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

Change-Id: I734539161beb99d37b9d297c536ae154c888b736

100 files changed, 4904 insertions, 1919 deletions

diff --git a/.qmake.conf b/.qmake.conf
index f03d05c7ac..4e4a28b8f9 100644
--- a/.qmake.conf
+++ b/.qmake.conf
@@ -1,4 +1,4 @@
 load(qt_build_config)
 CONFIG += warning_clean
 
-MODULE_VERSION = 5.9.0
+MODULE_VERSION = 5.10.0
diff --git a/examples/quick/demos/stocqt/doc/src/stocqt.qdoc b/examples/quick/demos/stocqt/doc/src/stocqt.qdoc
index bd204c8211..800bba570c 100644
--- a/examples/quick/demos/stocqt/doc/src/stocqt.qdoc
+++ b/examples/quick/demos/stocqt/doc/src/stocqt.qdoc
@@ -69,7 +69,7 @@
 
     \quotefromfile demos/stocqt/content/StockChart.qml
     \skipto Rectangle
-    \printuntil height
+    \printuntil id
     \dots
     \skipto Canvas
     \printuntil id
diff --git a/examples/quick/window/CurrentScreen.qml b/examples/quick/window/CurrentScreen.qml
index c65baab1f4..09fbce9a74 100644
--- a/examples/quick/window/CurrentScreen.qml
+++ b/examples/quick/window/CurrentScreen.qml
@@ -101,5 +101,12 @@ Item {
         Shared.Label { text: "primary orientation" }
         Shared.Label { text: orientationToString(Screen.primaryOrientation) + " (" + Screen.primaryOrientation + ")" }
         //! [screen]
+
+        Shared.Label { text: "10mm rectangle" }
+        Rectangle {
+            color: "red"
+            width: Screen.pixelDensity * 10
+            height: width
+        }
     }
 }
diff --git a/src/3rdparty/masm/assembler/ARMv7Assembler.h b/src/3rdparty/masm/assembler/ARMv7Assembler.h
index f0fa07a1bf..6b32fbf487 100644
--- a/src/3rdparty/masm/assembler/ARMv7Assembler.h
+++ b/src/3rdparty/masm/assembler/ARMv7Assembler.h
@@ -27,10 +27,11 @@
 #ifndef ARMAssembler_h
 #define ARMAssembler_h
 
-#if ENABLE(ASSEMBLER) && CPU(ARM_THUMB2)
+#if ENABLE(ASSEMBLER) && (CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP))
 
 #include "AssemblerBuffer.h"
 #include "MacroAssemblerCodeRef.h"
+#include "AbstractMacroAssembler.h"
 #include <wtf/Assertions.h>
 #include <wtf/Vector.h>
 #include <stdint.h>
@@ -491,8 +492,8 @@ public:
     private:
         union {
             struct RealTypes {
-                intptr_t m_from : 31;
-                intptr_t m_to : 31;
+                int32_t m_from : 31;
+                int32_t m_to : 31;
                 JumpType m_type : 8;
                 JumpLinkType m_linkType : 8;
                 Condition m_condition : 16;
@@ -510,6 +511,56 @@ public:
     {
     }
 
+
+    // Jump:
+    //
+    // A jump object is a reference to a jump instruction that has been planted
+    // into the code buffer - it is typically used to link the jump, setting the
+    // relative offset such that when executed it will jump to the desired
+    // destination.
+    template <typename LabelType>
+    class Jump {
+        template<class TemplateAssemblerType> friend class AbstractMacroAssembler;
+        friend class Call;
+        template <typename, template <typename> class> friend class LinkBufferBase;;
+    public:
+        Jump()
+        {
+        }
+
+        // Fixme: this information should be stored in the instruction stream, not in the Jump object.
+        Jump(AssemblerLabel jmp, ARMv7Assembler::JumpType type = ARMv7Assembler::JumpNoCondition, ARMv7Assembler::Condition condition = ARMv7Assembler::ConditionInvalid)
+            : m_label(jmp)
+            , m_type(type)
+            , m_condition(condition)
+        {
+        }
+
+        LabelType label() const
+        {
+            LabelType result;
+            result.m_label = m_label;
+            return result;
+        }
+
+        void link(AbstractMacroAssembler<ARMv7Assembler>* masm) const
+        {
+            masm->m_assembler.linkJump(m_label, masm->m_assembler.label(), m_type, m_condition);
+        }
+
+        void linkTo(LabelType label, AbstractMacroAssembler<ARMv7Assembler>* masm) const
+        {
+            masm->m_assembler.linkJump(m_label, label.label(), m_type, m_condition);
+        }
+
+        bool isSet() const { return m_label.isSet(); }
+
+    private:
+        AssemblerLabel m_label;
+        ARMv7Assembler::JumpType m_type;
+        ARMv7Assembler::Condition m_condition;
+    };
+
 private:
 
     // ARMv7, Appx-A.6.3
@@ -2115,6 +2166,7 @@ public:
         linkJumpAbsolute(location, to);
     }
 
+#if !defined(V4_BOOTSTRAP)
     static void linkCall(void* code, AssemblerLabel from, void* to)
     {
         ASSERT(!(reinterpret_cast<intptr_t>(code) & 1));
@@ -2123,12 +2175,14 @@ public:
 
         setPointer(reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset) - 1, to, false);
     }
+#endif
 
     static void linkPointer(void* code, AssemblerLabel where, void* value)
     {
         setPointer(reinterpret_cast<char*>(code) + where.m_offset, value, false);
     }
 
+#if !defined(V4_BOOTSTRAP)
     static void relinkJump(void* from, void* to)
     {
         ASSERT(!(reinterpret_cast<intptr_t>(from) & 1));
@@ -2146,11 +2200,12 @@ public:
 
         setPointer(reinterpret_cast<uint16_t*>(from) - 1, to, true);
     }
-    
+
     static void* readCallTarget(void* from)
     {
         return readPointer(reinterpret_cast<uint16_t*>(from) - 1);
     }
+#endif
 
     static void repatchInt32(void* where, int32_t value)
     {
@@ -2179,6 +2234,7 @@ public:
         cacheFlush(location, sizeof(uint16_t) * 2);
     }
 
+#if !defined(V4_BOOTSTRAP)
     static void repatchPointer(void* where, void* value)
     {
         ASSERT(!(reinterpret_cast<intptr_t>(where) & 1));
@@ -2190,7 +2246,8 @@ public:
     {
         return reinterpret_cast<void*>(readInt32(where));
     }
-    
+#endif
+
     static void replaceWithJump(void* instructionStart, void* to)
     {
         ASSERT(!(bitwise_cast<uintptr_t>(instructionStart) & 1));
@@ -2264,7 +2321,7 @@ public:
 
     unsigned debugOffset() { return m_formatter.debugOffset(); }
 
-#if OS(LINUX)
+#if OS(LINUX) && !defined(V4_BOOTSTRAP)
     static inline void linuxPageFlush(uintptr_t begin, uintptr_t end)
     {
         asm volatile(
@@ -2284,7 +2341,10 @@ public:
 
     static void cacheFlush(void* code, size_t size)
     {
-#if OS(IOS)
+#if defined(V4_BOOTSTRAP)
+        UNUSED_PARAM(code)
+        UNUSED_PARAM(size)
+#elif OS(IOS)
         sys_cache_control(kCacheFunctionPrepareForExecution, code, size);
 #elif OS(LINUX)
         size_t page = pageSize();
@@ -2430,7 +2490,9 @@ private:
 
     static void setPointer(void* code, void* value, bool flush)
     {
-        setInt32(code, reinterpret_cast<uint32_t>(value), flush);
+        // ### Deliberate "loss" of precision here. On 64-bit hosts void* is wider
+        // than uint32_t, but the target is 32-bit ARM anyway.
+        setInt32(code, static_cast<uint32_t>(reinterpret_cast<uintptr_t>(value)), flush);
     }
 
     static bool isB(void* address)
@@ -2594,6 +2656,11 @@ private:
     
     static void linkBX(uint16_t* instruction, void* target)
     {
+#if defined(V4_BOOTSTRAP)
+        UNUSED_PARAM(instruction);
+        UNUSED_PARAM(target);
+        RELEASE_ASSERT_NOT_REACHED();
+#else
         // FIMXE: this should be up in the MacroAssembler layer. :-(
         ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
         ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
@@ -2606,6 +2673,7 @@ private:
         instruction[-3] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
         instruction[-2] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, hi16);
         instruction[-1] = OP_BX | (JUMP_TEMPORARY_REGISTER << 3);
+#endif
     }
     
     void linkConditionalBX(Condition cond, uint16_t* instruction, void* target)
@@ -2638,6 +2706,9 @@ private:
             instruction[-3] = OP_NOP_T2b;
             linkJumpT4(instruction, target);
         } else {
+#if defined(V4_BOOTSTRAP)
+            RELEASE_ASSERT_NOT_REACHED();
+#else
             const uint16_t JUMP_TEMPORARY_REGISTER = ARMRegisters::ip;
             ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) + 1));
             ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) >> 16));
@@ -2646,6 +2717,7 @@ private:
             instruction[-3] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
             instruction[-2] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, hi16);
             instruction[-1] = OP_BX | (JUMP_TEMPORARY_REGISTER << 3);
+#endif
         }
     }
     
diff --git a/src/3rdparty/masm/assembler/AbstractMacroAssembler.h b/src/3rdparty/masm/assembler/AbstractMacroAssembler.h
index e90dd235c6..4f27e85c98 100644
--- a/src/3rdparty/masm/assembler/AbstractMacroAssembler.h
+++ b/src/3rdparty/masm/assembler/AbstractMacroAssembler.h
@@ -47,7 +47,10 @@
 namespace JSC {
 
 class JumpReplacementWatchpoint;
-class LinkBuffer;
+template <typename, template <typename> class>
+class LinkBufferBase;
+template <typename>
+class BranchCompactingLinkBuffer;
 class RepatchBuffer;
 class Watchpoint;
 namespace DFG {
@@ -63,7 +66,9 @@ public:
     typedef MacroAssemblerCodePtr CodePtr;
     typedef MacroAssemblerCodeRef CodeRef;
 
+#if !CPU(ARM_THUMB2) && !defined(V4_BOOTSTRAP)
     class Jump;
+#endif
 
     typedef typename AssemblerType::RegisterID RegisterID;
     typedef typename AssemblerType::FPRegisterID FPRegisterID;
@@ -325,7 +330,7 @@ public:
         friend class Jump;
         friend class JumpReplacementWatchpoint;
         friend class MacroAssemblerCodeRef;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
         friend class Watchpoint;
 
     public:
@@ -339,6 +344,8 @@ public:
         }
         
         bool isSet() const { return m_label.isSet(); }
+
+        const AssemblerLabel &label() const { return m_label; }
     private:
         AssemblerLabel m_label;
     };
@@ -356,7 +363,7 @@ public:
     class ConvertibleLoadLabel {
         template<class TemplateAssemblerType>
         friend class AbstractMacroAssembler;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
         
     public:
         ConvertibleLoadLabel()
@@ -380,7 +387,7 @@ public:
     class DataLabelPtr {
         template<class TemplateAssemblerType>
         friend class AbstractMacroAssembler;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
     public:
         DataLabelPtr()
         {
@@ -404,7 +411,7 @@ public:
     class DataLabel32 {
         template<class TemplateAssemblerType>
         friend class AbstractMacroAssembler;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
     public:
         DataLabel32()
         {
@@ -428,7 +435,7 @@ public:
     class DataLabelCompact {
         template<class TemplateAssemblerType>
         friend class AbstractMacroAssembler;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
     public:
         DataLabelCompact()
         {
@@ -448,6 +455,11 @@ public:
         AssemblerLabel m_label;
     };
 
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
+    using Jump = typename AssemblerType::template Jump<Label>;
+    friend Jump;
+#endif
+
     // Call:
     //
     // A Call object is a reference to a call instruction that has been planted
@@ -498,18 +510,19 @@ public:
     // into the code buffer - it is typically used to link the jump, setting the
     // relative offset such that when executed it will jump to the desired
     // destination.
+#if !CPU(ARM_THUMB2) && !defined(V4_BOOTSTRAP)
     class Jump {
         template<class TemplateAssemblerType>
         friend class AbstractMacroAssembler;
         friend class Call;
         friend struct DFG::OSRExit;
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
     public:
         Jump()
         {
         }
         
-#if CPU(ARM_THUMB2)
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
         // Fixme: this information should be stored in the instruction stream, not in the Jump object.
         Jump(AssemblerLabel jmp, ARMv7Assembler::JumpType type = ARMv7Assembler::JumpNoCondition, ARMv7Assembler::Condition condition = ARMv7Assembler::ConditionInvalid)
             : m_label(jmp)
@@ -610,10 +623,11 @@ public:
 
     private:
         AssemblerLabel m_label;
-#if CPU(ARM_THUMB2)
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
         ARMv7Assembler::JumpType m_type;
         ARMv7Assembler::Condition m_condition;
-#elif CPU(ARM64)
+#endif
+#if CPU(ARM64)
         ARM64Assembler::JumpType m_type;
         ARM64Assembler::Condition m_condition;
         bool m_is64Bit;
@@ -624,6 +638,7 @@ public:
         SH4Assembler::JumpType m_type;
 #endif
     };
+#endif
 
     struct PatchableJump {
         PatchableJump()
@@ -645,7 +660,7 @@ public:
     // A JumpList is a set of Jump objects.
     // All jumps in the set will be linked to the same destination.
     class JumpList {
-        friend class LinkBuffer;
+        template <typename, template <typename> class> friend class LinkBufferBase;
 
     public:
         typedef Vector<Jump, 2> JumpVector;
@@ -819,7 +834,8 @@ protected:
     static bool shouldBlindForSpecificArch(uint64_t) { return true; }
 #endif
 
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
+    template <typename> friend class BranchCompactingLinkBuffer;
     friend class RepatchBuffer;
 
     static void linkJump(void* code, Jump jump, CodeLocationLabel target)
@@ -867,10 +883,12 @@ protected:
         AssemblerType::repatchPointer(dataLabelPtr.dataLocation(), value);
     }
     
+#if !defined(V4_BOOTSTRAP)
     static void* readPointer(CodeLocationDataLabelPtr dataLabelPtr)
     {
         return AssemblerType::readPointer(dataLabelPtr.dataLocation());
     }
+#endif
     
     static void replaceWithLoad(CodeLocationConvertibleLoad label)
     {
diff --git a/src/3rdparty/masm/assembler/LinkBuffer.cpp b/src/3rdparty/masm/assembler/LinkBuffer.cpp
index 432a7ee227..74c278135b 100644
--- a/src/3rdparty/masm/assembler/LinkBuffer.cpp
+++ b/src/3rdparty/masm/assembler/LinkBuffer.cpp
@@ -32,140 +32,6 @@
 
 namespace JSC {
 
-LinkBuffer::CodeRef LinkBuffer::finalizeCodeWithoutDisassembly()
-{
-    performFinalization();
-    
-    return CodeRef(m_executableMemory);
-}
-
-LinkBuffer::CodeRef LinkBuffer::finalizeCodeWithDisassembly(const char* format, ...)
-{
-    ASSERT(Options::showDisassembly() || Options::showDFGDisassembly());
-    
-    CodeRef result = finalizeCodeWithoutDisassembly();
-    
-    dataLogF("Generated JIT code for ");
-    va_list argList;
-    va_start(argList, format);
-    WTF::dataLogFV(format, argList);
-    va_end(argList);
-    dataLogF(":\n");
-    
-    dataLogF(
-#if OS(WINDOWS)
-                "    Code at [0x%p, 0x%p):\n",
-#else
-                "    Code at [%p, %p):\n",
-#endif
-                result.code().executableAddress(), static_cast<char*>(result.code().executableAddress()) + result.size());
-    disassemble(result.code(), m_size, "    ", WTF::dataFile());
-    
-    return result;
-}
-
-void LinkBuffer::linkCode(void* ownerUID, JITCompilationEffort effort)
-{
-    ASSERT(!m_code);
-#if !ENABLE(BRANCH_COMPACTION)
-    m_executableMemory = m_assembler->m_assembler.executableCopy(*m_globalData, ownerUID, effort);
-    if (!m_executableMemory)
-        return;
-    m_code = m_executableMemory->start();
-    m_size = m_assembler->m_assembler.codeSize();
-    ASSERT(m_code);
-#else
-    m_initialSize = m_assembler->m_assembler.codeSize();
-    m_executableMemory = m_globalData->executableAllocator.allocate(*m_globalData, m_initialSize, ownerUID, effort);
-    if (!m_executableMemory)
-        return;
-    m_code = (uint8_t*)m_executableMemory->start();
-    ASSERT(m_code);
-    ExecutableAllocator::makeWritable(m_code, m_initialSize);
-    uint8_t* inData = (uint8_t*)m_assembler->unlinkedCode();
-    uint8_t* outData = reinterpret_cast<uint8_t*>(m_code);
-    int readPtr = 0;
-    int writePtr = 0;
-    Vector<LinkRecord, 0, UnsafeVectorOverflow>& jumpsToLink = m_assembler->jumpsToLink();
-    unsigned jumpCount = jumpsToLink.size();
-    for (unsigned i = 0; i < jumpCount; ++i) {
-        int offset = readPtr - writePtr;
-        ASSERT(!(offset & 1));
-            
-        // Copy the instructions from the last jump to the current one.
-        size_t regionSize = jumpsToLink[i].from() - readPtr;
-        uint16_t* copySource = reinterpret_cast_ptr<uint16_t*>(inData + readPtr);
-        uint16_t* copyEnd = reinterpret_cast_ptr<uint16_t*>(inData + readPtr + regionSize);
-        uint16_t* copyDst = reinterpret_cast_ptr<uint16_t*>(outData + writePtr);
-        ASSERT(!(regionSize % 2));
-        ASSERT(!(readPtr % 2));
-        ASSERT(!(writePtr % 2));
-        while (copySource != copyEnd)
-            *copyDst++ = *copySource++;
-        m_assembler->recordLinkOffsets(readPtr, jumpsToLink[i].from(), offset);
-        readPtr += regionSize;
-        writePtr += regionSize;
-            
-        // Calculate absolute address of the jump target, in the case of backwards
-        // branches we need to be precise, forward branches we are pessimistic
-        const uint8_t* target;
-        if (jumpsToLink[i].to() >= jumpsToLink[i].from())
-            target = outData + jumpsToLink[i].to() - offset; // Compensate for what we have collapsed so far
-        else
-            target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
-            
-        JumpLinkType jumpLinkType = m_assembler->computeJumpType(jumpsToLink[i], outData + writePtr, target);
-        // Compact branch if we can...
-        if (m_assembler->canCompact(jumpsToLink[i].type())) {
-            // Step back in the write stream
-            int32_t delta = m_assembler->jumpSizeDelta(jumpsToLink[i].type(), jumpLinkType);
-            if (delta) {
-                writePtr -= delta;
-                m_assembler->recordLinkOffsets(jumpsToLink[i].from() - delta, readPtr, readPtr - writePtr);
-            }
-        }
-        jumpsToLink[i].setFrom(writePtr);
-    }
-    // Copy everything after the last jump
-    memcpy(outData + writePtr, inData + readPtr, m_initialSize - readPtr);
-    m_assembler->recordLinkOffsets(readPtr, m_initialSize, readPtr - writePtr);
-        
-    for (unsigned i = 0; i < jumpCount; ++i) {
-        uint8_t* location = outData + jumpsToLink[i].from();
-        uint8_t* target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
-        m_assembler->link(jumpsToLink[i], location, target);
-    }
-
-    jumpsToLink.clear();
-    m_size = writePtr + m_initialSize - readPtr;
-    m_executableMemory->shrink(m_size);
-
-#if DUMP_LINK_STATISTICS
-    dumpLinkStatistics(m_code, m_initialSize, m_size);
-#endif
-#if DUMP_CODE
-    dumpCode(m_code, m_size);
-#endif
-#endif
-}
-
-void LinkBuffer::performFinalization()
-{
-#ifndef NDEBUG
-    ASSERT(!m_completed);
-    ASSERT(isValid());
-    m_completed = true;
-#endif
-    
-#if ENABLE(BRANCH_COMPACTION)
-    ExecutableAllocator::makeExecutable(code(), m_initialSize);
-#else
-    ASSERT(m_size <= INT_MAX);
-    ExecutableAllocator::makeExecutable(code(), static_cast<int>(m_size));
-#endif
-    MacroAssembler::cacheFlush(code(), m_size);
-}
-
 #if DUMP_LINK_STATISTICS
 void LinkBuffer::dumpLinkStatistics(void* code, size_t initializeSize, size_t finalSize)
 {
diff --git a/src/3rdparty/masm/assembler/LinkBuffer.h b/src/3rdparty/masm/assembler/LinkBuffer.h
index e1882433c1..3a659a23ce 100644
--- a/src/3rdparty/masm/assembler/LinkBuffer.h
+++ b/src/3rdparty/masm/assembler/LinkBuffer.h
@@ -36,6 +36,7 @@
 
 #include "JITCompilationEffort.h"
 #include "MacroAssembler.h"
+#include "Options.h"
 #include <wtf/DataLog.h>
 #include <wtf/Noncopyable.h>
 
@@ -43,6 +44,12 @@ namespace JSC {
 
 class JSGlobalData;
 
+template <typename T>
+struct DefaultExecutableOffsetCalculator {
+    template <typename Assembler>
+    static T applyOffset(Assembler *, T src) { return src; }
+};
+
 // LinkBuffer:
 //
 // This class assists in linking code generated by the macro assembler, once code generation
@@ -57,30 +64,24 @@ class JSGlobalData;
 //   * The address of a Label pointing into the code may be resolved.
 //   * The value referenced by a DataLabel may be set.
 //
-class LinkBuffer {
-    WTF_MAKE_NONCOPYABLE(LinkBuffer);
+template <typename MacroAssembler, template <typename T> class ExecutableOffsetCalculator>
+class LinkBufferBase {
+    WTF_MAKE_NONCOPYABLE(LinkBufferBase);
     typedef MacroAssemblerCodeRef CodeRef;
     typedef MacroAssemblerCodePtr CodePtr;
-    typedef MacroAssembler::Label Label;
-    typedef MacroAssembler::Jump Jump;
-    typedef MacroAssembler::PatchableJump PatchableJump;
-    typedef MacroAssembler::JumpList JumpList;
-    typedef MacroAssembler::Call Call;
-    typedef MacroAssembler::DataLabelCompact DataLabelCompact;
-    typedef MacroAssembler::DataLabel32 DataLabel32;
-    typedef MacroAssembler::DataLabelPtr DataLabelPtr;
-    typedef MacroAssembler::ConvertibleLoadLabel ConvertibleLoadLabel;
-#if ENABLE(BRANCH_COMPACTION)
-    typedef MacroAssembler::LinkRecord LinkRecord;
-    typedef MacroAssembler::JumpLinkType JumpLinkType;
-#endif
+    typedef typename MacroAssembler::Label Label;
+    typedef typename MacroAssembler::Jump Jump;
+    typedef typename MacroAssembler::PatchableJump PatchableJump;
+    typedef typename MacroAssembler::JumpList JumpList;
+    typedef typename MacroAssembler::Call Call;
+    typedef typename MacroAssembler::DataLabelCompact DataLabelCompact;
+    typedef typename MacroAssembler::DataLabel32 DataLabel32;
+    typedef typename MacroAssembler::DataLabelPtr DataLabelPtr;
+    typedef typename MacroAssembler::ConvertibleLoadLabel ConvertibleLoadLabel;
 
 public:
-    LinkBuffer(JSGlobalData& globalData, MacroAssembler* masm, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+    LinkBufferBase(JSGlobalData& globalData, MacroAssembler* masm, JITCompilationEffort effort = JITCompilationMustSucceed)
         : m_size(0)
-#if ENABLE(BRANCH_COMPACTION)
-        , m_initialSize(0)
-#endif
         , m_code(0)
         , m_assembler(masm)
         , m_globalData(&globalData)
@@ -89,10 +90,13 @@ public:
         , m_effort(effort)
 #endif
     {
-        linkCode(ownerUID, effort);
+#ifdef NDEBUG
+        UNUSED_PARAM(effort)
+#endif
+        // Simon: Moved this to the sub-classes linkCode(ownerUID, effort);
     }
 
-    ~LinkBuffer()
+    ~LinkBufferBase()
     {
         ASSERT(m_completed || (!m_executableMemory && m_effort == JITCompilationCanFail));
     }
@@ -204,8 +208,8 @@ public:
     // finalizeCodeWithoutDisassembly() directly if you have your own way of
     // displaying disassembly.
     
-    CodeRef finalizeCodeWithoutDisassembly();
-    CodeRef finalizeCodeWithDisassembly(const char* format, ...) WTF_ATTRIBUTE_PRINTF(2, 3);
+    inline CodeRef finalizeCodeWithoutDisassembly();
+    inline CodeRef finalizeCodeWithDisassembly(const char* format, ...) WTF_ATTRIBUTE_PRINTF(2, 3);
 
     CodePtr trampolineAt(Label label)
     {
@@ -225,21 +229,19 @@ public:
 private:
     template <typename T> T applyOffset(T src)
     {
-#if ENABLE(BRANCH_COMPACTION)
-        src.m_offset -= m_assembler->executableOffsetFor(src.m_offset);
-#endif
-        return src;
+        return ExecutableOffsetCalculator<T>::applyOffset(m_assembler, src);
     }
     
+protected:
     // Keep this private! - the underlying code should only be obtained externally via finalizeCode().
     void* code()
     {
         return m_code;
     }
 
-    void linkCode(void* ownerUID, JITCompilationEffort);
+    inline void linkCode(void* ownerUID, JITCompilationEffort);
 
-    void performFinalization();
+    inline void performFinalization();
 
 #if DUMP_LINK_STATISTICS
     static void dumpLinkStatistics(void* code, size_t initialSize, size_t finalSize);
@@ -251,12 +253,10 @@ private:
     
     RefPtr<ExecutableMemoryHandle> m_executableMemory;
     size_t m_size;
-#if ENABLE(BRANCH_COMPACTION)
-    size_t m_initialSize;
-#endif
     void* m_code;
     MacroAssembler* m_assembler;
     JSGlobalData* m_globalData;
+protected:
 #ifndef NDEBUG
     bool m_completed;
     JITCompilationEffort m_effort;
@@ -290,6 +290,234 @@ private:
 #define FINALIZE_DFG_CODE(linkBufferReference, dataLogFArgumentsForHeading)  \
     FINALIZE_CODE_IF((Options::showDisassembly() || Options::showDFGDisassembly()), linkBufferReference, dataLogFArgumentsForHeading)
 
+
+template <typename MacroAssembler, template <typename T> class ExecutableOffsetCalculator>
+inline typename LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::CodeRef LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::finalizeCodeWithoutDisassembly()
+{
+    performFinalization();
+
+    return CodeRef(m_executableMemory);
+}
+
+template <typename MacroAssembler, template <typename T> class ExecutableOffsetCalculator>
+inline typename LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::CodeRef LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::finalizeCodeWithDisassembly(const char* format, ...)
+{
+    ASSERT(Options::showDisassembly() || Options::showDFGDisassembly());
+
+    CodeRef result = finalizeCodeWithoutDisassembly();
+
+    dataLogF("Generated JIT code for ");
+    va_list argList;
+    va_start(argList, format);
+    WTF::dataLogFV(format, argList);
+    va_end(argList);
+    dataLogF(":\n");
+
+    dataLogF(
+#if OS(WINDOWS)
+                "    Code at [0x%p, 0x%p):\n",
+#else
+                "    Code at [%p, %p):\n",
+#endif
+                result.code().executableAddress(), static_cast<char*>(result.code().executableAddress()) + result.size());
+    disassemble(result.code(), m_size, "    ", WTF::dataFile());
+
+    return result;
+}
+
+template <typename MacroAssembler, template <typename T> class ExecutableOffsetCalculator>
+inline void LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::linkCode(void* ownerUID, JITCompilationEffort effort)
+{
+    UNUSED_PARAM(ownerUID)
+    UNUSED_PARAM(effort)
+    ASSERT(!m_code);
+    m_executableMemory = m_assembler->m_assembler.executableCopy(*m_globalData, ownerUID, effort);
+    if (!m_executableMemory)
+        return;
+    m_code = m_executableMemory->start();
+    m_size = m_assembler->m_assembler.codeSize();
+    ASSERT(m_code);
+}
+
+template <typename MacroAssembler, template <typename T> class ExecutableOffsetCalculator>
+inline void LinkBufferBase<MacroAssembler, ExecutableOffsetCalculator>::performFinalization()
+{
+    // NOTE: This function is specialized in LinkBuffer<MacroAssemblerARMv7>
+#ifndef NDEBUG
+    ASSERT(!m_completed);
+    ASSERT(isValid());
+    m_completed = true;
+#endif
+
+    ASSERT(m_size <= INT_MAX);
+    ExecutableAllocator::makeExecutable(code(), static_cast<int>(m_size));
+    MacroAssembler::cacheFlush(code(), m_size);
+}
+
+template <typename MacroAssembler>
+class LinkBuffer : public LinkBufferBase<MacroAssembler, DefaultExecutableOffsetCalculator>
+{
+public:
+    LinkBuffer(JSGlobalData& globalData, MacroAssembler* masm, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+        : LinkBufferBase<MacroAssembler, DefaultExecutableOffsetCalculator>(globalData, masm, effort)
+    {
+        this->linkCode(ownerUID, effort);
+    }
+};
+
+#if CPU(ARM_THUMB2) || CPU(ARM64) || defined(V4_BOOTSTRAP)
+
+template <typename T>
+struct BranchCompactingExecutableOffsetCalculator {
+    template <typename Assembler>
+    static T applyOffset(Assembler *as, T src) {
+        src.m_offset -= as->executableOffsetFor(src.m_offset);
+        return src;
+    }
+};
+
+template <typename MacroAssembler>
+class BranchCompactingLinkBuffer : public LinkBufferBase<MacroAssembler, BranchCompactingExecutableOffsetCalculator>
+{
+public:
+    BranchCompactingLinkBuffer(JSGlobalData& globalData, MacroAssembler* masm, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+        : LinkBufferBase<MacroAssembler, BranchCompactingExecutableOffsetCalculator>(globalData, masm, effort)
+    {
+        linkCode(ownerUID, effort);
+    }
+
+    inline void performFinalization();
+
+    inline void linkCode(void* ownerUID, JITCompilationEffort);
+
+private:
+    using Base = LinkBufferBase<MacroAssembler, BranchCompactingExecutableOffsetCalculator>;
+#ifndef NDEBUG
+    using Base::m_completed;
+#endif
+    using Base::isValid;
+    using Base::code;
+    using Base::m_code;
+    using Base::m_size;
+    using Base::m_assembler;
+    using Base::m_executableMemory;
+    using Base::m_globalData;
+
+    using LinkRecord = typename MacroAssembler::LinkRecord;
+    using JumpLinkType = typename MacroAssembler::JumpLinkType;
+
+    size_t m_initialSize = 0;
+};
+
+template <typename MacroAssembler>
+inline void BranchCompactingLinkBuffer<MacroAssembler>::performFinalization()
+{
+#ifndef NDEBUG
+    ASSERT(!m_completed);
+    ASSERT(isValid());
+    this->m_completed = true;
+#endif
+
+    ExecutableAllocator::makeExecutable(code(), m_initialSize);
+    MacroAssembler::cacheFlush(code(), m_size);
+}
+
+template <typename MacroAssembler>
+inline void BranchCompactingLinkBuffer<MacroAssembler>::linkCode(void* ownerUID, JITCompilationEffort effort)
+{
+    UNUSED_PARAM(ownerUID)
+    UNUSED_PARAM(effort)
+    ASSERT(!m_code);
+    m_initialSize = m_assembler->m_assembler.codeSize();
+    m_executableMemory = m_globalData->executableAllocator.allocate(*m_globalData, m_initialSize, ownerUID, effort);
+    if (!m_executableMemory)
+        return;
+    m_code = (uint8_t*)m_executableMemory->start();
+    ASSERT(m_code);
+    ExecutableAllocator::makeWritable(m_code, m_initialSize);
+    uint8_t* inData = (uint8_t*)m_assembler->unlinkedCode();
+    uint8_t* outData = reinterpret_cast<uint8_t*>(m_code);
+    int readPtr = 0;
+    int writePtr = 0;
+    Vector<LinkRecord, 0, UnsafeVectorOverflow>& jumpsToLink = m_assembler->jumpsToLink();
+    unsigned jumpCount = unsigned(jumpsToLink.size());
+    for (unsigned i = 0; i < jumpCount; ++i) {
+        int offset = readPtr - writePtr;
+        ASSERT(!(offset & 1));
+
+        // Copy the instructions from the last jump to the current one.
+        unsigned regionSize = unsigned(jumpsToLink[i].from() - readPtr);
+        uint16_t* copySource = reinterpret_cast_ptr<uint16_t*>(inData + readPtr);
+        uint16_t* copyEnd = reinterpret_cast_ptr<uint16_t*>(inData + readPtr + regionSize);
+        uint16_t* copyDst = reinterpret_cast_ptr<uint16_t*>(outData + writePtr);
+        ASSERT(!(regionSize % 2));
+        ASSERT(!(readPtr % 2));
+        ASSERT(!(writePtr % 2));
+        while (copySource != copyEnd)
+            *copyDst++ = *copySource++;
+        m_assembler->recordLinkOffsets(readPtr, jumpsToLink[i].from(), offset);
+        readPtr += regionSize;
+        writePtr += regionSize;
+
+        // Calculate absolute address of the jump target, in the case of backwards
+        // branches we need to be precise, forward branches we are pessimistic
+        const uint8_t* target;
+        if (jumpsToLink[i].to() >= jumpsToLink[i].from())
+            target = outData + jumpsToLink[i].to() - offset; // Compensate for what we have collapsed so far
+        else
+            target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
+
+        JumpLinkType jumpLinkType = m_assembler->computeJumpType(jumpsToLink[i], outData + writePtr, target);
+        // Compact branch if we can...
+        if (m_assembler->canCompact(jumpsToLink[i].type())) {
+            // Step back in the write stream
+            int32_t delta = m_assembler->jumpSizeDelta(jumpsToLink[i].type(), jumpLinkType);
+            if (delta) {
+                writePtr -= delta;
+                m_assembler->recordLinkOffsets(jumpsToLink[i].from() - delta, readPtr, readPtr - writePtr);
+            }
+        }
+        jumpsToLink[i].setFrom(writePtr);
+    }
+    // Copy everything after the last jump
+    memcpy(outData + writePtr, inData + readPtr, m_initialSize - readPtr);
+    m_assembler->recordLinkOffsets(readPtr, unsigned(m_initialSize), readPtr - writePtr);
+
+    for (unsigned i = 0; i < jumpCount; ++i) {
+        uint8_t* location = outData + jumpsToLink[i].from();
+        uint8_t* target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
+        m_assembler->link(jumpsToLink[i], location, target);
+    }
+
+    jumpsToLink.clear();
+    m_size = writePtr + m_initialSize - readPtr;
+    m_executableMemory->shrink(m_size);
+}
+
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
+template <>
+class LinkBuffer<JSC::MacroAssembler<MacroAssemblerARMv7>> : public BranchCompactingLinkBuffer<JSC::MacroAssembler<MacroAssemblerARMv7>>
+{
+public:
+    LinkBuffer(JSGlobalData& globalData, JSC::MacroAssembler<MacroAssemblerARMv7>* masm, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+        : BranchCompactingLinkBuffer<JSC::MacroAssembler<MacroAssemblerARMv7>>(globalData, masm, ownerUID, effort)
+    {}
+};
+#endif
+
+#if CPU(ARM64)
+template <>
+class LinkBuffer<JSC::MacroAssembler<MacroAssemblerARM64>> : public BranchCompactingLinkBuffer<JSC::MacroAssembler<MacroAssemblerARM64>>
+{
+public:
+    LinkBuffer(JSGlobalData& globalData, JSC::MacroAssembler<MacroAssemblerARM64>* masm, void* ownerUID, JITCompilationEffort effort = JITCompilationMustSucceed)
+        : BranchCompactingLinkBuffer<JSC::MacroAssembler<JSC::MacroAssemblerARM64>>(globalData, masm, ownerUID, effort)
+    {}
+};
+#endif
+
+#endif
+
 } // namespace JSC
 
 #endif // ENABLE(ASSEMBLER)
diff --git a/src/3rdparty/masm/assembler/MacroAssembler.h b/src/3rdparty/masm/assembler/MacroAssembler.h
index e122e2f3ae..87794c8ef4 100644
--- a/src/3rdparty/masm/assembler/MacroAssembler.h
+++ b/src/3rdparty/masm/assembler/MacroAssembler.h
@@ -30,8 +30,9 @@
 
 #if ENABLE(ASSEMBLER)
 
-#if CPU(ARM_THUMB2)
 #include "MacroAssemblerARMv7.h"
+
+#if CPU(ARM_THUMB2)
 namespace JSC { typedef MacroAssemblerARMv7 MacroAssemblerBase; };
 
 #elif CPU(ARM64)
@@ -68,13 +69,53 @@ typedef MacroAssemblerSH4 MacroAssemblerBase;
 
 namespace JSC {
 
+template <typename MacroAssemblerBase>
 class MacroAssembler : public MacroAssemblerBase {
 public:
 
+    using DoubleCondition = typename MacroAssemblerBase::DoubleCondition;
+    using ResultCondition = typename MacroAssemblerBase::ResultCondition;
+    using RelationalCondition = typename MacroAssemblerBase::RelationalCondition;
+    using RegisterID = typename MacroAssemblerBase::RegisterID;
+    using Address = typename MacroAssemblerBase::Address;
+    using ExtendedAddress = typename MacroAssemblerBase::ExtendedAddress;
+    using BaseIndex = typename MacroAssemblerBase::BaseIndex;
+    using ImplicitAddress = typename MacroAssemblerBase::ImplicitAddress;
+    using AbsoluteAddress = typename MacroAssemblerBase::AbsoluteAddress;
+    using TrustedImm32 = typename MacroAssemblerBase::TrustedImm32;
+    using TrustedImm64 = typename MacroAssemblerBase::TrustedImm64;
+    using TrustedImmPtr = typename MacroAssemblerBase::TrustedImmPtr;
+    using Imm32 = typename MacroAssemblerBase::Imm32;
+    using Imm64 = typename MacroAssemblerBase::Imm64;
+    using ImmPtr = typename MacroAssemblerBase::ImmPtr;
+    using Label = typename MacroAssemblerBase::Label;
+    using DataLabelPtr = typename MacroAssemblerBase::DataLabelPtr;
+    using DataLabel32 = typename MacroAssemblerBase::DataLabel32;
+    using DataLabelCompact = typename MacroAssemblerBase::DataLabelCompact;
+    using Jump = typename MacroAssemblerBase::Jump;
+    using PatchableJump = typename MacroAssemblerBase::PatchableJump;
+
     using MacroAssemblerBase::pop;
     using MacroAssemblerBase::jump;
     using MacroAssemblerBase::branch32;
     using MacroAssemblerBase::move;
+    using MacroAssemblerBase::store32;
+    using MacroAssemblerBase::add32;
+    using MacroAssemblerBase::xor32;
+    using MacroAssemblerBase::sub32;
+    using MacroAssemblerBase::load32;
+
+
+#if defined(V4_BOOTSTRAP)
+    using MacroAssemblerBase::loadPtr;
+    using MacroAssemblerBase::storePtr;
+#elif CPU(X86_64) || CPU(ARM64)
+    using MacroAssemblerBase::add64;
+    using MacroAssemblerBase::sub64;
+    using MacroAssemblerBase::xor64;
+    using MacroAssemblerBase::load64;
+    using MacroAssemblerBase::store64;
+#endif
 
 #if ENABLE(JIT_CONSTANT_BLINDING)
     using MacroAssemblerBase::add32;
@@ -100,41 +141,41 @@ public:
     static DoubleCondition invert(DoubleCondition cond)
     {
         switch (cond) {
-        case DoubleEqual:
-            return DoubleNotEqualOrUnordered;
-        case DoubleNotEqual:
-            return DoubleEqualOrUnordered;
-        case DoubleGreaterThan:
-            return DoubleLessThanOrEqualOrUnordered;
-        case DoubleGreaterThanOrEqual:
-            return DoubleLessThanOrUnordered;
-        case DoubleLessThan:
-            return DoubleGreaterThanOrEqualOrUnordered;
-        case DoubleLessThanOrEqual:
-            return DoubleGreaterThanOrUnordered;
-        case DoubleEqualOrUnordered:
-            return DoubleNotEqual;
-        case DoubleNotEqualOrUnordered:
-            return DoubleEqual;
-        case DoubleGreaterThanOrUnordered:
-            return DoubleLessThanOrEqual;
-        case DoubleGreaterThanOrEqualOrUnordered:
-            return DoubleLessThan;
-        case DoubleLessThanOrUnordered:
-            return DoubleGreaterThanOrEqual;
-        case DoubleLessThanOrEqualOrUnordered:
-            return DoubleGreaterThan;
+        case DoubleCondition::DoubleEqual:
+            return DoubleCondition::DoubleNotEqualOrUnordered;
+        case DoubleCondition::DoubleNotEqual:
+            return DoubleCondition::DoubleEqualOrUnordered;
+        case DoubleCondition::DoubleGreaterThan:
+            return DoubleCondition::DoubleLessThanOrEqualOrUnordered;
+        case DoubleCondition::DoubleGreaterThanOrEqual:
+            return DoubleCondition::DoubleLessThanOrUnordered;
+        case DoubleCondition::DoubleLessThan:
+            return DoubleCondition::DoubleGreaterThanOrEqualOrUnordered;
+        case DoubleCondition::DoubleLessThanOrEqual:
+            return DoubleCondition::DoubleGreaterThanOrUnordered;
+        case DoubleCondition::DoubleEqualOrUnordered:
+            return DoubleCondition::DoubleNotEqual;
+        case DoubleCondition::DoubleNotEqualOrUnordered:
+            return DoubleCondition::DoubleEqual;
+        case DoubleCondition::DoubleGreaterThanOrUnordered:
+            return DoubleCondition::DoubleLessThanOrEqual;
+        case DoubleCondition::DoubleGreaterThanOrEqualOrUnordered:
+            return DoubleCondition::DoubleLessThan;
+        case DoubleCondition::DoubleLessThanOrUnordered:
+            return DoubleCondition::DoubleGreaterThanOrEqual;
+        case DoubleCondition::DoubleLessThanOrEqualOrUnordered:
+            return DoubleCondition::DoubleGreaterThan;
         default:
             RELEASE_ASSERT_NOT_REACHED();
-            return DoubleEqual; // make compiler happy
+            return DoubleCondition::DoubleEqual; // make compiler happy
         }
     }
     
     static bool isInvertible(ResultCondition cond)
     {
         switch (cond) {
-        case Zero:
-        case NonZero:
+        case ResultCondition::Zero:
+        case ResultCondition::NonZero:
             return true;
         default:
             return false;
@@ -144,13 +185,13 @@ public:
     static ResultCondition invert(ResultCondition cond)
     {
         switch (cond) {
-        case Zero:
-            return NonZero;
-        case NonZero:
-            return Zero;
+        case ResultCondition::Zero:
+            return ResultCondition::NonZero;
+        case ResultCondition::NonZero:
+            return ResultCondition::Zero;
         default:
             RELEASE_ASSERT_NOT_REACHED();
-            return Zero; // Make compiler happy for release builds.
+            return ResultCondition::Zero; // Make compiler happy for release builds.
         }
     }
 #endif
@@ -159,17 +200,17 @@ public:
     // described in terms of other macro assembly methods.
     void pop()
     {
-        addPtr(TrustedImm32(sizeof(void*)), stackPointerRegister);
+        addPtr(TrustedImm32(sizeof(void*)), MacroAssemblerBase::stackPointerRegister);
     }
     
     void peek(RegisterID dest, int index = 0)
     {
-        loadPtr(Address(stackPointerRegister, (index * sizeof(void*))), dest);
+        loadPtr(Address(MacroAssemblerBase::stackPointerRegister, (index * sizeof(void*))), dest);
     }
 
     Address addressForPoke(int index)
     {
-        return Address(stackPointerRegister, (index * sizeof(void*)));
+        return Address(MacroAssemblerBase::stackPointerRegister, (index * sizeof(void*)));
     }
     
     void poke(RegisterID src, int index = 0)
@@ -187,10 +228,10 @@ public:
         storePtr(imm, addressForPoke(index));
     }
 
-#if CPU(X86_64) || CPU(ARM64)
+#if (CPU(X86_64) || CPU(ARM64)) && !defined(V4_BOOTSTRAP)
     void peek64(RegisterID dest, int index = 0)
     {
-        load64(Address(stackPointerRegister, (index * sizeof(void*))), dest);
+        load64(Address(MacroAssemblerBase::stackPointerRegister, (index * sizeof(void*))), dest);
     }
 
     void poke(TrustedImm64 value, int index = 0)
@@ -296,36 +337,37 @@ public:
     static RelationalCondition commute(RelationalCondition condition)
     {
         switch (condition) {
-        case Above:
-            return Below;
-        case AboveOrEqual:
-            return BelowOrEqual;
-        case Below:
-            return Above;
-        case BelowOrEqual:
-            return AboveOrEqual;
-        case GreaterThan:
-            return LessThan;
-        case GreaterThanOrEqual:
-            return LessThanOrEqual;
-        case LessThan:
-            return GreaterThan;
-        case LessThanOrEqual:
-            return GreaterThanOrEqual;
+        case RelationalCondition::Above:
+            return RelationalCondition::Below;
+        case RelationalCondition::AboveOrEqual:
+            return RelationalCondition::BelowOrEqual;
+        case RelationalCondition::Below:
+            return RelationalCondition::Above;
+        case RelationalCondition::BelowOrEqual:
+            return RelationalCondition::AboveOrEqual;
+        case RelationalCondition::GreaterThan:
+            return RelationalCondition::LessThan;
+        case RelationalCondition::GreaterThanOrEqual:
+            return RelationalCondition::LessThanOrEqual;
+        case RelationalCondition::LessThan:
+            return RelationalCondition::GreaterThan;
+        case RelationalCondition::LessThanOrEqual:
+            return RelationalCondition::GreaterThanOrEqual;
         default:
             break;
         }
 
-        ASSERT(condition == Equal || condition == NotEqual);
+        ASSERT(condition == RelationalCondition::Equal || condition == RelationalCondition::NotEqual);
         return condition;
     }
 
     static const unsigned BlindingModulus = 64;
     bool shouldConsiderBlinding()
     {
-        return !(random() & (BlindingModulus - 1));
+        return !(this->random() & (BlindingModulus - 1));
     }
 
+#if !defined(V4_BOOTSTRAP)
     // Ptr methods
     // On 32-bit platforms (i.e. x86), these methods directly map onto their 32-bit equivalents.
     // FIXME: should this use a test for 32-bitness instead of this specific exception?
@@ -850,6 +892,7 @@ public:
     {
         return branchSub64(cond, src1, src2, dest);
     }
+#endif // !defined(V4_BOOTSTRAP)
 
 #if ENABLE(JIT_CONSTANT_BLINDING)
     using MacroAssemblerBase::and64;
@@ -1447,6 +1490,22 @@ public:
 #endif
 };
 
+#if CPU(ARM_THUMB2)
+typedef MacroAssembler<MacroAssemblerARMv7> DefaultMacroAssembler;
+#elif CPU(ARM64)
+typedef MacroAssembler<MacroAssemblerARM64> DefaultMacroAssembler;
+#elif CPU(ARM_TRADITIONAL)
+typedef MacroAssembler<MacroAssemblerARM> DefaultMacroAssembler;
+#elif CPU(MIPS)
+typedef MacroAssembler<MacroAssemblerMIPS> DefaultMacroAssembler;
+#elif CPU(X86)
+typedef MacroAssembler<MacroAssemblerX86> DefaultMacroAssembler;
+#elif CPU(X86_64)
+typedef MacroAssembler<MacroAssemblerX86_64> DefaultMacroAssembler;
+#elif CPU(SH4)
+typedef JSC::MacroAssemblerSH4 DefaultMacroAssembler;
+#endif
+
 } // namespace JSC
 
 #else // ENABLE(ASSEMBLER)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerARM.h b/src/3rdparty/masm/assembler/MacroAssemblerARM.h
index 01e34c97cd..268fe5fe73 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerARM.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerARM.h
@@ -1349,7 +1349,7 @@ protected:
     }
 
 private:
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
     void internalCompare32(RegisterID left, TrustedImm32 right)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerARM64.h b/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
index bd85b6b2c1..3e425a0246 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerARM64.h
@@ -3353,7 +3353,7 @@ private:
         return makeBranch(cond);
     }
 
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     void recordLinkOffsets(int32_t regionStart, int32_t regionEnd, int32_t offset) {return m_assembler.recordLinkOffsets(regionStart, regionEnd, offset); }
     int executableOffsetFor(int location) { return m_assembler.executableOffsetFor(location); }
 
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h b/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
index 0938383513..806f2e13b6 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerARMv7.h
@@ -27,7 +27,7 @@
 #ifndef MacroAssemblerARMv7_h
 #define MacroAssemblerARMv7_h
 
-#if ENABLE(ASSEMBLER) && CPU(ARM_THUMB2)
+#if ENABLE(ASSEMBLER) && (CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP))
 
 #include "ARMv7Assembler.h"
 #include "AbstractMacroAssembler.h"
@@ -160,12 +160,41 @@ public:
     {
         add32(imm, dest, dest);
     }
+
+#if defined(V4_BOOTSTRAP)
+    void loadPtr(ImplicitAddress address, RegisterID dest)
+    {
+        load32(address, dest);
+    }
+
+    void subPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        sub32(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        add32(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID src, RegisterID dest)
+    {
+        add32(imm, src, dest);
+    }
+
+    void storePtr(RegisterID src, ImplicitAddress address)
+    {
+        store32(src, address);
+    }
+#endif
     
+#if !defined(V4_BOOTSTRAP)
     void add32(AbsoluteAddress src, RegisterID dest)
     {
         load32(src.m_ptr, dataTempRegister);
         add32(dataTempRegister, dest);
     }
+#endif
 
     void add32(TrustedImm32 imm, RegisterID src, RegisterID dest)
     {
@@ -206,6 +235,7 @@ public:
         add32(dataTempRegister, dest);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void add32(TrustedImm32 imm, AbsoluteAddress address)
     {
         load32(address.m_ptr, dataTempRegister);
@@ -242,6 +272,7 @@ public:
         m_assembler.adc(dataTempRegister, dataTempRegister, ARMThumbImmediate::makeEncodedImm(imm.m_value >> 31));
         m_assembler.str(dataTempRegister, addressTempRegister, ARMThumbImmediate::makeUInt12(4));
     }
+#endif
 
     void and32(RegisterID op1, RegisterID op2, RegisterID dest)
     {
@@ -343,6 +374,7 @@ public:
         or32(dataTempRegister, dest);
     }
     
+#if !defined(V4_BOOTSTRAP)
     void or32(RegisterID src, AbsoluteAddress dest)
     {
         move(TrustedImmPtr(dest.m_ptr), addressTempRegister);
@@ -350,6 +382,7 @@ public:
         or32(src, dataTempRegister);
         store32(dataTempRegister, addressTempRegister);
     }
+#endif
 
     void or32(TrustedImm32 imm, RegisterID dest)
     {
@@ -461,6 +494,7 @@ public:
         sub32(dataTempRegister, dest);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void sub32(TrustedImm32 imm, AbsoluteAddress address)
     {
         load32(address.m_ptr, dataTempRegister);
@@ -477,6 +511,7 @@ public:
 
         store32(dataTempRegister, address.m_ptr);
     }
+#endif
 
     void xor32(Address src, RegisterID dest)
     {
@@ -526,7 +561,8 @@ public:
     // operand objects to loads and store will be implicitly constructed if a
     // register is passed.
 
