int i = 1; i < argc; ++i) {
         const char *arg = argv[i];
-        if (!qstrcmp(arg, "--disable-context-sharing"))
+        if (!qstrcmp(arg, "--disable-context-sharing")) {
             options.applicationAttributes.removeAll(Qt::AA_ShareOpenGLContexts);
-        else if (!qstrcmp(arg, "--gles"))
+        } else if (!qstrcmp(arg, "--gles")) {
             options.applicationAttributes.append(Qt::AA_UseOpenGLES);
-        else if (!qstrcmp(arg, "--software"))
+        } else if (!qstrcmp(arg, "--software")) {
             options.applicationAttributes.append(Qt::AA_UseSoftwareOpenGL);
-        else if (!qstrcmp(arg, "--desktop"))
+        } else if (!qstrcmp(arg, "--desktop")) {
             options.applicationAttributes.append(Qt::AA_UseDesktopOpenGL);
-        else if (!qstrcmp(arg, "--scaling"))
+        } else if (!qstrcmp(arg, "--scaling")) {
             options.applicationAttributes.append(Qt::AA_EnableHighDpiScaling);
-        else if (!qstrcmp(arg, "--no-scaling"))
+        } else if (!qstrcmp(arg, "--no-scaling")) {
             options.applicationAttributes.append(Qt::AA_DisableHighDpiScaling);
+        } else if (!qstrcmp(arg, "--apptype")) {
+            if (++i >= argc)
+                usage();
+            if (!qstrcmp(argv[i], "gui"))
+                options.applicationType = Options::QmlApplicationTypeGui;
+        }
     }
 
     for (Qt::ApplicationAttribute a : qAsConst(options.applicationAttributes))
         QCoreApplication::setAttribute(a);
+    QScopedPointer<QGuiApplication> app;
 #ifdef QT_WIDGETS_LIB
-    QApplication app(argc, argv);
-#else
-    QGuiApplication app(argc, argv);
+    if (options.applicationType == Options::QmlApplicationTypeWidget)
+        app.reset(new QApplication(argc, argv));
 #endif
-    app.setApplicationName("QtQmlViewer");
-    app.setOrganizationName("QtProject");
-    app.setOrganizationDomain("qt-project.org");
+    if (app.isNull())
+        app.reset(new QGuiApplication(argc, argv));
+    QCoreApplication::setApplicationName(QStringLiteral("QtQmlViewer"));
+    QCoreApplication::setOrganizationName(QStringLiteral("QtProject"));
+    QCoreApplication::setOrganizationDomain(QStringLiteral("qt-project.org"));
     QCoreApplication::setApplicationVersion(QLatin1String(QT_VERSION_STR));
 
     const QStringList arguments = QCoreApplication::arguments();
@@ -501,6 +529,8 @@ int main(int argc, char ** argv)
                 imports.append(arguments.at(++i));
             else if (lowerArgument == QLatin1String("-p") && i + 1 < size)
                 pluginPaths.append(arguments.at(++i));
+            else if (lowerArgument == QLatin1String("--apptype"))
+                ++i; // Consume previously parsed argument
             else if (lowerArgument == QLatin1String("--help")
                      || lowerArgument == QLatin1String("-help")
                      || lowerArgument == QLatin1String("--h")
@@ -514,14 +544,14 @@ int main(int argc, char ** argv)
     QTranslator qtTranslator;
     QString sysLocale = QLocale::system().name();
     if (qtTranslator.load(QLatin1String("qt_") + sysLocale, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
-        app.installTranslator(&qtTranslator);
+        app->installTranslator(&qtTranslator);
     if (translator.load(QLatin1String("qmlscene_") + sysLocale, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
-        app.installTranslator(&translator);
+        app->installTranslator(&translator);
 
     QTranslator qmlTranslator;
     if (!options.translationFile.isEmpty()) {
         if (qmlTranslator.load(options.translationFile)) {
-            app.installTranslator(&qmlTranslator);
+            app->installTranslator(&qmlTranslator);
         } else {
             fprintf(stderr, "Could not load the translation file \"%s\"\n",
                     qPrintable(options.translationFile));
@@ -629,7 +659,7 @@ int main(int argc, char ** argv)
 
             // Now would be a good time to inform the debug service to start listening.
 
-            exitCode = app.exec();
+            exitCode = app->exec();
 
 #ifdef QML_RUNTIME_TESTING
             RenderStatistics::printTotalStats();
diff --git a/tools/tools.pro b/tools/tools.pro
index bf39a649df..20a3600fb8 100644
--- a/tools/tools.pro
+++ b/tools/tools.pro
@@ -2,15 +2,16 @@ TEMPLATE = subdirs
 QT_FOR_CONFIG += qml-private
 SUBDIRS += \
     qmlmin \
-    qmlimportscanner \
-    qmlcachegen
+    qmlimportscanner
+
+qtConfig(commandlineparser): SUBDIRS += qmlcachegen
 
 !android|android_app {
     SUBDIRS += \
         qml \
         qmllint
 
-    qtConfig(qml-network):!contains(QT_CONFIG, no-qml-debug): SUBDIRS += qmlprofiler
+    qtConfig(qml-profiler): SUBDIRS += qmlprofiler
 
     qtHaveModule(quick) {
         !static: {
@@ -18,7 +19,7 @@ SUBDIRS += \
                 qmlscene \
                 qmltime
 
-            qtConfig(regularexpression) {
+            qtConfig(regularexpression):qtConfig(process) {
                 SUBDIRS += \
                     qmlplugindump
             }