-private:
+    // internal function, but public because of "using load32;" in template sub-classes to pull
+    // in the other public overloads.
     void load32(ArmAddress address, RegisterID dest)
     {
         if (address.type == ArmAddress::HasIndex)
@@ -541,6 +577,7 @@ private:
         }
     }
 
+private:
     void load16(ArmAddress address, RegisterID dest)
     {
         if (address.type == ArmAddress::HasIndex)
@@ -646,11 +683,13 @@ public:
         load16(setupArmAddress(address), dest);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void load32(const void* address, RegisterID dest)
     {
         move(TrustedImmPtr(address), addressTempRegister);
         m_assembler.ldr(dest, addressTempRegister, ARMThumbImmediate::makeUInt16(0));
     }
+#endif
     
     ConvertibleLoadLabel convertibleLoadPtr(Address address, RegisterID dest)
     {
@@ -755,6 +794,7 @@ public:
         store32(dataTempRegister, setupArmAddress(address));
     }
 
+#if !defined(V4_BOOTSTRAP)
     void store32(RegisterID src, const void* address)
     {
         move(TrustedImmPtr(address), addressTempRegister);
@@ -766,12 +806,14 @@ public:
         move(imm, dataTempRegister);
         store32(dataTempRegister, address);
     }
+#endif
 
     void store8(RegisterID src, BaseIndex address)
     {
         store8(src, setupArmAddress(address));
     }
     
+#if !defined(V4_BOOTSTRAP)
     void store8(RegisterID src, void* address)
     {
         move(TrustedImmPtr(address), addressTempRegister);
@@ -783,6 +825,7 @@ public:
         move(imm, dataTempRegister);
         store8(dataTempRegister, address);
     }
+#endif
     
     void store16(RegisterID src, BaseIndex address)
     {
@@ -880,11 +923,13 @@ public:
             m_assembler.vmov(dest, src);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void loadDouble(const void* address, FPRegisterID dest)
     {
         move(TrustedImmPtr(address), addressTempRegister);
         m_assembler.vldr(dest, addressTempRegister, 0);
     }
+#endif
 
     void storeDouble(FPRegisterID src, ImplicitAddress address)
     {
@@ -916,11 +961,13 @@ public:
         m_assembler.fsts(ARMRegisters::asSingle(src), base, offset);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void storeDouble(FPRegisterID src, const void* address)
     {
         move(TrustedImmPtr(address), addressTempRegister);
         storeDouble(src, addressTempRegister);
     }
+#endif
 
     void storeDouble(FPRegisterID src, BaseIndex address)
     {
@@ -954,11 +1001,13 @@ public:
         m_assembler.vadd(dest, op1, op2);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void addDouble(AbsoluteAddress address, FPRegisterID dest)
     {
         loadDouble(address.m_ptr, fpTempRegister);
         m_assembler.vadd(dest, dest, fpTempRegister);
     }
+#endif
 
     void divDouble(FPRegisterID src, FPRegisterID dest)
     {
@@ -1037,6 +1086,7 @@ public:
         m_assembler.vcvt_signedToFloatingPoint(dest, fpTempRegisterAsSingle());
     }
 
+#if !defined(V4_BOOTSTRAP)
     void convertInt32ToDouble(AbsoluteAddress address, FPRegisterID dest)
     {
         // Fixme: load directly into the fpr!
@@ -1044,6 +1094,7 @@ public:
         m_assembler.vmov(fpTempRegister, dataTempRegister, dataTempRegister);
         m_assembler.vcvt_signedToFloatingPoint(dest, fpTempRegisterAsSingle());
     }
+#endif
 
     void convertUInt32ToDouble(RegisterID src, FPRegisterID dest, RegisterID /*scratch*/)
     {
@@ -1197,7 +1248,7 @@ public:
     void push(RegisterID src)
     {
         // store preindexed with writeback
-        m_assembler.str(src, ARMRegisters::sp, -sizeof(void*), true, true);
+        m_assembler.str(src, ARMRegisters::sp, -4 /*sizeof(void*)*/, true, true);
     }
 
     void push(Address address)
@@ -1239,10 +1290,12 @@ public:
             m_assembler.mov(dest, src);
     }
 
+#if !defined(V4_BOOTSTRAP)
     void move(TrustedImmPtr imm, RegisterID dest)
     {
         move(TrustedImm32(imm), dest);
     }
+#endif
 
     void swap(RegisterID reg1, RegisterID reg2)
     {
@@ -1383,6 +1436,7 @@ public:
         return branch32(cond, addressTempRegister, right);
     }
 
+#if !defined(V4_BOOTSTRAP)
     Jump branch32(RelationalCondition cond, AbsoluteAddress left, RegisterID right)
     {
         load32(left.m_ptr, dataTempRegister);
@@ -1395,6 +1449,7 @@ public:
         load32(left.m_ptr, addressTempRegister);
         return branch32(cond, addressTempRegister, right);
     }
+#endif
 
     Jump branch8(RelationalCondition cond, RegisterID left, TrustedImm32 right)
     {
@@ -1451,6 +1506,7 @@ public:
         return branchTest32(cond, addressTempRegister, mask);
     }
 
+#if !defined(V4_BOOTSTRAP)
     Jump branchTest8(ResultCondition cond, AbsoluteAddress address, TrustedImm32 mask = TrustedImm32(-1))
     {
         // use addressTempRegister incase the branchTest8 we call uses dataTempRegister. :-/
@@ -1458,6 +1514,7 @@ public:
         load8(Address(addressTempRegister), addressTempRegister);
         return branchTest32(cond, addressTempRegister, mask);
     }
+#endif
 
     void jump(RegisterID target)
     {
@@ -1471,12 +1528,14 @@ public:
         m_assembler.bx(dataTempRegister);
     }
     
+#if !defined(V4_BOOTSTRAP)
     void jump(AbsoluteAddress address)
     {
         move(TrustedImmPtr(address.m_ptr), dataTempRegister);
         load32(Address(dataTempRegister), dataTempRegister);
         m_assembler.bx(dataTempRegister);
     }
+#endif
 
 
     // Arithmetic control flow operations:
@@ -1517,6 +1576,7 @@ public:
         return branchAdd32(cond, dest, imm, dest);
     }
 
+#if !defined(V4_BOOTSTRAP)
     Jump branchAdd32(ResultCondition cond, TrustedImm32 imm, AbsoluteAddress dest)
     {
         // Move the high bits of the address into addressTempRegister,
@@ -1542,6 +1602,7 @@ public:
 
         return Jump(makeBranch(cond));
     }
+#endif
 
     Jump branchMul32(ResultCondition cond, RegisterID src1, RegisterID src2, RegisterID dest)
     {
@@ -1712,6 +1773,7 @@ public:
         return DataLabel32(this);
     }
 
+#if !defined(V4_BOOTSTRAP)
     ALWAYS_INLINE DataLabelPtr moveWithPatch(TrustedImmPtr imm, RegisterID dst)
     {
         padBeforePatch();
@@ -1739,7 +1801,8 @@ public:
         m_makeJumpPatchable = false;
         return PatchableJump(result);
     }
-    
+#endif
+
     PatchableJump patchableBranchTest32(ResultCondition cond, RegisterID reg, TrustedImm32 mask = TrustedImm32(-1))
     {
         m_makeJumpPatchable = true;
@@ -1756,6 +1819,7 @@ public:
         return PatchableJump(result);
     }
 
+#if !defined(V4_BOOTSTRAP)
     PatchableJump patchableBranchPtrWithPatch(RelationalCondition cond, Address left, DataLabelPtr& dataLabel, TrustedImmPtr initialRightValue = TrustedImmPtr(0))
     {
         m_makeJumpPatchable = true;
@@ -1763,6 +1827,7 @@ public:
         m_makeJumpPatchable = false;
         return PatchableJump(result);
     }
+#endif
 
     PatchableJump patchableJump()
     {
@@ -1773,6 +1838,7 @@ public:
         return PatchableJump(result);
     }
 
+#if !defined(V4_BOOTSTRAP)
     ALWAYS_INLINE DataLabelPtr storePtrWithPatch(TrustedImmPtr initialValue, ImplicitAddress address)
     {
         DataLabelPtr label = moveWithPatch(initialValue, dataTempRegister);
@@ -1780,7 +1846,7 @@ public:
         return label;
     }
     ALWAYS_INLINE DataLabelPtr storePtrWithPatch(ImplicitAddress address) { return storePtrWithPatch(TrustedImmPtr(0), address); }
-
+#endif
 
     ALWAYS_INLINE Call tailRecursiveCall()
     {
@@ -1801,6 +1867,7 @@ public:
         return m_assembler.executableOffsetFor(location);
     }
 
+#if !defined(V4_BOOTSTRAP)
     static FunctionPtr readCallTarget(CodeLocationCall call)
     {
         return FunctionPtr(reinterpret_cast<void(*)()>(ARMv7Assembler::readCallTarget(call.dataLocation())));
@@ -1813,7 +1880,8 @@ public:
         const unsigned twoWordOpSize = 4;
         return label.labelAtOffset(-twoWordOpSize * 2);
     }
-    
+#endif
+
     static void revertJumpReplacementToBranchPtrWithPatch(CodeLocationLabel instructionStart, RegisterID rd, void* initialValue)
     {
 #if OS(LINUX) || OS(QNX)
@@ -1927,9 +1995,10 @@ protected:
     }
     
 private:
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
+#if !defined(V4_BOOTSTRAP)
     static void linkCall(void* code, Call call, FunctionPtr function)
     {
         ARMv7Assembler::linkCall(code, call.m_label, function.value());
@@ -1944,6 +2013,7 @@ private:
     {
         ARMv7Assembler::relinkCall(call.dataLocation(), destination.executableAddress());
     }
+#endif
 
     bool m_makeJumpPatchable;
 };
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h b/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
index 734e779c70..68584527fc 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerMIPS.h
@@ -2802,7 +2802,7 @@ private:
     // Otherwise, we can emit any number of instructions.
     bool m_fixedWidth;
 
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
     static void linkCall(void* code, Call call, FunctionPtr function)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerSH4.h b/src/3rdparty/masm/assembler/MacroAssemblerSH4.h
index 56fb74d45b..1e5a3113bb 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerSH4.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerSH4.h
@@ -2278,7 +2278,7 @@ protected:
         return static_cast<SH4Assembler::Condition>(cond);
     }
 private:
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
     static void linkCall(void*, Call, FunctionPtr);
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerX86.h b/src/3rdparty/masm/assembler/MacroAssemblerX86.h
index 9a33fe870e..742a4b48f7 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerX86.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerX86.h
@@ -54,6 +54,38 @@ public:
     using MacroAssemblerX86Common::convertInt32ToDouble;
     using MacroAssemblerX86Common::branchTest8;
 
+#if defined(V4_BOOTSTRAP)
+    void loadPtr(ImplicitAddress address, RegisterID dest)
+    {
+        load32(address, dest);
+    }
+
+    void subPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        sub32(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        add32(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID src, RegisterID dest)
+    {
+        add32(imm, src, dest);
+    }
+
+    void storePtr(RegisterID src, ImplicitAddress address)
+    {
+        store32(src, address);
+    }
+
+    Jump branchTest8(ResultCondition cond, ExtendedAddress address, TrustedImm32 mask = TrustedImm32(-1))
+    {
+        return branchTest8(cond, Address(address.base, address.offset), mask);
+    }
+#endif
+
     void add32(TrustedImm32 imm, RegisterID src, RegisterID dest)
     {
         m_assembler.leal_mr(imm.m_value, src, dest);
@@ -306,7 +338,7 @@ public:
     }
 
 private:
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
     static void linkCall(void* code, Call call, FunctionPtr function)
diff --git a/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h b/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
index 9e74f1c29f..3566702413 100644
--- a/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
+++ b/src/3rdparty/masm/assembler/MacroAssemblerX86_64.h
@@ -52,6 +52,33 @@ public:
     using MacroAssemblerX86Common::loadDouble;
     using MacroAssemblerX86Common::convertInt32ToDouble;
 
+#if defined(V4_BOOTSTRAP)
+    void loadPtr(ImplicitAddress address, RegisterID dest)
+    {
+        load64(address, dest);
+    }
+
+    void subPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        sub64(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID dest)
+    {
+        add64(imm, dest);
+    }
+
+    void addPtr(TrustedImm32 imm, RegisterID src, RegisterID dest)
+    {
+        add64(imm, src, dest);
+    }
+
+    void storePtr(RegisterID src, ImplicitAddress address)
+    {
+        store64(src, address);
+    }
+#endif
+
     void add32(TrustedImm32 imm, AbsoluteAddress address)
     {
         move(TrustedImmPtr(address.m_ptr), scratchRegister);
@@ -634,7 +661,7 @@ public:
     }
 
 private:
-    friend class LinkBuffer;
+    template <typename, template <typename> class> friend class LinkBufferBase;
     friend class RepatchBuffer;
 
     static void linkCall(void* code, Call call, FunctionPtr function)
diff --git a/src/3rdparty/masm/assembler/X86Assembler.h b/src/3rdparty/masm/assembler/X86Assembler.h
index 1875ebaff0..24462ef38f 100644
--- a/src/3rdparty/masm/assembler/X86Assembler.h
+++ b/src/3rdparty/masm/assembler/X86Assembler.h
@@ -29,6 +29,7 @@
 #if ENABLE(ASSEMBLER) && (CPU(X86) || CPU(X86_64))
 
 #include "AssemblerBuffer.h"
+#include "AbstractMacroAssembler.h"
 #include "JITCompilationEffort.h"
 #include <stdint.h>
 #include <wtf/Assertions.h>
@@ -252,6 +253,45 @@ public:
     {
     }
 
+    template <typename LabelType>
+    class Jump {
+        template<class TemplateAssemblerType>
+        friend class AbstractMacroAssembler;
+        friend class Call;
+        template <typename, template <typename> class> friend class LinkBufferBase;
+    public:
+        Jump()
+        {
+        }
+
+        Jump(AssemblerLabel jmp)
+            : m_label(jmp)
+        {
+        }
+
+        LabelType label() const
+        {
+            LabelType result;
+            result.m_label = m_label;
+            return result;
+        }
+
+        void link(AbstractMacroAssembler<X86Assembler>* masm) const
+        {
+            masm->m_assembler.linkJump(m_label, masm->m_assembler.label());
+        }
+
+        void linkTo(LabelType label, AbstractMacroAssembler<X86Assembler>* masm) const
+        {
+            masm->m_assembler.linkJump(m_label, label.label());
+        }
+
+        bool isSet() const { return m_label.isSet(); }
+
+    private:
+        AssemblerLabel m_label;
+    };
+
     // Stack operations:
 
     void push_r(RegisterID reg)
diff --git a/src/3rdparty/masm/masm.pri b/src/3rdparty/masm/masm.pri
index afa1438974..c63cd5da66 100644
--- a/src/3rdparty/masm/masm.pri
+++ b/src/3rdparty/masm/masm.pri
@@ -13,6 +13,7 @@ HEADERS += $$PWD/wtf/RawPointer.h
 
 winrt: SOURCES += $$PWD/wtf/OSAllocatorWinRT.cpp
 else:win32: SOURCES += $$PWD/wtf/OSAllocatorWin.cpp
+else:integrity: SOURCES += $$PWD/wtf/OSAllocatorIntegrity.cpp
 else: SOURCES += $$PWD/wtf/OSAllocatorPosix.cpp
 HEADERS += $$PWD/wtf/OSAllocator.h
 
diff --git a/src/3rdparty/masm/stubs/ExecutableAllocator.h b/src/3rdparty/masm/stubs/ExecutableAllocator.h
index 8617229b06..9a2a9773b5 100644
--- a/src/3rdparty/masm/stubs/ExecutableAllocator.h
+++ b/src/3rdparty/masm/stubs/ExecutableAllocator.h
@@ -61,7 +61,7 @@ namespace JSC {
 class JSGlobalData;
 
 struct ExecutableMemoryHandle : public RefCounted<ExecutableMemoryHandle> {
-    ExecutableMemoryHandle(QV4::ExecutableAllocator *allocator, int size)
+    ExecutableMemoryHandle(QV4::ExecutableAllocator *allocator, size_t size)
         : m_allocator(allocator)
         , m_size(size)
     {
@@ -79,14 +79,14 @@ struct ExecutableMemoryHandle : public RefCounted<ExecutableMemoryHandle> {
     inline bool isManaged() const { return true; }
 
     void* start() { return m_allocation->start(); }
-    int sizeInBytes() { return m_size; }
+    size_t sizeInBytes() { return m_size; }
 
     QV4::ExecutableAllocator::ChunkOfPages *chunk() const
     { return m_allocator->chunkForAllocation(m_allocation); }
 
     QV4::ExecutableAllocator *m_allocator;
     QV4::ExecutableAllocator::Allocation *m_allocation;
-    int m_size;
+    size_t m_size;
 };
 
 struct ExecutableAllocator {
@@ -94,7 +94,7 @@ struct ExecutableAllocator {
         : realAllocator(alloc)
     {}
 
-    PassRefPtr<ExecutableMemoryHandle> allocate(JSGlobalData&, int size, void*, int)
+    PassRefPtr<ExecutableMemoryHandle> allocate(JSGlobalData&, size_t size, void*, int)
     {
         return adoptRef(new ExecutableMemoryHandle(realAllocator, size));
     }
diff --git a/src/3rdparty/masm/wtf/OSAllocatorIntegrity.cpp b/src/3rdparty/masm/wtf/OSAllocatorIntegrity.cpp
new file mode 100644
index 0000000000..451ca147d1
--- /dev/null
+++ b/src/3rdparty/masm/wtf/OSAllocatorIntegrity.cpp
@@ -0,0 +1,232 @@
+/****************************************************************************
+**
+** Copyright (C) Rolland Dudemaine All rights reserved.
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "config.h"
+#include "OSAllocator.h"
+
+#include <INTEGRITY.h>
+#include <memory_region.h>
+#include <set>
+#include <wtf/Assertions.h>
+#include <wtf/UnusedParam.h>
+
+#define ASP_PAGESIZE    0x1000
+
+namespace WTF {
+struct MRPair {
+    mutable MemoryRegion    pmr;
+    mutable MemoryRegion    vmr;
+
+    mutable bool mapped;
+
+    Address start;
+
+    MRPair(Address _start = 0) :
+        pmr(0),
+        vmr(0),
+        mapped(false),
+        start(_start)
+    {}
+
+    bool operator<(const MRPair& rhs) const
+    {
+        return this->start < rhs.start;
+    }
+};
+
+class MRContainer
+{
+private:
+    std::set<MRPair>        mrset;
+    LocalMutex              iteratorGuard;
+public:
+    MRContainer() {
+        CheckSuccess(CreateLocalMutex(&iteratorGuard));
+    }
+    const MRPair* getMRPair(Address start) {
+        WaitForLocalMutex(iteratorGuard);
+        auto pairIterator = mrset.find(MRPair(start));
+        const MRPair* result = ((pairIterator == mrset.end()) ? NULL : &(*pairIterator));
+        ReleaseLocalMutex(iteratorGuard);
+        return result;
+    }
+    Error deleteMRPair(const MRPair* pair) {
+        int erased = 0;
+        WaitForLocalMutex(iteratorGuard);
+        erased = mrset.erase(*pair);
+        ReleaseLocalMutex(iteratorGuard);
+        if(erased == 1)
+            return Success;
+        else
+            return ArgumentError;   /* An exception could be thrown in this case */
+    }
+    Error insertMRPair(MRPair* pair) {
+        WaitForLocalMutex(iteratorGuard);
+        auto inserted = mrset.insert(*pair);
+        ReleaseLocalMutex(iteratorGuard);
+        if(inserted.second == true)
+            return Success;
+        else
+            return Failure;         /* An exception could be thrown in this case */
+    }
+    ~MRContainer() {
+        CheckSuccess(CloseLocalMutex(iteratorGuard));
+    }
+};
+
+static MRContainer memoryRegionsContainer;
+
+Error setAttributes(MemoryRegion mr, bool writable, bool executable)
+{
+    Value attributes = MEMORY_READ;
+    if(writable)
+        attributes |= MEMORY_WRITE;
+    if(executable)
+        attributes |= MEMORY_EXEC;
+    return SetMemoryRegionAttributes(mr, attributes);
+}
+
+void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, bool executable)
+{
+    MemoryRegion VMR;
+
+    Address virtualStart, length;
+
+    CheckSuccess(AllocateAnyMemoryRegion(__ghs_VirtualMemoryRegionPool, bytes, &VMR));
+    CheckSuccess(GetMemoryRegionAddresses(VMR, &virtualStart, &length));
+    Address addressIterator = virtualStart;
+    for(int i=0; i<(bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE; i++) {
+        MRPair pair;
+        CheckSuccess(SplitMemoryRegion(VMR, ASP_PAGESIZE, &pair.vmr));
+        CheckSuccess(setAttributes(pair.vmr, writable, executable));
+        pair.start = addressIterator;
+
+        memoryRegionsContainer.insertMRPair(&pair);
+        addressIterator += ASP_PAGESIZE;
+    }
+
+    CheckSuccess(CloseMemoryRegion(VMR));
+    return (void*)virtualStart;
+}
+
+void* OSAllocator::reserveAndCommit(size_t bytes, Usage usage, bool writable, bool executable, bool includesGuardPages)
+{
+    MemoryRegion VMR;
+
+    Address virtualStart, length;
+
+    CheckSuccess(AllocateAnyMemoryRegion(__ghs_VirtualMemoryRegionPool, bytes, &VMR));
+    CheckSuccess(GetMemoryRegionAddresses(VMR, &virtualStart, &length));
+
+    Address addressIterator = virtualStart;
+    for(int i=0; i<(bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE; i++) {
+        MRPair pair;
+        pair.start = addressIterator;
+        CheckSuccess(SplitMemoryRegion(VMR, ASP_PAGESIZE, &pair.vmr));
+        CheckSuccess(setAttributes(pair.vmr, writable, executable));
+        /* Do not map the first and the last pages if guard pages are required */
+        if(!includesGuardPages || (i!=0 && i!= (bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE -1))
+        {
+            CheckSuccess(GetPageFromAddressSpaceFreeList(GetCurrentAddressSpace(), &pair.pmr));
+            CheckSuccess(MapMemoryRegion(pair.vmr, pair.pmr));
+            pair.mapped = true;
+        }
+
+        memoryRegionsContainer.insertMRPair(&pair);
+        addressIterator += ASP_PAGESIZE;
+    }
+
+    CheckSuccess(CloseMemoryRegion(VMR));
+    return (void*)virtualStart;
+}
+
+void OSAllocator::commit(void* address, size_t bytes, bool writable, bool executable)
+{
+    for(int i=0; i<(bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE; i++)
+    {
+        const MRPair* pair = memoryRegionsContainer.getMRPair((Address)address);
+        if(pair == NULL)
+            return;
+        CheckSuccess(setAttributes(pair->vmr, writable, executable));
+        CheckSuccess(GetPageFromAddressSpaceFreeList(GetCurrentAddressSpace(), &pair->pmr));
+        CheckSuccess(MapMemoryRegion(pair->vmr, pair->pmr));
+        pair->mapped = true;
+        address = (char*)address +  ASP_PAGESIZE;
+    }
+}
+
+void OSAllocator::decommit(void* address, size_t bytes)
+{
+    for(int i=0; i<(bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE; i++)
+    {
+        const MRPair* pair = memoryRegionsContainer.getMRPair((Address)address);
+        if(pair == NULL)
+            return;
+        if(pair->mapped == false)
+            continue;
+
+        CheckSuccess(UnmapMemoryRegion(pair->vmr));
+        CheckSuccess(PutPageOnAddressSpaceFreeList(GetCurrentAddressSpace(), pair->pmr));
+        pair->mapped = false;
+        address = (char*)address + ASP_PAGESIZE;
+    }
+}
+
+void OSAllocator::releaseDecommitted(void* address, size_t bytes)
+{
+    for(int i=0; i<(bytes + ASP_PAGESIZE -1)/ASP_PAGESIZE; i++)
+    {
+        const MRPair* pair = memoryRegionsContainer.getMRPair((Address)address);
+        if(pair == NULL)
+            return;
+        /* Check if the memory is still committed */
+        if(pair->mapped == true)
+        {
+            CheckSuccess(UnmapMemoryRegion(pair->vmr));
+            CheckSuccess(PutPageOnAddressSpaceFreeList(GetCurrentAddressSpace(), pair->pmr));
+            pair->mapped = false;
+        }
+        CheckSuccess(AddToMemoryPool(__ghs_VirtualMemoryRegionPool, pair->vmr));
+        address = (char*)address + ASP_PAGESIZE;
+
+        memoryRegionsContainer.deleteMRPair(pair);
+    }
+}
+} // namespace WTF
diff --git a/src/3rdparty/masm/wtf/Platform.h b/src/3rdparty/masm/wtf/Platform.h
index bc62c381db..7f2023a68a 100644
--- a/src/3rdparty/masm/wtf/Platform.h
+++ b/src/3rdparty/masm/wtf/Platform.h
@@ -949,10 +949,6 @@
 #define WTF_USE_ACCESSIBILITY_CONTEXT_MENUS 1
 #endif
 
-#if CPU(ARM_THUMB2) || CPU(ARM64)
-#define ENABLE_BRANCH_COMPACTION 1
-#endif
-
 #if !defined(ENABLE_THREADING_LIBDISPATCH) && HAVE(DISPATCH_H)
 #define ENABLE_THREADING_LIBDISPATCH 1
 #elif !defined(ENABLE_THREADING_OPENMP) && defined(_OPENMP)
diff --git a/src/3rdparty/masm/yarr/YarrJIT.cpp b/src/3rdparty/masm/yarr/YarrJIT.cpp
index d8211ec4b2..e4f2d97759 100644
--- a/src/3rdparty/masm/yarr/YarrJIT.cpp
+++ b/src/3rdparty/masm/yarr/YarrJIT.cpp
@@ -39,7 +39,7 @@ using namespace WTF;
 namespace JSC { namespace Yarr {
 
 template<YarrJITCompileMode compileMode>
-class YarrGenerator : private MacroAssembler {
+class YarrGenerator : private DefaultMacroAssembler {
     friend void jitCompile(JSGlobalData*, YarrCodeBlock& jitObject, const String& pattern, unsigned& numSubpatterns, const char*& error, bool ignoreCase, bool multiline);
 
 #if CPU(ARM)
@@ -599,7 +599,7 @@ class YarrGenerator : private MacroAssembler {
         }
 
         // Called at the end of code generation to link all return addresses.
-        void linkDataLabels(LinkBuffer& linkBuffer)
+        void linkDataLabels(LinkBuffer<JSC::DefaultMacroAssembler>& linkBuffer)
         {
             ASSERT(isEmpty());
             for (unsigned i = 0; i < m_backtrackRecords.size(); ++i)
@@ -2676,7 +2676,7 @@ public:
         backtrack();
 
         // Link & finalize the code.
-        LinkBuffer linkBuffer(*globalData, this, REGEXP_CODE_ID);
+        LinkBuffer<JSC::DefaultMacroAssembler> linkBuffer(*globalData, this, REGEXP_CODE_ID);
         m_backtrackingState.linkDataLabels(linkBuffer);
 
         if (compileMode == MatchOnly) {
diff --git a/src/imports/imports.pro b/src/imports/imports.pro
index 0d84bf538f..6dab501d71 100644
--- a/src/imports/imports.pro
+++ b/src/imports/imports.pro
@@ -16,6 +16,7 @@ qtHaveModule(quick) {
         layouts \
         qtquick2 \
         window \
+        sharedimage \
         testlib
 
     qtConfig(opengl(es1|es2)?): \
diff --git a/src/imports/sharedimage/plugin.cpp b/src/imports/sharedimage/plugin.cpp
new file mode 100644
index 0000000000..f20edc641c
--- /dev/null
+++ b/src/imports/sharedimage/plugin.cpp
@@ -0,0 +1,134 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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 <qqmlextensionplugin.h>
+#include <qqmlengine.h>
+#include <sharedimageprovider.h>
+
+
+/*!
+    \qmlmodule QtQuick.SharedImage 1
+    \title Qt Quick Shared Image Provider
+    \ingroup qmlmodules
+    \brief Adds an image provider which utilizes shared CPU memory
+
+    \section2 Summary
+
+    This module provides functionality to save memory in use cases where
+    several Qt Quick applications use the same local image files. It does this
+    by placing the decoded QImage data in shared system memory, making it
+    accessible to all the processes (see QSharedMemory).
+
+    This module only shares CPU memory. It does not provide sharing of GPU
+    memory or textures.
+
+    \section2 Usage
+
+    To use this module, import it like this:
+    \code
+    import QtQuick.SharedImage 1.0
+    \endcode
+
+    The sharing functionality is provided through a QQuickImageProvider. Use
+    the "image:" scheme for the URL source of the image, followed by the
+    identifier \e shared, followed by the image file path. For example:
+
+    \code
+    Image { source: "image://shared/usr/share/wallpapers/mybackground.jpg" }
+    \endcode
+
+    This will look for the file \e /usr/share/wallpapers/mybackground.jpg.
+    The first process that does this will read the image file
+    using normal Qt image loading. The decoded image data will then be placed
+    in shared memory, using the full file path as key. Later processes
+    requesting the same image will discover that the data is already available
+    in shared memory. They will then use that instead of loading the image file
+    again.
+
+    The shared image data will be kept available until the last process has deleted
+    its last reference to the shared image, at which point it is automatically released.
+
+    If system memory sharing is not available, the shared image provider falls
+    back to normal, unshared image loading.
+
+    The file path must be absolute. To use a relative path, make it absolute
+    using \e Qt.resolvedUrl() and replace the URL scheme. For example:
+
+    \code
+    ...
+    property string imagePrefix: Qt.resolvedUrl("../myimages/").replace("file://", "image://shared/")
+    Image { source: imagePrefix + "myimage.png" }
+    \endcode
+
+    The shared image module does not provide any directly usable QML types.
+*/
+
+static void initResources()
+{
+#ifdef QT_STATIC
+    Q_INIT_RESOURCE(qmake_QtQuick_SharedImage);
+#endif
+}
+
+QT_BEGIN_NAMESPACE
+
+class QtQuickSharedImagePlugin : public QQmlExtensionPlugin
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID QQmlExtensionInterface_iid)
+public:
+    QtQuickSharedImagePlugin(QObject *parent = 0) : QQmlExtensionPlugin(parent) { initResources(); }
+
+    void registerTypes(const char *uri) Q_DECL_OVERRIDE
+    {
+        Q_ASSERT(uri == QStringLiteral("QtQuick.SharedImage"));
+        // Need to register *something* to let our version number be known:
+        qmlRegisterTypeNotAvailable(uri, 1, 0, "nosuchtype", QStringLiteral("Just a dummy type, do not use"));
+    }
+
+    void initializeEngine(QQmlEngine *engine, const char *uri) override
+    {
+        Q_UNUSED(uri);
+        engine->addImageProvider("shared", new SharedImageProvider);
+    }
+};
+
+QT_END_NAMESPACE
+
+#include "plugin.moc"
diff --git a/src/imports/sharedimage/qmldir b/src/imports/sharedimage/qmldir
new file mode 100644
index 0000000000..64a5aa8ac1
--- /dev/null
+++ b/src/imports/sharedimage/qmldir
@@ -0,0 +1,3 @@
+module QtQuick.SharedImage
+plugin sharedimageplugin
+classname QtQuickSharedImagePlugin
diff --git a/src/imports/sharedimage/qsharedimageloader.cpp b/src/imports/sharedimage/qsharedimageloader.cpp
new file mode 100644
index 0000000000..65cbd92bb4
--- /dev/null
+++ b/src/imports/sharedimage/qsharedimageloader.cpp
@@ -0,0 +1,265 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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 "qsharedimageloader_p.h"
+#include <private/qobject_p.h>
+#include <private/qimage_p.h>
+#include <QSharedMemory>
+
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcSharedImage, "qt.quick.sharedimage");
+
+struct SharedImageHeader {
+    quint8 magic;
+    quint8 version;
+    quint16 offset;
+    qint32 width;
+    qint32 height;
+    qint32 bpl;
+    QImage::Format format;
+};
+Q_STATIC_ASSERT(sizeof(SharedImageHeader) % 4 == 0);
+
+#ifndef QT_NO_SHAREDMEMORY
+struct SharedImageInfo {
+    QString path;
+    QPointer<QSharedMemory> shmp;
+};
+
+void cleanupSharedImage(void *cleanupInfo)
+{
+    if (!cleanupInfo)
+        return;
+    SharedImageInfo *sii = static_cast<SharedImageInfo *>(cleanupInfo);
+    qCDebug(lcSharedImage) << "Cleanup called for" << sii->path;
+    if (sii->shmp.isNull()) {
+        qCDebug(lcSharedImage) << "shm is 0 for" << sii->path;
+        return;
+    }
+    QSharedMemory *shm = sii->shmp.data();
+    sii->shmp.clear();
+    delete shm;    // destructor detaches
+    delete sii;
+}
+#else
+void cleanupSharedImage(void *) {}
+#endif
+
+class QSharedImageLoaderPrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QSharedImageLoader)
+
+public:
+    QSharedImageLoaderPrivate()
+        : QObjectPrivate()
+    {}
+
+    QImage load(const QString &path, QSharedImageLoader::ImageParameters *params);
+
+    void storeImageToMem(void *data, const QImage &img);
+
+    bool verifyMem(const void *data, int size);
+
+    QImage createImageFromMem(const void *data, void *cleanupInfo);
+
+};
+
+
+void QSharedImageLoaderPrivate::storeImageToMem(void *data, const QImage &img)
+{
+    Q_ASSERT(data && !img.isNull());
+
+    SharedImageHeader *h = static_cast<SharedImageHeader *>(data);
+    h->magic = 'Q';
+    h->version = 1;
+    h->offset = sizeof(SharedImageHeader);
+    h->width = img.width();
+    h->height = img.height();
+    h->bpl = img.bytesPerLine();
+    h->format = img.format();
+
+    uchar *p = static_cast<uchar *>(data) + sizeof(SharedImageHeader);
+    memcpy(p, img.constBits(), img.byteCount());
+}
+
+
+bool QSharedImageLoaderPrivate::verifyMem(const void *data, int size)
+{
+    if (!data || size < int(sizeof(SharedImageHeader)))
+        return false;
+
+    const SharedImageHeader *h = static_cast<const SharedImageHeader *>(data);
+    if ((h->magic != 'Q')
+        || (h->version < 1)
+        || (h->offset < sizeof(SharedImageHeader))
+        || (h->width <= 0)
+        || (h->height <= 0)
+        || (h->bpl <= 0)
+        || (h->format <= QImage::Format_Invalid)
+        || (h->format >= QImage::NImageFormats)) {
+        return false;
+    }
+
+    int availSize = size - h->offset;
+    if (h->height * h->bpl > availSize)
+        return false;
+    if ((qt_depthForFormat(h->format) * h->width * h->height) > (8 * availSize))
+        return false;
+
+    return true;
+}
+
+
+QImage QSharedImageLoaderPrivate::createImageFromMem(const void *data, void *cleanupInfo)
+{
+    const SharedImageHeader *h = static_cast<const SharedImageHeader *>(data);
+    const uchar *p = static_cast<const uchar *>(data) + h->offset;
+
+    QImage img(p, h->width, h->height, h->bpl, h->format, cleanupSharedImage, cleanupInfo);
+    return img;
+}
+
+
+QImage QSharedImageLoaderPrivate::load(const QString &path, QSharedImageLoader::ImageParameters *params)
+{
+#ifndef QT_NO_SHAREDMEMORY
+    Q_Q(QSharedImageLoader);
+
+    QImage nil;
+    if (path.isEmpty())
+        return nil;
+
+    QScopedPointer<QSharedMemory> shm(new QSharedMemory(q->key(path, params)));
+    bool locked = false;
+
+    if (!shm->attach(QSharedMemory::ReadOnly)) {
+        QImage img = q->loadFile(path, params);
+        if (img.isNull())
+            return nil;
+        int size = sizeof(SharedImageHeader) + img.byteCount();
+        if (shm->create(size)) {
+            qCDebug(lcSharedImage) << "Created new shm segment of size" << size << "for image" << path;
+            if (!shm->lock()) {
+                qCDebug(lcSharedImage) << "Lock1 failed!?" << shm->errorString();
+                return nil;
+            }
+            locked = true;
+            storeImageToMem(shm->data(), img);
+        } else if (shm->error() == QSharedMemory::AlreadyExists) {
+            // race handling: other process may have created the share while
+            // we loaded the image, so try again to just attach
+            if (!shm->attach(QSharedMemory::ReadOnly)) {
+                qCDebug(lcSharedImage) << "Attach to existing failed?" << shm->errorString();
+                return nil;
+            }
+        } else {
+            qCDebug(lcSharedImage) << "Create failed?" << shm->errorString();
+            return nil;
+        }
+    }
+
+    Q_ASSERT(shm->isAttached());
+
+    if (!locked) {
+        if (!shm->lock()) {
+            qCDebug(lcSharedImage) << "Lock2 failed!?" << shm->errorString();
+            return nil;
+        }
+        locked = true;
+    }
+
+    if (!verifyMem(shm->constData(), shm->size())) {
+        qCDebug(lcSharedImage) << "Verifymem failed!?";
+        shm->unlock();
+        return nil;
+    }
+
+    QSharedMemory *shmp = shm.take();
+    SharedImageInfo *sii = new SharedImageInfo;
+    sii->path = path;
+    sii->shmp = shmp;
+    QImage shImg = createImageFromMem(shmp->constData(), sii);
+
+    if (!shmp->unlock()) {
+        qCDebug(lcSharedImage) << "UnLock failed!?";
+    }
+
+    return shImg;
+#else
+    Q_UNUSED(path);
+    Q_UNUSED(params);
+    return QImage();
+#endif
+}
+
+
+QSharedImageLoader::QSharedImageLoader(QObject *parent)
+    : QObject(*new QSharedImageLoaderPrivate, parent)
+{
+}
+
+QSharedImageLoader::~QSharedImageLoader()
+{
+}
+
+QImage QSharedImageLoader::load(const QString &path, ImageParameters *params)
+{
+    Q_D(QSharedImageLoader);
+
+    return d->load(path, params);
+}
+
+QImage QSharedImageLoader::loadFile(const QString &path, ImageParameters *params)
+{
+    Q_UNUSED(params);
+
+    return QImage(path);
+}
+
+QString QSharedImageLoader::key(const QString &path, ImageParameters *params)
+{
+    Q_UNUSED(params);
+
+    return path;
+}
+
+
+QT_END_NAMESPACE
diff --git a/src/imports/sharedimage/qsharedimageloader_p.h b/src/imports/sharedimage/qsharedimageloader_p.h
new file mode 100644
index 0000000000..afb50e5088
--- /dev/null
+++ b/src/imports/sharedimage/qsharedimageloader_p.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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 QSHAREDIMAGELOADER_H
+#define QSHAREDIMAGELOADER_H
+
+#include <QImage>
+#include <QVariant>
+#include <QLoggingCategory>
+
+QT_BEGIN_NAMESPACE
+
+Q_DECLARE_LOGGING_CATEGORY(lcSharedImage);
+
+class QSharedImageLoaderPrivate;
+
+class QSharedImageLoader : public QObject
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QSharedImageLoader)
+
+public:
+    enum ImageParameter {
+        OriginalSize = 0,
+        RequestedSize,
+        NumImageParameters
+    };
+    typedef QVector<QVariant> ImageParameters;
+
+    QSharedImageLoader(QObject *parent = Q_NULLPTR);
+    ~QSharedImageLoader();
+
+    QImage load(const QString &path, ImageParameters *params = Q_NULLPTR);
+
+protected:
+    virtual QImage loadFile(const QString &path, ImageParameters *params);
+    virtual QString key(const QString &path, ImageParameters *params);
+
+private:
+    Q_DISABLE_COPY(QSharedImageLoader)
+};
+
+QT_END_NAMESPACE
+
+#endif // QSHAREDIMAGELOADER_H
diff --git a/src/imports/sharedimage/sharedimage.pro b/src/imports/sharedimage/sharedimage.pro
new file mode 100644
index 0000000000..523de66ac1
--- /dev/null
+++ b/src/imports/sharedimage/sharedimage.pro
@@ -0,0 +1,17 @@
+CXX_MODULE = qml
+TARGET = sharedimageplugin
+TARGETPATH = QtQuick/SharedImage
+IMPORT_VERSION = 1.0
+
+QT *= quick qml gui-private core-private
+
+SOURCES += \
+    plugin.cpp \
+    sharedimageprovider.cpp \
+    qsharedimageloader.cpp
+
+HEADERS += \
+    sharedimageprovider.h \
+    qsharedimageloader_p.h
+
+load(qml_plugin)
diff --git a/src/imports/sharedimage/sharedimageprovider.cpp b/src/imports/sharedimage/sharedimageprovider.cpp
new file mode 100644
index 0000000000..2dd3a130e9
--- /dev/null
+++ b/src/imports/sharedimage/sharedimageprovider.cpp
@@ -0,0 +1,156 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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 <sharedimageprovider.h>
+#include <qsharedimageloader_p.h>
+#include <qquickimageprovider.h>
+#include <private/qimage_p.h>
+#include <QImageReader>
+#include <QFileInfo>
+#include <QDir>
+
+class QuickSharedImageLoader : public QSharedImageLoader
+{
+    Q_OBJECT
+    friend class SharedImageProvider;
+
+public:
+    QuickSharedImageLoader(QObject *parent = Q_NULLPTR)
+        : QSharedImageLoader(parent)
+    {
+    }
+
+protected:
+    QImage loadFile(const QString &path, ImageParameters *params) override
+    {
+        QImageReader imgio(path);
+        QSize realSize = imgio.size();
+        QSize requestSize = params ? params->value(RequestedSize).toSize() : QSize();
+
+        // Following qquickpixmapcache's readImage, from here...
+        const bool force_scale = imgio.format() == "svg" || imgio.format() == "svgz";
+
+        if (requestSize.width() > 0 || requestSize.height() > 0) {
+            QSize s = realSize;
+            qreal ratio = 0.0;
+            if (requestSize.width() && (force_scale || requestSize.width() < s.width())) {
+                ratio = qreal(requestSize.width())/s.width();
+            }
+            if (requestSize.height() && (force_scale || requestSize.height() < s.height())) {
+                qreal hr = qreal(requestSize.height())/s.height();
+                if (ratio == 0.0 || hr < ratio)
+                    ratio = hr;
+            }
+            if (ratio > 0.0) {
+                s.setHeight(qRound(s.height() * ratio));
+                s.setWidth(qRound(s.width() * ratio));
+                imgio.setScaledSize(s);
+            }
+        }
+        // ... to here
+
+        QImage image;
+        if (imgio.read(&image)) {
+            if (realSize.isEmpty())
+                realSize = image.size();
+            // Make sure we have acceptable format for texture uploader, or it will convert & lose sharing
+            // This mimics the testing & conversion normally done by the quick pixmapcache & texturefactory
+            if (image.format() != QImage::Format_RGB32 && image.format() != QImage::Format_ARGB32_Premultiplied) {
+                QImage::Format newFmt = QImage::Format_RGB32;
+                if (image.hasAlphaChannel() && image.data_ptr()->checkForAlphaPixels())
+                    newFmt = QImage::Format_ARGB32_Premultiplied;
+                qCDebug(lcSharedImage) << "Convert on load from format" << image.format() << "to" << newFmt;
+                image = image.convertToFormat(newFmt);
+            }
+        }
+
+        if (params && params->count() > OriginalSize)
+            params->replace(OriginalSize, realSize);
+
+        return image;
+    }
+
+    QString key(const QString &path, ImageParameters *params) override
+    {
+        QSize reqSz = params->value(RequestedSize).toSize();
+        if (!reqSz.isValid())
+            return path;
+
+        QString key = path + QStringLiteral("_%1x%2").arg(reqSz.width()).arg(reqSz.height());
+        qCDebug(lcSharedImage) << "KEY:" << key;
+        return key;
+    }
+};
+
+
+SharedImageProvider::SharedImageProvider()
+    : QQuickImageProvider(QQuickImageProvider::Image), loader(new QuickSharedImageLoader)
+{
+}
+
+QImage SharedImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+{
+    QFileInfo fi(QDir::root(), id);
+    QString path = fi.canonicalFilePath();
+    if (path.isEmpty())
+        return QImage();
+
+    QSharedImageLoader::ImageParameters params(QSharedImageLoader::NumImageParameters);
+    params[QSharedImageLoader::RequestedSize].setValue(requestedSize);
+
+    QImage img = loader->load(path, &params);
+    if (img.isNull()) {
+        // May be sharing problem, fall back to normal local load
+        img = loader->loadFile(path, &params);
+        if (!img.isNull())
+            qCWarning(lcSharedImage) << "Sharing problem; loading" << id << "unshared";
+    }
+
+    //... QSize realSize = params.value(QSharedImageLoader::OriginalSize).toSize();
+    // quickpixmapcache's readImage() reports back the original size, prior to requestedSize scaling, in the *size
+    // parameter. That value is currently ignored by quick however, which only cares about the present size of the
+    // returned image. So handling and sharing of info on pre-scaled size is currently not implemented.
+    if (size) {
+        *size = img.size();
+    }
+
+    return img;
+}
+
+#include "sharedimageprovider.moc"
diff --git a/src/imports/sharedimage/sharedimageprovider.h b/src/imports/sharedimage/sharedimageprovider.h
new file mode 100644
index 0000000000..a2f6b6ef2f
--- /dev/null
+++ b/src/imports/sharedimage/sharedimageprovider.h
@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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 SHAREDIMAGEPROVIDER_H
+#define SHAREDIMAGEPROVIDER_H
+
+#include <QQuickImageProvider>
+#include <QScopedPointer>
+
+class QuickSharedImageLoader;
+
+class SharedImageProvider : public QQuickImageProvider
+{
+public:
+    SharedImageProvider();
+
+    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
+
+protected:
+    QScopedPointer<QuickSharedImageLoader> loader;
+};
+#endif // SHAREDIMAGEPROVIDER_H
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgglyphnode.cpp b/src/plugins/scenegraph/openvg/qsgopenvgglyphnode.cpp
index 8be2a97034..9cf4184c20 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgglyphnode.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvgglyphnode.cpp
@@ -43,6 +43,7 @@
 #include "qsgopenvghelpers.h"
 #include "qsgopenvgfontglyphcache.h"
 #include "qopenvgoffscreensurface.h"
+#include <cmath>
 
 QT_BEGIN_NAMESPACE
 
@@ -143,7 +144,7 @@ void QSGOpenVGGlyphNode::render()
         vgLoadMatrix(transform().constData());
     } else {
         vgLoadIdentity();
-        offscreenSurface = new QOpenVGOffscreenSurface(QSize(ceil(m_bounding_rect.width()), ceil(m_bounding_rect.height())));
+        offscreenSurface = new QOpenVGOffscreenSurface(QSize(std::ceil(m_bounding_rect.width()), std::ceil(m_bounding_rect.height())));
         offscreenSurface->makeCurrent();
     }
 
diff --git a/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp b/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
index be437303bc..0bd51cbf46 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
@@ -39,7 +39,7 @@
 
 #include "qsgopenvginternalrectanglenode.h"
 #include "qsgopenvghelpers.h"
-
+#include <cmath>
 #include <VG/vgu.h>
 
 QSGOpenVGInternalRectangleNode::QSGOpenVGInternalRectangleNode()
@@ -207,9 +207,9 @@ void QSGOpenVGInternalRectangleNode::render()
         vgLoadIdentity();
         if (m_radius > 0) {
             // Fallback to rendering to an image for rounded rects with perspective transforms
-            if (m_offscreenSurface == nullptr || m_offscreenSurface->size() != QSize(ceil(m_rect.width()), ceil(m_rect.height()))) {
+            if (m_offscreenSurface == nullptr || m_offscreenSurface->size() != QSize(std::ceil(m_rect.width()), std::ceil(m_rect.height()))) {
                 delete m_offscreenSurface;
-                m_offscreenSurface = new QOpenVGOffscreenSurface(QSize(ceil(m_rect.width()), ceil(m_rect.height())));
+                m_offscreenSurface = new QOpenVGOffscreenSurface(QSize(std::ceil(m_rect.width()), std::ceil(m_rect.height())));
             }
 
             m_offscreenSurface->makeCurrent();
diff --git a/src/qml/compiler/compiler.pri b/src/qml/compiler/compiler.pri
index 1de5dfa6fa..fa66d3a6e3 100644
--- a/src/qml/compiler/compiler.pri
+++ b/src/qml/compiler/compiler.pri
@@ -39,7 +39,10 @@ SOURCES += \
 unix: SOURCES += $$PWD/qv4compilationunitmapper_unix.cpp
 else: SOURCES += $$PWD/qv4compilationunitmapper_win.cpp
 
-qtConfig(qml-interpreter) {
+qtConfig(private_tests): LIBS_PRIVATE += $$QMAKE_LIBS_DYNLOAD
+}
+
+qmldevtools_build|qtConfig(qml-interpreter) {
     HEADERS += \
         $$PWD/qv4instr_moth_p.h \
         $$PWD/qv4isel_moth_p.h
@@ -48,6 +51,3 @@ qtConfig(qml-interpreter) {
         $$PWD/qv4isel_moth.cpp
 }
 
-
-qtConfig(private_tests): LIBS_PRIVATE += $$QMAKE_LIBS_DYNLOAD
-}
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 54d0cb4f46..8a7507c92e 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -2061,4 +2061,156 @@ QQmlPropertyData *PropertyResolver::signal(const QString &name, bool *notInRevis
     return 0;
 }
 
+IRLoader::IRLoader(const QV4::CompiledData::Unit *qmlData, QmlIR::Document *output)
+    : unit(qmlData)
+    , output(output)
+{
+    pool = output->jsParserEngine.pool();
+}
+
+void IRLoader::load()
+{
+    output->jsGenerator.stringTable.clear();
+    for (uint i = 0; i < unit->stringTableSize; ++i)
+        output->jsGenerator.stringTable.registerString(unit->stringAt(i));
+
+    for (quint32 i = 0; i < unit->nImports; ++i)
+        output->imports << unit->importAt(i);
+
+    if (unit->flags & QV4::CompiledData::Unit::IsSingleton) {
+        QmlIR::Pragma *p = New<QmlIR::Pragma>();
+        p->location = QV4::CompiledData::Location();
+        p->type = QmlIR::Pragma::PragmaSingleton;
+        output->pragmas << p;
+    }
+
+    output->indexOfRootObject = unit->indexOfRootObject;
+
+    for (uint i = 0; i < unit->nObjects; ++i) {
+        const QV4::CompiledData::Object *serializedObject = unit->objectAt(i);
+        QmlIR::Object *object = loadObject(serializedObject);
+        output->objects.append(object);
+    }
+}
+
+struct FakeExpression : public QQmlJS::AST::NullExpression
+{
+    FakeExpression(int start, int length)
+        : location(start, length)
+    {}
+
+    virtual QQmlJS::AST::SourceLocation firstSourceLocation() const
+    { return location; }
+
+    virtual QQmlJS::AST::SourceLocation lastSourceLocation() const
+    { return location; }
+
+private:
+    QQmlJS::AST::SourceLocation location;
+};
+
+QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedObject)
+{
+    QmlIR::Object *object = pool->New<QmlIR::Object>();
+    object->init(pool, serializedObject->inheritedTypeNameIndex, serializedObject->idNameIndex);
+
+    object->indexOfDefaultPropertyOrAlias = serializedObject->indexOfDefaultPropertyOrAlias;
+    object->defaultPropertyIsAlias = serializedObject->defaultPropertyIsAlias;
+
+    object->location = serializedObject->location;
+    object->locationOfIdProperty = serializedObject->locationOfIdProperty;
+
+    QVector<int> functionIndices;
+    functionIndices.reserve(serializedObject->nFunctions + serializedObject->nBindings / 2);
+
+    for (uint i = 0; i < serializedObject->nBindings; ++i) {
+        QmlIR::Binding *b = pool->New<QmlIR::Binding>();
+        *static_cast<QV4::CompiledData::Binding*>(b) = serializedObject->bindingTable()[i];
+        object->bindings->append(b);
+        if (b->type == QV4::CompiledData::Binding::Type_Script) {
+            functionIndices.append(b->value.compiledScriptIndex);
+            b->value.compiledScriptIndex = functionIndices.count() - 1;
+
+            QmlIR::CompiledFunctionOrExpression *foe = pool->New<QmlIR::CompiledFunctionOrExpression>();
+            foe->disableAcceleratedLookups = true;
+            foe->nameIndex = 0;
+
+            QQmlJS::AST::ExpressionNode *expr;
+
+            if (b->stringIndex != quint32(0)) {
+                const int start = output->code.length();
+                const QString script = output->stringAt(b->stringIndex);
+                const int length = script.length();
+                output->code.append(script);
+                expr = new (pool) FakeExpression(start, length);
+            } else
+                expr = new (pool) QQmlJS::AST::NullExpression();
+            foe->node = new (pool) QQmlJS::AST::ExpressionStatement(expr); // dummy
+            object->functionsAndExpressions->append(foe);
+        }
+    }
+
+    Q_ASSERT(object->functionsAndExpressions->count == functionIndices.count());
+
+    for (uint i = 0; i < serializedObject->nSignals; ++i) {
+        const QV4::CompiledData::Signal *serializedSignal = serializedObject->signalAt(i);
+        QmlIR::Signal *s = pool->New<QmlIR::Signal>();
+        s->nameIndex = serializedSignal->nameIndex;
+        s->location = serializedSignal->location;
+        s->parameters = pool->New<QmlIR::PoolList<QmlIR::SignalParameter> >();
+
+        for (uint i = 0; i < serializedSignal->nParameters; ++i) {
+            QmlIR::SignalParameter *p = pool->New<QmlIR::SignalParameter>();
+            *static_cast<QV4::CompiledData::Parameter*>(p) = *serializedSignal->parameterAt(i);
+            s->parameters->append(p);
+        }
+
+        object->qmlSignals->append(s);
+    }
+
+    const QV4::CompiledData::Property *serializedProperty = serializedObject->propertyTable();
+    for (uint i = 0; i < serializedObject->nProperties; ++i, ++serializedProperty) {
+        QmlIR::Property *p = pool->New<QmlIR::Property>();
+        *static_cast<QV4::CompiledData::Property*>(p) = *serializedProperty;
+        object->properties->append(p);
+    }
+
+    QQmlJS::Engine *jsParserEngine = &output->jsParserEngine;
+
+    const QV4::CompiledData::LEUInt32 *functionIdx = serializedObject->functionOffsetTable();
+    for (uint i = 0; i < serializedObject->nFunctions; ++i, ++functionIdx) {
+        QmlIR::Function *f = pool->New<QmlIR::Function>();
+        const QV4::CompiledData::Function *compiledFunction = unit->functionAt(*functionIdx);
+
+        functionIndices.append(*functionIdx);
+        f->index = functionIndices.count() - 1;
+        f->location = compiledFunction->location;
+        f->nameIndex = compiledFunction->nameIndex;
+
+        QQmlJS::AST::FormalParameterList *paramList = 0;
+        const QV4::CompiledData::LEUInt32 *formalNameIdx = compiledFunction->formalsTable();
+        for (uint i = 0; i < compiledFunction->nFormals; ++i, ++formalNameIdx) {
+            const QString formal = unit->stringAt(*formalNameIdx);
+            QStringRef paramNameRef = jsParserEngine->newStringRef(formal);
+
+            if (paramList)
+                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramList, paramNameRef);
+            else
+                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramNameRef);
+        }
+
+        if (paramList)
+            paramList = paramList->finish();
+
+        const QString name = unit->stringAt(compiledFunction->nameIndex);
+        f->functionDeclaration = new(pool) QQmlJS::AST::FunctionDeclaration(jsParserEngine->newStringRef(name), paramList, /*body*/0);
+
+        object->functions->append(f);
+    }
+
+    object->runtimeFunctionIndices.allocate(pool, functionIndices);
+
+    return object;
+}
+
 #endif // V4_BOOTSTRAP
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index 95756845c3..2022112e07 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -622,6 +622,21 @@ private:
     int _importedScriptsTemp;
 };
 
+struct IRLoader {
+    IRLoader(const QV4::CompiledData::Unit *unit, QmlIR::Document *output);
+
+    void load();
+
+private:
+    QmlIR::Object *loadObject(const QV4::CompiledData::Object *serializedObject);
+
+    template <typename _Tp> _Tp *New() { return pool->New<_Tp>(); }
+
+    const QV4::CompiledData::Unit *unit;
+    QmlIR::Document *output;
+    QQmlJS::MemoryPool *pool;
+};
+
 } // namespace QmlIR
 
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 7d3ad38f97..b5b70dbf45 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -216,6 +216,10 @@ bool Codegen::ScanFunctions::visit(VariableDeclaration *ast)
     checkName(ast->name, ast->identifierToken);
     if (ast->name == QLatin1String("arguments"))
         _env->usesArgumentsObject = Environment::ArgumentsObjectNotUsed;
+    if (ast->readOnly && !ast->expression) {
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Missing initializer in const declaration"));
+        return false;
+    }
     _env->enter(ast->name.toString(), ast->expression ? Environment::VariableDefinition : Environment::VariableDeclaration);
     return true;
 }
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index 25b090f555..8f8d374e24 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -52,7 +52,6 @@
 #include "qv4compilationunitmapper_p.h"
 #include <QQmlPropertyMap>
 #include <QDateTime>
-#include <QSaveFile>
 #include <QFile>
 #include <QFileInfo>
 #include <QScopedValueRollback>
@@ -62,6 +61,7 @@
 #include <private/qqmlirbuilder_p.h>
 #include <QCoreApplication>
 #include <QCryptographicHash>
+#include <QSaveFile>
 
 #include <algorithm>
 
@@ -77,6 +77,27 @@ namespace QV4 {
 
 namespace CompiledData {
 
+#ifdef V4_BOOTSTRAP
+static QString cacheFilePath(const QString &localSourcePath)
+{
+    const QString localCachePath = localSourcePath + QLatin1Char('c');
+    return localCachePath;
+}
+#else
+static QString cacheFilePath(const QUrl &url)
+{
+    const QString localSourcePath = QQmlFile::urlToLocalFileOrQrc(url);
+    const QString localCachePath = localSourcePath + QLatin1Char('c');
+    if (QFileInfo(QFileInfo(localSourcePath).dir().absolutePath()).isWritable())
+        return localCachePath;
+    QCryptographicHash fileNameHash(QCryptographicHash::Sha1);
+    fileNameHash.addData(localSourcePath.toUtf8());
+    QString directory = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/qmlcache/");
+    QDir::root().mkpath(directory);
+    return directory + QString::fromUtf8(fileNameHash.result().toHex()) + QLatin1Char('.') + QFileInfo(localCachePath).completeSuffix();
+}
+#endif
+
 #ifndef V4_BOOTSTRAP
 CompilationUnit::CompilationUnit()
     : data(0)
@@ -329,20 +350,68 @@ bool CompilationUnit::verifyChecksum(QQmlEngine *engine,
                   sizeof(data->dependencyMD5Checksum)) == 0;
 }
 
-static QString cacheFilePath(const QUrl &url)
+bool CompilationUnit::loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory, QString *errorString)
 {
-    const QString localSourcePath = QQmlFile::urlToLocalFileOrQrc(url);
-    const QString localCachePath = localSourcePath + QLatin1Char('c');
-    if (QFileInfo(QFileInfo(localSourcePath).dir().absolutePath()).isWritable())
-        return localCachePath;
-    QCryptographicHash fileNameHash(QCryptographicHash::Sha1);
-    fileNameHash.addData(localSourcePath.toUtf8());
-    QString directory = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/qmlcache/");
-    QDir::root().mkpath(directory);
-    return directory + QString::fromUtf8(fileNameHash.result().toHex()) + QLatin1Char('.') + QFileInfo(localCachePath).completeSuffix();
+    if (!QQmlFile::isLocalFile(url)) {
+        *errorString = QStringLiteral("File has to be a local file.");
+        return false;
+    }
+
+    const QString sourcePath = QQmlFile::urlToLocalFileOrQrc(url);
+    QScopedPointer<CompilationUnitMapper> cacheFile(new CompilationUnitMapper());
+
+    CompiledData::Unit *mappedUnit = cacheFile->open(cacheFilePath(url), sourcePath, 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))) {
+        *errorString = QStringLiteral("QML source file has moved to a different location.");
+        return false;
+    }
+
+    {
+        const QString foundArchitecture = stringAt(data->architectureIndex);
+        const QString expectedArchitecture = QSysInfo::buildAbi();
+        if (foundArchitecture != expectedArchitecture) {
+            *errorString = QString::fromUtf8("Architecture mismatch. Found %1 expected %2").arg(foundArchitecture).arg(expectedArchitecture);
+            return false;
+        }
+    }
+
+    {
+        const QString foundCodeGenerator = stringAt(data->codeGeneratorIndex);
+        const QString expectedCodeGenerator = iselFactory->codeGeneratorName;
+        if (foundCodeGenerator != expectedCodeGenerator) {
+            *errorString = QString::fromUtf8("Code generator mismatch. Found code generated by %1 but expected %2").arg(foundCodeGenerator).arg(expectedCodeGenerator);
+            return false;
+        }
+    }
+
+    if (!memoryMapCode(errorString))
+        return false;
+
+    dataPtrChange.commit();
+    free(const_cast<Unit*>(oldDataPtr));
+    backingFile.reset(cacheFile.take());
+    return true;
+}
+
+bool CompilationUnit::memoryMapCode(QString *errorString)
+{
+    *errorString = QStringLiteral("Missing code mapping backend");
+    return false;
 }
 
+#endif // V4_BOOTSTRAP
+
+#if defined(V4_BOOTSTRAP)
+bool CompilationUnit::saveToDisk(const QString &unitUrl, QString *errorString)
+#else
 bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
+#endif
 {
     errorString->clear();
 
@@ -351,10 +420,12 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
         return false;
     }
 
+#if !defined(V4_BOOTSTRAP)
     if (!QQmlFile::isLocalFile(unitUrl)) {
         *errorString = QStringLiteral("File has to be a local file.");
         return false;
     }
+#endif
 
     // Foo.qml -> Foo.qmlc
     QSaveFile cacheFile(cacheFilePath(unitUrl));
@@ -390,78 +461,105 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
     return true;
 }
 
-bool CompilationUnit::loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory, QString *errorString)
+void CompilationUnit::prepareCodeOffsetsForDiskStorage(Unit *unit)
 {
-    if (!QQmlFile::isLocalFile(url)) {
-        *errorString = QStringLiteral("File has to be a local file.");
-        return false;
-    }
+    Q_UNUSED(unit);
+}
 
-    const QString sourcePath = QQmlFile::urlToLocalFileOrQrc(url);
-    QScopedPointer<CompilationUnitMapper> cacheFile(new CompilationUnitMapper());
+bool CompilationUnit::saveCodeToDisk(QIODevice *device, const Unit *unit, QString *errorString)
+{
+    Q_UNUSED(device);
+    Q_UNUSED(unit);
+    *errorString = QStringLiteral("Saving code to disk is not supported in this configuration");
+    return false;
+}
 
-    CompiledData::Unit *mappedUnit = cacheFile->open(cacheFilePath(url), sourcePath, errorString);
-    if (!mappedUnit)
-        return false;
+Unit *CompilationUnit::createUnitData(QmlIR::Document *irDocument)
+{
+    if (!irDocument->javaScriptCompilationUnit->data)
+        return irDocument->jsGenerator.generateUnit(QV4::Compiler::JSUnitGenerator::GenerateWithoutStringTable);
 
-    const Unit * const oldDataPtr = (data && !(data->flags & QV4::CompiledData::Unit::StaticData)) ? data : nullptr;
-    QScopedValueRollback<const Unit *> dataPtrChange(data, mappedUnit);
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = irDocument->javaScriptCompilationUnit;
+    QV4::CompiledData::Unit *jsUnit = const_cast<QV4::CompiledData::Unit*>(irDocument->javaScriptCompilationUnit->data);
 
-    if (sourcePath != QQmlFile::urlToLocalFileOrQrc(stringAt(data->sourceFileIndex))) {
-        *errorString = QStringLiteral("QML source file has moved to a different location.");
-        return false;
-    }
+    QV4::Compiler::StringTableGenerator &stringTable = irDocument->jsGenerator.stringTable;
 
-    {
-        const QString foundArchitecture = stringAt(data->architectureIndex);
-        const QString expectedArchitecture = QSysInfo::buildAbi();
-        if (foundArchitecture != expectedArchitecture) {
-            *errorString = QString::fromUtf8("Architecture mismatch. Found %1 expected %2").arg(foundArchitecture).arg(expectedArchitecture);
-            return false;
+    // 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.
+    QVector<quint32> changedSignals;
+    QVector<QQmlJS::AST::FormalParameterList*> changedSignalParameters;
+    for (QmlIR::Object *o: qAsConst(irDocument->objects)) {
+        for (QmlIR::Binding *binding = o->firstBinding(); binding; binding = binding->next) {
+            if (!(binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression))
+                continue;
+
+            quint32 functionIndex = binding->value.compiledScriptIndex;
+            QmlIR::CompiledFunctionOrExpression *foe = o->functionsAndExpressions->slowAt(functionIndex);
+            if (!foe)
+                continue;
+
+            // save absolute index
+            changedSignals << o->runtimeFunctionIndices.at(functionIndex);
+
+            Q_ASSERT(foe->node);
+            Q_ASSERT(QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration*>(foe->node));
+
+            QQmlJS::AST::FormalParameterList *parameters = QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration*>(foe->node)->formals;
+            changedSignalParameters << parameters;
+
+            for (; parameters; parameters = parameters->next)
+                stringTable.registerString(parameters->name.toString());
         }
     }
 
-    {
-        const QString foundCodeGenerator = stringAt(data->codeGeneratorIndex);
-        const QString expectedCodeGenerator = iselFactory->codeGeneratorName;
-        if (foundCodeGenerator != expectedCodeGenerator) {
-            *errorString = QString::fromUtf8("Code generator mismatch. Found code generated by %1 but expected %2").arg(foundCodeGenerator).arg(expectedCodeGenerator);
-            return false;
+    QVector<quint32> signalParameterNameTable;
+    quint32 signalParameterNameTableOffset = jsUnit->unitSize;
+
+    // Update signal signatures
+    if (!changedSignals.isEmpty()) {
+        if (jsUnit == compilationUnit->data) {
+            char *unitCopy = (char*)malloc(jsUnit->unitSize);
+            memcpy(unitCopy, jsUnit, jsUnit->unitSize);
+            jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitCopy);
         }
-    }
 
-    if (!memoryMapCode(errorString))
-        return false;
+        for (int i = 0; i < changedSignals.count(); ++i) {
+            const uint functionIndex = changedSignals.at(i);
+            // The data is now read-write due to the copy above, so the const_cast is ok.
+            QV4::CompiledData::Function *function = const_cast<QV4::CompiledData::Function *>(jsUnit->functionAt(functionIndex));
+            Q_ASSERT(function->nFormals == quint32(0));
 
-    dataPtrChange.commit();
-    free(const_cast<Unit*>(oldDataPtr));
-    backingFile.reset(cacheFile.take());
-    return true;
-}
+            function->formalsOffset = signalParameterNameTableOffset - jsUnit->functionOffsetTable()[functionIndex];
 
-void CompilationUnit::prepareCodeOffsetsForDiskStorage(Unit *unit)
-{
-    Q_UNUSED(unit);
-}
+            for (QQmlJS::AST::FormalParameterList *parameters = changedSignalParameters.at(i);
+                 parameters; parameters = parameters->next) {
+                signalParameterNameTable.append(stringTable.getStringId(parameters->name.toString()));
+                function->nFormals = function->nFormals + 1;
+            }
 
-bool CompilationUnit::saveCodeToDisk(QIODevice *device, const Unit *unit, QString *errorString)
-{
-    Q_UNUSED(device);
-    Q_UNUSED(unit);
-    *errorString = QStringLiteral("Saving code to disk is not supported in this configuration");
-    return false;
-}
+            // Hack to ensure an activation is created.
+            function->flags |= QV4::CompiledData::Function::HasCatchOrWith | QV4::CompiledData::Function::HasDirectEval;
 
-bool CompilationUnit::memoryMapCode(QString *errorString)
-{
-    *errorString = QStringLiteral("Missing code mapping backend");
-    return false;
-}
-#endif // V4_BOOTSTRAP
+            signalParameterNameTableOffset += function->nFormals * sizeof(quint32);
+        }
+    }
 
-Unit *CompilationUnit::createUnitData(QmlIR::Document *irDocument)
-{
-    return irDocument->jsGenerator.generateUnit(QV4::Compiler::JSUnitGenerator::GenerateWithoutStringTable);
+    if (!signalParameterNameTable.isEmpty()) {
+        Q_ASSERT(jsUnit != compilationUnit->data);
+        const uint signalParameterTableSize = signalParameterNameTable.count() * sizeof(quint32);
+        uint newSize = jsUnit->unitSize + signalParameterTableSize;
+        const uint oldSize = jsUnit->unitSize;
+        char *unitWithSignalParameters = (char*)realloc(jsUnit, newSize);
+        memcpy(unitWithSignalParameters + oldSize, signalParameterNameTable.constData(), signalParameterTableSize);
+        jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitWithSignalParameters);
+        jsUnit->unitSize = newSize;
+    }
+
+    if (jsUnit != compilationUnit->data)
+        jsUnit->flags &= ~QV4::CompiledData::Unit::StaticData;
+
+    return jsUnit;
 }
 
 QString Binding::valueAsString(const Unit *unit) const
@@ -624,7 +722,7 @@ static QByteArray ownLibraryChecksum()
     if (checksumInitialized)
         return libraryChecksum;
     checksumInitialized = true;
-#if defined(Q_OS_UNIX) && !defined(QT_NO_DYNAMIC_CAST)
+#if defined(Q_OS_UNIX) && !defined(QT_NO_DYNAMIC_CAST) && !defined(Q_OS_INTEGRITY)
     Dl_info libInfo;
     if (dladdr(reinterpret_cast<const void *>(&ownLibraryChecksum), &libInfo) != 0) {
         QFile library(QFile::decodeName(libInfo.dli_fname));
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 97623b4d86..13a0c4b075 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 0x08
+#define QV4_DATA_STRUCTURE_VERSION 0x09
 
 class QIODevice;
 class QQmlPropertyCache;
@@ -133,7 +133,7 @@ struct Location
         QJsonPrivate::qle_bitfield<20, 12> column;
     };
 
-    Location() { line = 0; column = 0; }
+    Location() { line.val = 0; column.val = 0; }
 
     inline bool operator<(const Location &other) const {
         return line < other.line ||
@@ -153,7 +153,7 @@ struct RegExp
         QJsonPrivate::qle_bitfield<4, 28> stringIndex;
     };
 
-    RegExp() { flags = 0; stringIndex = 0; }
+    RegExp() { flags.val = 0; stringIndex.val = 0; }
 };
 
 struct Lookup
@@ -171,7 +171,7 @@ struct Lookup
         QJsonPrivate::qle_bitfield<4, 28> nameIndex;
     };
 
-    Lookup() { type_and_flags = 0; nameIndex = 0; }
+    Lookup() { type_and_flags.val = 0; nameIndex.val = 0; }
 };
 
 struct JSClassMember
@@ -625,7 +625,8 @@ struct Unit
         StaticData = 0x4, // Unit data persistent in memory?
         IsSingleton = 0x8,
         IsSharedLibrary = 0x10, // .pragma shared?
-        ContainsMachineCode = 0x20 // used to determine if we need to mmap with execute permissions
+        ContainsMachineCode = 0x20, // used to determine if we need to mmap with execute permissions
+        PendingTypeCompilation = 0x40 // the QML data structures present are incomplete and require type compilation
     };
     LEUInt32 flags;
     LEUInt32 stringTableSize;
@@ -777,31 +778,7 @@ struct TypeReferenceMap : QHash<int, TypeReference>
 };
 
 #ifndef V4_BOOTSTRAP
-struct ResolvedTypeReference
-{
-    ResolvedTypeReference()
-        : type(0)
-        , majorVersion(0)
-        , minorVersion(0)
-        , isFullyDynamicType(false)
-    {}
-
-    QQmlType *type;
-    QQmlRefPointer<QQmlPropertyCache> typePropertyCache;
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
-
-    int majorVersion;
-    int minorVersion;
-    // Types such as QQmlPropertyMap can add properties dynamically at run-time and
-    // therefore cannot have a property cache installed when instantiated.
-    bool isFullyDynamicType;
-
-    QQmlPropertyCache *propertyCache() const;
-    QQmlPropertyCache *createPropertyCache(QQmlEngine *);
-    bool addToHash(QCryptographicHash *hash, QQmlEngine *engine);
-
-    void doDynamicTypeCheck();
-};
+struct ResolvedTypeReference;
 // map from name index
 // While this could be a hash, a map is chosen here to provide a stable
 // order, which is used to calculating a check-sum on dependent meta-objects.
@@ -841,10 +818,14 @@ 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; }
 
-    QV4::Heap::String **runtimeStrings; // Array
     QV4::Lookup *runtimeLookups;
     QV4::Value *runtimeRegularExpressions;
     QV4::InternalClass **runtimeClasses;
@@ -918,17 +899,53 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public QQmlRefCount
 
     void destroy() Q_DECL_OVERRIDE;
 
-    bool saveToDisk(const QUrl &unitUrl, QString *errorString);
     bool loadFromDisk(const QUrl &url, EvalISelFactory *iselFactory, QString *errorString);
 
 protected:
     virtual void linkBackendToEngine(QV4::ExecutionEngine *engine) = 0;
-    virtual void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit);
-    virtual bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString);
     virtual bool memoryMapCode(QString *errorString);
 #endif // V4_BOOTSTRAP
+
+public:
+#if defined(V4_BOOTSTRAP)
+    bool saveToDisk(const QString &unitUrl, QString *errorString);
+#else
+    bool saveToDisk(const QUrl &unitUrl, QString *errorString);
+#endif
+
+protected:
+    virtual void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit);
+    virtual bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString);
 };
 
+#ifndef V4_BOOTSTRAP
+struct ResolvedTypeReference
+{
+    ResolvedTypeReference()
+        : type(0)
+        , majorVersion(0)
+        , minorVersion(0)
+        , isFullyDynamicType(false)
+    {}
+
+    QQmlType *type;
+    QQmlRefPointer<QQmlPropertyCache> typePropertyCache;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
+
+    int majorVersion;
+    int minorVersion;
+    // Types such as QQmlPropertyMap can add properties dynamically at run-time and
+    // therefore cannot have a property cache installed when instantiated.
+    bool isFullyDynamicType;
+
+    QQmlPropertyCache *propertyCache() const;
+    QQmlPropertyCache *createPropertyCache(QQmlEngine *);
+    bool addToHash(QCryptographicHash *hash, QQmlEngine *engine);
+
+    void doDynamicTypeCheck();
+};
+#endif
+
 }
 
 }
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index ca4e0b73d4..53d9956315 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -52,10 +52,11 @@
 //
 #include <private/qv4global_p.h>
 #include <private/qv4value_p.h>
-#include <private/qv4function_p.h>
 #include <private/qv4runtime_p.h>
 
+#if !defined(V4_BOOTSTRAP)
 QT_REQUIRE_CONFIG(qml_interpreter);
+#endif
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/qml/compiler/qv4isel_moth.cpp b/src/qml/compiler/qv4isel_moth.cpp
index 9dbebd1128..04844302d9 100644
--- a/src/qml/compiler/qv4isel_moth.cpp
+++ b/src/qml/compiler/qv4isel_moth.cpp
@@ -39,15 +39,15 @@
 
 #include "qv4isel_util_p.h"
 #include "qv4isel_moth_p.h"
-#include "qv4vme_moth_p.h"
 #include "qv4ssa_p.h"
-#include <private/qv4debugging_p.h>
-#include <private/qv4function_p.h>
-#include <private/qv4regexpobject_p.h>
 #include <private/qv4compileddata_p.h>
-#include <private/qqmlengine_p.h>
 #include <wtf/MathExtras.h>
 
+#if !defined(V4_BOOTSTRAP)
+#include "qv4vme_moth_p.h"
+#include <private/qv4function_p.h>
+#endif
+
 #undef USE_TYPE_INFO
 
 using namespace QV4;
@@ -1185,8 +1185,11 @@ void InstructionSelection::callBuiltinPushWithScope(IR::Expr *arg)
 
 void InstructionSelection::callBuiltinPopScope()
 {
+    QT_WARNING_PUSH
+    QT_WARNING_DISABLE_GCC("-Wuninitialized")
     Instruction::CallBuiltinPopScope call;
     addInstruction(call);
+    QT_WARNING_POP
 }
 
 void InstructionSelection::callBuiltinDeclareVar(bool deletable, const QString &name)
@@ -1335,8 +1338,11 @@ void InstructionSelection::callBuiltinSetupArgumentObject(IR::Expr *result)
 
 void QV4::Moth::InstructionSelection::callBuiltinConvertThisToObject()
 {
+    QT_WARNING_PUSH
+    QT_WARNING_DISABLE_GCC("-Wuninitialized")
     Instruction::CallBuiltinConvertThisToObject call;
     addInstruction(call);
+    QT_WARNING_POP
 }
 
 ptrdiff_t InstructionSelection::addInstructionHelper(Instr::Type type, Instr &instr)
@@ -1425,6 +1431,8 @@ CompilationUnit::~CompilationUnit()
 {
 }
 
+#if !defined(V4_BOOTSTRAP)
+
 void CompilationUnit::linkBackendToEngine(QV4::ExecutionEngine *engine)
 {
 #ifdef MOTH_THREADED_INTERPRETER
@@ -1461,6 +1469,31 @@ void CompilationUnit::linkBackendToEngine(QV4::ExecutionEngine *engine)
     }
 }
 
+bool CompilationUnit::memoryMapCode(QString *errorString)
+{
+    Q_UNUSED(errorString);
+    codeRefs.resize(data->functionTableSize);
+
+    const char *basePtr = reinterpret_cast<const char *>(data);
+
+    for (uint i = 0; i < data->functionTableSize; ++i) {
+        const CompiledData::Function *compiledFunction = data->functionAt(i);
+        const char *codePtr = const_cast<const char *>(reinterpret_cast<const char *>(basePtr + compiledFunction->codeOffset));
+#ifdef MOTH_THREADED_INTERPRETER
+        // for the threaded interpreter we need to make a copy of the data because it needs to be
+        // modified for the instruction handler addresses.
+        QByteArray code(codePtr, compiledFunction->codeSize);
+#else
+        QByteArray code = QByteArray::fromRawData(codePtr, compiledFunction->codeSize);
+#endif
+        codeRefs[i] = code;
+    }
+
+    return true;
+}
+
+#endif // V4_BOOTSTRAP
+
 void CompilationUnit::prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit)
 {
     const int codeAlignment = 16;
@@ -1482,7 +1515,7 @@ bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit
 
     QByteArray padding;
 
-#ifdef MOTH_THREADED_INTERPRETER
+#if defined(MOTH_THREADED_INTERPRETER) && !defined(V4_BOOTSTRAP)
     // Map from instruction label back to instruction type. Only needed when persisting
     // already linked compilation units;
     QHash<void*, int> reverseInstructionMapping;
@@ -1511,7 +1544,7 @@ bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit
 
         QByteArray code = codeRefs.at(i);
 
-#ifdef MOTH_THREADED_INTERPRETER
+#if defined(MOTH_THREADED_INTERPRETER) && !defined(V4_BOOTSTRAP)
         if (!reverseInstructionMapping.isEmpty()) {
             char *codePtr = code.data(); // detaches
             int index = 0;
@@ -1541,29 +1574,6 @@ bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit
     return true;
 }
 
-bool CompilationUnit::memoryMapCode(QString *errorString)
-{
-    Q_UNUSED(errorString);
-    codeRefs.resize(data->functionTableSize);
-
-    const char *basePtr = reinterpret_cast<const char *>(data);
-
-    for (uint i = 0; i < data->functionTableSize; ++i) {
-        const CompiledData::Function *compiledFunction = data->functionAt(i);
-        const char *codePtr = const_cast<const char *>(reinterpret_cast<const char *>(basePtr + compiledFunction->codeOffset));
-#ifdef MOTH_THREADED_INTERPRETER
-        // for the threaded interpreter we need to make a copy of the data because it needs to be
-        // modified for the instruction handler addresses.
-        QByteArray code(codePtr, compiledFunction->codeSize);
-#else
-        QByteArray code = QByteArray::fromRawData(codePtr, compiledFunction->codeSize);
-#endif
-        codeRefs[i] = code;
-    }
-
-    return true;
-}
-
 QQmlRefPointer<CompiledData::CompilationUnit> ISelFactory::createUnitForLoading()
 {
     QQmlRefPointer<CompiledData::CompilationUnit> result;
diff --git a/src/qml/compiler/qv4isel_moth_p.h b/src/qml/compiler/qv4isel_moth_p.h
index afe5fe342e..41469f1985 100644
--- a/src/qml/compiler/qv4isel_moth_p.h
+++ b/src/qml/compiler/qv4isel_moth_p.h
@@ -59,7 +59,9 @@
 #include <private/qv4value_p.h>
 #include "qv4instr_moth_p.h"
 
+#if !defined(V4_BOOTSTRAP)
 QT_REQUIRE_CONFIG(qml_interpreter);
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -69,10 +71,12 @@ namespace Moth {
 struct CompilationUnit : public QV4::CompiledData::CompilationUnit
 {
     virtual ~CompilationUnit();
+#if !defined(V4_BOOTSTRAP)
     void linkBackendToEngine(QV4::ExecutionEngine *engine) Q_DECL_OVERRIDE;
+    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
+#endif
     void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit) Q_DECL_OVERRIDE;
     bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString) Q_DECL_OVERRIDE;
-    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
 
     QVector<QByteArray> codeRefs;
 
diff --git a/src/qml/compiler/qv4jsir_p.h b/src/qml/compiler/qv4jsir_p.h
index 73aa6c4975..04bc3d86e5 100644
--- a/src/qml/compiler/qv4jsir_p.h
+++ b/src/qml/compiler/qv4jsir_p.h
@@ -315,20 +315,20 @@ struct Q_AUTOTEST_EXPORT Expr {
     Expr(ExprKind exprKind): type(UnknownType), exprKind(exprKind) {}
     bool isLValue() const;
 
-    Const *asConst() { return as<Const>(); }
-    String *asString() { return as<String>(); }
-    RegExp *asRegExp() { return as<RegExp>(); }
-    Name *asName() { return as<Name>(); }
-    Temp *asTemp() { return as<Temp>(); }
-    ArgLocal *asArgLocal() { return as<ArgLocal>(); }
-    Closure *asClosure() { return as<Closure>(); }
-    Convert *asConvert() { return as<Convert>(); }
-    Unop *asUnop() { return as<Unop>(); }
-    Binop *asBinop() { return as<Binop>(); }
-    Call *asCall() { return as<Call>(); }
-    New *asNew() { return as<New>(); }
-    Subscript *asSubscript() { return as<Subscript>(); }
-    Member *asMember() { return as<Member>(); }
+    Const *asConst();
+    String *asString();
+    RegExp *asRegExp();
+    Name *asName();
+    Temp *asTemp();
+    ArgLocal *asArgLocal();
+    Closure *asClosure();
+    Convert *asConvert();
+    Unop *asUnop();
+    Binop *asBinop();
+    Call *asCall();
+    New *asNew();
+    Subscript *asSubscript();
+    Member *asMember();
 };
 
 #define EXPR_VISIT_ALL_KINDS(e) \
@@ -773,12 +773,12 @@ struct Stmt {
 
     Stmt *asTerminator();
 
-    Exp *asExp() { return as<Exp>(); }
-    Move *asMove() { return as<Move>(); }
-    Jump *asJump() { return as<Jump>(); }
-    CJump *asCJump() { return as<CJump>(); }
-    Ret *asRet() { return as<Ret>(); }
-    Phi *asPhi() { return as<Phi>(); }
+    Exp *asExp();
+    Move *asMove();
+    Jump *asJump();
+    CJump *asCJump();
+    Ret *asRet();
+    Phi *asPhi();
 
     int id() const { return _id; }
 
@@ -1720,6 +1720,28 @@ inline Stmt *BasicBlock::RET(Expr *expr)
     return s;
 }
 
+inline Const *Expr::asConst() { return as<Const>(); }
+inline String *Expr::asString() { return as<String>(); }
+inline RegExp *Expr::asRegExp() { return as<RegExp>(); }
+inline Name *Expr::asName() { return as<Name>(); }
+inline Temp *Expr::asTemp() { return as<Temp>(); }
+inline ArgLocal *Expr::asArgLocal() { return as<ArgLocal>(); }
+inline Closure *Expr::asClosure() { return as<Closure>(); }
+inline Convert *Expr::asConvert() { return as<Convert>(); }
+inline Unop *Expr::asUnop() { return as<Unop>(); }
+inline Binop *Expr::asBinop() { return as<Binop>(); }
+inline Call *Expr::asCall() { return as<Call>(); }
+inline New *Expr::asNew() { return as<New>(); }
+inline Subscript *Expr::asSubscript() { return as<Subscript>(); }
+inline Member *Expr::asMember() { return as<Member>(); }
+
+inline Exp *Stmt::asExp() { return as<Exp>(); }
+inline Move *Stmt::asMove() { return as<Move>(); }
+inline Jump *Stmt::asJump() { return as<Jump>(); }
+inline CJump *Stmt::asCJump() { return as<CJump>(); }
+inline Ret *Stmt::asRet() { return as<Ret>(); }
+inline Phi *Stmt::asPhi() { return as<Phi>(); }
+
 } // end of namespace IR
 
 } // end of namespace QV4
diff --git a/src/qml/compiler/qv4ssa.cpp b/src/qml/compiler/qv4ssa.cpp
index 1d512711b8..10f0bbcf8f 100644
--- a/src/qml/compiler/qv4ssa.cpp
+++ b/src/qml/compiler/qv4ssa.cpp
@@ -5123,7 +5123,7 @@ void LifeTimeInterval::setFrom(int from) {
     Q_ASSERT(from > 0);
 
     if (_ranges.isEmpty()) { // this is the case where there is no use, only a define
-        _ranges.prepend(Range(from, from));
+        _ranges.prepend(LifeTimeIntervalRange(from, from));
         if (_end == InvalidPosition)
             _end = from;
     } else {
@@ -5137,17 +5137,17 @@ void LifeTimeInterval::addRange(int from, int to) {
     Q_ASSERT(to >= from);
 
     if (_ranges.isEmpty()) {
-        _ranges.prepend(Range(from, to));
+        _ranges.prepend(LifeTimeIntervalRange(from, to));
         _end = to;
         return;
     }
 
-    Range *p = &_ranges.first();
+    LifeTimeIntervalRange *p = &_ranges.first();
     if (to + 1 >= p->start && p->end + 1 >= from) {
         p->start = qMin(p->start, from);
         p->end = qMax(p->end, to);
         while (_ranges.count() > 1) {
-            Range *p1 = p + 1;
+            LifeTimeIntervalRange *p1 = p + 1;
             if (p->end + 1 < p1->start || p1->end + 1 < p->start)
                 break;
             p1->start = qMin(p->start, p1->start);
@@ -5157,10 +5157,10 @@ void LifeTimeInterval::addRange(int from, int to) {
         }
     } else {
         if (to < p->start) {
-            _ranges.prepend(Range(from, to));
+            _ranges.prepend(LifeTimeIntervalRange(from, to));
         } else {
             Q_ASSERT(from > _ranges.last().end);
-            _ranges.push_back(Range(from, to));
+            _ranges.push_back(LifeTimeIntervalRange(from, to));
         }
     }
 
@@ -5206,7 +5206,7 @@ LifeTimeInterval LifeTimeInterval::split(int atPosition, int newStart)
     } else {
         // find the first range where the temp will get active again:
         while (!newInterval._ranges.isEmpty()) {
-            const Range &range = newInterval._ranges.first();
+            const LifeTimeIntervalRange &range = newInterval._ranges.first();
             if (range.start > newStart) {
                 // The split position is before the start of the range. Either we managed to skip
                 // over the correct range, or we got an invalid split request. Either way, this
diff --git a/src/qml/compiler/qv4ssa_p.h b/src/qml/compiler/qv4ssa_p.h
index db8b6edd1a..c07abd04c4 100644
--- a/src/qml/compiler/qv4ssa_p.h
+++ b/src/qml/compiler/qv4ssa_p.h
@@ -63,20 +63,28 @@ class QQmlEnginePrivate;
 namespace QV4 {
 namespace IR {
 
-class Q_AUTOTEST_EXPORT LifeTimeInterval {
-public:
-    struct Range {
-        int start;
-        int end;
+struct LifeTimeIntervalRange {
+    int start;
+    int end;
 
-        Range(int start = InvalidPosition, int end = InvalidPosition)
-            : start(start)
-            , end(end)
-        {}
+    LifeTimeIntervalRange(int start = -1, int end = -1)
+        : start(start)
+        , end(end)
+    {}
 
-        bool covers(int position) const { return start <= position && position <= end; }
-    };
-    typedef QVarLengthArray<Range, 4> Ranges;
+    bool covers(int position) const { return start <= position && position <= end; }
+};
+} // IR namespace
+} // QV4 namespace
+
+Q_DECLARE_TYPEINFO(QV4::IR::LifeTimeIntervalRange, Q_PRIMITIVE_TYPE);
+
+namespace QV4 {
+namespace IR {
+
+class Q_AUTOTEST_EXPORT LifeTimeInterval {
+public:
+    typedef QVarLengthArray<LifeTimeIntervalRange, 4> Ranges;
 
 private:
     Temp _temp;
@@ -137,7 +145,7 @@ public:
         // Validate the new range
         if (_end != InvalidPosition) {
             Q_ASSERT(!_ranges.isEmpty());
-            for (const Range &range : qAsConst(_ranges)) {
+            for (const LifeTimeIntervalRange &range : qAsConst(_ranges)) {
                 Q_ASSERT(range.start >= 0);
                 Q_ASSERT(range.end >= 0);
                 Q_ASSERT(range.start <= range.end);
@@ -457,7 +465,6 @@ protected:
 
 
 Q_DECLARE_TYPEINFO(QV4::IR::LifeTimeInterval, Q_MOVABLE_TYPE);
-Q_DECLARE_TYPEINFO(QV4::IR::LifeTimeInterval::Range, Q_PRIMITIVE_TYPE);
 
 QT_END_NAMESPACE
 
diff --git a/src/qml/jit/qv4assembler.cpp b/src/qml/jit/qv4assembler.cpp
index 018396318e..646d9a8871 100644
--- a/src/qml/jit/qv4assembler.cpp
+++ b/src/qml/jit/qv4assembler.cpp
@@ -39,11 +39,6 @@
 
 #include "qv4isel_masm_p.h"
 #include "qv4runtime_p.h"
-#include "qv4object_p.h"
-#include "qv4functionobject_p.h"
-#include "qv4regexpobject_p.h"
-#include "qv4lookup_p.h"
-#include "qv4function_p.h"
 #include "qv4ssa_p.h"
 #include "qv4regalloc_p.h"
 #include "qv4assembler_p.h"
@@ -51,6 +46,10 @@
 #include <assembler/LinkBuffer.h>
 #include <WTFStubs.h>
 
+#if !defined(V4_BOOTSTRAP)
+#include "qv4function_p.h"
+#endif
+
 #include <iostream>
 #include <QBuffer>
 #include <QCoreApplication>
@@ -68,6 +67,8 @@ CompilationUnit::~CompilationUnit()
 {
 }
 
+#if !defined(V4_BOOTSTRAP)
+
 void CompilationUnit::linkBackendToEngine(ExecutionEngine *engine)
 {
     runtimeFunctions.resize(data->functionTableSize);
@@ -81,6 +82,26 @@ void CompilationUnit::linkBackendToEngine(ExecutionEngine *engine)
     }
 }
 
+bool CompilationUnit::memoryMapCode(QString *errorString)
+{
+    Q_UNUSED(errorString);
+    codeRefs.resize(data->functionTableSize);
+
+    const char *basePtr = reinterpret_cast<const char *>(data);
+
+    for (uint i = 0; i < data->functionTableSize; ++i) {
+        const CompiledData::Function *compiledFunction = data->functionAt(i);
+        void *codePtr = const_cast<void *>(reinterpret_cast<const void *>(basePtr + compiledFunction->codeOffset));
+        JSC::MacroAssemblerCodeRef codeRef = JSC::MacroAssemblerCodeRef::createSelfManagedCodeRef(JSC::MacroAssemblerCodePtr(codePtr));
+        JSC::ExecutableAllocator::makeExecutable(codePtr, compiledFunction->codeSize);
+        codeRefs[i] = codeRef;
+    }
+
+    return true;
+}
+
+#endif // !defined(V4_BOOTSTRAP)
+
 void CompilationUnit::prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit)
 {
     const int codeAlignment = 16;
@@ -128,27 +149,11 @@ bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit
     return true;
 }
 
-bool CompilationUnit::memoryMapCode(QString *errorString)
-{
-    Q_UNUSED(errorString);
-    codeRefs.resize(data->functionTableSize);
-
-    const char *basePtr = reinterpret_cast<const char *>(data);
-
-    for (uint i = 0; i < data->functionTableSize; ++i) {
-        const CompiledData::Function *compiledFunction = data->functionAt(i);
-        void *codePtr = const_cast<void *>(reinterpret_cast<const void *>(basePtr + compiledFunction->codeOffset));
-        JSC::MacroAssemblerCodeRef codeRef = JSC::MacroAssemblerCodeRef::createSelfManagedCodeRef(JSC::MacroAssemblerCodePtr(codePtr));
-        JSC::ExecutableAllocator::makeExecutable(codePtr, compiledFunction->codeSize);
-        codeRefs[i] = codeRef;
-    }
-
-    return true;
-}
-
-const Assembler::VoidType Assembler::Void;
+template <typename TargetConfiguration>
+const typename Assembler<TargetConfiguration>::VoidType Assembler<TargetConfiguration>::Void;
 
-Assembler::Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator)
+template <typename TargetConfiguration>
+Assembler<TargetConfiguration>::Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator)
     : _function(function)
     , _nextBlock(0)
     , _executableAllocator(executableAllocator)
@@ -159,14 +164,16 @@ Assembler::Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function*
     _labelPatches.resize(_function->basicBlockCount());
 }
 
-void Assembler::registerBlock(IR::BasicBlock* block, IR::BasicBlock *nextBlock)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::registerBlock(IR::BasicBlock* block, IR::BasicBlock *nextBlock)
 {
     _addrs[block->index()] = label();
     catchBlock = block->catchBlock;
     _nextBlock = nextBlock;
 }
 
-void Assembler::jumpToBlock(IR::BasicBlock* current, IR::BasicBlock *target)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::jumpToBlock(IR::BasicBlock* current, IR::BasicBlock *target)
 {
     Q_UNUSED(current);
 
@@ -174,12 +181,14 @@ void Assembler::jumpToBlock(IR::BasicBlock* current, IR::BasicBlock *target)
         _patches[target->index()].push_back(jump());
 }
 
-void Assembler::addPatch(IR::BasicBlock* targetBlock, Jump targetJump)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::addPatch(IR::BasicBlock* targetBlock, Jump targetJump)
 {
     _patches[targetBlock->index()].push_back(targetJump);
 }
 
-void Assembler::addPatch(DataLabelPtr patch, Label target)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::addPatch(DataLabelPtr patch, Label target)
 {
     DataLabelPatch p;
     p.dataLabel = patch;
@@ -187,37 +196,21 @@ void Assembler::addPatch(DataLabelPtr patch, Label target)
     _dataLabelPatches.push_back(p);
 }
 
-void Assembler::addPatch(DataLabelPtr patch, IR::BasicBlock *target)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::addPatch(DataLabelPtr patch, IR::BasicBlock *target)
 {
     _labelPatches[target->index()].push_back(patch);
 }
 
-void Assembler::generateCJumpOnNonZero(RegisterID reg, IR::BasicBlock *currentBlock,
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::generateCJumpOnNonZero(RegisterID reg, IR::BasicBlock *currentBlock,
                                        IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
 {
-    generateCJumpOnCompare(NotEqual, reg, TrustedImm32(0), currentBlock, trueBlock, falseBlock);
-}
-
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-void Assembler::generateCJumpOnCompare(RelationalCondition cond,
-                                       RegisterID left,
-                                       TrustedImm64 right,
-                                       IR::BasicBlock *currentBlock,
-                                       IR::BasicBlock *trueBlock,
-                                       IR::BasicBlock *falseBlock)
-{
-    if (trueBlock == _nextBlock) {
-        Jump target = branch64(invert(cond), left, right);
-        addPatch(falseBlock, target);
-    } else {
-        Jump target = branch64(cond, left, right);
-        addPatch(trueBlock, target);
-        jumpToBlock(currentBlock, falseBlock);
-    }
+    generateCJumpOnCompare(RelationalCondition::NotEqual, reg, TrustedImm32(0), currentBlock, trueBlock, falseBlock);
 }
-#endif
 
-void Assembler::generateCJumpOnCompare(RelationalCondition cond,
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::generateCJumpOnCompare(RelationalCondition cond,
                                        RegisterID left,
                                        TrustedImm32 right,
                                        IR::BasicBlock *currentBlock,
@@ -234,7 +227,8 @@ void Assembler::generateCJumpOnCompare(RelationalCondition cond,
     }
 }
 
-void Assembler::generateCJumpOnCompare(RelationalCondition cond,
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::generateCJumpOnCompare(RelationalCondition cond,
                                        RegisterID left,
                                        RegisterID right,
                                        IR::BasicBlock *currentBlock,
@@ -251,7 +245,8 @@ void Assembler::generateCJumpOnCompare(RelationalCondition cond,
     }
 }
 
-Assembler::Pointer Assembler::loadAddress(RegisterID tmp, IR::Expr *e)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadAddress(RegisterID tmp, IR::Expr *e)
 {
     IR::Temp *t = e->asTemp();
     if (t)
@@ -260,7 +255,8 @@ Assembler::Pointer Assembler::loadAddress(RegisterID tmp, IR::Expr *e)
         return loadArgLocalAddress(tmp, e->asArgLocal());
 }
 
-Assembler::Pointer Assembler::loadTempAddress(IR::Temp *t)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadTempAddress(IR::Temp *t)
 {
     if (t->kind == IR::Temp::StackSlot)
         return stackSlotPointer(t);
@@ -268,7 +264,8 @@ Assembler::Pointer Assembler::loadTempAddress(IR::Temp *t)
         Q_UNREACHABLE();
 }
 
-Assembler::Pointer Assembler::loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadArgLocalAddress(RegisterID baseReg, IR::ArgLocal *al)
 {
     int32_t offset = 0;
     int scope = al->scope;
@@ -298,7 +295,8 @@ Assembler::Pointer Assembler::loadArgLocalAddress(RegisterID baseReg, IR::ArgLoc
     return Pointer(baseReg, offset);
 }
 
-Assembler::Pointer Assembler::loadStringAddress(RegisterID reg, const QString &string)
+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);
@@ -307,12 +305,14 @@ Assembler::Pointer Assembler::loadStringAddress(RegisterID reg, const QString &s
     return Pointer(reg, id * sizeof(QV4::String*));
 }
 
-Assembler::Address Assembler::loadConstant(IR::Const *c, RegisterID baseReg)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(IR::Const *c, RegisterID baseReg)
 {
     return loadConstant(convertToValue(c), baseReg);
 }
 
-Assembler::Address Assembler::loadConstant(const Primitive &v, RegisterID baseReg)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(const Primitive &v, RegisterID baseReg)
 {
     loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), baseReg);
     loadPtr(Address(baseReg, qOffsetOf(QV4::Heap::ExecutionContext, constantTable)), baseReg);
@@ -320,33 +320,36 @@ Assembler::Address Assembler::loadConstant(const Primitive &v, RegisterID baseRe
     return Address(baseReg, index * sizeof(QV4::Value));
 }
 
-void Assembler::loadStringRef(RegisterID reg, const QString &string)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::loadStringRef(RegisterID reg, const QString &string)
 {
     const int id = _jsGenerator->registerString(string);
     move(TrustedImm32(id), reg);
 }
 
-void Assembler::storeValue(QV4::Primitive value, IR::Expr *destination)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::storeValue(QV4::Primitive value, IR::Expr *destination)
 {
     Address addr = loadAddress(ScratchRegister, destination);
     storeValue(value, addr);
 }
 
-void Assembler::enterStandardStackFrame(const RegisterInformation &regularRegistersToSave,
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::enterStandardStackFrame(const RegisterInformation &regularRegistersToSave,
                                         const RegisterInformation &fpRegistersToSave)
 {
     platformEnterStandardStackFrame(this);
 
-    move(StackPointerRegister, FramePointerRegister);
+    move(StackPointerRegister, JITTargetPlatform::FramePointerRegister);
 
     const int frameSize = _stackLayout->calculateStackFrameSize();
     subPtr(TrustedImm32(frameSize), StackPointerRegister);
 
-    Address slotAddr(FramePointerRegister, 0);
+    Address slotAddr(JITTargetPlatform::FramePointerRegister, 0);
     for (int i = 0, ei = fpRegistersToSave.size(); i < ei; ++i) {
         Q_ASSERT(fpRegistersToSave.at(i).isFloatingPoint());
         slotAddr.offset -= sizeof(double);
-        JSC::MacroAssembler::storeDouble(fpRegistersToSave.at(i).reg<FPRegisterID>(), slotAddr);
+        TargetConfiguration::MacroAssembler::storeDouble(fpRegistersToSave.at(i).reg<FPRegisterID>(), slotAddr);
     }
     for (int i = 0, ei = regularRegistersToSave.size(); i < ei; ++i) {
         Q_ASSERT(regularRegistersToSave.at(i).isRegularRegister());
@@ -355,10 +358,11 @@ void Assembler::enterStandardStackFrame(const RegisterInformation &regularRegist
     }
 }
 
-void Assembler::leaveStandardStackFrame(const RegisterInformation &regularRegistersToSave,
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::leaveStandardStackFrame(const RegisterInformation &regularRegistersToSave,
                                         const RegisterInformation &fpRegistersToSave)
 {
-    Address slotAddr(FramePointerRegister, -regularRegistersToSave.size() * RegisterSize - fpRegistersToSave.size() * sizeof(double));
+    Address slotAddr(JITTargetPlatform::FramePointerRegister, -regularRegistersToSave.size() * RegisterSize - fpRegistersToSave.size() * sizeof(double));
 
     // restore the callee saved registers
     for (int i = regularRegistersToSave.size() - 1; i >= 0; --i) {
@@ -368,7 +372,7 @@ void Assembler::leaveStandardStackFrame(const RegisterInformation &regularRegist
     }
     for (int i = fpRegistersToSave.size() - 1; i >= 0; --i) {
         Q_ASSERT(fpRegistersToSave.at(i).isFloatingPoint());
-        JSC::MacroAssembler::loadDouble(slotAddr, fpRegistersToSave.at(i).reg<FPRegisterID>());
+        TargetConfiguration::MacroAssembler::loadDouble(slotAddr, fpRegistersToSave.at(i).reg<FPRegisterID>());
         slotAddr.offset += sizeof(double);
     }
 
@@ -393,7 +397,8 @@ void Assembler::leaveStandardStackFrame(const RegisterInformation &regularRegist
 // Try to load the source expression into the destination FP register. This assumes that two
 // general purpose (integer) registers are available: the ScratchRegister and the
 // ReturnValueRegister. It returns a Jump if no conversion can be performed.
-Assembler::Jump Assembler::genTryDoubleConversion(IR::Expr *src, Assembler::FPRegisterID dest)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::genTryDoubleConversion(IR::Expr *src, FPRegisterID dest)
 {
     switch (src->type) {
     case IR::DoubleType:
@@ -436,11 +441,10 @@ Assembler::Jump Assembler::genTryDoubleConversion(IR::Expr *src, Assembler::FPRe
     isNoInt.link(this);
 #ifdef QV4_USE_64_BIT_VALUE_ENCODING
     rshift32(TrustedImm32(Value::IsDoubleTag_Shift), ScratchRegister);
-    Assembler::Jump isNoDbl = branch32(Equal, ScratchRegister, TrustedImm32(0));
+    Assembler::Jump isNoDbl = branch32(RelationalCondition::Equal, JITTargetPlatform::ScratchRegister, TrustedImm32(0));
 #else
     and32(Assembler::TrustedImm32(Value::NotDouble_Mask), Assembler::ScratchRegister);
-    Assembler::Jump isNoDbl = branch32(Assembler::Equal, Assembler::ScratchRegister,
-                                            Assembler::TrustedImm32(Value::NotDouble_Mask));
+    Assembler::Jump isNoDbl = branch32(RelationalCondition::Equal, JITTargetPlatform::ScratchRegister, TrustedImm32(Value::NotDouble_Mask));
 #endif
     toDoubleRegister(src, dest);
     intDone.link(this);
@@ -448,10 +452,11 @@ Assembler::Jump Assembler::genTryDoubleConversion(IR::Expr *src, Assembler::FPRe
     return isNoDbl;
 }
 
-Assembler::Jump Assembler::branchDouble(bool invertCondition, IR::AluOp op,
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::branchDouble(bool invertCondition, IR::AluOp op,
                                                    IR::Expr *left, IR::Expr *right)
 {
-    Assembler::DoubleCondition cond;
+    DoubleCondition cond;
     switch (op) {
     case IR::OpGt: cond = Assembler::DoubleGreaterThan; break;
     case IR::OpLt: cond = Assembler::DoubleLessThan; break;
@@ -465,12 +470,13 @@ Assembler::Jump Assembler::branchDouble(bool invertCondition, IR::AluOp op,
         Q_UNREACHABLE();
     }
     if (invertCondition)
-        cond = JSC::MacroAssembler::invert(cond);
+        cond = TargetConfiguration::MacroAssembler::invert(cond);
 
-    return JSC::MacroAssembler::branchDouble(cond, toDoubleRegister(left, FPGpr0), toDoubleRegister(right, FPGpr1));
+    return TargetConfiguration::MacroAssembler::branchDouble(cond, toDoubleRegister(left, FPGpr0), toDoubleRegister(right, JITTargetPlatform::FPGpr1));
 }
 
-Assembler::Jump Assembler::branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right)
+template <typename TargetConfiguration>
+typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right)
 {
     Assembler::RelationalCondition cond;
     switch (op) {
@@ -486,18 +492,51 @@ Assembler::Jump Assembler::branchInt32(bool invertCondition, IR::AluOp op, IR::E
         Q_UNREACHABLE();
     }
     if (invertCondition)
-        cond = JSC::MacroAssembler::invert(cond);
+        cond = TargetConfiguration::MacroAssembler::invert(cond);
 
-    return JSC::MacroAssembler::branch32(cond,
-                                         toInt32Register(left, Assembler::ScratchRegister),
-                                         toInt32Register(right, Assembler::ReturnValueRegister));
+    return TargetConfiguration::MacroAssembler::branch32(cond,
+                                                         toInt32Register(left, Assembler::ScratchRegister),
+                                                         toInt32Register(right, Assembler::ReturnValueRegister));
 }
 
-void Assembler::setStackLayout(int maxArgCountForBuiltins, int regularRegistersToSave, int fpRegistersToSave)
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::setStackLayout(int maxArgCountForBuiltins, int regularRegistersToSave, int fpRegistersToSave)
 {
     _stackLayout.reset(new StackLayout(_function, maxArgCountForBuiltins, regularRegistersToSave, fpRegistersToSave));
 }
 
+template <typename TargetConfiguration>
+void Assembler<TargetConfiguration>::returnFromFunction(IR::Ret *s, RegisterInformation regularRegistersToSave, RegisterInformation fpRegistersToSave)
+{
+    if (!s) {
+        // this only happens if the method doesn't have a return statement and can
+        // only exit through an exception
+    } 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);
+        RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
+    } else {
+        Q_UNREACHABLE();
+        Q_UNUSED(s);
+    }
+
+    Label leaveStackFrame = label();
+
+    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)));
+
+    leaveStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
+    ret();
+
+    exceptionReturnLabel = label();
+    QV4::Primitive retVal = Primitive::undefinedValue();
+    RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
+    jump(leaveStackFrame);
+}
 
 namespace {
 class QIODevicePrintStream: public FilePrintStream
@@ -563,7 +602,8 @@ static void qt_closePmap()
 
 #endif
 
-JSC::MacroAssemblerCodeRef Assembler::link(int *codeSize)
+template <typename TargetConfiguration>
+JSC::MacroAssemblerCodeRef Assembler<TargetConfiguration>::link(int *codeSize)
 {
     Label endOfCode = label();
 
@@ -577,7 +617,7 @@ JSC::MacroAssemblerCodeRef Assembler::link(int *codeSize)
     }
 
     JSC::JSGlobalData dummy(_executableAllocator);
-    JSC::LinkBuffer linkBuffer(dummy, this, 0);
+    JSC::LinkBuffer<typename TargetConfiguration::MacroAssembler> linkBuffer(dummy, this, 0);
 
     for (const DataLabelPatch &p : qAsConst(_dataLabelPatches))
         linkBuffer.patch(p.dataLabel, linkBuffer.locationOf(p.target));
@@ -668,4 +708,9 @@ JSC::MacroAssemblerCodeRef Assembler::link(int *codeSize)
     return codeRef;
 }
 
+template class QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>;
+#if defined(V4_BOOTSTRAP) && CPU(X86_64)
+template class QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>;
+#endif
+
 #endif
diff --git a/src/qml/jit/qv4assembler_p.h b/src/qml/jit/qv4assembler_p.h
index de9c246ed6..6d8d773ff0 100644
--- a/src/qml/jit/qv4assembler_p.h
+++ b/src/qml/jit/qv4assembler_p.h
@@ -55,7 +55,8 @@
 #include "private/qv4isel_p.h"
 #include "private/qv4isel_util_p.h"
 #include "private/qv4value_p.h"
-#include "private/qv4lookup_p.h"
+#include "private/qv4context_p.h"
+#include "private/qv4engine_p.h"
 #include "qv4targetplatform_p.h"
 
 #include <config.h>
@@ -73,46 +74,637 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
 
-class InstructionSelection;
-
 struct CompilationUnit : public QV4::CompiledData::CompilationUnit
 {
     virtual ~CompilationUnit();
 
+#if !defined(V4_BOOTSTRAP)
     void linkBackendToEngine(QV4::ExecutionEngine *engine) Q_DECL_OVERRIDE;
+    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
+#endif
     void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit) Q_DECL_OVERRIDE;
     bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString) Q_DECL_OVERRIDE;
-    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
 
     // Coderef + execution engine
 
     QVector<JSC::MacroAssemblerCodeRef> codeRefs;
 };
 
-struct LookupCall {
-    JSC::MacroAssembler::Address addr;
-    uint getterSetterOffset;
+template <typename PlatformAssembler, TargetOperatingSystemSpecialization Specialization>
+struct AssemblerTargetConfiguration
+{
+    typedef JSC::MacroAssembler<PlatformAssembler> MacroAssembler;
+    typedef TargetPlatform<PlatformAssembler, Specialization> Platform;
+    // More things coming here in the future, such as Target OS
+};
+
+#if CPU(ARM_THUMB2)
+typedef JSC::MacroAssemblerARMv7 DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#elif CPU(ARM64)
+typedef JSC::MacroAssemblerARM64 DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#elif CPU(ARM_TRADITIONAL)
+typedef JSC::MacroAssemblerARM DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#elif CPU(MIPS)
+typedef JSC::MacroAssemblerMIPS DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#elif CPU(X86)
+typedef JSC::MacroAssemblerX86 DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#elif CPU(X86_64)
+typedef JSC::MacroAssemblerX86_64 DefaultPlatformMacroAssembler;
+
+#if OS(WINDOWS)
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, WindowsSpecialization> DefaultAssemblerTargetConfiguration;
+#else
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#endif
 
-    LookupCall(const JSC::MacroAssembler::Address &addr, uint getterSetterOffset)
-        : addr(addr)
-        , getterSetterOffset(getterSetterOffset)
-    {}
+#elif CPU(SH4)
+typedef JSC::MacroAssemblerSH4 DefaultPlatformMacroAssembler;
+typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
+#endif
+
+#define isel_stringIfyx(s) #s
+#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__)
+
+
+template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform, int RegisterSize>
+struct RegisterSizeDependentAssembler
+{
 };
 
-struct RuntimeCall {
-    JSC::MacroAssembler::Address addr;
+template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform>
+struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatform, 4>
+{
+    using RegisterID = typename JITAssembler::RegisterID;
+    using FPRegisterID = typename JITAssembler::FPRegisterID;
+    using RelationalCondition = typename JITAssembler::RelationalCondition;
+    using Address = typename JITAssembler::Address;
+    using Pointer = typename JITAssembler::Pointer;
+    using TrustedImm32 = typename JITAssembler::TrustedImm32;
+    using TrustedImm64 = typename JITAssembler::TrustedImm64;
+    using Jump = typename JITAssembler::Jump;
+
+    static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
+    {
+        as->MacroAssembler::loadDouble(addr, dest);
+    }
+
+    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr)
+    {
+        as->MacroAssembler::storeDouble(source, addr);
+    }
+
+    static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
+    {
+        Pointer ptr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+        as->storeDouble(source, ptr);
+    }
+
+    static void storeValue(JITAssembler *as, QV4::Primitive value, Address destination)
+    {
+        as->store32(TrustedImm32(value.int_32()), destination);
+        destination.offset += 4;
+        as->store32(TrustedImm32(value.tag()), destination);
+    }
+
+    template <typename Source, typename Destination>
+    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination)
+    {
+        as->loadDouble(source, TargetPlatform::FPGpr0);
+        as->storeDouble(TargetPlatform::FPGpr0, destination);
+    }
+
+    static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
+    {
+        as->MacroAssembler::loadDouble(as->loadConstant(c, TargetPlatform::ScratchRegister), target);
+    }
+
+    static void storeReturnValue(JITAssembler *as, FPRegisterID dest)
+    {
+        as->moveIntsToDouble(TargetPlatform::LowReturnValueRegister, TargetPlatform::HighReturnValueRegister, dest, TargetPlatform::FPGpr0);
+    }
+
+    static void storeReturnValue(JITAssembler *as, const Pointer &dest)
+    {
+        Address destination = dest;
+        as->store32(TargetPlatform::LowReturnValueRegister, destination);
+        destination.offset += 4;
+        as->store32(TargetPlatform::HighReturnValueRegister, destination);
+    }
+
+    static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
+    {
+        const auto lowReg = TargetPlatform::LowReturnValueRegister;
+        const auto highReg = TargetPlatform::HighReturnValueRegister;
+
+        if (t->kind == IR::Temp::PhysicalRegister) {
+            switch (t->type) {
+            case IR::DoubleType:
+                as->moveDoubleToInts((FPRegisterID) t->index, lowReg, highReg);
+                break;
+            case IR::UInt32Type: {
+                RegisterID srcReg = (RegisterID) t->index;
+                Jump intRange = as->branch32(JITAssembler::GreaterThanOrEqual, srcReg, TrustedImm32(0));
+                as->convertUInt32ToDouble(srcReg, TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
+                as->moveDoubleToInts(TargetPlatform::FPGpr0, lowReg, highReg);
+                Jump done = as->jump();
+                intRange.link(as);
+                as->move(srcReg, lowReg);
+                as->move(TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
+                done.link(as);
+            } break;
+            case IR::SInt32Type:
+                as->move((RegisterID) t->index, lowReg);
+                as->move(TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
+                break;
+            case IR::BoolType:
+                as->move((RegisterID) t->index, lowReg);
+                as->move(TrustedImm32(QV4::Value::Boolean_Type_Internal), highReg);
+                break;
+            default:
+                Q_UNREACHABLE();
+            }
+        } else {
+            Pointer addr = as->loadAddress(TargetPlatform::ScratchRegister, t);
+            as->load32(addr, lowReg);
+            addr.offset += 4;
+            as->load32(addr, highReg);
+        }
+    }
+
+    static void setFunctionReturnValueFromConst(JITAssembler *as, QV4::Primitive retVal)
+    {
+        as->move(TrustedImm32(retVal.int_32()), TargetPlatform::LowReturnValueRegister);
+        as->move(TrustedImm32(retVal.tag()), TargetPlatform::HighReturnValueRegister);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Temp* temp, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(as);
+        Q_UNUSED(temp);
+        Q_UNUSED(dest);
+        Q_UNUSED(argumentNumber);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::ArgLocal* al, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(as);
+        Q_UNUSED(al);
+        Q_UNUSED(dest);
+        Q_UNUSED(argumentNumber);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Const* c, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(as);
+        Q_UNUSED(c);
+        Q_UNUSED(dest);
+        Q_UNUSED(argumentNumber);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Expr* expr, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(as);
+        Q_UNUSED(expr);
+        Q_UNUSED(dest);
+        Q_UNUSED(argumentNumber);
+    }
+
+    static void zeroRegister(JITAssembler *as, RegisterID reg)
+    {
+        as->move(TrustedImm32(0), reg);
+    }
+
+    static void zeroStackSlot(JITAssembler *as, int slot)
+    {
+        as->poke(TrustedImm32(0), slot);
+    }
+
+    static void generateCJumpOnUndefined(JITAssembler *as,
+                                  RelationalCondition cond, IR::Expr *right,
+                                  RegisterID scratchRegister, RegisterID tagRegister,
+                                  IR::BasicBlock *nextBlock, IR::BasicBlock *currentBlock,
+                                  IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
+    {
+        Pointer tagAddr = as->loadAddress(scratchRegister, right);
+        as->load32(tagAddr, tagRegister);
+        Jump j = as->branch32(JITAssembler::invert(cond), tagRegister, TrustedImm32(0));
+        as->addPatch(falseBlock, j);
+
+        tagAddr.offset += 4;
+        as->load32(tagAddr, tagRegister);
+        const TrustedImm32 tag(QV4::Value::Managed_Type_Internal);
+        Q_ASSERT(nextBlock == as->nextBlock());
+        Q_UNUSED(nextBlock);
+        as->generateCJumpOnCompare(cond, tagRegister, tag, currentBlock, trueBlock, falseBlock);
+    }
+
+    static void convertVarToSInt32(JITAssembler *as, IR::Expr *source, IR::Expr *target)
+    {
+        Q_ASSERT(source->type == IR::VarType);
+        // load the tag:
+        Pointer addr = as->loadAddress(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));
+        IR::Temp *targetTemp = target->asTemp();
+        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
+            as->load32(addr, TargetPlatform::ReturnValueRegister);
+            Pointer targetAddr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+            as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
+            targetAddr.offset += 4;
+            as->store32(TrustedImm32(Value::Integer_Type_Internal), targetAddr);
+        } else {
+            as->load32(addr, (RegisterID) targetTemp->index);
+        }
+        Jump intDone = as->jump();
+
+        // not an int:
+        fallback.link(as);
+        generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
+                            as->loadAddress(TargetPlatform::ScratchRegister, source));
+        as->storeInt32(TargetPlatform::ReturnValueRegister, target);
+
+        intDone.link(as);
+    }
+
+    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr)
+    {
+        as->store32(registerWithPtr, destAddr);
+        destAddr.offset += 4;
+        as->store32(TrustedImm32(QV4::Value::Managed_Type_Internal_32), destAddr);
+    }
+
+    static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
+    {
+        as->and32(TrustedImm32(Value::NotDouble_Mask), tagOrValueRegister);
+        return as->branch32(RelationalCondition::NotEqual, tagOrValueRegister,
+                            TrustedImm32(Value::NotDouble_Mask));
+    }
+};
+
+template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform>
+struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatform, 8>
+{
+    using RegisterID = typename JITAssembler::RegisterID;
+    using FPRegisterID = typename JITAssembler::FPRegisterID;
+    using Address = typename JITAssembler::Address;
+    using TrustedImm32 = typename JITAssembler::TrustedImm32;
+    using TrustedImm64 = typename JITAssembler::TrustedImm64;
+    using Pointer = typename JITAssembler::Pointer;
+    using RelationalCondition = typename JITAssembler::RelationalCondition;
+    using BranchTruncateType = typename JITAssembler::BranchTruncateType;
+    using Jump = typename JITAssembler::Jump;
+
+    static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
+    {
+        as->load64(addr, TargetPlatform::ReturnValueRegister);
+        as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+        as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+        as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
+    }
+
+    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr)
+    {
+        as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
+        as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+        as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+        as->store64(TargetPlatform::ReturnValueRegister, addr);
+    }
+
+    static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
+    {
+        as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
+        as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+        as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+        Pointer ptr = as->loadAddress(TargetPlatform::ScratchRegister, target);
+        as->store64(TargetPlatform::ReturnValueRegister, ptr);
+    }
+
+    static void storeReturnValue(JITAssembler *as, FPRegisterID dest)
+    {
+        as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+        as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+        as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
+    }
+
+    static void storeReturnValue(JITAssembler *as, const Pointer &dest)
+    {
+        as->store64(TargetPlatform::ReturnValueRegister, dest);
+    }
+
+    static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
+    {
+        if (t->kind == IR::Temp::PhysicalRegister) {
+            if (t->type == IR::DoubleType) {
+                as->moveDoubleTo64((FPRegisterID) t->index,
+                                    TargetPlatform::ReturnValueRegister);
+                as->move(TrustedImm64(QV4::Value::NaNEncodeMask),
+                         TargetPlatform::ScratchRegister);
+                as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+            } else if (t->type == IR::UInt32Type) {
+                RegisterID srcReg = (RegisterID) t->index;
+                Jump intRange = as->branch32(RelationalCondition::GreaterThanOrEqual, srcReg, TrustedImm32(0));
+                as->convertUInt32ToDouble(srcReg, TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
+                as->moveDoubleTo64(TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
+                as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+                as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+                Jump done = as->jump();
+                intRange.link(as);
+                as->zeroExtend32ToPtr(srcReg, TargetPlatform::ReturnValueRegister);
+                quint64 tag = QV4::Value::Integer_Type_Internal;
+                as->or64(TrustedImm64(tag << 32),
+                         TargetPlatform::ReturnValueRegister);
+                done.link(as);
+            } else {
+                as->zeroExtend32ToPtr((RegisterID) t->index, TargetPlatform::ReturnValueRegister);
+                quint64 tag;
+                switch (t->type) {
+                case IR::SInt32Type:
+                    tag = QV4::Value::Integer_Type_Internal;
+                    break;
+                case IR::BoolType:
+                    tag = QV4::Value::Boolean_Type_Internal;
+                    break;
+                default:
+                    tag = 31337; // bogus value
+                    Q_UNREACHABLE();
+                }
+                as->or64(TrustedImm64(tag << 32),
+                         TargetPlatform::ReturnValueRegister);
+            }
+        } else {
+            as->copyValue(TargetPlatform::ReturnValueRegister, t);
+        }
+    }
+
+    static void setFunctionReturnValueFromConst(JITAssembler *as, QV4::Primitive retVal)
+    {
+        as->move(TrustedImm64(retVal.rawValue()), TargetPlatform::ReturnValueRegister);
+    }
+
+    static void storeValue(JITAssembler *as, QV4::Primitive value, Address destination)
+    {
+        as->store64(TrustedImm64(value.rawValue()), destination);
+    }
+
+    template <typename Source, typename Destination>
+    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination)
+    {
+        // Use ReturnValueRegister as "scratch" register because loadArgument
+        // and storeArgument are functions that may need a scratch register themselves.
+        as->loadArgumentInRegister(source, TargetPlatform::ReturnValueRegister, 0);
+        as->storeReturnValue(destination);
+    }
+
+    static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
+    {
+        Q_STATIC_ASSERT(sizeof(int64_t) == sizeof(double));
+        int64_t i;
+        memcpy(&i, &c->value, sizeof(double));
+        as->move(TrustedImm64(i), TargetPlatform::ReturnValueRegister);
+        as->move64ToDouble(TargetPlatform::ReturnValueRegister, target);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Temp* temp, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(argumentNumber);
+
+        if (temp) {
+            Pointer addr = as->loadTempAddress(temp);
+            as->load64(addr, dest);
+        } else {
+            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            as->move(TrustedImm64(undefined.rawValue()), dest);
+        }
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::ArgLocal* al, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(argumentNumber);
+
+        if (al) {
+            Pointer addr = as->loadArgLocalAddress(dest, al);
+            as->load64(addr, dest);
+        } else {
+            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            as->move(TrustedImm64(undefined.rawValue()), dest);
+        }
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Const* c, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(argumentNumber);
+
+        QV4::Value v = convertToValue(c);
+        as->move(TrustedImm64(v.rawValue()), dest);
+    }
+
+    static void loadArgumentInRegister(JITAssembler *as, IR::Expr* expr, RegisterID dest, int argumentNumber)
+    {
+        Q_UNUSED(argumentNumber);
+
+        if (!expr) {
+            QV4::Value undefined = QV4::Primitive::undefinedValue();
+            as->move(TrustedImm64(undefined.rawValue()), dest);
+        } else if (IR::Temp *t = expr->asTemp()){
+            loadArgumentInRegister(as, t, dest, argumentNumber);
+        } else if (IR::ArgLocal *al = expr->asArgLocal()) {
+            loadArgumentInRegister(as, al, dest, argumentNumber);
+        } else if (IR::Const *c = expr->asConst()) {
+            loadArgumentInRegister(as, c, dest, argumentNumber);
+        } else {
+            Q_ASSERT(!"unimplemented expression type in loadArgument");
+        }
+    }
+
+    static void zeroRegister(JITAssembler *as, RegisterID reg)
+    {
+        as->move(TrustedImm64(0), reg);
+    }
 
-    inline RuntimeCall(uint offset = uint(INT_MIN));
-    bool isValid() const { return addr.offset >= 0; }
+    static void zeroStackSlot(JITAssembler *as, int slot)
+    {
+        as->store64(TrustedImm64(0), as->addressForPoke(slot));
+    }
+
+    static void generateCJumpOnCompare(JITAssembler *as,
+                                       RelationalCondition cond,
+                                       RegisterID left,
+                                       TrustedImm64 right,
+                                       IR::BasicBlock *nextBlock,
+                                       IR::BasicBlock *currentBlock,
+                                       IR::BasicBlock *trueBlock,
+                                       IR::BasicBlock *falseBlock)
+    {
+        if (trueBlock == nextBlock) {
+            Jump target = as->branch64(as->invert(cond), left, right);
+            as->addPatch(falseBlock, target);
+        } else {
+            Jump target = as->branch64(cond, left, right);
+            as->addPatch(trueBlock, target);
+            as->jumpToBlock(currentBlock, falseBlock);
+        }
+    }
+
+    static void generateCJumpOnUndefined(JITAssembler *as,
+                                  RelationalCondition cond, IR::Expr *right,
+                                  RegisterID scratchRegister, RegisterID tagRegister,
+                                  IR::BasicBlock *nextBlock,  IR::BasicBlock *currentBlock,
+                                  IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
+    {
+        Pointer addr = as->loadAddress(scratchRegister, right);
+        as->load64(addr, tagRegister);
+        const TrustedImm64 tag(0);
+        generateCJumpOnCompare(as, cond, tagRegister, tag, nextBlock, currentBlock, trueBlock, falseBlock);
+    }
+
+    static void convertVarToSInt32(JITAssembler *as, IR::Expr *source, IR::Expr *target)
+    {
+        Q_ASSERT(source->type == IR::VarType);
+        Pointer addr = as->loadAddress(TargetPlatform::ScratchRegister, source);
+        as->load64(addr, TargetPlatform::ScratchRegister);
+        as->move(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+
+        // check if it's integer convertible
+        as->urshift64(TrustedImm32(QV4::Value::IsIntegerConvertible_Shift), TargetPlatform::ScratchRegister);
+        Jump isIntConvertible = as->branch32(RelationalCondition::Equal, TargetPlatform::ScratchRegister, TrustedImm32(3));
+
+        // nope, not integer convertible, so check for a double:
+        as->urshift64(TrustedImm32(
+                           QV4::Value::IsDoubleTag_Shift - QV4::Value::IsIntegerConvertible_Shift),
+                       TargetPlatform::ScratchRegister);
+        Jump fallback = as->branch32(RelationalCondition::GreaterThan, TargetPlatform::ScratchRegister, TrustedImm32(0));
+
+        // it's a double
+        as->move(TrustedImm64(QV4::Value::NaNEncodeMask), TargetPlatform::ScratchRegister);
+        as->xor64(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
+        as->move64ToDouble(TargetPlatform::ReturnValueRegister, TargetPlatform::FPGpr0);
+        Jump success =
+                as->branchTruncateDoubleToInt32(TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister,
+                                                 BranchTruncateType::BranchIfTruncateSuccessful);
+
+        // not an int:
+        fallback.link(as);
+        generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
+                            as->loadAddress(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);
+            as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
+            targetAddr.offset += 4;
+            as->store32(TrustedImm32(Value::Integer_Type_Internal), targetAddr);
+        } else {
+            as->storeInt32(TargetPlatform::ReturnValueRegister, target);
+        }
+    }
+
+    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr)
+    {
+        as->store64(registerWithPtr, destAddr);
+    }
+
+    static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
+    {
+        as->rshift32(TrustedImm32(Value::IsDoubleTag_Shift), tagOrValueRegister);
+        return as->branch32(RelationalCondition::NotEqual, tagOrValueRegister,
+                            TrustedImm32(0));
+    }
 };
 
-class Assembler : public JSC::MacroAssembler, public TargetPlatform
+template <typename TargetConfiguration>
+class Assembler : public TargetConfiguration::MacroAssembler, public TargetConfiguration::Platform
 {
     Q_DISABLE_COPY(Assembler)
 
 public:
     Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator);
 
+    using MacroAssembler = typename TargetConfiguration::MacroAssembler;
+    using RegisterID = typename MacroAssembler::RegisterID;
+    using FPRegisterID = typename MacroAssembler::FPRegisterID;
+    using Address = typename MacroAssembler::Address;
+    using Label = typename MacroAssembler::Label;
+    using Jump = typename MacroAssembler::Jump;
+    using DataLabelPtr = typename MacroAssembler::DataLabelPtr;
+    using TrustedImm32 = typename MacroAssembler::TrustedImm32;
+    using TrustedImm64 = typename MacroAssembler::TrustedImm64;
+    using TrustedImmPtr = typename MacroAssembler::TrustedImmPtr;
+    using RelationalCondition = typename MacroAssembler::RelationalCondition;
+    using typename MacroAssembler::DoubleCondition;
+    using MacroAssembler::label;
+    using MacroAssembler::move;
+    using MacroAssembler::jump;
+    using MacroAssembler::add32;
+    using MacroAssembler::and32;
+    using MacroAssembler::store32;
+    using MacroAssembler::loadPtr;
+    using MacroAssembler::load32;
+    using MacroAssembler::branch32;
+    using MacroAssembler::subDouble;
+    using MacroAssembler::subPtr;
+    using MacroAssembler::addPtr;
+    using MacroAssembler::call;
+    using MacroAssembler::poke;
+    using MacroAssembler::branchTruncateDoubleToUint32;
+    using MacroAssembler::or32;
+    using MacroAssembler::moveDouble;
+    using MacroAssembler::convertUInt32ToDouble;
+    using MacroAssembler::invert;
+    using MacroAssembler::convertInt32ToDouble;
+    using MacroAssembler::rshift32;
+    using MacroAssembler::storePtr;
+    using MacroAssembler::ret;
+
+    using JITTargetPlatform = typename TargetConfiguration::Platform;
+    using JITTargetPlatform::RegisterArgumentCount;
+    using JITTargetPlatform::StackSpaceAllocatedUponFunctionEntry;
+    using JITTargetPlatform::RegisterSize;
+    using JITTargetPlatform::StackAlignment;
+    using JITTargetPlatform::ReturnValueRegister;
+    using JITTargetPlatform::StackPointerRegister;
+    using JITTargetPlatform::ScratchRegister;
+    using JITTargetPlatform::EngineRegister;
+    using JITTargetPlatform::StackShadowSpace;
+    using JITTargetPlatform::registerForArgument;
+    using JITTargetPlatform::FPGpr0;
+    using JITTargetPlatform::platformEnterStandardStackFrame;
+    using JITTargetPlatform::platformLeaveStandardStackFrame;
+
+    using RegisterSizeDependentOps = RegisterSizeDependentAssembler<Assembler<TargetConfiguration>, MacroAssembler, JITTargetPlatform, RegisterSize>;
+
+    struct LookupCall {
+        Address addr;
+        uint getterSetterOffset;
+
+        LookupCall(const Address &addr, uint getterSetterOffset)
+            : addr(addr)
+            , getterSetterOffset(getterSetterOffset)
+        {}
+    };
+
+    struct RuntimeCall {
+        Address addr;
+
+        inline RuntimeCall(uint offset = uint(INT_MIN));
+        bool isValid() const { return addr.offset >= 0; }
+    };
+
     // Explicit type to allow distinguishing between
     // pushing an address itself or the value it points
     // to onto the stack when calling functions.
@@ -319,20 +911,29 @@ public:
     void addPatch(DataLabelPtr patch, IR::BasicBlock *target);
     void generateCJumpOnNonZero(RegisterID reg, IR::BasicBlock *currentBlock,
                              IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    void generateCJumpOnCompare(RelationalCondition cond, RegisterID left, TrustedImm64 right,
-                                IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
-                                IR::BasicBlock *falseBlock);
-#endif
     void generateCJumpOnCompare(RelationalCondition cond, RegisterID left, TrustedImm32 right,
                                 IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
                                 IR::BasicBlock *falseBlock);
     void generateCJumpOnCompare(RelationalCondition cond, RegisterID left, RegisterID right,
                                 IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
                                 IR::BasicBlock *falseBlock);
-    Jump genTryDoubleConversion(IR::Expr *src, Assembler::FPRegisterID dest);
-    Assembler::Jump branchDouble(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
-    Assembler::Jump branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
+    void generateCJumpOnUndefined(RelationalCondition cond, IR::Expr *right,
+                                  RegisterID scratchRegister, RegisterID tagRegister,
+                                  IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
+                                  IR::BasicBlock *falseBlock)
+    {
+        RegisterSizeDependentOps::generateCJumpOnUndefined(this, cond, right, scratchRegister, tagRegister,
+                                                           _nextBlock, currentBlock, trueBlock, falseBlock);
+    }
+
+    Jump generateIsDoubleCheck(RegisterID tagOrValueRegister)
+    {
+        return RegisterSizeDependentOps::generateIsDoubleCheck(this, tagOrValueRegister);
+    }
+
+    Jump genTryDoubleConversion(IR::Expr *src, FPRegisterID dest);
+    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 loadTempAddress(IR::Temp *t);
@@ -396,7 +997,7 @@ public:
     void loadArgumentInRegister(PointerToValue temp, RegisterID dest, int argumentNumber)
     {
         if (!temp.value) {
-            move(TrustedImmPtr(0), dest);
+            RegisterSizeDependentOps::zeroRegister(this, dest);
         } else {
             Pointer addr = toAddress(dest, temp.value, argumentNumber);
             loadArgumentInRegister(addr, dest, argumentNumber);
@@ -415,70 +1016,31 @@ public:
         loadArgumentInRegister(addr, dest, argumentNumber);
     }
 
-#ifdef VALUE_FITS_IN_REGISTER
     void loadArgumentInRegister(IR::Temp* temp, RegisterID dest, int argumentNumber)
     {
-        Q_UNUSED(argumentNumber);
-
-        if (temp) {
-            Pointer addr = loadTempAddress(temp);
-            load64(addr, dest);
-        } else {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
-            move(TrustedImm64(undefined.rawValue()), dest);
-        }
+        RegisterSizeDependentOps::loadArgumentInRegister(this, temp, dest, argumentNumber);
     }
 
     void loadArgumentInRegister(IR::ArgLocal* al, RegisterID dest, int argumentNumber)
     {
-        Q_UNUSED(argumentNumber);
-
-        if (al) {
-            Pointer addr = loadArgLocalAddress(dest, al);
-            load64(addr, dest);
-        } else {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
-            move(TrustedImm64(undefined.rawValue()), dest);
-        }
+        RegisterSizeDependentOps::loadArgumentInRegister(this, al, dest, argumentNumber);
     }
 
     void loadArgumentInRegister(IR::Const* c, RegisterID dest, int argumentNumber)
     {
-        Q_UNUSED(argumentNumber);
-
-        QV4::Value v = convertToValue(c);
-        move(TrustedImm64(v.rawValue()), dest);
+        RegisterSizeDependentOps::loadArgumentInRegister(this, c, dest, argumentNumber);
     }
 
     void loadArgumentInRegister(IR::Expr* expr, RegisterID dest, int argumentNumber)
     {
-        Q_UNUSED(argumentNumber);
-
-        if (!expr) {
-            QV4::Value undefined = QV4::Primitive::undefinedValue();
-            move(TrustedImm64(undefined.rawValue()), dest);
-        } else if (IR::Temp *t = expr->asTemp()){
-            loadArgumentInRegister(t, dest, argumentNumber);
-        } else if (IR::ArgLocal *al = expr->asArgLocal()) {
-            loadArgumentInRegister(al, dest, argumentNumber);
-        } else if (IR::Const *c = expr->asConst()) {
-            loadArgumentInRegister(c, dest, argumentNumber);
-        } else {
-            Q_ASSERT(!"unimplemented expression type in loadArgument");
-        }
-    }
-#else
-    void loadArgumentInRegister(IR::Expr*, RegisterID)
-    {
-        Q_ASSERT(!"unimplemented: expression in loadArgument");
+        RegisterSizeDependentOps::loadArgumentInRegister(this, expr, dest, argumentNumber);
     }
-#endif
 
     void loadArgumentInRegister(TrustedImm32 imm32, RegisterID dest, int argumentNumber)
     {
         Q_UNUSED(argumentNumber);
 
-        xorPtr(dest, dest);
+        RegisterSizeDependentOps::zeroRegister(this, dest);
         if (imm32.m_value)
             move(imm32, dest);
     }
@@ -499,55 +1061,13 @@ public:
 
     void storeReturnValue(FPRegisterID dest)
     {
-#ifdef VALUE_FITS_IN_REGISTER
-        move(TrustedImm64(QV4::Value::NaNEncodeMask), ScratchRegister);
-        xor64(ScratchRegister, ReturnValueRegister);
-        move64ToDouble(ReturnValueRegister, dest);
-#elif defined(Q_PROCESSOR_ARM)
-        moveIntsToDouble(JSC::ARMRegisters::r0, JSC::ARMRegisters::r1, dest, FPGpr0);
-#elif defined(Q_PROCESSOR_X86)
-        moveIntsToDouble(JSC::X86Registers::eax, JSC::X86Registers::edx, dest, FPGpr0);
-#elif defined(Q_PROCESSOR_MIPS)
-        moveIntsToDouble(JSC::MIPSRegisters::v0, JSC::MIPSRegisters::v1, dest, FPGpr0);
-#else
-        subPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
-        Pointer tmp(StackPointerRegister, 0);
-        storeReturnValue(tmp);
-        loadDouble(tmp, dest);
-        addPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
-#endif
+        RegisterSizeDependentOps::storeReturnValue(this, dest);
     }
 
-#ifdef VALUE_FITS_IN_REGISTER
-    void storeReturnValue(const Pointer &dest)
-    {
-        store64(ReturnValueRegister, dest);
-    }
-#elif defined(Q_PROCESSOR_X86)
-    void storeReturnValue(const Pointer &dest)
-    {
-        Pointer destination = dest;
-        store32(JSC::X86Registers::eax, destination);
-        destination.offset += 4;
-        store32(JSC::X86Registers::edx, destination);
-    }
-#elif defined(Q_PROCESSOR_ARM)
-    void storeReturnValue(const Pointer &dest)
-    {
-        Pointer destination = dest;
-        store32(JSC::ARMRegisters::r0, destination);
-        destination.offset += 4;
-        store32(JSC::ARMRegisters::r1, destination);
-    }
-#elif defined(Q_PROCESSOR_MIPS)
     void storeReturnValue(const Pointer &dest)
     {
-        Pointer destination = dest;
-        store32(JSC::MIPSRegisters::v0, destination);
-        destination.offset += 4;
-        store32(JSC::MIPSRegisters::v1, destination);
+        RegisterSizeDependentOps::storeReturnValue(this, dest);
     }
-#endif
 
     void storeReturnValue(IR::Expr *target)
     {
@@ -609,7 +1129,7 @@ public:
             Pointer ptr = toAddress(ScratchRegister, temp.value, argumentNumber);
             loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
         } else {
-            poke(TrustedImmPtr(0), StackSlot);
+            RegisterSizeDependentOps::zeroStackSlot(this, StackSlot);
         }
     }
 
@@ -648,38 +1168,18 @@ public:
             moveDouble(source, (FPRegisterID) targetTemp->index);
             return;
         }
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-        moveDoubleTo64(source, ReturnValueRegister);
-        move(TrustedImm64(QV4::Value::NaNEncodeMask), ScratchRegister);
-        xor64(ScratchRegister, ReturnValueRegister);
-        Pointer ptr = loadAddress(ScratchRegister, target);
-        store64(ReturnValueRegister, ptr);
-#else
-        Pointer ptr = loadAddress(ScratchRegister, target);
-        storeDouble(source, ptr);
-#endif
+        RegisterSizeDependentOps::storeDouble(this, source, target);
     }
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    // We need to (de)mangle the double
+
     void loadDouble(Address addr, FPRegisterID dest)
     {
-        load64(addr, ReturnValueRegister);
-        move(TrustedImm64(QV4::Value::NaNEncodeMask), ScratchRegister);
-        xor64(ScratchRegister, ReturnValueRegister);
-        move64ToDouble(ReturnValueRegister, dest);
+        RegisterSizeDependentOps::loadDouble(this, addr, dest);
     }
 
     void storeDouble(FPRegisterID source, Address addr)
     {
-        moveDoubleTo64(source, ReturnValueRegister);
-        move(TrustedImm64(QV4::Value::NaNEncodeMask), ScratchRegister);
-        xor64(ScratchRegister, ReturnValueRegister);
-        store64(ReturnValueRegister, addr);
+        RegisterSizeDependentOps::storeDouble(this, source, addr);
     }
-#else
-    using JSC::MacroAssembler::loadDouble;
-    using JSC::MacroAssembler::storeDouble;
-#endif
 
     template <typename Result, typename Source>
     void copyValue(Result result, Source source);
@@ -691,8 +1191,15 @@ public:
     {
         Q_ASSERT(!source->asTemp() || source->asTemp()->kind != IR::Temp::PhysicalRegister);
         Q_ASSERT(target.base != scratchRegister);
-        JSC::MacroAssembler::loadDouble(loadAddress(scratchRegister, source), FPGpr0);
-        JSC::MacroAssembler::storeDouble(FPGpr0, target);
+        TargetConfiguration::MacroAssembler::loadDouble(loadAddress(scratchRegister, source), FPGpr0);
+        TargetConfiguration::MacroAssembler::storeDouble(FPGpr0, target);
+    }
+
+    // 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));
     }
 
     void storeValue(QV4::Primitive value, RegisterID destination)
@@ -704,13 +1211,7 @@ public:
 
     void storeValue(QV4::Primitive value, Address destination)
     {
-#ifdef VALUE_FITS_IN_REGISTER
-        store64(TrustedImm64(value.rawValue()), destination);
-#else
-        store32(TrustedImm32(value.int_32()), destination);
-        destination.offset += 4;
-        store32(TrustedImm32(value.tag()), destination);
-#endif
+        RegisterSizeDependentOps::storeValue(this, value, destination);
     }
 
     void storeValue(QV4::Primitive value, IR::Expr* temp);
@@ -722,7 +1223,7 @@ public:
 
     void checkException() {
         load32(Address(EngineRegister, qOffsetOf(QV4::ExecutionEngine, hasException)), ScratchRegister);
-        Jump exceptionThrown = branch32(NotEqual, ScratchRegister, TrustedImm32(0));
+        Jump exceptionThrown = branch32(RelationalCondition::NotEqual, ScratchRegister, TrustedImm32(0));
         if (catchBlock)
             addPatch(catchBlock, exceptionThrown);
         else
@@ -781,6 +1282,27 @@ public:
         enum { Size = 0 };
     };
 
+    template <typename T> bool prepareCall(T &)
+    { return true; }
+
+    bool prepareCall(LookupCall &lookupCall)
+    {
+        // 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)),
+                    lookupCall.addr.base);
+        // pre-calculate the indirect address for the lookupCall table:
+        if (lookupCall.addr.offset)
+            addPtr(TrustedImm32(lookupCall.addr.offset), lookupCall.addr.base);
+        // store it as the first argument
+        loadArgumentOnStackOrRegister<0>(lookupCall.addr.base);
+        // set the destination addresses offset to the getterSetterOffset. The base is the lookupCall table's address
+        lookupCall.addr.offset = lookupCall.getterSetterOffset;
+        return false;
+    }
+
     template <typename ArgRet, typename Callable, typename Arg1, typename Arg2, typename Arg3, typename Arg4, typename Arg5, typename Arg6>
     void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4, Arg5 arg5, Arg6 arg6)
     {
@@ -813,11 +1335,11 @@ public:
         loadArgumentOnStackOrRegister<2>(arg3);
         loadArgumentOnStackOrRegister<1>(arg2);
 
-        if (prepareCall(function, this))
+        if (prepareCall(function))
             loadArgumentOnStackOrRegister<0>(arg1);
 
 #ifdef RESTORE_EBX_ON_CALL
-        load32(ebxAddressOnStack(), JSC::X86Registers::ebx); // restore the GOT ptr
+        load32(this->ebxAddressOnStack(), JSC::X86Registers::ebx); // restore the GOT ptr
 #endif
 
         callAbsolute(functionName, function);
@@ -957,7 +1479,7 @@ public:
     void storeUInt32(RegisterID reg, Pointer addr)
     {
         // The UInt32 representation in QV4::Value is really convoluted. See also toUInt32Register.
-        Jump intRange = branch32(GreaterThanOrEqual, reg, TrustedImm32(0));
+        Jump intRange = branch32(RelationalCondition::GreaterThanOrEqual, reg, TrustedImm32(0));
         convertUInt32ToDouble(reg, FPGpr0, ReturnValueRegister);
         storeDouble(FPGpr0, addr);
         Jump done = jump();
@@ -980,15 +1502,7 @@ public:
     FPRegisterID toDoubleRegister(IR::Expr *e, FPRegisterID target = FPGpr0)
     {
         if (IR::Const *c = e->asConst()) {
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-            Q_STATIC_ASSERT(sizeof(int64_t) == sizeof(double));
-            int64_t i;
-            memcpy(&i, &c->value, sizeof(double));
-            move(TrustedImm64(i), ReturnValueRegister);
-            move64ToDouble(ReturnValueRegister, target);
-#else
-            JSC::MacroAssembler::loadDouble(loadConstant(c, ScratchRegister), target);
-#endif
+            RegisterSizeDependentOps::loadDoubleConstant(this, c, target);
             return target;
         }
 
@@ -1047,7 +1561,7 @@ public:
         Pointer tagAddr = addr;
         tagAddr.offset += 4;
         load32(tagAddr, scratchReg);
-        Jump inIntRange = branch32(Equal, scratchReg, TrustedImm32(QV4::Value::Integer_Type_Internal));
+        Jump inIntRange = branch32(RelationalCondition::Equal, scratchReg, TrustedImm32(QV4::Value::Integer_Type_Internal));
 
         // it's not in signed int range, so load it as a double, and truncate it down
         loadDouble(addr, FPGpr0);
@@ -1065,6 +1579,8 @@ public:
         return scratchReg;
     }
 
+    void returnFromFunction(IR::Ret *s, RegisterInformation regularRegistersToSave, RegisterInformation fpRegistersToSave);
+
     JSC::MacroAssemblerCodeRef link(int *codeSize);
 
     void setStackLayout(int maxArgCountForBuiltins, int regularRegistersToSave, int fpRegistersToSave);
@@ -1095,22 +1611,16 @@ private:
     QV4::Compiler::JSUnitGenerator *_jsGenerator;
 };
 
+template <typename TargetConfiguration>
 template <typename Result, typename Source>
-void Assembler::copyValue(Result result, Source source)
+void Assembler<TargetConfiguration>::copyValue(Result result, Source source)
 {
-#ifdef VALUE_FITS_IN_REGISTER
-    // Use ReturnValueRegister as "scratch" register because loadArgument
-    // and storeArgument are functions that may need a scratch register themselves.
-    loadArgumentInRegister(source, ReturnValueRegister, 0);
-    storeReturnValue(result);
-#else
-    loadDouble(source, FPGpr0);
-    storeDouble(FPGpr0, result);
-#endif
+    RegisterSizeDependentOps::copyValueViaRegisters(this, source, result);
 }
 
+template <typename TargetConfiguration>
 template <typename Result>
-void Assembler::copyValue(Result result, IR::Expr* source)
+void Assembler<TargetConfiguration>::copyValue(Result result, IR::Expr* source)
 {
     if (source->type == IR::BoolType) {
         RegisterID reg = toInt32Register(source, ScratchRegister);
@@ -1124,15 +1634,7 @@ void Assembler::copyValue(Result result, IR::Expr* source)
     } else if (source->type == IR::DoubleType) {
         storeDouble(toDoubleRegister(source), result);
     } else if (source->asTemp() || source->asArgLocal()) {
-#ifdef VALUE_FITS_IN_REGISTER
-            // Use ReturnValueRegister as "scratch" register because loadArgument
-            // and storeArgument are functions that may need a scratch register themselves.
-            loadArgumentInRegister(source, ReturnValueRegister, 0);
-            storeReturnValue(result);
-#else
-            loadDouble(source, FPGpr0);
-            storeDouble(FPGpr0, result);
-#endif
+        RegisterSizeDependentOps::copyValueViaRegisters(this, source, result);
     } else if (IR::Const *c = source->asConst()) {
         QV4::Primitive v = convertToValue(c);
         storeValue(v, result);
@@ -1141,34 +1643,12 @@ void Assembler::copyValue(Result result, IR::Expr* source)
     }
 }
 
-inline RuntimeCall::RuntimeCall(uint offset)
+template <typename TargetConfiguration>
+inline Assembler<TargetConfiguration>::RuntimeCall::RuntimeCall(uint offset)
     : addr(Assembler::EngineRegister, offset + qOffsetOf(QV4::ExecutionEngine, runtime))
 {
 }
 
-
-
-template <typename T> inline bool prepareCall(T &, Assembler *)
-{ return true; }
-
-template <> inline bool prepareCall(LookupCall &lookupCall, Assembler *as)
-{
-    // IMPORTANT! See generateLookupCall in qv4isel_masm_p.h for details!
-
-    // load the table from the context
-    as->loadPtr(Assembler::Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), Assembler::ScratchRegister);
-    as->loadPtr(Assembler::Address(Assembler::ScratchRegister, qOffsetOf(QV4::Heap::ExecutionContext, lookups)),
-                lookupCall.addr.base);
-    // pre-calculate the indirect address for the lookupCall table:
-    if (lookupCall.addr.offset)
-        as->addPtr(Assembler::TrustedImm32(lookupCall.addr.offset), lookupCall.addr.base);
-    // store it as the first argument
-    as->loadArgumentOnStackOrRegister<0>(lookupCall.addr.base);
-    // set the destination addresses offset to the getterSetterOffset. The base is the lookupCall table's address
-    lookupCall.addr.offset = lookupCall.getterSetterOffset;
-    return false;
-}
-
 } // end of namespace JIT
 } // end of namespace QV4
 
diff --git a/src/qml/jit/qv4binop.cpp b/src/qml/jit/qv4binop.cpp
index d2758c4a47..8468bf65a6 100644
--- a/src/qml/jit/qv4binop.cpp
+++ b/src/qml/jit/qv4binop.cpp
@@ -57,7 +57,8 @@ using namespace JIT;
 #define NULL_OP \
     { 0, 0, 0, 0, 0, false }
 
-const Binop::OpInfo Binop::operations[IR::LastAluOp + 1] = {
+template <typename JITAssembler>
+const typename Binop<JITAssembler>::OpInfo Binop<JITAssembler>::operations[IR::LastAluOp + 1] = {
     NULL_OP, // OpInvalid
     NULL_OP, // OpIfTrue
     NULL_OP, // OpNot
@@ -67,20 +68,20 @@ const Binop::OpInfo Binop::operations[IR::LastAluOp + 1] = {
     NULL_OP, // OpIncrement
     NULL_OP, // OpDecrement
 
-    INLINE_OP(bitAnd, &Binop::inline_and32, &Binop::inline_and32), // OpBitAnd
-    INLINE_OP(bitOr, &Binop::inline_or32, &Binop::inline_or32), // OpBitOr
-    INLINE_OP(bitXor, &Binop::inline_xor32, &Binop::inline_xor32), // OpBitXor
+    INLINE_OP(bitAnd, &Binop<JITAssembler>::inline_and32, &Binop<JITAssembler>::inline_and32), // OpBitAnd
+    INLINE_OP(bitOr, &Binop<JITAssembler>::inline_or32, &Binop<JITAssembler>::inline_or32), // OpBitOr
+    INLINE_OP(bitXor, &Binop<JITAssembler>::inline_xor32, &Binop<JITAssembler>::inline_xor32), // OpBitXor
 
-    INLINE_OPCONTEXT(add, &Binop::inline_add32, &Binop::inline_add32), // OpAdd
-    INLINE_OP(sub, &Binop::inline_sub32, &Binop::inline_sub32), // OpSub
-    INLINE_OP(mul, &Binop::inline_mul32, &Binop::inline_mul32), // OpMul
+    INLINE_OPCONTEXT(add, &Binop<JITAssembler>::inline_add32, &Binop<JITAssembler>::inline_add32), // OpAdd
+    INLINE_OP(sub, &Binop<JITAssembler>::inline_sub32, &Binop<JITAssembler>::inline_sub32), // OpSub
+    INLINE_OP(mul, &Binop<JITAssembler>::inline_mul32, &Binop<JITAssembler>::inline_mul32), // OpMul
 
     OP(div), // OpDiv
     OP(mod), // OpMod
 
-    INLINE_OP(shl, &Binop::inline_shl32, &Binop::inline_shl32), // OpLShift
-    INLINE_OP(shr, &Binop::inline_shr32, &Binop::inline_shr32), // OpRShift
-    INLINE_OP(ushr, &Binop::inline_ushr32, &Binop::inline_ushr32), // OpURShift
+    INLINE_OP(shl, &Binop<JITAssembler>::inline_shl32, &Binop<JITAssembler>::inline_shl32), // OpLShift
+    INLINE_OP(shr, &Binop<JITAssembler>::inline_shr32, &Binop<JITAssembler>::inline_shr32), // OpRShift
+    INLINE_OP(ushr, &Binop<JITAssembler>::inline_ushr32, &Binop<JITAssembler>::inline_ushr32), // OpURShift
 
     OP(greaterThan), // OpGt
     OP(lessThan), // OpLt
@@ -100,7 +101,8 @@ const Binop::OpInfo Binop::operations[IR::LastAluOp + 1] = {
 
 
 
-void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
+template <typename JITAssembler>
+void Binop<JITAssembler>::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 {
     if (op != IR::OpMod
             && lhs->type == IR::DoubleType && rhs->type == IR::DoubleType) {
@@ -125,15 +127,15 @@ void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
         info = stringAdd;
     }
 
-    RuntimeCall fallBack(info.fallbackImplementation);
-    RuntimeCall context(info.contextImplementation);
+    typename JITAssembler::RuntimeCall fallBack(info.fallbackImplementation);
+    typename JITAssembler::RuntimeCall context(info.contextImplementation);
     if (fallBack.isValid()) {
         as->generateFunctionCallImp(info.needsExceptionCheck, target, info.name, fallBack,
                                      PointerToValue(lhs),
                                      PointerToValue(rhs));
     } else if (context.isValid()) {
         as->generateFunctionCallImp(info.needsExceptionCheck, target, info.name, context,
-                                     Assembler::EngineRegister,
+                                     JITAssembler::EngineRegister,
                                      PointerToValue(lhs),
                                      PointerToValue(rhs));
     } else {
@@ -145,14 +147,15 @@ void Binop::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 
 }
 
-void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
+template <typename JITAssembler>
+void Binop<JITAssembler>::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 {
     IR::Temp *targetTemp = target->asTemp();
     FPRegisterID targetReg;
     if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
         targetReg = (FPRegisterID) targetTemp->index;
     else
-        targetReg = Assembler::FPGpr0;
+        targetReg = JITAssembler::FPGpr0;
 
     switch (op) {
     case IR::OpAdd:
@@ -162,7 +165,7 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 #if CPU(X86)
         if (IR::Const *c = rhs->asConst()) { // Y = X + constant -> Y = X; Y += [constant-address]
             as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, Assembler::ScratchRegister);
+            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
             as->addDouble(addr, targetReg);
             break;
         }
@@ -174,7 +177,7 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
             }
         }
 #endif
-        as->addDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), as->toDoubleRegister(rhs, Assembler::FPGpr1), targetReg);
+        as->addDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
         break;
 
     case IR::OpMul:
@@ -184,7 +187,7 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
 #if CPU(X86)
         if (IR::Const *c = rhs->asConst()) { // Y = X * constant -> Y = X; Y *= [constant-address]
             as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, Assembler::ScratchRegister);
+            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
             as->mulDouble(addr, targetReg);
             break;
         }
@@ -196,14 +199,14 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
             }
         }
 #endif
-        as->mulDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), as->toDoubleRegister(rhs, Assembler::FPGpr1), targetReg);
+        as->mulDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
         break;
 
     case IR::OpSub:
 #if CPU(X86)
         if (IR::Const *c = rhs->asConst()) { // Y = X - constant -> Y = X; Y -= [constant-address]
             as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, Assembler::ScratchRegister);
+            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
             as->subDouble(addr, targetReg);
             break;
         }
@@ -219,19 +222,19 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
                 && targetTemp
                 && targetTemp->kind == IR::Temp::PhysicalRegister
                 && targetTemp->index == rhs->asTemp()->index) { // Y = X - Y -> Tmp = Y; Y = X - Tmp
-            as->moveDouble(as->toDoubleRegister(rhs, Assembler::FPGpr1), Assembler::FPGpr1);
-            as->subDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), Assembler::FPGpr1, targetReg);
+            as->moveDouble(as->toDoubleRegister(rhs, JITAssembler::FPGpr1), JITAssembler::FPGpr1);
+            as->subDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), JITAssembler::FPGpr1, targetReg);
             break;
         }
 
-        as->subDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), as->toDoubleRegister(rhs, Assembler::FPGpr1), targetReg);
+        as->subDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
         break;
 
     case IR::OpDiv:
 #if CPU(X86)
         if (IR::Const *c = rhs->asConst()) { // Y = X / constant -> Y = X; Y /= [constant-address]
             as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, Assembler::ScratchRegister);
+            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
             as->divDouble(addr, targetReg);
             break;
         }
@@ -248,12 +251,12 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
                 && targetTemp
                 && targetTemp->kind == IR::Temp::PhysicalRegister
                 && targetTemp->index == rhs->asTemp()->index) { // Y = X / Y -> Tmp = Y; Y = X / Tmp
-            as->moveDouble(as->toDoubleRegister(rhs, Assembler::FPGpr1), Assembler::FPGpr1);
-            as->divDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), Assembler::FPGpr1, targetReg);
+            as->moveDouble(as->toDoubleRegister(rhs, JITAssembler::FPGpr1), JITAssembler::FPGpr1);
+            as->divDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), JITAssembler::FPGpr1, targetReg);
             break;
         }
 
-        as->divDouble(as->toDoubleRegister(lhs, Assembler::FPGpr0), as->toDoubleRegister(rhs, Assembler::FPGpr1), targetReg);
+        as->divDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
         break;
 
     default: {
@@ -271,8 +274,8 @@ void Binop::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
         as->storeDouble(targetReg, target);
 }
 
-
-bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
+template <typename JITAssembler>
+bool Binop<JITAssembler>::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
     Q_ASSERT(leftSource->type == IR::SInt32Type);
     Q_ASSERT(rightSource->type == IR::SInt32Type);
@@ -305,7 +308,7 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
     bool inplaceOpWithAddress = false;
 
     IR::Temp *targetTemp = target->asTemp();
-    RegisterID targetReg = Assembler::ReturnValueRegister;
+    RegisterID targetReg = JITAssembler::ReturnValueRegister;
     if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
         IR::Temp *rhs = rightSource->asTemp();
         if (!rhs || rhs->kind != IR::Temp::PhysicalRegister || rhs->index != targetTemp->index) {
@@ -369,12 +372,12 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
                 && targetTemp->index == rightSource->asTemp()->index) {
             // X = Y - X -> Tmp = X; X = Y; X -= Tmp
             targetReg = (RegisterID) targetTemp->index;
-            as->move(targetReg, Assembler::ScratchRegister);
+            as->move(targetReg, JITAssembler::ScratchRegister);
             as->move(as->toInt32Register(leftSource, targetReg), targetReg);
-            as->sub32(Assembler::ScratchRegister, targetReg);
+            as->sub32(JITAssembler::ScratchRegister, targetReg);
         } else {
             as->move(as->toInt32Register(leftSource, targetReg), targetReg);
-            as->sub32(as->toInt32Register(rightSource, Assembler::ScratchRegister), targetReg);
+            as->sub32(as->toInt32Register(rightSource, JITAssembler::ScratchRegister), targetReg);
         }
         as->storeInt32(targetReg, target);
         return true;
@@ -419,7 +422,7 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
             return false;
         }
     } else if (inplaceOpWithAddress) { // All cases of X = X op [address-of-Y]
-        Pointer rhsAddr = as->loadAddress(Assembler::ScratchRegister, rightSource);
+        Pointer rhsAddr = as->loadAddress(JITAssembler::ScratchRegister, rightSource);
         switch (op) {
         case IR::OpBitAnd: as->and32(rhsAddr, targetReg); break;
         case IR::OpBitOr:  as->or32 (rhsAddr, targetReg); break;
@@ -433,7 +436,7 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
             return false;
         }
     } else { // All cases of Z = X op Y
-        RegisterID r = as->toInt32Register(rightSource, Assembler::ScratchRegister);
+        RegisterID r = as->toInt32Register(rightSource, JITAssembler::ScratchRegister);
         switch (op) {
         case IR::OpBitAnd: as->and32(l, r, targetReg); break;
         case IR::OpBitOr:  as->or32 (l, r, targetReg); break;
@@ -452,18 +455,18 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
         // Not all CPUs accept shifts over more than 31 bits, and some CPUs (like ARM) will do
         // surprising stuff when shifting over 0 bits.
 #define CHECK_RHS(op) { \
-    as->and32(TrustedImm32(0x1f), r, Assembler::ScratchRegister); \
-    Jump notZero = as->branch32(RelationalCondition::NotEqual, Assembler::ScratchRegister, TrustedImm32(0)); \
+    as->and32(TrustedImm32(0x1f), r, JITAssembler::ScratchRegister); \
+    Jump notZero = as->branch32(RelationalCondition::NotEqual, JITAssembler::ScratchRegister, TrustedImm32(0)); \
     as->move(l, targetReg); \
     Jump done = as->jump(); \
     notZero.link(as); \
     op; \
     done.link(as); \
 }
-        case IR::OpLShift: CHECK_RHS(as->lshift32(l, Assembler::ScratchRegister, targetReg)); break;
-        case IR::OpRShift: CHECK_RHS(as->rshift32(l, Assembler::ScratchRegister, targetReg)); break;
+        case IR::OpLShift: CHECK_RHS(as->lshift32(l, JITAssembler::ScratchRegister, targetReg)); break;
+        case IR::OpRShift: CHECK_RHS(as->rshift32(l, JITAssembler::ScratchRegister, targetReg)); break;
         case IR::OpURShift:
-            CHECK_RHS(as->urshift32(l, Assembler::ScratchRegister, targetReg));
+            CHECK_RHS(as->urshift32(l, JITAssembler::ScratchRegister, targetReg));
             as->storeUInt32(targetReg, target);
             // IMPORTANT: do NOT do a break here! The stored type of an urshift is different from the other binary operations!
             return true;
@@ -481,17 +484,19 @@ bool Binop::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *ta
     return true;
 }
 
-static inline Assembler::FPRegisterID getFreeFPReg(IR::Expr *shouldNotOverlap, unsigned hint)
+template <typename JITAssembler>
+inline typename JITAssembler::FPRegisterID getFreeFPReg(IR::Expr *shouldNotOverlap, unsigned hint)
 {
     if (IR::Temp *t = shouldNotOverlap->asTemp())
         if (t->type == IR::DoubleType)
             if (t->kind == IR::Temp::PhysicalRegister)
                 if (t->index == hint)
-                    return Assembler::FPRegisterID(hint + 1);
-    return Assembler::FPRegisterID(hint);
+                    return typename JITAssembler::FPRegisterID(hint + 1);
+    return typename JITAssembler::FPRegisterID(hint);
 }
 
-Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
+template <typename JITAssembler>
+typename JITAssembler::Jump Binop<JITAssembler>::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
     Jump done;
 
@@ -505,8 +510,8 @@ Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSourc
     //       register.
     switch (op) {
     case IR::OpAdd: {
-        FPRegisterID lReg = getFreeFPReg(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg(leftSource, 4);
+        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
+        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
         Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
         Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
 
@@ -520,8 +525,8 @@ Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSourc
             rightIsNoDbl.link(as);
     } break;
     case IR::OpMul: {
-        FPRegisterID lReg = getFreeFPReg(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg(leftSource, 4);
+        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
+        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
         Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
         Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
 
@@ -535,8 +540,8 @@ Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSourc
             rightIsNoDbl.link(as);
     } break;
     case IR::OpSub: {
-        FPRegisterID lReg = getFreeFPReg(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg(leftSource, 4);
+        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
+        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
         Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
         Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
 
@@ -550,8 +555,8 @@ Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSourc
             rightIsNoDbl.link(as);
     } break;
     case IR::OpDiv: {
-        FPRegisterID lReg = getFreeFPReg(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg(leftSource, 4);
+        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
+        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
         Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
         Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
 
@@ -571,4 +576,9 @@ Assembler::Jump Binop::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSourc
     return done;
 }
 
+template struct QV4::JIT::Binop<QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>>;
+#if defined(V4_BOOTSTRAP) && CPU(X86_64)
+template struct QV4::JIT::Binop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>>;
+#endif
+
 #endif
diff --git a/src/qml/jit/qv4binop_p.h b/src/qml/jit/qv4binop_p.h
index 3742e99e5a..d2d9ba7753 100644
--- a/src/qml/jit/qv4binop_p.h
+++ b/src/qml/jit/qv4binop_p.h
@@ -61,21 +61,22 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
 
+template <typename JITAssembler>
 struct Binop {
-    Binop(Assembler *assembler, IR::AluOp operation)
+    Binop(JITAssembler *assembler, IR::AluOp operation)
         : as(assembler)
         , op(operation)
     {}
 
-    using Jump = Assembler::Jump;
-    using Address = Assembler::Address;
-    using RegisterID = Assembler::RegisterID;
-    using FPRegisterID = Assembler::FPRegisterID;
-    using TrustedImm32 = Assembler::TrustedImm32;
-    using ResultCondition = Assembler::ResultCondition;
-    using RelationalCondition = Assembler::RelationalCondition;
-    using Pointer = Assembler::Pointer;
-    using PointerToValue = Assembler::PointerToValue;
+    using Jump = typename JITAssembler::Jump;
+    using Address = typename JITAssembler::Address;
+    using RegisterID = typename JITAssembler::RegisterID;
+    using FPRegisterID = typename JITAssembler::FPRegisterID;
+    using TrustedImm32 = typename JITAssembler::TrustedImm32;
+    using ResultCondition = typename JITAssembler::ResultCondition;
+    using RelationalCondition = typename JITAssembler::RelationalCondition;
+    using Pointer = typename JITAssembler::Pointer;
+    using PointerToValue = typename JITAssembler::PointerToValue;
 
     void generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
     void doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
@@ -103,8 +104,8 @@ struct Binop {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
         return as->branchAdd32(ResultCondition::Overflow, addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        return as->branchAdd32(ResultCondition::Overflow, Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        return as->branchAdd32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
 #endif
     }
 
@@ -118,8 +119,8 @@ struct Binop {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
         return as->branchSub32(ResultCondition::Overflow, addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        return as->branchSub32(ResultCondition::Overflow, Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        return as->branchSub32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
 #endif
     }
 
@@ -131,10 +132,10 @@ struct Binop {
     Jump inline_mul32(Address addr, RegisterID reg)
     {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        return as->branchMul32(Assembler::Overflow, addr, reg);
+        return as->branchMul32(JITAssembler::Overflow, addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        return as->branchMul32(ResultCondition::Overflow, Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        return as->branchMul32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
 #endif
     }
 
@@ -145,9 +146,9 @@ struct Binop {
 
     Jump inline_shl32(Address addr, RegisterID reg)
     {
-        as->load32(addr, Assembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), Assembler::ScratchRegister);
-        as->lshift32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
+        as->lshift32(JITAssembler::ScratchRegister, reg);
         return Jump();
     }
 
@@ -160,9 +161,9 @@ struct Binop {
 
     Jump inline_shr32(Address addr, RegisterID reg)
     {
-        as->load32(addr, Assembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), Assembler::ScratchRegister);
-        as->rshift32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
+        as->rshift32(JITAssembler::ScratchRegister, reg);
         return Jump();
     }
 
@@ -175,9 +176,9 @@ struct Binop {
 
     Jump inline_ushr32(Address addr, RegisterID reg)
     {
-        as->load32(addr, Assembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), Assembler::ScratchRegister);
-        as->urshift32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
+        as->urshift32(JITAssembler::ScratchRegister, reg);
         return as->branchTest32(ResultCondition::Signed, reg, reg);
     }
 
@@ -193,8 +194,8 @@ struct Binop {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
         as->and32(addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        as->and32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->and32(JITAssembler::ScratchRegister, reg);
 #endif
         return Jump();
     }
@@ -210,8 +211,8 @@ struct Binop {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
         as->or32(addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        as->or32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->or32(JITAssembler::ScratchRegister, reg);
 #endif
         return Jump();
     }
@@ -227,8 +228,8 @@ struct Binop {
 #if HAVE(ALU_OPS_WITH_MEM_OPERAND)
         as->xor32(addr, reg);
 #else
-        as->load32(addr, Assembler::ScratchRegister);
-        as->xor32(Assembler::ScratchRegister, reg);
+        as->load32(addr, JITAssembler::ScratchRegister);
+        as->xor32(JITAssembler::ScratchRegister, reg);
 #endif
         return Jump();
     }
@@ -241,7 +242,7 @@ struct Binop {
 
 
 
-    Assembler *as;
+    JITAssembler *as;
     IR::AluOp op;
 };
 
diff --git a/src/qml/jit/qv4isel_masm.cpp b/src/qml/jit/qv4isel_masm.cpp
index 279ccabf81..b1134d2bec 100644
--- a/src/qml/jit/qv4isel_masm.cpp
+++ b/src/qml/jit/qv4isel_masm.cpp
@@ -39,11 +39,7 @@
 
 #include "qv4isel_masm_p.h"
 #include "qv4runtime_p.h"
-#include "qv4object_p.h"
-#include "qv4functionobject_p.h"
-#include "qv4regexpobject_p.h"
 #include "qv4lookup_p.h"
-#include "qv4function_p.h"
 #include "qv4ssa_p.h"
 #include "qv4regalloc_p.h"
 #include "qv4assembler_p.h"
@@ -68,7 +64,8 @@ using namespace QV4;
 using namespace QV4::JIT;
 
 
-InstructionSelection::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory)
+template <typename JITAssembler>
+InstructionSelection<JITAssembler>::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory)
     : EvalInstructionSelection(execAllocator, module, jsGenerator, iselFactory)
     , _block(0)
     , _as(0)
@@ -79,12 +76,14 @@ InstructionSelection::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::Ex
     module->unitFlags |= QV4::CompiledData::Unit::ContainsMachineCode;
 }
 
-InstructionSelection::~InstructionSelection()
+template <typename JITAssembler>
+InstructionSelection<JITAssembler>::~InstructionSelection()
 {
     delete _as;
 }
 
-void InstructionSelection::run(int functionIndex)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::run(int functionIndex)
 {
     IR::Function *function = irModule->functions[functionIndex];
     qSwap(_function, function);
@@ -93,8 +92,8 @@ void InstructionSelection::run(int functionIndex)
     opt.run(qmlEngine);
 
     static const bool withRegisterAllocator = qEnvironmentVariableIsEmpty("QV4_NO_REGALLOC");
-    if (Assembler::RegAllocIsSupported && opt.isInSSA() && withRegisterAllocator) {
-        RegisterAllocator regalloc(Assembler::getRegisterInfo());
+    if (JITTargetPlatform::RegAllocIsSupported && opt.isInSSA() && withRegisterAllocator) {
+        RegisterAllocator regalloc(JITTargetPlatform::getRegisterInfo());
         regalloc.run(_function, opt);
         calculateRegistersToSave(regalloc.usedRegisters());
     } else {
@@ -103,47 +102,47 @@ void InstructionSelection::run(int functionIndex)
             opt.convertOutOfSSA();
         ConvertTemps().toStackSlots(_function);
         IR::Optimizer::showMeTheCode(_function, "After stack slot allocation");
-        calculateRegistersToSave(Assembler::getRegisterInfo()); // FIXME: this saves all registers. We can probably do with a subset: those that are not used by the register allocator.
+        calculateRegistersToSave(JITTargetPlatform::getRegisterInfo()); // FIXME: this saves all registers. We can probably do with a subset: those that are not used by the register allocator.
     }
     BitVector removableJumps = opt.calculateOptionalJumps();
     qSwap(_removableJumps, removableJumps);
 
-    Assembler* oldAssembler = _as;
-    _as = new Assembler(jsGenerator, _function, executableAllocator);
+    JITAssembler* oldAssembler = _as;
+    _as = new JITAssembler(jsGenerator, _function, executableAllocator);
     _as->setStackLayout(6, // 6 == max argc for calls to built-ins with an argument array
                         regularRegistersToSave.size(),
                         fpRegistersToSave.size());
     _as->enterStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
 
 #ifdef ARGUMENTS_IN_REGISTERS
-    _as->move(_as->registerForArgument(0), Assembler::EngineRegister);
+    _as->move(_as->registerForArgument(0), JITTargetPlatform::EngineRegister);
 #else
-    _as->loadPtr(addressForArgument(0), Assembler::EngineRegister);
+    _as->loadPtr(addressForArgument(0), JITTargetPlatform::EngineRegister);
 #endif
 
     const int locals = _as->stackLayout().calculateJSStackFrameSize();
     if (locals > 0) {
-        _as->loadPtr(Address(Assembler::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)), Assembler::LocalsRegister);
+        _as->loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)), JITTargetPlatform::LocalsRegister);
 #ifdef VALUE_FITS_IN_REGISTER
-        _as->move(Assembler::TrustedImm64(0), Assembler::ReturnValueRegister);
-        _as->move(Assembler::TrustedImm32(locals), Assembler::ScratchRegister);
-        Assembler::Label loop = _as->label();
-        _as->store64(Assembler::ReturnValueRegister, Assembler::Address(Assembler::LocalsRegister));
-        _as->add64(Assembler::TrustedImm32(8), Assembler::LocalsRegister);
-        Assembler::Jump jump = _as->branchSub32(Assembler::NonZero, Assembler::TrustedImm32(1), Assembler::ScratchRegister);
+        _as->move(TrustedImm64(0), JITTargetPlatform::ReturnValueRegister);
+        _as->move(TrustedImm32(locals), JITTargetPlatform::ScratchRegister);
+        Label loop = _as->label();
+        _as->store64(JITTargetPlatform::ReturnValueRegister, Address(JITTargetPlatform::LocalsRegister));
+        _as->add64(TrustedImm32(8), JITTargetPlatform::LocalsRegister);
+        Jump jump = _as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), JITTargetPlatform::ScratchRegister);
         jump.linkTo(loop, _as);
 #else
-        _as->move(Assembler::TrustedImm32(0), Assembler::ReturnValueRegister);
-        _as->move(Assembler::TrustedImm32(locals), Assembler::ScratchRegister);
-        Assembler::Label loop = _as->label();
-        _as->store32(Assembler::ReturnValueRegister, Assembler::Address(Assembler::LocalsRegister));
-        _as->add32(Assembler::TrustedImm32(4), Assembler::LocalsRegister);
-        _as->store32(Assembler::ReturnValueRegister, Assembler::Address(Assembler::LocalsRegister));
-        _as->add32(Assembler::TrustedImm32(4), Assembler::LocalsRegister);
-        Assembler::Jump jump = _as->branchSub32(Assembler::NonZero, Assembler::TrustedImm32(1), Assembler::ScratchRegister);
+        _as->move(TrustedImm32(0), JITTargetPlatform::ReturnValueRegister);
+        _as->move(TrustedImm32(locals), JITTargetPlatform::ScratchRegister);
+        Label loop = _as->label();
+        _as->store32(JITTargetPlatform::ReturnValueRegister, Address(JITTargetPlatform::LocalsRegister));
+        _as->add32(TrustedImm32(4), JITTargetPlatform::LocalsRegister);
+        _as->store32(JITTargetPlatform::ReturnValueRegister, Address(JITTargetPlatform::LocalsRegister));
+        _as->add32(TrustedImm32(4), JITTargetPlatform::LocalsRegister);
+        Jump jump = _as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), JITTargetPlatform::ScratchRegister);
         jump.linkTo(loop, _as);
 #endif
-        _as->storePtr(Assembler::LocalsRegister, Address(Assembler::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)));
+        _as->storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, qOffsetOf(ExecutionEngine, jsStackTop)));
     }
 
 
@@ -158,9 +157,9 @@ void InstructionSelection::run(int functionIndex)
         for (IR::Stmt *s : _block->statements()) {
             if (s->location.isValid()) {
                 if (int(s->location.startLine) != lastLine) {
-                    _as->loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), Assembler::ScratchRegister);
-                    Assembler::Address lineAddr(Assembler::ScratchRegister, qOffsetOf(QV4::ExecutionContext::Data, lineNumber));
-                    _as->store32(Assembler::TrustedImm32(s->location.startLine), lineAddr);
+                    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), JITTargetPlatform::ScratchRegister);
+                    Address lineAddr(JITTargetPlatform::ScratchRegister, qOffsetOf(QV4::ExecutionContext::Data, lineNumber));
+                    _as->store32(TrustedImm32(s->location.startLine), lineAddr);
                     lastLine = s->location.startLine;
                 }
             }
@@ -181,165 +180,187 @@ void InstructionSelection::run(int functionIndex)
     qSwap(_removableJumps, removableJumps);
 }
 
-QQmlRefPointer<QV4::CompiledData::CompilationUnit> InstructionSelection::backendCompileStep()
+template <typename JITAssembler>
+QQmlRefPointer<QV4::CompiledData::CompilationUnit> InstructionSelection<JITAssembler>::backendCompileStep()
 {
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> result;
     result.adopt(compilationUnit.take());
     return result;
 }
 
-void InstructionSelection::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result)
 {
     prepareCallData(args, 0);
 
     if (useFastLookups && func->global) {
         uint index = registerGlobalGetterLookup(*func->id);
-        generateRuntimeCall(result, callGlobalLookup,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(index),
+        generateRuntimeCall(_as, result, callGlobalLookup,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(index),
                              baseAddressForCallData());
     } else {
-        generateRuntimeCall(result, callActivationProperty,
-                             Assembler::EngineRegister,
-                             Assembler::StringToIndex(*func->id),
+        generateRuntimeCall(_as, result, callActivationProperty,
+                             JITTargetPlatform::EngineRegister,
+                             StringToIndex(*func->id),
                              baseAddressForCallData());
     }
 }
 
-void InstructionSelection::callBuiltinTypeofQmlContextProperty(IR::Expr *base,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinTypeofQmlContextProperty(IR::Expr *base,
                                                                IR::Member::MemberKind kind,
                                                                int propertyIndex, IR::Expr *result)
 {
     if (kind == IR::Member::MemberOfQmlScopeObject) {
-        generateRuntimeCall(result, typeofScopeObjectProperty, Assembler::EngineRegister,
-                             Assembler::PointerToValue(base),
-                             Assembler::TrustedImm32(propertyIndex));
+        generateRuntimeCall(_as, result, typeofScopeObjectProperty, JITTargetPlatform::EngineRegister,
+                             PointerToValue(base),
+                             TrustedImm32(propertyIndex));
     } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        generateRuntimeCall(result, typeofContextObjectProperty,
-                             Assembler::EngineRegister, Assembler::PointerToValue(base),
-                             Assembler::TrustedImm32(propertyIndex));
+        generateRuntimeCall(_as, result, typeofContextObjectProperty,
+                             JITTargetPlatform::EngineRegister, PointerToValue(base),
+                             TrustedImm32(propertyIndex));
     } else {
         Q_UNREACHABLE();
     }
 }
 
-void InstructionSelection::callBuiltinTypeofMember(IR::Expr *base, const QString &name,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinTypeofMember(IR::Expr *base, const QString &name,
                                                    IR::Expr *result)
 {
-    generateRuntimeCall(result, typeofMember, Assembler::EngineRegister,
-                         Assembler::PointerToValue(base), Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, result, typeofMember, JITTargetPlatform::EngineRegister,
+                         PointerToValue(base), StringToIndex(name));
 }
 
-void InstructionSelection::callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index,
                                                       IR::Expr *result)
 {
-    generateRuntimeCall(result, typeofElement,
-                         Assembler::EngineRegister,
-                         Assembler::PointerToValue(base), Assembler::PointerToValue(index));
+    generateRuntimeCall(_as, result, typeofElement,
+                         JITTargetPlatform::EngineRegister,
+                         PointerToValue(base), PointerToValue(index));
 }
 
-void InstructionSelection::callBuiltinTypeofName(const QString &name, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinTypeofName(const QString &name, IR::Expr *result)
 {
-    generateRuntimeCall(result, typeofName, Assembler::EngineRegister,
-                         Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, result, typeofName, JITTargetPlatform::EngineRegister,
+                         StringToIndex(name));
 }
 
-void InstructionSelection::callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result)
 {
-    generateRuntimeCall(result, typeofValue, Assembler::EngineRegister,
-                         Assembler::PointerToValue(value));
+    generateRuntimeCall(_as, result, typeofValue, JITTargetPlatform::EngineRegister,
+                         PointerToValue(value));
 }
 
-void InstructionSelection::callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result)
 {
-    generateRuntimeCall(result, deleteMember, Assembler::EngineRegister,
-                         Assembler::Reference(base), Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, result, deleteMember, JITTargetPlatform::EngineRegister,
+                         Reference(base), StringToIndex(name));
 }
 
-void InstructionSelection::callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index,
                                                       IR::Expr *result)
 {
-    generateRuntimeCall(result, deleteElement, Assembler::EngineRegister,
-                         Assembler::Reference(base), Assembler::PointerToValue(index));
+    generateRuntimeCall(_as, result, deleteElement, JITTargetPlatform::EngineRegister,
+                         Reference(base), PointerToValue(index));
 }
 
-void InstructionSelection::callBuiltinDeleteName(const QString &name, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDeleteName(const QString &name, IR::Expr *result)
 {
-    generateRuntimeCall(result, deleteName, Assembler::EngineRegister,
-                         Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, result, deleteName, JITTargetPlatform::EngineRegister,
+                         StringToIndex(name));
 }
 
-void InstructionSelection::callBuiltinDeleteValue(IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDeleteValue(IR::Expr *result)
 {
     _as->storeValue(Primitive::fromBoolean(false), result);
 }
 
-void InstructionSelection::callBuiltinThrow(IR::Expr *arg)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinThrow(IR::Expr *arg)
 {
-    generateRuntimeCall(Assembler::ReturnValueRegister, throwException, Assembler::EngineRegister,
-                         Assembler::PointerToValue(arg));
+    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, throwException, JITTargetPlatform::EngineRegister,
+                         PointerToValue(arg));
 }
 
-void InstructionSelection::callBuiltinReThrow()
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinReThrow()
 {
     _as->jumpToExceptionHandler();
 }
 
-void InstructionSelection::callBuiltinUnwindException(IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinUnwindException(IR::Expr *result)
 {
-    generateRuntimeCall(result, unwindException, Assembler::EngineRegister);
+    generateRuntimeCall(_as, result, unwindException, JITTargetPlatform::EngineRegister);
 
 }
 
-void InstructionSelection::callBuiltinPushCatchScope(const QString &exceptionName)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinPushCatchScope(const QString &exceptionName)
 {
-    generateRuntimeCall(Assembler::Void, pushCatchScope, Assembler::EngineRegister, Assembler::StringToIndex(exceptionName));
+    generateRuntimeCall(_as, JITAssembler::Void, pushCatchScope, JITTargetPlatform::EngineRegister, StringToIndex(exceptionName));
 }
 
-void InstructionSelection::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result)
 {
     Q_ASSERT(arg);
     Q_ASSERT(result);
 
-    generateRuntimeCall(result, foreachIterator, Assembler::EngineRegister, Assembler::PointerToValue(arg));
+    generateRuntimeCall(_as, result, foreachIterator, JITTargetPlatform::EngineRegister, PointerToValue(arg));
 }
 
-void InstructionSelection::callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result)
 {
     Q_ASSERT(arg);
     Q_ASSERT(result);
 
-    generateRuntimeCall(result, foreachNextPropertyName, Assembler::Reference(arg));
+    generateRuntimeCall(_as, result, foreachNextPropertyName, Reference(arg));
 }
 
-void InstructionSelection::callBuiltinPushWithScope(IR::Expr *arg)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinPushWithScope(IR::Expr *arg)
 {
     Q_ASSERT(arg);
 
-    generateRuntimeCall(Assembler::Void, pushWithScope, Assembler::Reference(arg), Assembler::EngineRegister);
+    generateRuntimeCall(_as, JITAssembler::Void, pushWithScope, Reference(arg), JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::callBuiltinPopScope()
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinPopScope()
 {
-    generateRuntimeCall(Assembler::Void, popScope, Assembler::EngineRegister);
+    generateRuntimeCall(_as, JITAssembler::Void, popScope, JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::callBuiltinDeclareVar(bool deletable, const QString &name)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDeclareVar(bool deletable, const QString &name)
 {
-    generateRuntimeCall(Assembler::Void, declareVar, Assembler::EngineRegister,
-                         Assembler::TrustedImm32(deletable), Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, JITAssembler::Void, declareVar, JITTargetPlatform::EngineRegister,
+                         TrustedImm32(deletable), StringToIndex(name));
 }
 
-void InstructionSelection::callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args)
 {
     Q_ASSERT(result);
 
     int length = prepareVariableArguments(args);
-    generateRuntimeCall(result, arrayLiteral, Assembler::EngineRegister,
-                         baseAddressForCallArguments(), Assembler::TrustedImm32(length));
+    generateRuntimeCall(_as, result, arrayLiteral, JITTargetPlatform::EngineRegister,
+                         baseAddressForCallArguments(), TrustedImm32(length));
 }
 
-void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
 {
     Q_ASSERT(result);
 
@@ -415,81 +436,89 @@ void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Expr *result, int
         it = it->next;
     }
 
-    generateRuntimeCall(result, objectLiteral, Assembler::EngineRegister,
-                         baseAddressForCallArguments(), Assembler::TrustedImm32(classId),
-                         Assembler::TrustedImm32(arrayValueCount), Assembler::TrustedImm32(arrayGetterSetterCount | (needSparseArray << 30)));
+    generateRuntimeCall(_as, result, objectLiteral, JITTargetPlatform::EngineRegister,
+                         baseAddressForCallArguments(), TrustedImm32(classId),
+                         TrustedImm32(arrayValueCount), TrustedImm32(arrayGetterSetterCount | (needSparseArray << 30)));
 }
 
-void InstructionSelection::callBuiltinSetupArgumentObject(IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinSetupArgumentObject(IR::Expr *result)
 {
-    generateRuntimeCall(result, setupArgumentsObject, Assembler::EngineRegister);
+    generateRuntimeCall(_as, result, setupArgumentsObject, JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::callBuiltinConvertThisToObject()
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callBuiltinConvertThisToObject()
 {
-    generateRuntimeCall(Assembler::Void, convertThisToObject, Assembler::EngineRegister);
+    generateRuntimeCall(_as, JITAssembler::Void, convertThisToObject, JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(value);
 
     prepareCallData(args, 0);
     if (value->asConst())
-        generateRuntimeCall(result, callValue, Assembler::EngineRegister,
-                             Assembler::PointerToValue(value),
+        generateRuntimeCall(_as, result, callValue, JITTargetPlatform::EngineRegister,
+                             PointerToValue(value),
                              baseAddressForCallData());
     else
-        generateRuntimeCall(result, callValue, Assembler::EngineRegister,
-                             Assembler::Reference(value),
+        generateRuntimeCall(_as, result, callValue, JITTargetPlatform::EngineRegister,
+                             Reference(value),
                              baseAddressForCallData());
 }
 
-void InstructionSelection::loadThisObject(IR::Expr *temp)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadThisObject(IR::Expr *temp)
 {
-    _as->loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), Assembler::ScratchRegister);
-    _as->loadPtr(Address(Assembler::ScratchRegister, qOffsetOf(ExecutionContext::Data, callData)), Assembler::ScratchRegister);
+    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), JITTargetPlatform::ScratchRegister);
+    _as->loadPtr(Address(JITTargetPlatform::ScratchRegister, qOffsetOf(ExecutionContext::Data, callData)), JITTargetPlatform::ScratchRegister);
 #if defined(VALUE_FITS_IN_REGISTER)
-    _as->load64(Pointer(Assembler::ScratchRegister, qOffsetOf(CallData, thisObject)),
-                Assembler::ReturnValueRegister);
+    _as->load64(Pointer(JITTargetPlatform::ScratchRegister, qOffsetOf(CallData, thisObject)),
+                JITTargetPlatform::ReturnValueRegister);
     _as->storeReturnValue(temp);
 #else
-    _as->copyValue(temp, Pointer(Assembler::ScratchRegister, qOffsetOf(CallData, thisObject)));
+    _as->copyValue(temp, Pointer(JITTargetPlatform::ScratchRegister, qOffsetOf(CallData, thisObject)));
 #endif
 }
 
-void InstructionSelection::loadQmlContext(IR::Expr *temp)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadQmlContext(IR::Expr *temp)
 {
-    generateRuntimeCall(temp, getQmlContext, Assembler::EngineRegister);
+    generateRuntimeCall(_as, temp, getQmlContext, JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::loadQmlImportedScripts(IR::Expr *temp)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadQmlImportedScripts(IR::Expr *temp)
 {
-    generateRuntimeCall(temp, getQmlImportedScripts, Assembler::EngineRegister);
+    generateRuntimeCall(_as, temp, getQmlImportedScripts, JITTargetPlatform::EngineRegister);
 }
 
-void InstructionSelection::loadQmlSingleton(const QString &name, IR::Expr *temp)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadQmlSingleton(const QString &name, IR::Expr *temp)
 {
-    generateRuntimeCall(temp, getQmlSingleton, Assembler::EngineRegister, Assembler::StringToIndex(name));
+    generateRuntimeCall(_as, temp, getQmlSingleton, JITTargetPlatform::EngineRegister, StringToIndex(name));
 }
 
-void InstructionSelection::loadConst(IR::Const *sourceConst, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadConst(IR::Const *sourceConst, IR::Expr *target)
 {
     if (IR::Temp *targetTemp = target->asTemp()) {
         if (targetTemp->kind == IR::Temp::PhysicalRegister) {
             if (targetTemp->type == IR::DoubleType) {
                 Q_ASSERT(sourceConst->type == IR::DoubleType);
-                _as->toDoubleRegister(sourceConst, (Assembler::FPRegisterID) targetTemp->index);
+                _as->toDoubleRegister(sourceConst, (FPRegisterID) targetTemp->index);
             } else if (targetTemp->type == IR::SInt32Type) {
                 Q_ASSERT(sourceConst->type == IR::SInt32Type);
-                _as->toInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
+                _as->toInt32Register(sourceConst, (RegisterID) targetTemp->index);
             } else if (targetTemp->type == IR::UInt32Type) {
                 Q_ASSERT(sourceConst->type == IR::UInt32Type);
-                _as->toUInt32Register(sourceConst, (Assembler::RegisterID) targetTemp->index);
+                _as->toUInt32Register(sourceConst, (RegisterID) targetTemp->index);
             } else if (targetTemp->type == IR::BoolType) {
                 Q_ASSERT(sourceConst->type == IR::BoolType);
-                _as->move(Assembler::TrustedImm32(convertToValue(sourceConst).int_32()),
-                          (Assembler::RegisterID) targetTemp->index);
+                _as->move(TrustedImm32(convertToValue(sourceConst).int_32()),
+                          (RegisterID) targetTemp->index);
             } else {
                 Q_UNREACHABLE();
             }
@@ -500,147 +529,155 @@ void InstructionSelection::loadConst(IR::Const *sourceConst, IR::Expr *target)
     _as->storeValue(convertToValue(sourceConst), target);
 }
 
-void InstructionSelection::loadString(const QString &str, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadString(const QString &str, IR::Expr *target)
 {
-    Pointer srcAddr = _as->loadStringAddress(Assembler::ReturnValueRegister, str);
-    _as->loadPtr(srcAddr, Assembler::ReturnValueRegister);
-    Pointer destAddr = _as->loadAddress(Assembler::ScratchRegister, target);
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    _as->store64(Assembler::ReturnValueRegister, destAddr);
-#else
-    _as->store32(Assembler::ReturnValueRegister, destAddr);
-    destAddr.offset += 4;
-    _as->store32(Assembler::TrustedImm32(QV4::Value::Managed_Type_Internal), destAddr);
-#endif
+    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);
 }
 
-void InstructionSelection::loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target)
 {
     int id = registerRegExp(sourceRegexp);
-    generateRuntimeCall(target, regexpLiteral, Assembler::EngineRegister, Assembler::TrustedImm32(id));
+    generateRuntimeCall(_as, target, regexpLiteral, JITTargetPlatform::EngineRegister, TrustedImm32(id));
 }
 
-void InstructionSelection::getActivationProperty(const IR::Name *name, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::getActivationProperty(const IR::Name *name, IR::Expr *target)
 {
     if (useFastLookups && name->global) {
         uint index = registerGlobalGetterLookup(*name->id);
-        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, globalGetter), Assembler::EngineRegister, Assembler::Void);
+        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, globalGetter), JITTargetPlatform::EngineRegister, JITAssembler::Void);
         return;
     }
-    generateRuntimeCall(target, getActivationProperty, Assembler::EngineRegister, Assembler::StringToIndex(*name->id));
+    generateRuntimeCall(_as, target, getActivationProperty, JITTargetPlatform::EngineRegister, StringToIndex(*name->id));
 }
 
-void InstructionSelection::setActivationProperty(IR::Expr *source, const QString &targetName)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::setActivationProperty(IR::Expr *source, const QString &targetName)
 {
     // ### should use a lookup call here
-    generateRuntimeCall(Assembler::Void, setActivationProperty,
-                         Assembler::EngineRegister, Assembler::StringToIndex(targetName), Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, JITAssembler::Void, setActivationProperty,
+                         JITTargetPlatform::EngineRegister, StringToIndex(targetName), PointerToValue(source));
 }
 
-void InstructionSelection::initClosure(IR::Closure *closure, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::initClosure(IR::Closure *closure, IR::Expr *target)
 {
     int id = closure->value;
-    generateRuntimeCall(target, closure, Assembler::EngineRegister, Assembler::TrustedImm32(id));
+    generateRuntimeCall(_as, target, closure, JITTargetPlatform::EngineRegister, TrustedImm32(id));
 }
 
-void InstructionSelection::getProperty(IR::Expr *base, const QString &name, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::getProperty(IR::Expr *base, const QString &name, IR::Expr *target)
 {
     if (useFastLookups) {
         uint index = registerGetterLookup(name);
-        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, getter), Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::Void);
+        generateLookupCall(target, index, qOffsetOf(QV4::Lookup, getter), JITTargetPlatform::EngineRegister, PointerToValue(base), JITAssembler::Void);
     } else {
-        generateRuntimeCall(target, getProperty, Assembler::EngineRegister,
-                             Assembler::PointerToValue(base), Assembler::StringToIndex(name));
+        generateRuntimeCall(_as, target, getProperty, JITTargetPlatform::EngineRegister,
+                             PointerToValue(base), StringToIndex(name));
     }
 }
 
-void InstructionSelection::getQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::getQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target)
 {
     if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(target, getQmlScopeObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::TrustedImm32(index), Assembler::TrustedImm32(captureRequired));
+        generateRuntimeCall(_as, target, getQmlScopeObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index), TrustedImm32(captureRequired));
     else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(target, getQmlContextObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::TrustedImm32(index), Assembler::TrustedImm32(captureRequired));
+        generateRuntimeCall(_as, target, getQmlContextObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index), TrustedImm32(captureRequired));
     else if (kind == IR::Member::MemberOfIdObjectsArray)
-        generateRuntimeCall(target, getQmlIdObject, Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::TrustedImm32(index));
+        generateRuntimeCall(_as, target, getQmlIdObject, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index));
     else
         Q_ASSERT(false);
 }
 
-void InstructionSelection::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingleton, int attachedPropertiesId, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingleton, int attachedPropertiesId, IR::Expr *target)
 {
     if (attachedPropertiesId != 0)
-        generateRuntimeCall(target, getQmlAttachedProperty, Assembler::EngineRegister, Assembler::TrustedImm32(attachedPropertiesId), Assembler::TrustedImm32(propertyIndex));
+        generateRuntimeCall(_as, target, getQmlAttachedProperty, JITTargetPlatform::EngineRegister, TrustedImm32(attachedPropertiesId), TrustedImm32(propertyIndex));
     else if (isSingleton)
-        generateRuntimeCall(target, getQmlSingletonQObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::TrustedImm32(propertyIndex),
-                             Assembler::TrustedImm32(captureRequired));
+        generateRuntimeCall(_as, target, getQmlSingletonQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(propertyIndex),
+                             TrustedImm32(captureRequired));
     else
-        generateRuntimeCall(target, getQmlQObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(base), Assembler::TrustedImm32(propertyIndex),
-                             Assembler::TrustedImm32(captureRequired));
+        generateRuntimeCall(_as, target, getQmlQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(propertyIndex),
+                             TrustedImm32(captureRequired));
 }
 
-void InstructionSelection::setProperty(IR::Expr *source, IR::Expr *targetBase,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::setProperty(IR::Expr *source, IR::Expr *targetBase,
                                        const QString &targetName)
 {
     if (useFastLookups) {
         uint index = registerSetterLookup(targetName);
-        generateLookupCall(Assembler::Void, index, qOffsetOf(QV4::Lookup, setter),
-                           Assembler::EngineRegister,
-                           Assembler::PointerToValue(targetBase),
-                           Assembler::PointerToValue(source));
+        generateLookupCall(JITAssembler::Void, index, qOffsetOf(QV4::Lookup, setter),
+                           JITTargetPlatform::EngineRegister,
+                           PointerToValue(targetBase),
+                           PointerToValue(source));
     } else {
-        generateRuntimeCall(Assembler::Void, setProperty, Assembler::EngineRegister,
-                             Assembler::PointerToValue(targetBase), Assembler::StringToIndex(targetName),
-                             Assembler::PointerToValue(source));
+        generateRuntimeCall(_as, JITAssembler::Void, setProperty, JITTargetPlatform::EngineRegister,
+                             PointerToValue(targetBase), StringToIndex(targetName),
+                             PointerToValue(source));
     }
 }
 
-void InstructionSelection::setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex)
 {
     if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(Assembler::Void, setQmlScopeObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(targetBase),
-                             Assembler::TrustedImm32(propertyIndex), Assembler::PointerToValue(source));
+        generateRuntimeCall(_as, JITAssembler::Void, setQmlScopeObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
+                             TrustedImm32(propertyIndex), PointerToValue(source));
     else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(Assembler::Void, setQmlContextObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(targetBase),
-                             Assembler::TrustedImm32(propertyIndex), Assembler::PointerToValue(source));
+        generateRuntimeCall(_as, JITAssembler::Void, setQmlContextObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
+                             TrustedImm32(propertyIndex), PointerToValue(source));
     else
         Q_ASSERT(false);
 }
 
-void InstructionSelection::setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex)
 {
-    generateRuntimeCall(Assembler::Void, setQmlQObjectProperty, Assembler::EngineRegister, Assembler::PointerToValue(targetBase),
-                         Assembler::TrustedImm32(propertyIndex), Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, JITAssembler::Void, setQmlQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
+                         TrustedImm32(propertyIndex), PointerToValue(source));
 }
 
-void InstructionSelection::getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target)
 {
     if (useFastLookups) {
         uint lookup = registerIndexedGetterLookup();
         generateLookupCall(target, lookup, qOffsetOf(QV4::Lookup, indexedGetter),
-                           Assembler::PointerToValue(base),
-                           Assembler::PointerToValue(index));
+                           PointerToValue(base),
+                           PointerToValue(index));
         return;
     }
 
-    generateRuntimeCall(target, getElement, Assembler::EngineRegister,
-                         Assembler::PointerToValue(base), Assembler::PointerToValue(index));
+    generateRuntimeCall(_as, target, getElement, JITTargetPlatform::EngineRegister,
+                         PointerToValue(base), PointerToValue(index));
 }
 
-void InstructionSelection::setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex)
 {
     if (useFastLookups) {
         uint lookup = registerIndexedSetterLookup();
-        generateLookupCall(Assembler::Void, lookup, qOffsetOf(QV4::Lookup, indexedSetter),
-                           Assembler::PointerToValue(targetBase), Assembler::PointerToValue(targetIndex),
-                           Assembler::PointerToValue(source));
+        generateLookupCall(JITAssembler::Void, lookup, qOffsetOf(QV4::Lookup, indexedSetter),
+                           PointerToValue(targetBase), PointerToValue(targetIndex),
+                           PointerToValue(source));
         return;
     }
-    generateRuntimeCall(Assembler::Void, setElement, Assembler::EngineRegister,
-                         Assembler::PointerToValue(targetBase), Assembler::PointerToValue(targetIndex),
-                         Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, JITAssembler::Void, setElement, JITTargetPlatform::EngineRegister,
+                         PointerToValue(targetBase), PointerToValue(targetIndex),
+                         PointerToValue(source));
 }
 
-void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::copyValue(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *sourceTemp = source->asTemp();
     IR::Temp *targetTemp = target->asTemp();
@@ -655,25 +692,25 @@ void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
     if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
             if (sourceTemp->type == IR::DoubleType)
-                _as->moveDouble((Assembler::FPRegisterID) sourceTemp->index,
-                                (Assembler::FPRegisterID) targetTemp->index);
+                _as->moveDouble((FPRegisterID) sourceTemp->index,
+                                (FPRegisterID) targetTemp->index);
             else
-                _as->move((Assembler::RegisterID) sourceTemp->index,
-                          (Assembler::RegisterID) targetTemp->index);
+                _as->move((RegisterID) sourceTemp->index,
+                          (RegisterID) targetTemp->index);
             return;
         } else {
             switch (sourceTemp->type) {
             case IR::DoubleType:
-                _as->storeDouble((Assembler::FPRegisterID) sourceTemp->index, target);
+                _as->storeDouble((FPRegisterID) sourceTemp->index, target);
                 break;
             case IR::SInt32Type:
-                _as->storeInt32((Assembler::RegisterID) sourceTemp->index, target);
+                _as->storeInt32((RegisterID) sourceTemp->index, target);
                 break;
             case IR::UInt32Type:
-                _as->storeUInt32((Assembler::RegisterID) sourceTemp->index, target);
+                _as->storeUInt32((RegisterID) sourceTemp->index, target);
                 break;
             case IR::BoolType:
-                _as->storeBool((Assembler::RegisterID) sourceTemp->index, target);
+                _as->storeBool((RegisterID) sourceTemp->index, target);
                 break;
             default:
                 Q_ASSERT(!"Unreachable");
@@ -685,19 +722,19 @@ void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
         switch (targetTemp->type) {
         case IR::DoubleType:
             Q_ASSERT(source->type == IR::DoubleType);
-            _as->toDoubleRegister(source, (Assembler::FPRegisterID) targetTemp->index);
+            _as->toDoubleRegister(source, (FPRegisterID) targetTemp->index);
             return;
         case IR::BoolType:
             Q_ASSERT(source->type == IR::BoolType);
-            _as->toInt32Register(source, (Assembler::RegisterID) targetTemp->index);
+            _as->toInt32Register(source, (RegisterID) targetTemp->index);
             return;
         case IR::SInt32Type:
             Q_ASSERT(source->type == IR::SInt32Type);
-            _as->toInt32Register(source, (Assembler::RegisterID) targetTemp->index);
+            _as->toInt32Register(source, (RegisterID) targetTemp->index);
             return;
         case IR::UInt32Type:
             Q_ASSERT(source->type == IR::UInt32Type);
-            _as->toUInt32Register(source, (Assembler::RegisterID) targetTemp->index);
+            _as->toUInt32Register(source, (RegisterID) targetTemp->index);
             return;
         default:
             Q_ASSERT(!"Unreachable");
@@ -706,10 +743,11 @@ void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
     }
 
     // The target is not a physical register, nor is the source. So we can do a memory-to-memory copy:
-    _as->memcopyValue(_as->loadAddress(Assembler::ReturnValueRegister, target), source, Assembler::ScratchRegister);
+    _as->memcopyValue(_as->loadAddress(JITTargetPlatform::ReturnValueRegister, target), source, JITTargetPlatform::ScratchRegister);
 }
 
-void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *sourceTemp = source->asTemp();
     IR::Temp *targetTemp = target->asTemp();
@@ -719,26 +757,27 @@ void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
             Q_ASSERT(sourceTemp->type == targetTemp->type);
 
             if (sourceTemp->type == IR::DoubleType) {
-                _as->moveDouble((Assembler::FPRegisterID) targetTemp->index, Assembler::FPGpr0);
-                _as->moveDouble((Assembler::FPRegisterID) sourceTemp->index,
-                                (Assembler::FPRegisterID) targetTemp->index);
-                _as->moveDouble(Assembler::FPGpr0, (Assembler::FPRegisterID) sourceTemp->index);
+                _as->moveDouble((FPRegisterID) targetTemp->index, JITTargetPlatform::FPGpr0);
+                _as->moveDouble((FPRegisterID) sourceTemp->index,
+                                (FPRegisterID) targetTemp->index);
+                _as->moveDouble(JITTargetPlatform::FPGpr0, (FPRegisterID) sourceTemp->index);
             } else {
-                _as->swap((Assembler::RegisterID) sourceTemp->index,
-                          (Assembler::RegisterID) targetTemp->index);
+                _as->swap((RegisterID) sourceTemp->index,
+                          (RegisterID) targetTemp->index);
             }
             return;
         }
     } 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.
-            Assembler::Pointer sAddr = _as->loadAddress(Assembler::ScratchRegister, source);
-            Assembler::Pointer tAddr = _as->loadAddress(Assembler::ReturnValueRegister, target);
+            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
-            _as->JSC::MacroAssembler::loadDouble(sAddr, Assembler::FPGpr0);
-            _as->JSC::MacroAssembler::loadDouble(tAddr, Assembler::FPGpr1);
-            _as->JSC::MacroAssembler::storeDouble(Assembler::FPGpr1, sAddr);
-            _as->JSC::MacroAssembler::storeDouble(Assembler::FPGpr0, tAddr);
+            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);
             return;
         }
     }
@@ -749,18 +788,18 @@ void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
     Q_ASSERT(memExpr);
     Q_ASSERT(regTemp);
 
-    Assembler::Pointer addr = _as->loadAddress(Assembler::ReturnValueRegister, memExpr);
+    Pointer addr = _as->loadAddress(JITTargetPlatform::ReturnValueRegister, memExpr);
     if (regTemp->type == IR::DoubleType) {
-        _as->loadDouble(addr, Assembler::FPGpr0);
-        _as->storeDouble((Assembler::FPRegisterID) regTemp->index, addr);
-        _as->moveDouble(Assembler::FPGpr0, (Assembler::FPRegisterID) regTemp->index);
+        _as->loadDouble(addr, JITTargetPlatform::FPGpr0);
+        _as->storeDouble((FPRegisterID) regTemp->index, addr);
+        _as->moveDouble(JITTargetPlatform::FPGpr0, (FPRegisterID) regTemp->index);
     } else if (regTemp->type == IR::UInt32Type) {
-        _as->toUInt32Register(addr, Assembler::ScratchRegister);
-        _as->storeUInt32((Assembler::RegisterID) regTemp->index, addr);
-        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) regTemp->index);
+        _as->toUInt32Register(addr, JITTargetPlatform::ScratchRegister);
+        _as->storeUInt32((RegisterID) regTemp->index, addr);
+        _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
     } else {
-        _as->load32(addr, Assembler::ScratchRegister);
-        _as->store32((Assembler::RegisterID) regTemp->index, addr);
+        _as->load32(addr, JITTargetPlatform::ScratchRegister);
+        _as->store32((RegisterID) regTemp->index, addr);
         if (regTemp->type != memExpr->type) {
             addr.offset += 4;
             quint32 tag;
@@ -775,55 +814,59 @@ void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
                 tag = 31337; // bogus value
                 Q_UNREACHABLE();
             }
-            _as->store32(Assembler::TrustedImm32(tag), addr);
+            _as->store32(TrustedImm32(tag), addr);
         }
-        _as->move(Assembler::ScratchRegister, (Assembler::RegisterID) regTemp->index);
+        _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
     }
 }
 
 #define setOp(op, opName, operation) \
     do { \
-        op = RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
+        op = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
         needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 #define setOpContext(op, opName, operation) \
     do { \
-        opContext = RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
+        opContext = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); opName = "Runtime::" isel_stringIfy(operation); \
         needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 
-void InstructionSelection::unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target)
 {
-    QV4::JIT::Unop unop(_as, oper);
+    QV4::JIT::Unop<JITAssembler> unop(_as, oper);
     unop.generate(source, target);
 }
 
 
-void InstructionSelection::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
 {
-    QV4::JIT::Binop binop(_as, oper);
+    QV4::JIT::Binop<JITAssembler> binop(_as, oper);
     binop.generate(leftSource, rightSource, target);
 }
 
-void InstructionSelection::callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result)
 {
     prepareCallData(args, base);
 
     if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(result, callQmlScopeObjectProperty,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(propertyIndex),
+        generateRuntimeCall(_as, result, callQmlScopeObjectProperty,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(propertyIndex),
                              baseAddressForCallData());
     else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(result, callQmlContextObjectProperty,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(propertyIndex),
+        generateRuntimeCall(_as, result, callQmlContextObjectProperty,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(propertyIndex),
                              baseAddressForCallData());
     else
         Q_ASSERT(false);
 }
 
-void InstructionSelection::callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
                                         IR::Expr *result)
 {
     Q_ASSERT(base != 0);
@@ -832,29 +875,31 @@ void InstructionSelection::callProperty(IR::Expr *base, const QString &name, IR:
 
     if (useFastLookups) {
         uint index = registerGetterLookup(name);
-        generateRuntimeCall(result, callPropertyLookup,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(index),
+        generateRuntimeCall(_as, result, callPropertyLookup,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(index),
                              baseAddressForCallData());
     } else {
-        generateRuntimeCall(result, callProperty, Assembler::EngineRegister,
-                             Assembler::StringToIndex(name),
+        generateRuntimeCall(_as, result, callProperty, JITTargetPlatform::EngineRegister,
+                             StringToIndex(name),
                              baseAddressForCallData());
     }
 }
 
-void InstructionSelection::callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
                                          IR::Expr *result)
 {
     Q_ASSERT(base != 0);
 
     prepareCallData(args, base);
-    generateRuntimeCall(result, callElement, Assembler::EngineRegister,
-                         Assembler::PointerToValue(index),
+    generateRuntimeCall(_as, result, callElement, JITTargetPlatform::EngineRegister,
+                         PointerToValue(index),
                          baseAddressForCallData());
 }
 
-void InstructionSelection::convertType(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertType(IR::Expr *source, IR::Expr *target)
 {
     switch (target->type) {
     case IR::DoubleType:
@@ -875,7 +920,8 @@ void InstructionSelection::convertType(IR::Expr *source, IR::Expr *target)
     }
 }
 
-void InstructionSelection::convertTypeSlowPath(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertTypeSlowPath(IR::Expr *source, IR::Expr *target)
 {
     Q_ASSERT(target->type != IR::BoolType);
 
@@ -885,7 +931,8 @@ void InstructionSelection::convertTypeSlowPath(IR::Expr *source, IR::Expr *targe
         copyValue(source, target);
 }
 
-void InstructionSelection::convertTypeToDouble(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertTypeToDouble(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::SInt32Type:
@@ -897,51 +944,37 @@ void InstructionSelection::convertTypeToDouble(IR::Expr *source, IR::Expr *targe
         convertUIntToDouble(source, target);
         break;
     case IR::UndefinedType:
-        _as->loadDouble(_as->loadAddress(Assembler::ScratchRegister, source), Assembler::FPGpr0);
-        _as->storeDouble(Assembler::FPGpr0, target);
+        _as->loadDouble(_as->loadAddress(JITTargetPlatform::ScratchRegister, source), JITTargetPlatform::FPGpr0);
+        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
         break;
     case IR::StringType:
     case IR::VarType: {
         // load the tag:
-        Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, source);
+        Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
         tagAddr.offset += 4;
-        _as->load32(tagAddr, Assembler::ScratchRegister);
+        _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
 
         // check if it's an int32:
-        Assembler::Jump isNoInt = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                                Assembler::TrustedImm32(Value::Integer_Type_Internal));
+        Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
+                                                TrustedImm32(Value::Integer_Type_Internal));
         convertIntToDouble(source, target);
-        Assembler::Jump intDone = _as->jump();
+        Jump intDone = _as->jump();
 
         // not an int, check if it's NOT a double:
         isNoInt.link(_as);
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-        _as->rshift32(Assembler::TrustedImm32(Value::IsDoubleTag_Shift), Assembler::ScratchRegister);
-        Assembler::Jump isDbl = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                              Assembler::TrustedImm32(0));
-#else
-        _as->and32(Assembler::TrustedImm32(Value::NotDouble_Mask), Assembler::ScratchRegister);
-        Assembler::Jump isDbl = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                              Assembler::TrustedImm32(Value::NotDouble_Mask));
-#endif
+        Jump isDbl = _as->generateIsDoubleCheck(JITTargetPlatform::ScratchRegister);
 
-        generateRuntimeCall(target, toDouble, Assembler::PointerToValue(source));
-        Assembler::Jump noDoubleDone = _as->jump();
+        generateRuntimeCall(_as, target, toDouble, PointerToValue(source));
+        Jump noDoubleDone = _as->jump();
 
         // it is a double:
         isDbl.link(_as);
-        Assembler::Pointer addr2 = _as->loadAddress(Assembler::ScratchRegister, source);
+        Pointer addr2 = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
         IR::Temp *targetTemp = target->asTemp();
         if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-#if Q_PROCESSOR_WORDSIZE == 8
-            _as->load64(addr2, Assembler::ScratchRegister);
-            _as->store64(Assembler::ScratchRegister, _as->loadAddress(Assembler::ReturnValueRegister, target));
-#else
-            _as->loadDouble(addr2, Assembler::FPGpr0);
-            _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(Assembler::ReturnValueRegister, target));
-#endif
+            _as->memcopyValue(target, addr2, JITTargetPlatform::FPGpr0, JITTargetPlatform::ReturnValueRegister);
         } else {
-            _as->loadDouble(addr2, (Assembler::FPRegisterID) targetTemp->index);
+            _as->loadDouble(addr2, (FPRegisterID) targetTemp->index);
         }
 
         noDoubleDone.link(_as);
@@ -953,7 +986,8 @@ void InstructionSelection::convertTypeToDouble(IR::Expr *source, IR::Expr *targe
     }
 }
 
-void InstructionSelection::convertTypeToBool(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertTypeToBool(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *sourceTemp = source->asTemp();
     switch (source->type) {
@@ -965,16 +999,16 @@ void InstructionSelection::convertTypeToBool(IR::Expr *source, IR::Expr *target)
         // The source is in a register if the register allocator is used. If the register
         // allocator was not used, then that means that we can use any register for to
         // load the double into.
-        Assembler::FPRegisterID reg;
+        FPRegisterID reg;
         if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister)
-            reg = (Assembler::FPRegisterID) sourceTemp->index;
+            reg = (FPRegisterID) sourceTemp->index;
         else
-            reg = _as->toDoubleRegister(source, (Assembler::FPRegisterID) 1);
-        Assembler::Jump nonZero = _as->branchDoubleNonZero(reg, Assembler::FPGpr0);
+            reg = _as->toDoubleRegister(source, (FPRegisterID) 1);
+        Jump nonZero = _as->branchDoubleNonZero(reg, JITTargetPlatform::FPGpr0);
 
         // it's 0, so false:
         _as->storeBool(false, target);
-        Assembler::Jump done = _as->jump();
+        Jump done = _as->jump();
 
         // it's non-zero, so true:
         nonZero.link(_as);
@@ -988,283 +1022,220 @@ void InstructionSelection::convertTypeToBool(IR::Expr *source, IR::Expr *target)
         _as->storeBool(false, target);
         break;
     case IR::StringType:
-        generateRuntimeCall(Assembler::ReturnValueRegister, toBoolean,
-                            Assembler::PointerToValue(source));
-        _as->storeBool(Assembler::ReturnValueRegister, target);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
+                            PointerToValue(source));
+        _as->storeBool(JITTargetPlatform::ReturnValueRegister, target);
     case IR::VarType:
     default:
-        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
-        Assembler::Pointer tagAddr = addr;
+        Pointer addr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        Pointer tagAddr = addr;
         tagAddr.offset += 4;
-        _as->load32(tagAddr, Assembler::ReturnValueRegister);
+        _as->load32(tagAddr, JITTargetPlatform::ReturnValueRegister);
 
         // checkif it's a bool:
-        Assembler::Jump notBool = _as->branch32(Assembler::NotEqual, Assembler::ReturnValueRegister,
-                                                Assembler::TrustedImm32(Value::Boolean_Type_Internal));
-        _as->load32(addr, Assembler::ReturnValueRegister);
-        Assembler::Jump boolDone = _as->jump();
+        Jump notBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
+                                                TrustedImm32(Value::Boolean_Type_Internal));
+        _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
+        Jump boolDone = _as->jump();
         // check if it's an int32:
         notBool.link(_as);
-        Assembler::Jump fallback = _as->branch32(Assembler::NotEqual, Assembler::ReturnValueRegister,
-                                                 Assembler::TrustedImm32(Value::Integer_Type_Internal));
-        _as->load32(addr, Assembler::ReturnValueRegister);
-        Assembler::Jump isZero = _as->branch32(Assembler::Equal, Assembler::ReturnValueRegister,
-                                               Assembler::TrustedImm32(0));
-        _as->move(Assembler::TrustedImm32(1), Assembler::ReturnValueRegister);
-        Assembler::Jump intDone = _as->jump();
+        Jump fallback = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
+                                                 TrustedImm32(Value::Integer_Type_Internal));
+        _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
+        Jump isZero = _as->branch32(RelationalCondition::Equal, JITTargetPlatform::ReturnValueRegister,
+                                               TrustedImm32(0));
+        _as->move(TrustedImm32(1), JITTargetPlatform::ReturnValueRegister);
+        Jump intDone = _as->jump();
 
         // not an int:
         fallback.link(_as);
-        generateRuntimeCall(Assembler::ReturnValueRegister, toBoolean,
-                            Assembler::PointerToValue(source));
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
+                            PointerToValue(source));
 
         isZero.link(_as);
         intDone.link(_as);
         boolDone.link(_as);
-        _as->storeBool(Assembler::ReturnValueRegister, target);
+        _as->storeBool(JITTargetPlatform::ReturnValueRegister, target);
 
         break;
     }
 }
 
-void InstructionSelection::convertTypeToSInt32(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertTypeToSInt32(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::VarType: {
-
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
-        _as->load64(addr, Assembler::ScratchRegister);
-        _as->move(Assembler::ScratchRegister, Assembler::ReturnValueRegister);
-
-        // check if it's integer convertible
-        _as->urshift64(Assembler::TrustedImm32(QV4::Value::IsIntegerConvertible_Shift), Assembler::ScratchRegister);
-        Assembler::Jump isIntConvertible = _as->branch32(Assembler::Equal, Assembler::ScratchRegister, Assembler::TrustedImm32(3));
-
-        // nope, not integer convertible, so check for a double:
-        _as->urshift64(Assembler::TrustedImm32(
-                           QV4::Value::IsDoubleTag_Shift - QV4::Value::IsIntegerConvertible_Shift),
-                       Assembler::ScratchRegister);
-        Assembler::Jump fallback = _as->branch32(Assembler::GreaterThan, Assembler::ScratchRegister, Assembler::TrustedImm32(0));
-
-        // it's a double
-        _as->move(Assembler::TrustedImm64(QV4::Value::NaNEncodeMask), Assembler::ScratchRegister);
-        _as->xor64(Assembler::ScratchRegister, Assembler::ReturnValueRegister);
-        _as->move64ToDouble(Assembler::ReturnValueRegister, Assembler::FPGpr0);
-        Assembler::Jump success =
-                _as->branchTruncateDoubleToInt32(Assembler::FPGpr0, Assembler::ReturnValueRegister,
-                                                 Assembler::BranchIfTruncateSuccessful);
-
-        // not an int:
-        fallback.link(_as);
-        generateRuntimeCall(Assembler::ReturnValueRegister, toInt,
-                             _as->loadAddress(Assembler::ScratchRegister, source));
-
-        isIntConvertible.link(_as);
-        success.link(_as);
-        IR::Temp *targetTemp = target->asTemp();
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            Assembler::Pointer targetAddr = _as->loadAddress(Assembler::ScratchRegister, target);
-            _as->store32(Assembler::ReturnValueRegister, targetAddr);
-            targetAddr.offset += 4;
-            _as->store32(Assembler::TrustedImm32(Value::Integer_Type_Internal), targetAddr);
-        } else {
-            _as->storeInt32(Assembler::ReturnValueRegister, target);
-        }
-#else
-        // load the tag:
-        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
-        Assembler::Pointer tagAddr = addr;
-        tagAddr.offset += 4;
-        _as->load32(tagAddr, Assembler::ReturnValueRegister);
-
-        // check if it's an int32:
-        Assembler::Jump fallback = _as->branch32(Assembler::NotEqual, Assembler::ReturnValueRegister,
-                                                Assembler::TrustedImm32(Value::Integer_Type_Internal));
-        IR::Temp *targetTemp = target->asTemp();
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            _as->load32(addr, Assembler::ReturnValueRegister);
-            Assembler::Pointer targetAddr = _as->loadAddress(Assembler::ScratchRegister, target);
-            _as->store32(Assembler::ReturnValueRegister, targetAddr);
-            targetAddr.offset += 4;
-            _as->store32(Assembler::TrustedImm32(Value::Integer_Type_Internal), targetAddr);
-        } else {
-            _as->load32(addr, (Assembler::RegisterID) targetTemp->index);
-        }
-        Assembler::Jump intDone = _as->jump();
-
-        // not an int:
-        fallback.link(_as);
-        generateRuntimeCall(Assembler::ReturnValueRegister, toInt,
-                             _as->loadAddress(Assembler::ScratchRegister, source));
-        _as->storeInt32(Assembler::ReturnValueRegister, target);
-
-        intDone.link(_as);
-#endif
-
+        JITAssembler::RegisterSizeDependentOps::convertVarToSInt32(_as, source, target);
     } break;
     case IR::DoubleType: {
-        Assembler::Jump success =
+        Jump success =
                 _as->branchTruncateDoubleToInt32(_as->toDoubleRegister(source),
-                                                 Assembler::ReturnValueRegister,
-                                                 Assembler::BranchIfTruncateSuccessful);
-        generateRuntimeCall(Assembler::ReturnValueRegister, doubleToInt,
-                             Assembler::PointerToValue(source));
+                                                 JITTargetPlatform::ReturnValueRegister,
+                                                 BranchTruncateType::BranchIfTruncateSuccessful);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, doubleToInt,
+                             PointerToValue(source));
         success.link(_as);
-        _as->storeInt32(Assembler::ReturnValueRegister, target);
+        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
     } break;
     case IR::UInt32Type:
-        _as->storeInt32(_as->toUInt32Register(source, Assembler::ReturnValueRegister), target);
+        _as->storeInt32(_as->toUInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
         break;
     case IR::NullType:
     case IR::UndefinedType:
-        _as->move(Assembler::TrustedImm32(0), Assembler::ReturnValueRegister);
-        _as->storeInt32(Assembler::ReturnValueRegister, target);
+        _as->move(TrustedImm32(0), JITTargetPlatform::ReturnValueRegister);
+        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
         break;
     case IR::BoolType:
-        _as->storeInt32(_as->toInt32Register(source, Assembler::ReturnValueRegister), target);
+        _as->storeInt32(_as->toInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
         break;
     case IR::StringType:
     default:
-        generateRuntimeCall(Assembler::ReturnValueRegister, toInt,
-                             _as->loadAddress(Assembler::ScratchRegister, source));
-        _as->storeInt32(Assembler::ReturnValueRegister, target);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toInt,
+                             _as->loadAddress(JITTargetPlatform::ScratchRegister, source));
+        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
         break;
     } // switch (source->type)
 }
 
-void InstructionSelection::convertTypeToUInt32(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::convertTypeToUInt32(IR::Expr *source, IR::Expr *target)
 {
     switch (source->type) {
     case IR::VarType: {
         // load the tag:
-        Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, source);
+        Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
         tagAddr.offset += 4;
-        _as->load32(tagAddr, Assembler::ScratchRegister);
+        _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
 
         // check if it's an int32:
-        Assembler::Jump isNoInt = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                                Assembler::TrustedImm32(Value::Integer_Type_Internal));
-        Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, source);
-        _as->storeUInt32(_as->toInt32Register(addr, Assembler::ScratchRegister), target);
-        Assembler::Jump intDone = _as->jump();
+        Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
+                                                TrustedImm32(Value::Integer_Type_Internal));
+        Pointer addr = _as->loadAddress(JITTargetPlatform::ScratchRegister, source);
+        _as->storeUInt32(_as->toInt32Register(addr, JITTargetPlatform::ScratchRegister), target);
+        Jump intDone = _as->jump();
 
         // not an int:
         isNoInt.link(_as);
-        generateRuntimeCall(Assembler::ReturnValueRegister, toUInt,
-                             _as->loadAddress(Assembler::ScratchRegister, source));
-        _as->storeInt32(Assembler::ReturnValueRegister, target);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toUInt,
+                             _as->loadAddress(JITTargetPlatform::ScratchRegister, source));
+        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
 
         intDone.link(_as);
     } break;
     case IR::DoubleType: {
-        Assembler::FPRegisterID reg = _as->toDoubleRegister(source);
-        Assembler::Jump success =
-                _as->branchTruncateDoubleToUint32(reg, Assembler::ReturnValueRegister,
-                                                  Assembler::BranchIfTruncateSuccessful);
-        generateRuntimeCall(Assembler::ReturnValueRegister, doubleToUInt,
-                             Assembler::PointerToValue(source));
+        FPRegisterID reg = _as->toDoubleRegister(source);
+        Jump success =
+                _as->branchTruncateDoubleToUint32(reg, JITTargetPlatform::ReturnValueRegister,
+                                                  BranchTruncateType::BranchIfTruncateSuccessful);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, doubleToUInt,
+                             PointerToValue(source));
         success.link(_as);
-        _as->storeUInt32(Assembler::ReturnValueRegister, target);
+        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
     } break;
     case IR::NullType:
     case IR::UndefinedType:
-        _as->move(Assembler::TrustedImm32(0), Assembler::ReturnValueRegister);
-        _as->storeUInt32(Assembler::ReturnValueRegister, target);
+        _as->move(TrustedImm32(0), JITTargetPlatform::ReturnValueRegister);
+        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
         break;
     case IR::StringType:
-        generateRuntimeCall(Assembler::ReturnValueRegister, toUInt,
-                             Assembler::PointerToValue(source));
-        _as->storeUInt32(Assembler::ReturnValueRegister, target);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toUInt,
+                             PointerToValue(source));
+        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
         break;
     case IR::SInt32Type:
     case IR::BoolType:
-        _as->storeUInt32(_as->toInt32Register(source, Assembler::ReturnValueRegister), target);
+        _as->storeUInt32(_as->toInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
         break;
     default:
         break;
     } // switch (source->type)
 }
 
-void InstructionSelection::constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(func != 0);
     prepareCallData(args, 0);
 
     if (useFastLookups && func->global) {
         uint index = registerGlobalGetterLookup(*func->id);
-        generateRuntimeCall(result, constructGlobalLookup,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(index), baseAddressForCallData());
+        generateRuntimeCall(_as, result, constructGlobalLookup,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(index), baseAddressForCallData());
         return;
     }
 
-    generateRuntimeCall(result, constructActivationProperty,
-                         Assembler::EngineRegister,
-                         Assembler::StringToIndex(*func->id),
+    generateRuntimeCall(_as, result, constructActivationProperty,
+                         JITTargetPlatform::EngineRegister,
+                         StringToIndex(*func->id),
                          baseAddressForCallData());
 }
 
 
-void InstructionSelection::constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result)
 {
     prepareCallData(args, base);
     if (useFastLookups) {
         uint index = registerGetterLookup(name);
-        generateRuntimeCall(result, constructPropertyLookup,
-                             Assembler::EngineRegister,
-                             Assembler::TrustedImm32(index),
+        generateRuntimeCall(_as, result, constructPropertyLookup,
+                             JITTargetPlatform::EngineRegister,
+                             TrustedImm32(index),
                              baseAddressForCallData());
         return;
     }
 
-    generateRuntimeCall(result, constructProperty, Assembler::EngineRegister,
-                         Assembler::StringToIndex(name),
+    generateRuntimeCall(_as, result, constructProperty, JITTargetPlatform::EngineRegister,
+                         StringToIndex(name),
                          baseAddressForCallData());
 }
 
-void InstructionSelection::constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
 {
     Q_ASSERT(value != 0);
 
     prepareCallData(args, 0);
-    generateRuntimeCall(result, constructValue,
-                         Assembler::EngineRegister,
-                         Assembler::Reference(value),
+    generateRuntimeCall(_as, result, constructValue,
+                         JITTargetPlatform::EngineRegister,
+                         Reference(value),
                          baseAddressForCallData());
 }
 
-void InstructionSelection::visitJump(IR::Jump *s)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::visitJump(IR::Jump *s)
 {
     if (!_removableJumps.at(_block->index()))
         _as->jumpToBlock(_block, s->target);
 }
 
-void InstructionSelection::visitCJump(IR::CJump *s)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::visitCJump(IR::CJump *s)
 {
     IR::Temp *t = s->cond->asTemp();
     if (t || s->cond->asArgLocal()) {
-        Assembler::RegisterID reg;
+        RegisterID reg;
         if (t && t->kind == IR::Temp::PhysicalRegister) {
             Q_ASSERT(t->type == IR::BoolType);
-            reg = (Assembler::RegisterID) t->index;
+            reg = (RegisterID) t->index;
         } else if (t && t->kind == IR::Temp::StackSlot && t->type == IR::BoolType) {
-            reg = Assembler::ReturnValueRegister;
+            reg = JITTargetPlatform::ReturnValueRegister;
             _as->toInt32Register(t, reg);
         } else {
-            Address temp = _as->loadAddress(Assembler::ScratchRegister, s->cond);
+            Address temp = _as->loadAddress(JITTargetPlatform::ScratchRegister, s->cond);
             Address tag = temp;
             tag.offset += QV4::Value::tagOffset();
-            Assembler::Jump booleanConversion = _as->branch32(Assembler::NotEqual, tag, Assembler::TrustedImm32(QV4::Value::Boolean_Type_Internal));
+            Jump booleanConversion = _as->branch32(RelationalCondition::NotEqual, tag, TrustedImm32(QV4::Value::Boolean_Type_Internal));
 
             Address data = temp;
             data.offset += QV4::Value::valueOffset();
-            _as->load32(data, Assembler::ReturnValueRegister);
-            Assembler::Jump testBoolean = _as->jump();
+            _as->load32(data, JITTargetPlatform::ReturnValueRegister);
+            Jump testBoolean = _as->jump();
 
             booleanConversion.link(_as);
-            reg = Assembler::ReturnValueRegister;
-            generateRuntimeCall(reg, toBoolean, Assembler::Reference(s->cond));
+            reg = JITTargetPlatform::ReturnValueRegister;
+            generateRuntimeCall(_as, reg, toBoolean, Reference(s->cond));
 
             testBoolean.link(_as);
         }
@@ -1274,9 +1245,9 @@ void InstructionSelection::visitCJump(IR::CJump *s)
     } else if (IR::Const *c = s->cond->asConst()) {
         // TODO: SSA optimization for constant condition evaluation should remove this.
         // See also visitCJump() in RegAllocInfo.
-        generateRuntimeCall(Assembler::ReturnValueRegister, toBoolean,
-                             Assembler::PointerToValue(c));
-        _as->generateCJumpOnNonZero(Assembler::ReturnValueRegister, _block, s->iftrue, s->iffalse);
+        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
+                             PointerToValue(c));
+        _as->generateCJumpOnNonZero(JITTargetPlatform::ReturnValueRegister, _block, s->iftrue, s->iffalse);
         return;
     } else if (IR::Binop *b = s->cond->asBinop()) {
         if (b->left->type == IR::DoubleType && b->right->type == IR::DoubleType
@@ -1296,8 +1267,8 @@ void InstructionSelection::visitCJump(IR::CJump *s)
             return;
         }
 
-        RuntimeCall op;
-        RuntimeCall opContext;
+        typename JITAssembler::RuntimeCall op;
+        typename JITAssembler::RuntimeCall opContext;
         const char *opName = 0;
         bool needsExceptionCheck;
         switch (b->op) {
@@ -1321,165 +1292,30 @@ void InstructionSelection::visitCJump(IR::CJump *s)
         // elimination (which isn't there either) would remove the whole else block.
         if (opContext.isValid())
             _as->generateFunctionCallImp(needsExceptionCheck,
-                                         Assembler::ReturnValueRegister, opName, opContext,
-                                         Assembler::EngineRegister,
-                                         Assembler::PointerToValue(b->left),
-                                         Assembler::PointerToValue(b->right));
+                                         JITTargetPlatform::ReturnValueRegister, opName, opContext,
+                                         JITTargetPlatform::EngineRegister,
+                                         PointerToValue(b->left),
+                                         PointerToValue(b->right));
         else
             _as->generateFunctionCallImp(needsExceptionCheck,
-                                         Assembler::ReturnValueRegister, opName, op,
-                                         Assembler::PointerToValue(b->left),
-                                         Assembler::PointerToValue(b->right));
+                                         JITTargetPlatform::ReturnValueRegister, opName, op,
+                                         PointerToValue(b->left),
+                                         PointerToValue(b->right));
 
-        _as->generateCJumpOnNonZero(Assembler::ReturnValueRegister, _block, s->iftrue, s->iffalse);
+        _as->generateCJumpOnNonZero(JITTargetPlatform::ReturnValueRegister, _block, s->iftrue, s->iffalse);
         return;
     }
     Q_UNREACHABLE();
 }
 
-void InstructionSelection::visitRet(IR::Ret *s)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::visitRet(IR::Ret *s)
 {
-    if (!s) {
-        // this only happens if the method doesn't have a return statement and can
-        // only exit through an exception
-    } else if (IR::Temp *t = s->expr->asTemp()) {
-#if CPU(X86) || CPU(ARM) || CPU(MIPS)
-
-#  if CPU(X86)
-        Assembler::RegisterID lowReg = JSC::X86Registers::eax;
-        Assembler::RegisterID highReg = JSC::X86Registers::edx;
-#  elif CPU(MIPS)
-        Assembler::RegisterID lowReg = JSC::MIPSRegisters::v0;
-        Assembler::RegisterID highReg = JSC::MIPSRegisters::v1;
-#  else // CPU(ARM)
-        Assembler::RegisterID lowReg = JSC::ARMRegisters::r0;
-        Assembler::RegisterID highReg = JSC::ARMRegisters::r1;
-#  endif
-
-        if (t->kind == IR::Temp::PhysicalRegister) {
-            switch (t->type) {
-            case IR::DoubleType:
-                _as->moveDoubleToInts((Assembler::FPRegisterID) t->index, lowReg, highReg);
-                break;
-            case IR::UInt32Type: {
-                Assembler::RegisterID srcReg = (Assembler::RegisterID) t->index;
-                Assembler::Jump intRange = _as->branch32(Assembler::GreaterThanOrEqual, srcReg, Assembler::TrustedImm32(0));
-                _as->convertUInt32ToDouble(srcReg, Assembler::FPGpr0, Assembler::ReturnValueRegister);
-                _as->moveDoubleToInts(Assembler::FPGpr0, lowReg, highReg);
-                Assembler::Jump done = _as->jump();
-                intRange.link(_as);
-                _as->move(srcReg, lowReg);
-                _as->move(Assembler::TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
-                done.link(_as);
-            } break;
-            case IR::SInt32Type:
-                _as->move((Assembler::RegisterID) t->index, lowReg);
-                _as->move(Assembler::TrustedImm32(QV4::Value::Integer_Type_Internal), highReg);
-                break;
-            case IR::BoolType:
-                _as->move((Assembler::RegisterID) t->index, lowReg);
-                _as->move(Assembler::TrustedImm32(QV4::Value::Boolean_Type_Internal), highReg);
-                break;
-            default:
-                Q_UNREACHABLE();
-            }
-        } else {
-            Pointer addr = _as->loadAddress(Assembler::ScratchRegister, t);
-            _as->load32(addr, lowReg);
-            addr.offset += 4;
-            _as->load32(addr, highReg);
-        }
-#else
-        if (t->kind == IR::Temp::PhysicalRegister) {
-            if (t->type == IR::DoubleType) {
-                _as->moveDoubleTo64((Assembler::FPRegisterID) t->index,
-                                    Assembler::ReturnValueRegister);
-                _as->move(Assembler::TrustedImm64(QV4::Value::NaNEncodeMask),
-                          Assembler::ScratchRegister);
-                _as->xor64(Assembler::ScratchRegister, Assembler::ReturnValueRegister);
-            } else if (t->type == IR::UInt32Type) {
-                Assembler::RegisterID srcReg = (Assembler::RegisterID) t->index;
-                Assembler::Jump intRange = _as->branch32(Assembler::GreaterThanOrEqual, srcReg, Assembler::TrustedImm32(0));
-                _as->convertUInt32ToDouble(srcReg, Assembler::FPGpr0, Assembler::ReturnValueRegister);
-                _as->moveDoubleTo64(Assembler::FPGpr0, Assembler::ReturnValueRegister);
-                _as->move(Assembler::TrustedImm64(QV4::Value::NaNEncodeMask), Assembler::ScratchRegister);
-                _as->xor64(Assembler::ScratchRegister, Assembler::ReturnValueRegister);
-                Assembler::Jump done = _as->jump();
-                intRange.link(_as);
-                _as->zeroExtend32ToPtr(srcReg, Assembler::ReturnValueRegister);
-                quint64 tag = QV4::Value::Integer_Type_Internal;
-                _as->or64(Assembler::TrustedImm64(tag << 32),
-                          Assembler::ReturnValueRegister);
-                done.link(_as);
-            } else {
-                _as->zeroExtend32ToPtr((Assembler::RegisterID) t->index, Assembler::ReturnValueRegister);
-                quint64 tag;
-                switch (t->type) {
-                case IR::SInt32Type:
-                    tag = QV4::Value::Integer_Type_Internal;
-                    break;
-                case IR::BoolType:
-                    tag = QV4::Value::Boolean_Type_Internal;
-                    break;
-                default:
-                    tag = 31337; // bogus value
-                    Q_UNREACHABLE();
-                }
-                _as->or64(Assembler::TrustedImm64(tag << 32),
-                          Assembler::ReturnValueRegister);
-            }
-        } else {
-            _as->copyValue(Assembler::ReturnValueRegister, t);
-        }
-#endif
-    } else if (IR::Const *c = s->expr->asConst()) {
-        QV4::Primitive retVal = convertToValue(c);
-#if CPU(X86)
-        _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::X86Registers::eax);
-        _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::X86Registers::edx);
-#elif CPU(ARM)
-        _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::ARMRegisters::r0);
-        _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::ARMRegisters::r1);
-#elif CPU(MIPS)
-        _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::MIPSRegisters::v0);
-        _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::MIPSRegisters::v1);
-#else
-        _as->move(Assembler::TrustedImm64(retVal.rawValue()), Assembler::ReturnValueRegister);
-#endif
-    } else {
-        Q_UNREACHABLE();
-        Q_UNUSED(s);
-    }
-
-    Assembler::Label leaveStackFrame = _as->label();
-
-    const int locals = _as->stackLayout().calculateJSStackFrameSize();
-    _as->subPtr(Assembler::TrustedImm32(sizeof(QV4::Value)*locals), Assembler::LocalsRegister);
-    _as->loadPtr(Address(Assembler::EngineRegister, qOffsetOf(QV4::ExecutionEngine, current)), Assembler::ScratchRegister);
-    _as->loadPtr(Address(Assembler::ScratchRegister, qOffsetOf(ExecutionContext::Data, engine)), Assembler::ScratchRegister);
-    _as->storePtr(Assembler::LocalsRegister, Address(Assembler::ScratchRegister, qOffsetOf(ExecutionEngine, jsStackTop)));
-
-    _as->leaveStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
-    _as->ret();
-
-    _as->exceptionReturnLabel = _as->label();
-    QV4::Primitive retVal = Primitive::undefinedValue();
-#if CPU(X86)
-    _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::X86Registers::eax);
-    _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::X86Registers::edx);
-#elif CPU(ARM)
-    _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::ARMRegisters::r0);
-    _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::ARMRegisters::r1);
-#elif CPU(MIPS)
-    _as->move(Assembler::TrustedImm32(retVal.int_32()), JSC::MIPSRegisters::v0);
-    _as->move(Assembler::TrustedImm32(retVal.tag()), JSC::MIPSRegisters::v1);
-#else
-    _as->move(Assembler::TrustedImm64(retVal.rawValue()), Assembler::ReturnValueRegister);
-#endif
-    _as->jump(leaveStackFrame);
+    _as->returnFromFunction(s, regularRegistersToSave, fpRegistersToSave);
 }
 
-int InstructionSelection::prepareVariableArguments(IR::ExprList* args)
+template <typename JITAssembler>
+int InstructionSelection<JITAssembler>::prepareVariableArguments(IR::ExprList* args)
 {
     int argc = 0;
     for (IR::ExprList *it = args; it; it = it->next) {
@@ -1492,7 +1328,7 @@ int InstructionSelection::prepareVariableArguments(IR::ExprList* args)
         Q_ASSERT(arg != 0);
         Pointer dst(_as->stackLayout().argumentAddressForCall(i));
         if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), Assembler::ScratchRegister);
+            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister);
         else
             _as->copyValue(dst, arg);
     }
@@ -1500,7 +1336,8 @@ int InstructionSelection::prepareVariableArguments(IR::ExprList* args)
     return argc;
 }
 
-int InstructionSelection::prepareCallData(IR::ExprList* args, IR::Expr *thisObject)
+template <typename JITAssembler>
+int InstructionSelection<JITAssembler>::prepareCallData(IR::ExprList* args, IR::Expr *thisObject)
 {
     int argc = 0;
     for (IR::ExprList *it = args; it; it = it->next) {
@@ -1508,9 +1345,9 @@ int InstructionSelection::prepareCallData(IR::ExprList* args, IR::Expr *thisObje
     }
 
     Pointer p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, tag));
-    _as->store32(Assembler::TrustedImm32(QV4::Value::Integer_Type_Internal), p);
+    _as->store32(TrustedImm32(QV4::Value::Integer_Type_Internal), p);
     p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, argc));
-    _as->store32(Assembler::TrustedImm32(argc), p);
+    _as->store32(TrustedImm32(argc), p);
     p = _as->stackLayout().callDataAddress(qOffsetOf(CallData, thisObject));
     if (!thisObject)
         _as->storeValue(QV4::Primitive::undefinedValue(), p);
@@ -1523,19 +1360,20 @@ int InstructionSelection::prepareCallData(IR::ExprList* args, IR::Expr *thisObje
         Q_ASSERT(arg != 0);
         Pointer dst(_as->stackLayout().argumentAddressForCall(i));
         if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), Assembler::ScratchRegister);
+            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister);
         else
             _as->copyValue(dst, arg);
     }
     return argc;
 }
 
-void InstructionSelection::calculateRegistersToSave(const RegisterInformation &used)
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::calculateRegistersToSave(const RegisterInformation &used)
 {
     regularRegistersToSave.clear();
     fpRegistersToSave.clear();
 
-    for (const RegisterInfo &ri : Assembler::getRegisterInfo()) {
+    for (const RegisterInfo &ri : JITTargetPlatform::getRegisterInfo()) {
 #if defined(RESTORE_EBX_ON_CALL)
         if (ri.isRegularRegister() && ri.reg<JSC::X86Registers::RegisterID>() == JSC::X86Registers::ebx) {
             regularRegistersToSave.append(ri);
@@ -1564,35 +1402,38 @@ bool operator==(const Primitive &v1, const Primitive &v2)
 } // QV4 namespace
 QT_END_NAMESPACE
 
-bool InstructionSelection::visitCJumpDouble(IR::AluOp op, IR::Expr *left, IR::Expr *right,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpDouble(IR::AluOp op, IR::Expr *left, IR::Expr *right,
                                             IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
 {
     if (_as->nextBlock() == iftrue) {
-        Assembler::Jump target = _as->branchDouble(true, op, left, right);
+        Jump target = _as->branchDouble(true, op, left, right);
         _as->addPatch(iffalse, target);
     } else {
-        Assembler::Jump target = _as->branchDouble(false, op, left, right);
+        Jump target = _as->branchDouble(false, op, left, right);
         _as->addPatch(iftrue, target);
         _as->jumpToBlock(_block, iffalse);
     }
     return true;
 }
 
-bool InstructionSelection::visitCJumpSInt32(IR::AluOp op, IR::Expr *left, IR::Expr *right,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpSInt32(IR::AluOp op, IR::Expr *left, IR::Expr *right,
                                             IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
 {
     if (_as->nextBlock() == iftrue) {
-        Assembler::Jump target = _as->branchInt32(true, op, left, right);
+        Jump target = _as->branchInt32(true, op, left, right);
         _as->addPatch(iffalse, target);
     } else {
-        Assembler::Jump target = _as->branchInt32(false, op, left, right);
+        Jump target = _as->branchInt32(false, op, left, right);
         _as->addPatch(iftrue, target);
         _as->jumpToBlock(_block, iffalse);
     }
     return true;
 }
 
-void InstructionSelection::visitCJumpStrict(IR::Binop *binop, IR::BasicBlock *trueBlock,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::visitCJumpStrict(IR::Binop *binop, IR::BasicBlock *trueBlock,
                                             IR::BasicBlock *falseBlock)
 {
     Q_ASSERT(binop->op == IR::OpStrictEqual || binop->op == IR::OpStrictNotEqual);
@@ -1607,15 +1448,16 @@ void InstructionSelection::visitCJumpStrict(IR::Binop *binop, IR::BasicBlock *tr
     IR::Expr *left = binop->left;
     IR::Expr *right = binop->right;
 
-    generateRuntimeCall(Assembler::ReturnValueRegister, compareStrictEqual,
-                                 Assembler::PointerToValue(left), Assembler::PointerToValue(right));
-    _as->generateCJumpOnCompare(binop->op == IR::OpStrictEqual ? Assembler::NotEqual : Assembler::Equal,
-                                Assembler::ReturnValueRegister, Assembler::TrustedImm32(0),
+    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, compareStrictEqual,
+                                 PointerToValue(left), PointerToValue(right));
+    _as->generateCJumpOnCompare(binop->op == IR::OpStrictEqual ? RelationalCondition::NotEqual : RelationalCondition::Equal,
+                                JITTargetPlatform::ReturnValueRegister, TrustedImm32(0),
                                 _block, trueBlock, falseBlock);
 }
 
 // Only load the non-null temp.
-bool InstructionSelection::visitCJumpStrictNull(IR::Binop *binop,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpStrictNull(IR::Binop *binop,
                                                 IR::BasicBlock *trueBlock,
                                                 IR::BasicBlock *falseBlock)
 {
@@ -1640,19 +1482,20 @@ bool InstructionSelection::visitCJumpStrictNull(IR::Binop *binop,
         return true;
     }
 
-    Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
+    Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, varSrc);
     tagAddr.offset += 4;
-    const Assembler::RegisterID tagReg = Assembler::ScratchRegister;
+    const RegisterID tagReg = JITTargetPlatform::ScratchRegister;
     _as->load32(tagAddr, tagReg);
 
-    Assembler::RelationalCondition cond = binop->op == IR::OpStrictEqual ? Assembler::Equal
-                                                                         : Assembler::NotEqual;
-    const Assembler::TrustedImm32 tag(QV4::Value::Null_Type_Internal);
+    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
+                                                                         : RelationalCondition::NotEqual;
+    const TrustedImm32 tag(QV4::Value::Null_Type_Internal);
     _as->generateCJumpOnCompare(cond, tagReg, tag, _block, trueBlock, falseBlock);
     return true;
 }
 
-bool InstructionSelection::visitCJumpStrictUndefined(IR::Binop *binop,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpStrictUndefined(IR::Binop *binop,
                                                      IR::BasicBlock *trueBlock,
                                                      IR::BasicBlock *falseBlock)
 {
@@ -1677,28 +1520,15 @@ bool InstructionSelection::visitCJumpStrictUndefined(IR::Binop *binop,
         return true;
     }
 
-    Assembler::RelationalCondition cond = binop->op == IR::OpStrictEqual ? Assembler::Equal
-                                                                         : Assembler::NotEqual;
-    const Assembler::RegisterID tagReg = Assembler::ReturnValueRegister;
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    Assembler::Pointer addr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
-    _as->load64(addr, tagReg);
-    const Assembler::TrustedImm64 tag(0);
-#else // !QV4_USE_64_BIT_VALUE_ENCODING
-    Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
-    _as->load32(tagAddr, tagReg);
-    Assembler::Jump j = _as->branch32(Assembler::invert(cond), tagReg, Assembler::TrustedImm32(0));
-    _as->addPatch(falseBlock, j);
-
-    tagAddr.offset += 4;
-    _as->load32(tagAddr, tagReg);
-    const Assembler::TrustedImm32 tag(QV4::Value::Managed_Type_Internal);
-#endif
-    _as->generateCJumpOnCompare(cond, tagReg, tag, _block, trueBlock, falseBlock);
+    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
+                                                                         : RelationalCondition::NotEqual;
+    const RegisterID tagReg = JITTargetPlatform::ReturnValueRegister;
+    _as->generateCJumpOnUndefined(cond, varSrc, JITTargetPlatform::ScratchRegister, tagReg, _block, trueBlock, falseBlock);
     return true;
 }
 
-bool InstructionSelection::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock *trueBlock,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock *trueBlock,
                                                 IR::BasicBlock *falseBlock)
 {
     IR::Expr *boolSrc = 0, *otherSrc = 0;
@@ -1720,12 +1550,12 @@ bool InstructionSelection::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock
         return false;
     }
 
-    Assembler::RelationalCondition cond = binop->op == IR::OpStrictEqual ? Assembler::Equal
-                                                                           : Assembler::NotEqual;
+    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
+                                                              : RelationalCondition::NotEqual;
 
     if (otherSrc->type == IR::BoolType) { // both are boolean
-        Assembler::RegisterID one = _as->toBoolRegister(boolSrc, Assembler::ReturnValueRegister);
-        Assembler::RegisterID two = _as->toBoolRegister(otherSrc, Assembler::ScratchRegister);
+        RegisterID one = _as->toBoolRegister(boolSrc, JITTargetPlatform::ReturnValueRegister);
+        RegisterID two = _as->toBoolRegister(otherSrc, JITTargetPlatform::ScratchRegister);
         _as->generateCJumpOnCompare(cond, one, two, _block, trueBlock, falseBlock);
         return true;
     }
@@ -1735,13 +1565,13 @@ bool InstructionSelection::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock
         return true;
     }
 
-    Assembler::Pointer otherAddr = _as->loadAddress(Assembler::ReturnValueRegister, otherSrc);
+    Pointer otherAddr = _as->loadAddress(JITTargetPlatform::ReturnValueRegister, otherSrc);
     otherAddr.offset += 4; // tag address
 
     // check if the tag of the var operand is indicates 'boolean'
-    _as->load32(otherAddr, Assembler::ScratchRegister);
-    Assembler::Jump noBool = _as->branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                           Assembler::TrustedImm32(QV4::Value::Boolean_Type_Internal));
+    _as->load32(otherAddr, JITTargetPlatform::ScratchRegister);
+    Jump noBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
+                                           TrustedImm32(QV4::Value::Boolean_Type_Internal));
     if (binop->op == IR::OpStrictEqual)
         _as->addPatch(falseBlock, noBool);
     else
@@ -1749,14 +1579,15 @@ bool InstructionSelection::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock
 
     // ok, both are boolean, so let's load them and compare them.
     otherAddr.offset -= 4; // int_32 address
-    _as->load32(otherAddr, Assembler::ReturnValueRegister);
-    Assembler::RegisterID boolReg = _as->toBoolRegister(boolSrc, Assembler::ScratchRegister);
-    _as->generateCJumpOnCompare(cond, boolReg, Assembler::ReturnValueRegister, _block, trueBlock,
+    _as->load32(otherAddr, JITTargetPlatform::ReturnValueRegister);
+    RegisterID boolReg = _as->toBoolRegister(boolSrc, JITTargetPlatform::ScratchRegister);
+    _as->generateCJumpOnCompare(cond, boolReg, JITTargetPlatform::ReturnValueRegister, _block, trueBlock,
                                 falseBlock);
     return true;
 }
 
-bool InstructionSelection::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Binop *binop,
+template <typename JITAssembler>
+bool InstructionSelection<JITAssembler>::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Binop *binop,
                                                          IR::BasicBlock *trueBlock,
                                                          IR::BasicBlock *falseBlock)
 {
@@ -1783,18 +1614,18 @@ bool InstructionSelection::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Bin
         return true;
     }
 
-    Assembler::Pointer tagAddr = _as->loadAddress(Assembler::ScratchRegister, varSrc);
+    Pointer tagAddr = _as->loadAddress(JITTargetPlatform::ScratchRegister, varSrc);
     tagAddr.offset += 4;
-    const Assembler::RegisterID tagReg = Assembler::ReturnValueRegister;
+    const RegisterID tagReg = JITTargetPlatform::ReturnValueRegister;
     _as->load32(tagAddr, tagReg);
 
     if (binop->op == IR::OpNotEqual)
         qSwap(trueBlock, falseBlock);
-    Assembler::Jump isNull = _as->branch32(Assembler::Equal, tagReg, Assembler::TrustedImm32(int(QV4::Value::Null_Type_Internal)));
-    Assembler::Jump isNotUndefinedTag = _as->branch32(Assembler::NotEqual, tagReg, Assembler::TrustedImm32(int(QV4::Value::Managed_Type_Internal)));
+    Jump isNull = _as->branch32(RelationalCondition::Equal, tagReg, TrustedImm32(int(QV4::Value::Null_Type_Internal)));
+    Jump isNotUndefinedTag = _as->branch32(RelationalCondition::NotEqual, tagReg, TrustedImm32(int(QV4::Value::Managed_Type_Internal)));
     tagAddr.offset -= 4;
     _as->load32(tagAddr, tagReg);
-    Assembler::Jump isNotUndefinedValue = _as->branch32(Assembler::NotEqual, tagReg, Assembler::TrustedImm32(0));
+    Jump isNotUndefinedValue = _as->branch32(RelationalCondition::NotEqual, tagReg, TrustedImm32(0));
     _as->addPatch(trueBlock, isNull);
     _as->addPatch(falseBlock, isNotUndefinedTag);
     _as->addPatch(falseBlock, isNotUndefinedValue);
@@ -1804,7 +1635,8 @@ bool InstructionSelection::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Bin
 }
 
 
-void InstructionSelection::visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *trueBlock,
+template <typename JITAssembler>
+void InstructionSelection<JITAssembler>::visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *trueBlock,
                                             IR::BasicBlock *falseBlock)
 {
     Q_ASSERT(binop->op == IR::OpEqual || binop->op == IR::OpNotEqual);
@@ -1815,18 +1647,54 @@ void InstructionSelection::visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *tru
     IR::Expr *left = binop->left;
     IR::Expr *right = binop->right;
 
-    generateRuntimeCall(Assembler::ReturnValueRegister, compareEqual,
-                                 Assembler::PointerToValue(left), Assembler::PointerToValue(right));
-    _as->generateCJumpOnCompare(binop->op == IR::OpEqual ? Assembler::NotEqual : Assembler::Equal,
-                                Assembler::ReturnValueRegister, Assembler::TrustedImm32(0),
+    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, compareEqual,
+                                 PointerToValue(left), PointerToValue(right));
+    _as->generateCJumpOnCompare(binop->op == IR::OpEqual ? RelationalCondition::NotEqual : RelationalCondition::Equal,
+                                JITTargetPlatform::ReturnValueRegister, TrustedImm32(0),
                                 _block, trueBlock, falseBlock);
 }
 
-QQmlRefPointer<CompiledData::CompilationUnit> ISelFactory::createUnitForLoading()
+template <typename JITAssembler>
+QQmlRefPointer<CompiledData::CompilationUnit> ISelFactory<JITAssembler>::createUnitForLoading()
 {
     QQmlRefPointer<CompiledData::CompilationUnit> result;
     result.adopt(new JIT::CompilationUnit);
     return result;
 }
 
+QT_BEGIN_NAMESPACE
+namespace QV4 { namespace JIT {
+template class Q_QML_EXPORT InstructionSelection<>;
+template class Q_QML_EXPORT ISelFactory<>;
+#if defined(V4_BOOTSTRAP) && CPU(X86_64)
+
+Q_QML_EXPORT QV4::EvalISelFactory *createISelForArchitecture(const QString &architecture)
+{
+    using ARMv7CrossAssembler = QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>;
+
+    if (architecture == QLatin1String("armv7"))
+        return new ISelFactory<ARMv7CrossAssembler>;
+
+    QString hostArch;
+#if CPU(ARM_THUMB2)
+    hostArch = QStringLiteral("armv7");
+#elif CPU(ARM64)
+    hostArch = QStringLiteral("armv8");
+#elif CPU(MIPS)
+    hostArch = QStringLiteral("mips");
+#elif CPU(X86)
+    hostArch = QStringLiteral("x86");
+#elif CPU(X86_64)
+    hostArch = QStringLiteral("x86_64");
+#endif
+    if (!hostArch.isEmpty() && architecture == hostArch)
+        return new ISelFactory<>;
+
+    return nullptr;
+}
+
+#endif
+} }
+QT_END_NAMESPACE
+
 #endif // ENABLE(ASSEMBLER)
diff --git a/src/qml/jit/qv4isel_masm_p.h b/src/qml/jit/qv4isel_masm_p.h
index 012745c5f2..6ae50c3260 100644
--- a/src/qml/jit/qv4isel_masm_p.h
+++ b/src/qml/jit/qv4isel_masm_p.h
@@ -72,6 +72,7 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
 
+template <typename JITAssembler = Assembler<DefaultAssemblerTargetConfiguration>>
 class Q_QML_EXPORT InstructionSelection:
         protected IR::IRDecoder,
         public EvalInstructionSelection
@@ -136,8 +137,23 @@ protected:
     void unop(IR::AluOp oper, IR::Expr *sourceTemp, IR::Expr *target) override;
     void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target) override;
 
-    typedef Assembler::Address Address;
-    typedef Assembler::Pointer Pointer;
+    using Address = typename JITAssembler::Address;
+    using Pointer = typename JITAssembler::Pointer;
+    using PointerToValue = typename JITAssembler::PointerToValue;
+    using RegisterID = typename JITAssembler::RegisterID;
+    using FPRegisterID = typename JITAssembler::FPRegisterID;
+    using ResultCondition = typename JITAssembler::ResultCondition;
+    using TrustedImm32 = typename JITAssembler::TrustedImm32;
+    using TrustedImm64 = typename JITAssembler::TrustedImm64;
+    using Label = typename JITAssembler::Label;
+    using Jump = typename JITAssembler::Jump;
+    using StringToIndex = typename JITAssembler::StringToIndex;
+    using Reference = typename JITAssembler::Reference;
+    using RelationalCondition = typename JITAssembler::RelationalCondition;
+    using BranchTruncateType = typename JITAssembler::BranchTruncateType;
+    using RuntimeCall = typename JITAssembler::RuntimeCall;
+
+    using JITTargetPlatform = typename JITAssembler::JITTargetPlatform;
 
 #if !defined(ARGUMENTS_IN_REGISTERS)
     Address addressForArgument(int index) const
@@ -145,7 +161,7 @@ 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(Assembler::FramePointerRegister, (index + 2) * sizeof(void*));
+        return Address(JITTargetPlatform::FramePointerRegister, (index + 2) * sizeof(void*));
     }
 #endif
 
@@ -192,61 +208,55 @@ private:
             if (targetTemp->kind == IR::Temp::PhysicalRegister) {
                 if (IR::Temp *sourceTemp = source->asTemp()) {
                     if (sourceTemp->kind == IR::Temp::PhysicalRegister) {
-                        _as->convertInt32ToDouble((Assembler::RegisterID) sourceTemp->index,
-                                                  (Assembler::FPRegisterID) targetTemp->index);
+                        _as->convertInt32ToDouble((RegisterID) sourceTemp->index,
+                                                  (FPRegisterID) targetTemp->index);
                     } else {
-                        _as->convertInt32ToDouble(_as->loadAddress(Assembler::ReturnValueRegister, sourceTemp),
-                                                  (Assembler::FPRegisterID) targetTemp->index);
+                        _as->convertInt32ToDouble(_as->loadAddress(JITTargetPlatform::ReturnValueRegister, sourceTemp),
+                                                  (FPRegisterID) targetTemp->index);
                     }
                 } else {
-                    _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
-                                              (Assembler::FPRegisterID) targetTemp->index);
+                    _as->convertInt32ToDouble(_as->toInt32Register(source, JITTargetPlatform::ScratchRegister),
+                                              (FPRegisterID) targetTemp->index);
                 }
 
                 return;
             }
         }
 
-        _as->convertInt32ToDouble(_as->toInt32Register(source, Assembler::ScratchRegister),
-                                  Assembler::FPGpr0);
-        _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(Assembler::ReturnValueRegister, target));
+        _as->convertInt32ToDouble(_as->toInt32Register(source, JITTargetPlatform::ScratchRegister),
+                                  JITTargetPlatform::FPGpr0);
+        _as->storeDouble(JITTargetPlatform::FPGpr0, _as->loadAddress(JITTargetPlatform::ReturnValueRegister, target));
     }
 
     void convertUIntToDouble(IR::Expr *source, IR::Expr *target)
     {
-        Assembler::RegisterID tmpReg = Assembler::ScratchRegister;
-        Assembler::RegisterID reg = _as->toInt32Register(source, tmpReg);
+        RegisterID tmpReg = JITTargetPlatform::ScratchRegister;
+        RegisterID reg = _as->toInt32Register(source, tmpReg);
 
         if (IR::Temp *targetTemp = target->asTemp()) {
             if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                _as->convertUInt32ToDouble(reg, (Assembler::FPRegisterID) targetTemp->index, tmpReg);
+                _as->convertUInt32ToDouble(reg, (FPRegisterID) targetTemp->index, tmpReg);
                 return;
             }
         }
 
         _as->convertUInt32ToDouble(_as->toUInt32Register(source, tmpReg),
-                                   Assembler::FPGpr0, tmpReg);
-        _as->storeDouble(Assembler::FPGpr0, _as->loadAddress(tmpReg, target));
+                                   JITTargetPlatform::FPGpr0, tmpReg);
+        _as->storeDouble(JITTargetPlatform::FPGpr0, _as->loadAddress(tmpReg, target));
     }
 
     void convertIntToBool(IR::Expr *source, IR::Expr *target)
     {
-        Assembler::RegisterID reg = Assembler::ScratchRegister;
+        RegisterID reg = JITTargetPlatform::ScratchRegister;
 
         if (IR::Temp *targetTemp = target->asTemp())
             if (targetTemp->kind == IR::Temp::PhysicalRegister)
-                reg = (Assembler::RegisterID) targetTemp->index;
+                reg = (RegisterID) targetTemp->index;
         _as->move(_as->toInt32Register(source, reg), reg);
-        _as->compare32(Assembler::NotEqual, reg, Assembler::TrustedImm32(0), reg);
+        _as->compare32(RelationalCondition::NotEqual, reg, TrustedImm32(0), reg);
         _as->storeBool(reg, target);
     }
 
-    #define isel_stringIfyx(s) #s
-    #define isel_stringIfy(s) isel_stringIfyx(s)
-
-    #define generateRuntimeCall(t, function, ...) \
-        _as->generateFunctionCallImp(Runtime::Method_##function##_NeedsExceptionCheck, t, "Runtime::" isel_stringIfy(function), RuntimeCall(qOffsetOf(QV4::Runtime, function)), __VA_ARGS__)
-
     int prepareVariableArguments(IR::ExprList* args);
     int prepareCallData(IR::ExprList* args, IR::Expr *thisObject);
 
@@ -259,22 +269,22 @@ private:
         // goes into the same register as the return value (currently only ARM), the prepareCall
         // will combine loading the looupAddr into the register and calculating the indirect call
         // address.
-        Assembler::Pointer lookupAddr(Assembler::ReturnValueRegister, index * sizeof(QV4::Lookup));
+        Pointer lookupAddr(JITTargetPlatform::ReturnValueRegister, index * sizeof(QV4::Lookup));
 
          _as->generateFunctionCallImp(true, retval, "lookup getter/setter",
-                                      LookupCall(lookupAddr, getterSetterOffset), lookupAddr,
+                                      typename JITAssembler::LookupCall(lookupAddr, getterSetterOffset), lookupAddr,
                                       arg1, arg2, arg3);
     }
 
     template <typename Retval, typename Arg1, typename Arg2>
     void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2)
     {
-        generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, Assembler::VoidType());
+        generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, typename JITAssembler::VoidType());
     }
 
     IR::BasicBlock *_block;
     BitVector _removableJumps;
-    Assembler* _as;
+    JITAssembler* _as;
 
     QScopedPointer<CompilationUnit> compilationUnit;
     QQmlEnginePrivate *qmlEngine;
@@ -282,13 +292,14 @@ private:
     RegisterInformation fpRegistersToSave;
 };
 
+template <typename JITAssembler = Assembler<DefaultAssemblerTargetConfiguration>>
 class Q_QML_EXPORT ISelFactory: public EvalISelFactory
 {
 public:
     ISelFactory() : EvalISelFactory(QStringLiteral("jit")) {}
     virtual ~ISelFactory() {}
     EvalInstructionSelection *create(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator) Q_DECL_OVERRIDE Q_DECL_FINAL
-    { return new InstructionSelection(qmlEngine, execAllocator, module, jsGenerator, this); }
+    { return new InstructionSelection<JITAssembler>(qmlEngine, execAllocator, module, jsGenerator, this); }
     bool jitCompileRegexps() const Q_DECL_OVERRIDE Q_DECL_FINAL
     { return true; }
     QQmlRefPointer<CompiledData::CompilationUnit> createUnitForLoading() Q_DECL_OVERRIDE Q_DECL_FINAL;
diff --git a/src/qml/jit/qv4regalloc.cpp b/src/qml/jit/qv4regalloc.cpp
index f2ae7e117a..d5da863ee0 100644
--- a/src/qml/jit/qv4regalloc.cpp
+++ b/src/qml/jit/qv4regalloc.cpp
@@ -1529,7 +1529,7 @@ static inline int indexOfRangeCoveringPosition(const LifeTimeInterval::Ranges &r
     return -1;
 }
 
-static inline int intersectionPosition(const LifeTimeInterval::Range &one, const LifeTimeInterval::Range &two)
+static inline int intersectionPosition(const LifeTimeIntervalRange &one, const LifeTimeIntervalRange &two)
 {
     if (one.covers(two.start))
         return two.start;
@@ -1787,9 +1787,9 @@ int RegisterAllocator::nextIntersection(const LifeTimeInterval &current,
         return -1;
 
     for (int currentEnd = currentRanges.size(); currentIt < currentEnd; ++currentIt) {
-        const LifeTimeInterval::Range currentRange = currentRanges.at(currentIt);
+        const LifeTimeIntervalRange currentRange = currentRanges.at(currentIt);
         for (int anotherIt = anotherItStart, anotherEnd = anotherRanges.size(); anotherIt < anotherEnd; ++anotherIt) {
-            const LifeTimeInterval::Range anotherRange = anotherRanges.at(anotherIt);
+            const LifeTimeIntervalRange anotherRange = anotherRanges.at(anotherIt);
             if (anotherRange.start > currentRange.end)
                 break;
             int intersectPos = intersectionPosition(currentRange, anotherRange);
diff --git a/src/qml/jit/qv4targetplatform_p.h b/src/qml/jit/qv4targetplatform_p.h
index 7e265258d5..1c29aa2a70 100644
--- a/src/qml/jit/qv4targetplatform_p.h
+++ b/src/qml/jit/qv4targetplatform_p.h
@@ -63,6 +63,11 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
 
+enum TargetOperatingSystemSpecialization {
+    NoOperatingSystemSpecialization,
+    WindowsSpecialization
+};
+
 // The TargetPlatform class describes how the stack and the registers work on a CPU+ABI combination.
 //
 // All combinations have a separate definition, guarded by #ifdefs. The exceptions are:
@@ -79,25 +84,37 @@ namespace JIT {
 // a call, we add a load it right before emitting the call instruction.
 //
 // NOTE: When adding new architecture, do not forget to whitelist it in qv4global_p.h!
+template <typename PlatformAssembler, TargetOperatingSystemSpecialization specialization = NoOperatingSystemSpecialization>
 class TargetPlatform
 {
-public:
+};
+
 #if CPU(X86) && (OS(LINUX) || OS(WINDOWS) || OS(QNX) || OS(FREEBSD) || defined(Q_OS_IOS))
-    enum { RegAllocIsSupported = 1 };
+template <>
+class TargetPlatform<JSC::MacroAssemblerX86, NoOperatingSystemSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerX86;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
 
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister       = JSC::X86Registers::edi;
-    static const JSC::MacroAssembler::RegisterID EngineRegister      = JSC::X86Registers::esi;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister      = JSC::X86Registers::ecx;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
+    enum { RegAllocIsSupported = 1 };
 
-    static RegisterInformation getPlatformRegisterInfo()
+    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
+    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
+    static const RegisterID LocalsRegister       = JSC::X86Registers::edi;
+    static const RegisterID EngineRegister      = JSC::X86Registers::esi;
+    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
+    static const RegisterID ScratchRegister      = JSC::X86Registers::ecx;
+    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
+    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
+    static const RegisterID LowReturnValueRegister = JSC::X86Registers::eax;
+    static const RegisterID HighReturnValueRegister = JSC::X86Registers::edx;
+
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 << RI(JSC::X86Registers::edx, QStringLiteral("edx"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::ebx, QStringLiteral("ebx"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::edi, QStringLiteral("edi"),   RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
@@ -109,6 +126,7 @@ public:
                 << RI(JSC::X86Registers::xmm6, QStringLiteral("xmm6"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::xmm7, QStringLiteral("xmm7"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                    ;
+        return info;
     }
 
 #  define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
@@ -117,19 +135,20 @@ public:
 
 #  undef ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 0;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int) { Q_UNREACHABLE(); }
+    static RegisterID registerForArgument(int) { Q_UNREACHABLE(); }
 
     static const int StackAlignment = 16;
     static const int StackShadowSpace = 0;
     static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as) { as->push(FramePointerRegister); }
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as) { as->pop(FramePointerRegister); }
+    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as) { as->pop(FramePointerRegister); }
 
 #if OS(WINDOWS) || OS(QNX) || \
     ((OS(LINUX) || OS(FREEBSD)) && (defined(__PIC__) || defined(__PIE__)))
 
 #define RESTORE_EBX_ON_CALL
-    static JSC::MacroAssembler::Address ebxAddressOnStack()
+    using Address = PlatformAssembler::Address;
+    static Address ebxAddressOnStack()
     {
         static int ebxIdx = -1;
         if (ebxIdx == -1) {
@@ -146,28 +165,36 @@ public:
             Q_ASSERT(ebxIdx >= 0);
             ebxIdx += 1;
         }
-        return JSC::MacroAssembler::Address(FramePointerRegister, ebxIdx * -int(sizeof(void*)));
+        return Address(FramePointerRegister, ebxIdx * -int(sizeof(void*)));
     }
 #endif
-
-#endif // Windows on x86
+};
+#endif // x86
 
 #if CPU(X86_64) && (OS(LINUX) || OS(MAC_OS_X) || OS(FREEBSD) || OS(QNX) || defined(Q_OS_IOS))
+template <>
+class TargetPlatform<JSC::MacroAssemblerX86_64, NoOperatingSystemSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerX86_64;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
+
     enum { RegAllocIsSupported = 1 };
 
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister       = JSC::X86Registers::r12;
-    static const JSC::MacroAssembler::RegisterID EngineRegister      = JSC::X86Registers::r14;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister      = JSC::X86Registers::r10;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
+    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
+    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
+    static const RegisterID LocalsRegister       = JSC::X86Registers::r12;
+    static const RegisterID EngineRegister      = JSC::X86Registers::r14;
+    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
+    static const RegisterID ScratchRegister      = JSC::X86Registers::r10;
+    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
+    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
 
-    static RegisterInformation getPlatformRegisterInfo()
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 << RI(JSC::X86Registers::ebx,  QStringLiteral("rbx"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::edi,  QStringLiteral("rdi"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::esi,  QStringLiteral("rsi"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
@@ -185,6 +212,7 @@ public:
                 << RI(JSC::X86Registers::xmm6, QStringLiteral("xmm6"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::X86Registers::xmm7, QStringLiteral("xmm7"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                    ;
+        return info;
     }
 
 #define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
@@ -193,9 +221,9 @@ public:
 
 #define ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 6;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int index)
+    static RegisterID registerForArgument(int index)
     {
-        static JSC::MacroAssembler::RegisterID regs[RegisterArgumentCount] = {
+        static RegisterID regs[RegisterArgumentCount] = {
             JSC::X86Registers::edi,
             JSC::X86Registers::esi,
             JSC::X86Registers::edx,
@@ -210,29 +238,38 @@ public:
     static const int StackAlignment = 16;
     static const int StackShadowSpace = 0;
     static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as) { as->push(FramePointerRegister); }
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as) { as->pop(FramePointerRegister); }
+    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as) { as->pop(FramePointerRegister); }
+};
 #endif // Linux/MacOS on x86_64
 
 #if CPU(X86_64) && OS(WINDOWS)
+template <>
+class TargetPlatform<JSC::MacroAssemblerX86_64, WindowsSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerX86_64;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
+
     // Register allocation is not (yet) supported on win64, because the ABI related stack handling
     // is not completely implemented. Specifically, the saving of xmm registers, and the saving of
     // incoming function parameters to the shadow space is missing.
     enum { RegAllocIsSupported = 0 };
 
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister       = JSC::X86Registers::r12;
-    static const JSC::MacroAssembler::RegisterID EngineRegister      = JSC::X86Registers::r14;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister      = JSC::X86Registers::r10;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
+    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
+    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
+    static const RegisterID LocalsRegister       = JSC::X86Registers::r12;
+    static const RegisterID EngineRegister      = JSC::X86Registers::r14;
+    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
+    static const RegisterID ScratchRegister      = JSC::X86Registers::r10;
+    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
+    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
 
-    static RegisterInformation getPlatformRegisterInfo()
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 << RI(JSC::X86Registers::ebx,  QStringLiteral("rbx"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
                 << RI(JSC::X86Registers::edi,  QStringLiteral("rdi"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
                 << RI(JSC::X86Registers::esi,  QStringLiteral("rsi"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
@@ -244,6 +281,7 @@ public:
                 << RI(JSC::X86Registers::r14,  QStringLiteral("r14"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
                 << RI(JSC::X86Registers::r15,  QStringLiteral("r15"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
                    ;
+        return info;
     }
 
 #define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
@@ -252,9 +290,9 @@ public:
 
 #define ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 4;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int index)
+    static RegisterID registerForArgument(int index)
     {
-        static JSC::MacroAssembler::RegisterID regs[RegisterArgumentCount] = {
+        static RegisterID regs[RegisterArgumentCount] = {
             JSC::X86Registers::ecx,
             JSC::X86Registers::edx,
             JSC::X86Registers::r8,
@@ -267,11 +305,20 @@ public:
     static const int StackAlignment = 16;
     static const int StackShadowSpace = 32;
     static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as) { as->push(FramePointerRegister); }
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as) { as->pop(FramePointerRegister); }
+    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as) { as->pop(FramePointerRegister); }
+};
 #endif // Windows on x86_64
 
-#if CPU(ARM)
+#if CPU(ARM) || defined(V4_BOOTSTRAP)
+template <>
+class TargetPlatform<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerARMv7;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
+
     enum { RegAllocIsSupported = 1 };
 
     // The AAPCS specifies that the platform ABI has to define the usage of r9. Known are:
@@ -287,23 +334,25 @@ public:
     // 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)
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister = JSC::ARMRegisters::r7;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister = JSC::ARMRegisters::r11;
+    static const RegisterID FramePointerRegister = JSC::ARMRegisters::r7;
+    static const RegisterID LocalsRegister = JSC::ARMRegisters::r11;
 #else // Thumbs down
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister = JSC::ARMRegisters::r11;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister = JSC::ARMRegisters::r7;
+    static const RegisterID FramePointerRegister = JSC::ARMRegisters::r11;
+    static const RegisterID LocalsRegister = JSC::ARMRegisters::r7;
 #endif
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::ARMRegisters::r13;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister = JSC::ARMRegisters::r5;
-    static const JSC::MacroAssembler::RegisterID EngineRegister = JSC::ARMRegisters::r10;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister = JSC::ARMRegisters::r0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0 = JSC::ARMRegisters::d0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1 = JSC::ARMRegisters::d1;
-
-    static RegisterInformation getPlatformRegisterInfo()
+    static const RegisterID StackPointerRegister = JSC::ARMRegisters::r13;
+    static const RegisterID ScratchRegister = JSC::ARMRegisters::r5;
+    static const RegisterID EngineRegister = JSC::ARMRegisters::r10;
+    static const RegisterID ReturnValueRegister = JSC::ARMRegisters::r0;
+    static const FPRegisterID FPGpr0 = JSC::ARMRegisters::d0;
+    static const FPRegisterID FPGpr1 = JSC::ARMRegisters::d1;
+    static const RegisterID LowReturnValueRegister = JSC::ARMRegisters::r0;
+    static const RegisterID HighReturnValueRegister = JSC::ARMRegisters::r1;
+
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 << RI(JSC::ARMRegisters::r0,  QStringLiteral("r0"),  RI::RegularRegister,       RI::CallerSaved, RI::Predefined)
                 << RI(JSC::ARMRegisters::r1,  QStringLiteral("r1"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::ARMRegisters::r2,  QStringLiteral("r2"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
@@ -336,6 +385,7 @@ public:
                 << RI(JSC::ARMRegisters::d14, QStringLiteral("d14"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
                 << RI(JSC::ARMRegisters::d15, QStringLiteral("d15"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
                    ;
+        return info;
     }
 
 #undef HAVE_ALU_OPS_WITH_MEM_OPERAND
@@ -344,9 +394,9 @@ public:
 
 #define ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 4;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int index)
+    static RegisterID registerForArgument(int index)
     {
-        static JSC::MacroAssembler::RegisterID regs[RegisterArgumentCount] = {
+        static RegisterID regs[RegisterArgumentCount] = {
             JSC::ARMRegisters::r0,
             JSC::ARMRegisters::r1,
             JSC::ARMRegisters::r2,
@@ -361,35 +411,44 @@ public:
     static const int StackShadowSpace = 0;
     static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
 
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformEnterStandardStackFrame(PlatformAssembler *as)
     {
         as->push(JSC::ARMRegisters::lr);
         as->push(FramePointerRegister);
     }
 
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as)
     {
         as->pop(FramePointerRegister);
         as->pop(JSC::ARMRegisters::lr);
     }
+};
 #endif // ARM (32 bit)
 
 #if CPU(ARM64)
+template <>
+class TargetPlatform<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerARM64;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
+
     enum { RegAllocIsSupported = 1 };
 
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister = JSC::ARM64Registers::fp;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister = JSC::ARM64Registers::x28;
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::ARM64Registers::sp;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister = JSC::ARM64Registers::x9;
-    static const JSC::MacroAssembler::RegisterID EngineRegister = JSC::ARM64Registers::x27;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister = JSC::ARM64Registers::x0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0 = JSC::ARM64Registers::q0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1 = JSC::ARM64Registers::q1;
+    static const RegisterID FramePointerRegister = JSC::ARM64Registers::fp;
+    static const RegisterID LocalsRegister = JSC::ARM64Registers::x28;
+    static const RegisterID StackPointerRegister = JSC::ARM64Registers::sp;
+    static const RegisterID ScratchRegister = JSC::ARM64Registers::x9;
+    static const RegisterID EngineRegister = JSC::ARM64Registers::x27;
+    static const RegisterID ReturnValueRegister = JSC::ARM64Registers::x0;
+    static const FPRegisterID FPGpr0 = JSC::ARM64Registers::q0;
+    static const FPRegisterID FPGpr1 = JSC::ARM64Registers::q1;
 
-    static RegisterInformation getPlatformRegisterInfo()
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 << RI(JSC::ARM64Registers::x0,  QStringLiteral("x0"),  RI::RegularRegister,       RI::CallerSaved, RI::Predefined)
                 << RI(JSC::ARM64Registers::x1,  QStringLiteral("x1"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::ARM64Registers::x2,  QStringLiteral("x2"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
@@ -447,6 +506,7 @@ public:
                 << RI(JSC::ARM64Registers::q30, QStringLiteral("q30"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::ARM64Registers::q31, QStringLiteral("q31"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
                    ;
+        return info;
     }
 
 #undef HAVE_ALU_OPS_WITH_MEM_OPERAND
@@ -455,9 +515,9 @@ public:
 
 #define ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 8;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int index)
+    static RegisterID registerForArgument(int index)
     {
-        static JSC::MacroAssembler::RegisterID regs[RegisterArgumentCount] = {
+        static RegisterID regs[RegisterArgumentCount] = {
             JSC::ARM64Registers::x0,
             JSC::ARM64Registers::x1,
             JSC::ARM64Registers::x2,
@@ -476,33 +536,43 @@ public:
     static const int StackShadowSpace = 0;
     static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
 
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformEnterStandardStackFrame(PlatformAssembler *as)
     {
         as->pushPair(FramePointerRegister, JSC::ARM64Registers::lr);
     }
 
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as)
     {
         as->popPair(FramePointerRegister, JSC::ARM64Registers::lr);
     }
+};
 #endif // ARM64
 
 #if defined(Q_PROCESSOR_MIPS_32) && defined(Q_OS_LINUX)
+template <>
+class TargetPlatform<JSC::MacroAssemblerMIPS, NoOperatingSystemSpecialization>
+{
+public:
+    using PlatformAssembler = JSC::MacroAssemblerMIPS;
+    using RegisterID = PlatformAssembler::RegisterID;
+    using FPRegisterID = PlatformAssembler::FPRegisterID;
     enum { RegAllocIsSupported = 1 };
 
-    static const JSC::MacroAssembler::RegisterID FramePointerRegister = JSC::MIPSRegisters::fp;
-    static const JSC::MacroAssembler::RegisterID StackPointerRegister = JSC::MIPSRegisters::sp;
-    static const JSC::MacroAssembler::RegisterID LocalsRegister = JSC::MIPSRegisters::s0;
-    static const JSC::MacroAssembler::RegisterID EngineRegister = JSC::MIPSRegisters::s1;
-    static const JSC::MacroAssembler::RegisterID ReturnValueRegister = JSC::MIPSRegisters::v0;
-    static const JSC::MacroAssembler::RegisterID ScratchRegister = JSC::MIPSRegisters::s2;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr0 = JSC::MIPSRegisters::f0;
-    static const JSC::MacroAssembler::FPRegisterID FPGpr1 = JSC::MIPSRegisters::f2;
-
-    static RegisterInformation getPlatformRegisterInfo()
+    static const RegisterID FramePointerRegister = JSC::MIPSRegisters::fp;
+    static const RegisterID StackPointerRegister = JSC::MIPSRegisters::sp;
+    static const RegisterID LocalsRegister = JSC::MIPSRegisters::s0;
+    static const RegisterID EngineRegister = JSC::MIPSRegisters::s1;
+    static const RegisterID ReturnValueRegister = JSC::MIPSRegisters::v0;
+    static const RegisterID ScratchRegister = JSC::MIPSRegisters::s2;
+    static const FPRegisterID FPGpr0 = JSC::MIPSRegisters::f0;
+    static const FPRegisterID FPGpr1 = JSC::MIPSRegisters::f2;
+    static const RegisterID LowReturnValueRegister = JSC::MIPSRegisters::v0;
+    static const RegisterID HighReturnValueRegister = JSC::MIPSRegisters::v1;
+
+    static RegisterInformation getRegisterInfo()
     {
         typedef RegisterInfo RI;
-        return RegisterInformation()
+        static RegisterInformation info = RegisterInformation()
                 // Note: t0, t1, t2, t3 and f16 are already used by MacroAssemblerMIPS.
                 << RI(JSC::MIPSRegisters::t4,  QStringLiteral("t4"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
                 << RI(JSC::MIPSRegisters::t5,  QStringLiteral("t5"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
@@ -524,6 +594,7 @@ public:
                 << RI(JSC::MIPSRegisters::f26, QStringLiteral("f26"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
                 << RI(JSC::MIPSRegisters::f28, QStringLiteral("f28"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
                    ;
+        return info;
     }
 
 #undef HAVE_ALU_OPS_WITH_MEM_OPERAND
@@ -532,9 +603,9 @@ public:
 
 #define ARGUMENTS_IN_REGISTERS
     static const int RegisterArgumentCount = 4;
-    static JSC::MacroAssembler::RegisterID registerForArgument(int index)
+    static RegisterID registerForArgument(int index)
     {
-        static JSC::MacroAssembler::RegisterID regs[RegisterArgumentCount] = {
+        static RegisterID regs[RegisterArgumentCount] = {
             JSC::MIPSRegisters::a0,
             JSC::MIPSRegisters::a1,
             JSC::MIPSRegisters::a2,
@@ -549,27 +620,19 @@ public:
     static const int StackShadowSpace = 4 * RegisterSize; // Stack space for 4 argument registers.
     static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
 
-    static void platformEnterStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformEnterStandardStackFrame(PlatformAssembler *as)
     {
         as->push(JSC::MIPSRegisters::ra);
         as->push(FramePointerRegister);
     }
 
-    static void platformLeaveStandardStackFrame(JSC::MacroAssembler *as)
+    static void platformLeaveStandardStackFrame(PlatformAssembler *as)
     {
         as->pop(FramePointerRegister);
         as->pop(JSC::MIPSRegisters::ra);
     }
-#endif // Linux on MIPS (32 bit)
-
-public: // utility functions
-    static const RegisterInformation getRegisterInfo()
-    {
-        static const RegisterInformation info = getPlatformRegisterInfo();
-
-        return info;
-    }
 };
+#endif // Linux on MIPS (32 bit)
 
 } // JIT namespace
 } // QV4 namespace
diff --git a/src/qml/jit/qv4unop.cpp b/src/qml/jit/qv4unop.cpp
index 799103849b..31355e5dce 100644
--- a/src/qml/jit/qv4unop.cpp
+++ b/src/qml/jit/qv4unop.cpp
@@ -48,14 +48,15 @@ using namespace JIT;
 #define stringIfy(s) stringIfyx(s)
 #define setOp(operation) \
     do { \
-        call = RuntimeCall(qOffsetOf(QV4::Runtime, operation)); name = "Runtime::" stringIfy(operation); \
+        call = typename JITAssembler::RuntimeCall(qOffsetOf(QV4::Runtime, operation)); name = "Runtime::" stringIfy(operation); \
         needsExceptionCheck = Runtime::Method_##operation##_NeedsExceptionCheck; \
     } while (0)
 
-void Unop::generate(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void Unop<JITAssembler>::generate(IR::Expr *source, IR::Expr *target)
 {
     bool needsExceptionCheck;
-    RuntimeCall call;
+    typename JITAssembler::RuntimeCall call;
     const char *name = 0;
     switch (op) {
     case IR::OpNot:
@@ -75,17 +76,18 @@ void Unop::generate(IR::Expr *source, IR::Expr *target)
     } // switch
 
     Q_ASSERT(call.isValid());
-    _as->generateFunctionCallImp(needsExceptionCheck, target, name, call, Assembler::PointerToValue(source));
+    _as->generateFunctionCallImp(needsExceptionCheck, target, name, call, PointerToValue(source));
 }
 
-void Unop::generateUMinus(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void Unop<JITAssembler>::generateUMinus(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::SInt32Type) {
-        Assembler::RegisterID tReg = Assembler::ScratchRegister;
+        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) targetTemp->index;
-        Assembler::RegisterID sReg = _as->toInt32Register(source, tReg);
+            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
+        typename JITAssembler::RegisterID sReg = _as->toInt32Register(source, tReg);
         _as->move(sReg, tReg);
         _as->neg32(tReg);
         if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
@@ -93,26 +95,27 @@ void Unop::generateUMinus(IR::Expr *source, IR::Expr *target)
         return;
     }
 
-    generateRuntimeCall(target, uMinus, Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, target, uMinus, PointerToValue(source));
 }
 
-void Unop::generateNot(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void Unop<JITAssembler>::generateNot(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::BoolType) {
-        Assembler::RegisterID tReg = Assembler::ScratchRegister;
+        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) targetTemp->index;
-        _as->xor32(Assembler::TrustedImm32(0x1), _as->toInt32Register(source, tReg), tReg);
+            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
+        _as->xor32(TrustedImm32(0x1), _as->toInt32Register(source, tReg), tReg);
         if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             _as->storeBool(tReg, target);
         return;
     } else if (source->type == IR::SInt32Type) {
-        Assembler::RegisterID tReg = Assembler::ScratchRegister;
+        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) targetTemp->index;
-        _as->compare32(Assembler::Equal,
-                      _as->toInt32Register(source, Assembler::ScratchRegister), Assembler::TrustedImm32(0),
+            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
+        _as->compare32(RelationalCondition::Equal,
+                      _as->toInt32Register(source, JITAssembler::ScratchRegister), TrustedImm32(0),
                       tReg);
         if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             _as->storeBool(tReg, target);
@@ -122,22 +125,28 @@ void Unop::generateNot(IR::Expr *source, IR::Expr *target)
     }
     // ## generic implementation testing for int/bool
 
-    generateRuntimeCall(target, uNot, Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, target, uNot, PointerToValue(source));
 }
 
-void Unop::generateCompl(IR::Expr *source, IR::Expr *target)
+template <typename JITAssembler>
+void Unop<JITAssembler>::generateCompl(IR::Expr *source, IR::Expr *target)
 {
     IR::Temp *targetTemp = target->asTemp();
     if (source->type == IR::SInt32Type) {
-        Assembler::RegisterID tReg = Assembler::ScratchRegister;
+        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
         if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (Assembler::RegisterID) targetTemp->index;
-        _as->xor32(Assembler::TrustedImm32(0xffffffff), _as->toInt32Register(source, tReg), tReg);
+            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
+        _as->xor32(TrustedImm32(0xffffffff), _as->toInt32Register(source, tReg), tReg);
         if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
             _as->storeInt32(tReg, target);
         return;
     }
-    generateRuntimeCall(target, complement, Assembler::PointerToValue(source));
+    generateRuntimeCall(_as, target, complement, PointerToValue(source));
 }
 
+template struct QV4::JIT::Unop<QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>>;
+#if defined(V4_BOOTSTRAP) && CPU(X86_64)
+template struct QV4::JIT::Unop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>>;
+#endif
+
 #endif
diff --git a/src/qml/jit/qv4unop_p.h b/src/qml/jit/qv4unop_p.h
index 1141a84913..fb68f80eec 100644
--- a/src/qml/jit/qv4unop_p.h
+++ b/src/qml/jit/qv4unop_p.h
@@ -60,21 +60,25 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
 
-class Assembler;
-
+template <typename JITAssembler>
 struct Unop {
-    Unop(Assembler *assembler, IR::AluOp operation)
+    Unop(JITAssembler *assembler, IR::AluOp operation)
         : _as(assembler)
         , op(operation)
     {}
 
+    using RelationalCondition = typename JITAssembler::RelationalCondition;
+    using PointerToValue = typename JITAssembler::PointerToValue;
+    using RuntimeCall = typename JITAssembler::RuntimeCall;
+    using TrustedImm32 = typename JITAssembler::TrustedImm32;
+
     void generate(IR::Expr *source, IR::Expr *target);
 
     void generateUMinus(IR::Expr *source, IR::Expr *target);
     void generateNot(IR::Expr *source, IR::Expr *target);
     void generateCompl(IR::Expr *source, IR::Expr *target);
 
-    Assembler *_as;
+    JITAssembler *_as;
     IR::AluOp op;
 };
 
diff --git a/src/qml/jsruntime/jsruntime.pri b/src/qml/jsruntime/jsruntime.pri
index 919524d1ed..955cf585e4 100644
--- a/src/qml/jsruntime/jsruntime.pri
+++ b/src/qml/jsruntime/jsruntime.pri
@@ -35,7 +35,6 @@ SOURCES += \
     $$PWD/qv4regexp.cpp \
     $$PWD/qv4serialize.cpp \
     $$PWD/qv4script.cpp \
-    $$PWD/qv4executableallocator.cpp \
     $$PWD/qv4sequenceobject.cpp \
     $$PWD/qv4include.cpp \
     $$PWD/qv4qobjectwrapper.cpp \
@@ -113,7 +112,8 @@ HEADERS += \
 SOURCES += \
     $$PWD/qv4runtime.cpp \
     $$PWD/qv4string.cpp \
-    $$PWD/qv4value.cpp
+    $$PWD/qv4value.cpp \
+    $$PWD/qv4executableallocator.cpp
 
 valgrind {
     DEFINES += V4_USE_VALGRIND
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index a11f7f0875..084ddc9010 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -91,7 +91,9 @@
 
 #if USE(PTHREADS)
 #  include <pthread.h>
+#if !defined(Q_OS_INTEGRITY)
 #  include <sys/resource.h>
+#endif
 #if HAVE(PTHREAD_NP_H)
 #  include <pthread_np.h>
 #endif
@@ -168,7 +170,7 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
         if (forceMoth) {
             factory = new Moth::ISelFactory;
         } else {
-            factory = new JIT::ISelFactory;
+            factory = new JIT::ISelFactory<>;
             jitDisabled = false;
         }
 #else // !V4_ENABLE_JIT
@@ -1109,7 +1111,7 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
     if (typeHint == qMetaTypeId<QJSValue>())
         return QVariant::fromValue(QJSValue(e, value.asReturnedValue()));
 
-    if (value.as<Object>()) {
+    if (value.as<QV4::Object>()) {
         QV4::ScopedObject object(scope, value);
         if (typeHint == QMetaType::QJsonObject
                    && !value.as<ArrayObject>() && !value.as<FunctionObject>()) {
@@ -1755,7 +1757,7 @@ bool ExecutionEngine::metaTypeFromJS(const Value *value, int type, void *data)
     return false;
 }
 
-static bool convertToNativeQObject(QV4::ExecutionEngine *e, const Value &value, const QByteArray &targetType, void **result)
+static bool convertToNativeQObject(QV4::ExecutionEngine *e, const QV4::Value &value, const QByteArray &targetType, void **result)
 {
     if (!targetType.endsWith('*'))
         return false;
@@ -1770,7 +1772,7 @@ static bool convertToNativeQObject(QV4::ExecutionEngine *e, const Value &value,
     return false;
 }
 
-static QObject *qtObjectFromJS(QV4::ExecutionEngine *engine, const Value &value)
+static QObject *qtObjectFromJS(QV4::ExecutionEngine *engine, const QV4::Value &value)
 {
     if (!value.isObject())
         return 0;
diff --git a/src/qml/jsruntime/qv4lookup_p.h b/src/qml/jsruntime/qv4lookup_p.h
index 52f54e25f5..c5ee92fedd 100644
--- a/src/qml/jsruntime/qv4lookup_p.h
+++ b/src/qml/jsruntime/qv4lookup_p.h
@@ -54,8 +54,11 @@
 #include "qv4runtime_p.h"
 #include "qv4engine_p.h"
 #include "qv4context_p.h"
+
+#if !defined(V4_BOOTSTRAP)
 #include "qv4object_p.h"
 #include "qv4internalclass_p.h"
+#endif
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index eb9cb80cee..2f664c6398 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -1155,6 +1155,49 @@ uint Object::getLength(const Managed *m)
     return v->toUInt32();
 }
 
+// 'var' is 'V' in 15.3.5.3.
+ReturnedValue Object::instanceOf(const Object *typeObject, const Value &var)
+{
+    QV4::ExecutionEngine *engine = typeObject->internalClass()->engine;
+
+    // 15.3.5.3, Assume F is a Function object.
+    const FunctionObject *function = typeObject->as<FunctionObject>();
+    if (!function)
+        return engine->throwTypeError();
+
+    Heap::FunctionObject *f = function->d();
+    if (function->isBoundFunction())
+        f = function->cast<BoundFunction>()->target();
+
+    // 15.3.5.3, 1: HasInstance can only be used on an object
+    const Object *lhs = var.as<Object>();
+    if (!lhs)
+        return Encode(false);
+
+    // 15.3.5.3, 2
+    const Object *o = f->protoProperty();
+    if (!o) // 15.3.5.3, 3
+        return engine->throwTypeError();
+
+    Heap::Object *v = lhs->d();
+
+    // 15.3.5.3, 4
+    while (v) {
+        // 15.3.5.3, 4, a
+        v = v->prototype;
+
+        // 15.3.5.3, 4, b
+        if (!v)
+            break; // will return false
+
+        // 15.3.5.3, 4, c
+        else if (o->d() == v)
+            return Encode(true);
+    }
+
+    return Encode(false);
+}
+
 bool Object::setArrayLength(uint newLen)
 {
     Q_ASSERT(isArrayObject());
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 4a78690f47..6a543ae1a8 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -140,6 +140,7 @@ struct ObjectVTable
     void (*setLookup)(Managed *m, Lookup *l, const Value &v);
     uint (*getLength)(const Managed *m);
     void (*advanceIterator)(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
+    ReturnedValue (*instanceOf)(const Object *typeObject, const Value &var);
 };
 
 #define DEFINE_OBJECT_VTABLE_BASE(classname) \
@@ -159,7 +160,8 @@ const QV4::ObjectVTable classname::static_vtbl =    \
     getLookup,                                  \
     setLookup,                                  \
     getLength,                                  \
-    advanceIterator                            \
+    advanceIterator,                            \
+    instanceOf                                  \
 }
 
 #define DEFINE_OBJECT_VTABLE(classname) \
@@ -351,6 +353,8 @@ public:
     void advanceIterator(ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
     { vtable()->advanceIterator(this, it, name, index, p, attributes); }
     uint getLength() const { return vtable()->getLength(this); }
+    ReturnedValue instanceOf(const Value &var) const
+    { return vtable()->instanceOf(this, var); }
 
     inline void construct(Scope &scope, CallData *d) const
     { return vtable()->construct(this, scope, d); }
@@ -372,6 +376,7 @@ protected:
     static void setLookup(Managed *m, Lookup *l, const Value &v);
     static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
     static uint getLength(const Managed *m);
+    static ReturnedValue instanceOf(const Object *typeObject, const Value &var);
 
 private:
     ReturnedValue internalGet(String *name, bool *hasProperty) const;
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 023a739e33..7f184f8221 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -343,35 +343,15 @@ ReturnedValue Runtime::method_deleteName(ExecutionEngine *engine, int nameIndex)
     return Encode(engine->currentContext->deleteProperty(name));
 }
 
-QV4::ReturnedValue Runtime::method_instanceof(ExecutionEngine *engine, const Value &left, const Value &right)
+QV4::ReturnedValue Runtime::method_instanceof(ExecutionEngine *engine, const Value &lval, const Value &rval)
 {
-    const FunctionObject *function = right.as<FunctionObject>();
-    if (!function)
-        return engine->throwTypeError();
-
-    Heap::FunctionObject *f = function->d();
-    if (function->isBoundFunction())
-        f = function->cast<BoundFunction>()->target();
-
-    const Object *o = left.as<Object>();
-    if (!o)
-        return Encode(false);
-    Heap::Object *v = o->d();
-
-    o = f->protoProperty();
-    if (!o)
-        return engine->throwTypeError();
-
-    while (v) {
-        v = v->prototype;
-
-        if (!v)
-            break;
-        else if (o->d() == v)
-            return Encode(true);
-    }
+    // 11.8.6, 5: rval must be an Object
+    const Object *rhs = rval.as<Object>();
+    if (!rhs)
+       return engine->throwTypeError();
 
-    return Encode(false);
+    // 11.8.6, 7: call "HasInstance", which we term instanceOf, and return the result.
+    return rhs->instanceOf(lval);
 }
 
 QV4::ReturnedValue Runtime::method_in(ExecutionEngine *engine, const Value &left, const Value &right)
diff --git a/src/qml/jsruntime/qv4value_p.h b/src/qml/jsruntime/qv4value_p.h
index 64f0f3a86f..4ff0565f9b 100644
--- a/src/qml/jsruntime/qv4value_p.h
+++ b/src/qml/jsruntime/qv4value_p.h
@@ -254,34 +254,47 @@ public:
         Q_ASSERT(isDouble()); return Double_Type;
     }
 
-#ifndef QV4_USE_64_BIT_VALUE_ENCODING
+    // Shared between 32-bit and 64-bit encoding
+    enum {
+        Tag_Shift = 32
+    };
+
+    // Used only by 64-bit encoding
+    static const quint64 NaNEncodeMask  = 0xfffc000000000000ll;
+    enum {
+        IsDouble_Shift = 64-14,
+        IsManagedOrUndefined_Shift = 64-15,
+        IsIntegerConvertible_Shift = 64-16,
+        IsDoubleTag_Shift = IsDouble_Shift - Tag_Shift,
+        Managed_Type_Internal_64 = 0
+    };
+    static const quint64 Immediate_Mask_64 = 0x00020000u; // bit 49
+
+    // Used only by 32-bit encoding
     enum Masks {
         SilentNaNBit           =                  0x00040000,
-        NaN_Mask               =                  0x7ff80000,
         NotDouble_Mask         =                  0x7ffa0000,
-        Immediate_Mask         = NotDouble_Mask | 0x00020000u | SilentNaNBit,
-        Tag_Shift = 32
     };
+    static const quint64 Immediate_Mask_32 = NotDouble_Mask | 0x00020000u | SilentNaNBit;
 
     enum {
-        Managed_Type_Internal  = NotDouble_Mask
+        Managed_Type_Internal_32  = NotDouble_Mask
     };
-#else
-    static const quint64 NaNEncodeMask  = 0xfffc000000000000ll;
-    static const quint64 Immediate_Mask = 0x00020000u; // bit 49
 
-    enum Masks {
-        NaN_Mask = 0x7ff80000,
+#ifdef QV4_USE_64_BIT_VALUE_ENCODING
+    enum {
+        Managed_Type_Internal  = Managed_Type_Internal_64
     };
+    static const quint64 Immediate_Mask = Immediate_Mask_64;
+#else
     enum {
-        IsDouble_Shift = 64-14,
-        IsManagedOrUndefined_Shift = 64-15,
-        IsIntegerConvertible_Shift = 64-16,
-        Tag_Shift = 32,
-        IsDoubleTag_Shift = IsDouble_Shift - Tag_Shift,
-        Managed_Type_Internal = 0
+        Managed_Type_Internal  = Managed_Type_Internal_32
     };
+    static const quint64 Immediate_Mask = Immediate_Mask_32;
 #endif
+    enum {
+        NaN_Mask = 0x7ff80000,
+    };
     enum ValueTypeInternal {
         Empty_Type_Internal   = Immediate_Mask   | 0,
         ConvertibleToInt      = Immediate_Mask   | 0x10000u, // bit 48
diff --git a/src/qml/parser/qqmljskeywords_p.h b/src/qml/parser/qqmljskeywords_p.h
index 84ebe5f210..a31c188efc 100644
--- a/src/qml/parser/qqmljskeywords_p.h
+++ b/src/qml/parser/qqmljskeywords_p.h
@@ -278,7 +278,7 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       if (s[2].unicode() == 'n') {
         if (s[3].unicode() == 's') {
           if (s[4].unicode() == 't') {
-            return qmlMode ? int(Lexer::T_CONST) : int(Lexer::T_RESERVED_WORD);
+            return int(Lexer::T_CONST);
           }
         }
       }
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index bd41659f27..c07d5c740a 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -238,6 +239,21 @@ typedef QPair<QStaticPlugin, QJsonArray> StaticPluginPair;
 
 /*!
     \internal
+    \class QQmlImportInstance
+
+    A QQmlImportType represents a single import of a document, held within a
+    namespace.
+
+    \note The uri here may not necessarily be unique (e.g. for file imports).
+
+    \note Version numbers may be -1 for file imports: this means that no
+    version was specified as part of the import. Type resolution will be
+    responsible for attempting to find the "best" possible version.
+*/
+
+/*!
+    \internal
+    \class QQmlImportNamespace
 
     A QQmlImportNamespace is a way of seperating imports into a local namespace.
 
@@ -253,56 +269,6 @@ typedef QPair<QStaticPlugin, QJsonArray> StaticPluginPair;
 
         import MyFoo 1.0 as Foo
 */
-class QQmlImportNamespace
-{
-public:
-    QQmlImportNamespace() : nextNamespace(0) {}
-    ~QQmlImportNamespace() { qDeleteAll(imports); }
-
-    /*!
-        \internal
-
-        A QQmlImportNamespace::Import represents an actual instance of an import
-        within a namespace.
-
-        \note The uri here may not necessarily be unique (e.g. for file imports).
-
-        \note Version numbers may be -1 for file imports: this means that no
-        version was specified as part of the import. Type resolution will be
-        responsible for attempting to find the "best" possible version.
-    */
-    struct Import {
-        QString uri; // e.g. QtQuick
-        QString url; // the base path of the import
-        int majversion; // the major version imported
-        int minversion; // the minor version imported
-        bool isLibrary; // true means that this is not a file import
-        QQmlDirComponents qmlDirComponents; // a copy of the components listed in the qmldir
-        QQmlDirScripts qmlDirScripts; // a copy of the scripts in the qmldir
-
-        bool setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoader::QmldirContent *qmldir,
-                              QQmlImportNamespace *nameSpace, QList<QQmlError> *errors);
-
-        static QQmlDirScripts getVersionedScripts(const QQmlDirScripts &qmldirscripts, int vmaj, int vmin);
-
-        bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef &type,
-                         int *vmajor, int *vminor, QQmlType** type_return,
-                         QString *base = 0, bool *typeRecursionDetected = 0) const;
-    };
-    QList<Import *> imports;
-
-    Import *findImport(const QString &uri) const;
-
-    bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef& type,
-                     int *vmajor, int *vminor, QQmlType** type_return,
-                     QString *base = 0, QList<QQmlError> *errors = 0);
-
-    // Prefix when used as a qualified import.  Otherwise empty.
-    QHashedString prefix;
-
-    // Used by QQmlImportsPrivate::qualifiedSets
-    QQmlImportNamespace *nextNamespace;
-};
 
 class QQmlImportsPrivate
 {
@@ -348,21 +314,21 @@ public:
                              QQmlImportDatabase *database,
                              QString *outQmldirFilePath, QString *outUrl);
 
-    static bool validateQmldirVersion(const QQmlTypeLoader::QmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
+    static bool validateQmldirVersion(const QQmlTypeLoaderQmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
                                       QList<QQmlError> *errors);
 
     bool importExtension(const QString &absoluteFilePath, const QString &uri,
                          int vmaj, int vmin,
                          QQmlImportDatabase *database,
-                         const QQmlTypeLoader::QmldirContent *qmldir,
+                         const QQmlTypeLoaderQmldirContent *qmldir,
                          QList<QQmlError> *errors);
 
     bool getQmldirContent(const QString &qmldirIdentifier, const QString &uri,
-                          const QQmlTypeLoader::QmldirContent **qmldir, QList<QQmlError> *errors);
+                          const QQmlTypeLoaderQmldirContent **qmldir, QList<QQmlError> *errors);
 
     QString resolvedUri(const QString &dir_arg, QQmlImportDatabase *database);
 
-    QQmlImportNamespace::Import *addImportToNamespace(QQmlImportNamespace *nameSpace,
+    QQmlImportInstance *addImportToNamespace(QQmlImportNamespace *nameSpace,
                                                       const QString &uri, const QString &url,
                                                       int vmaj, int vmin, QV4::CompiledData::Import::ImportType type,
                                                       QList<QQmlError> *errors, bool lowPrecedence = false);
@@ -427,12 +393,22 @@ QUrl QQmlImports::baseUrl() const
     return d->baseUrl;
 }
 
+/*
+    \internal
+
+    This method is responsible for populating data of all types visible in this
+    document's imports into the \a cache for resolution elsewhere (e.g. in JS,
+    or when loading additional types).
+
+    \note This is for C++ types only. Composite types are handled separately,
+    as they do not have a QQmlTypeModule.
+*/
 void QQmlImports::populateCache(QQmlTypeNameCache *cache) const
 {
     const QQmlImportNamespace &set = d->unqualifiedset;
 
     for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
-        const QQmlImportNamespace::Import *import = set.imports.at(ii);
+        const QQmlImportInstance *import = set.imports.at(ii);
         QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion);
         if (module) {
             cache->m_anonymousImports.append(QQmlTypeModuleVersion(module, import->minversion));
@@ -443,11 +419,14 @@ void QQmlImports::populateCache(QQmlTypeNameCache *cache) const
 
         const QQmlImportNamespace &set = *ns;
 
+        // positioning is important; we must create the namespace even if there is no module.
+        QQmlTypeNameCache::Import &typeimport = cache->m_namedImports[set.prefix];
+        typeimport.m_qualifier = set.prefix;
+
         for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
-            const QQmlImportNamespace::Import *import = set.imports.at(ii);
+            const QQmlImportInstance *import = set.imports.at(ii);
             QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion);
             if (module) {
-                QQmlTypeNameCache::Import &typeimport = cache->m_namedImports[set.prefix];
                 typeimport.modules.append(QQmlTypeModuleVersion(module, import->minversion));
             }
         }
@@ -476,7 +455,7 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
     typedef QQmlDirComponents::const_iterator ConstIterator;
 
     for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
-        const QQmlImportNamespace::Import *import = set.imports.at(ii);
+        const QQmlImportInstance *import = set.imports.at(ii);
 
         const QQmlDirComponents &components = import->qmlDirComponents;
 
@@ -494,6 +473,15 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
     }
 }
 
+/*
+    \internal
+
+    Returns a list of all composite singletons present in this document's
+    imports.
+
+    This information is used by QQmlTypeLoader to ensure that composite singletons
+    are marked as dependencies during type loading.
+*/
 QList<QQmlImports::CompositeSingletonReference> QQmlImports::resolvedCompositeSingletons() const
 {
     QList<QQmlImports::CompositeSingletonReference> compositeSingletons;
@@ -509,6 +497,12 @@ QList<QQmlImports::CompositeSingletonReference> QQmlImports::resolvedCompositeSi
     return compositeSingletons;
 }
 
+/*
+    \internal
+
+    Returns a list of scripts imported by this document. This is used by
+    QQmlTypeLoader to properly handle dependencies on imported scripts.
+*/
 QList<QQmlImports::ScriptReference> QQmlImports::resolvedScripts() const
 {
     QList<QQmlImports::ScriptReference> scripts;
@@ -516,7 +510,7 @@ QList<QQmlImports::ScriptReference> QQmlImports::resolvedScripts() const
     const QQmlImportNamespace &set = d->unqualifiedset;
 
     for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
-        const QQmlImportNamespace::Import *import = set.imports.at(ii);
+        const QQmlImportInstance *import = set.imports.at(ii);
 
         for (const QQmlDirParser::Script &script : import->qmlDirScripts) {
             ScriptReference ref;
@@ -530,7 +524,7 @@ QList<QQmlImports::ScriptReference> QQmlImports::resolvedScripts() const
         const QQmlImportNamespace &set = *ns;
 
         for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
-            const QQmlImportNamespace::Import *import = set.imports.at(ii);
+            const QQmlImportInstance *import = set.imports.at(ii);
 
             for (const QQmlDirParser::Script &script : import->qmlDirScripts) {
                 ScriptReference ref;
@@ -654,7 +648,7 @@ bool QQmlImports::resolveType(const QHashedStringRef &type,
     return false;
 }
 
-bool QQmlImportNamespace::Import::setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoader::QmldirContent *qmldir, QQmlImportNamespace *nameSpace, QList<QQmlError> *errors)
+bool QQmlImportInstance::setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent *qmldir, QQmlImportNamespace *nameSpace, QList<QQmlError> *errors)
 {
     Q_ASSERT(resolvedUrl.endsWith(Slash));
     url = resolvedUrl;
@@ -664,7 +658,7 @@ bool QQmlImportNamespace::Import::setQmldirContent(const QString &resolvedUrl, c
     const QQmlDirScripts &scripts = qmldir->scripts();
     if (!scripts.isEmpty()) {
         // Verify that we haven't imported these scripts already
-        for (QList<QQmlImportNamespace::Import *>::const_iterator it = nameSpace->imports.constBegin();
+        for (QList<QQmlImportInstance *>::const_iterator it = nameSpace->imports.constBegin();
              it != nameSpace->imports.constEnd(); ++it) {
             if ((*it != this) && ((*it)->uri == uri)) {
                 QQmlError error;
@@ -680,7 +674,7 @@ bool QQmlImportNamespace::Import::setQmldirContent(const QString &resolvedUrl, c
     return true;
 }
 
-QQmlDirScripts QQmlImportNamespace::Import::getVersionedScripts(const QQmlDirScripts &qmldirscripts, int vmaj, int vmin)
+QQmlDirScripts QQmlImportInstance::getVersionedScripts(const QQmlDirScripts &qmldirscripts, int vmaj, int vmin)
 {
     QMap<QString, QQmlDirParser::Script> versioned;
 
@@ -716,7 +710,7 @@ bool QQmlImports::resolveType(QQmlImportNamespace* ns, const QHashedStringRef &t
     return ns->resolveType(d->typeLoader,type,vmaj,vmin,type_return);
 }
 
-bool QQmlImportNamespace::Import::resolveType(QQmlTypeLoader *typeLoader,
+bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
                                               const QHashedStringRef& type, int *vmajor, int *vminor,
                                               QQmlType** type_return, QString *base, bool *typeRecursionDetected) const
 {
@@ -853,9 +847,9 @@ bool QQmlImportsPrivate::resolveType(const QHashedStringRef& type, int *vmajor,
     return false;
 }
 
-QQmlImportNamespace::Import *QQmlImportNamespace::findImport(const QString &uri) const
+QQmlImportInstance *QQmlImportNamespace::findImport(const QString &uri) const
 {
-    for (Import *import : imports) {
+    for (QQmlImportInstance *import : imports) {
         if (import->uri == uri)
             return import;
     }
@@ -868,13 +862,13 @@ bool QQmlImportNamespace::resolveType(QQmlTypeLoader *typeLoader, const QHashedS
 {
     bool typeRecursionDetected = false;
     for (int i=0; i<imports.count(); ++i) {
-        const Import *import = imports.at(i);
+        const QQmlImportInstance *import = imports.at(i);
         if (import->resolveType(typeLoader, type, vmajor, vminor, type_return,
                                base, &typeRecursionDetected)) {
             if (qmlCheckTypes()) {
                 // check for type clashes
                 for (int j = i+1; j<imports.count(); ++j) {
-                    const Import *import2 = imports.at(j);
+                    const QQmlImportInstance *import2 = imports.at(j);
                     if (import2->resolveType(typeLoader, type, vmajor, vminor, 0, base)) {
                         if (errors) {
                             QString u1 = import->url;
@@ -1017,10 +1011,12 @@ bool QQmlImportsPrivate::populatePluginPairVector(QVector<StaticPluginPair> &res
 }
 #endif
 
+#if defined(QT_SHARED) || !QT_CONFIG(library)
 static inline QString msgCannotLoadPlugin(const QString &uri, const QString &why)
 {
     return QQmlImportDatabase::tr("plugin cannot be loaded for module \"%1\": %2").arg(uri, why);
 }
+#endif
 
 /*!
 Import an extension defined by a qmldir file.
@@ -1031,7 +1027,7 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
                                          const QString &uri,
                                          int vmaj, int vmin,
                                          QQmlImportDatabase *database,
-                                         const QQmlTypeLoader::QmldirContent *qmldir,
+                                         const QQmlTypeLoaderQmldirContent *qmldir,
                                          QList<QQmlError> *errors)
 {
 #if QT_CONFIG(library)
@@ -1167,7 +1163,7 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
 }
 
 bool QQmlImportsPrivate::getQmldirContent(const QString &qmldirIdentifier, const QString &uri,
-                                          const QQmlTypeLoader::QmldirContent **qmldir, QList<QQmlError> *errors)
+                                          const QQmlTypeLoaderQmldirContent **qmldir, QList<QQmlError> *errors)
 {
     Q_ASSERT(errors);
     Q_ASSERT(qmldir);
@@ -1292,7 +1288,7 @@ bool QQmlImportsPrivate::locateQmldir(const QString &uri, int vmaj, int vmin, QQ
     return false;
 }
 
-bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoader::QmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
+bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoaderQmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
                                                QList<QQmlError> *errors)
 {
     int lowest_min = INT_MAX;
@@ -1375,7 +1371,7 @@ QQmlImportNamespace *QQmlImportsPrivate::importNamespace(const QString &prefix)
     return nameSpace;
 }
 
-QQmlImportNamespace::Import *QQmlImportsPrivate::addImportToNamespace(QQmlImportNamespace *nameSpace,
+QQmlImportInstance *QQmlImportsPrivate::addImportToNamespace(QQmlImportNamespace *nameSpace,
                                                                       const QString &uri, const QString &url, int vmaj, int vmin,
                                                                       QV4::CompiledData::Import::ImportType type,
                                                                       QList<QQmlError> *errors, bool lowPrecedence)
@@ -1385,7 +1381,7 @@ QQmlImportNamespace::Import *QQmlImportsPrivate::addImportToNamespace(QQmlImport
     Q_UNUSED(errors);
     Q_ASSERT(url.isEmpty() || url.endsWith(Slash));
 
-    QQmlImportNamespace::Import *import = new QQmlImportNamespace::Import;
+    QQmlImportInstance *import = new QQmlImportInstance;
     import->uri = uri;
     import->url = url;
     import->majversion = vmaj;
@@ -1411,11 +1407,11 @@ bool QQmlImportsPrivate::addLibraryImport(const QString& uri, const QString &pre
     QQmlImportNamespace *nameSpace = importNamespace(prefix);
     Q_ASSERT(nameSpace);
 
-    QQmlImportNamespace::Import *inserted = addImportToNamespace(nameSpace, uri, qmldirUrl, vmaj, vmin, QV4::CompiledData::Import::ImportLibrary, errors);
+    QQmlImportInstance *inserted = addImportToNamespace(nameSpace, uri, qmldirUrl, vmaj, vmin, QV4::CompiledData::Import::ImportLibrary, errors);
     Q_ASSERT(inserted);
 
     if (!incomplete) {
-        const QQmlTypeLoader::QmldirContent *qmldir = 0;
+        const QQmlTypeLoaderQmldirContent *qmldir = 0;
 
         if (!qmldirIdentifier.isEmpty()) {
             if (!getQmldirContent(qmldirIdentifier, uri, &qmldir, errors))
@@ -1512,11 +1508,11 @@ bool QQmlImportsPrivate::addFileImport(const QString& uri, const QString &prefix
     if (!url.endsWith(Slash) && !url.endsWith(Backslash))
         url += Slash;
 
-    QQmlImportNamespace::Import *inserted = addImportToNamespace(nameSpace, importUri, url, vmaj, vmin, QV4::CompiledData::Import::ImportFile, errors, isImplicitImport);
+    QQmlImportInstance *inserted = addImportToNamespace(nameSpace, importUri, url, vmaj, vmin, QV4::CompiledData::Import::ImportFile, errors, isImplicitImport);
     Q_ASSERT(inserted);
 
     if (!incomplete && !qmldirIdentifier.isEmpty()) {
-        const QQmlTypeLoader::QmldirContent *qmldir = 0;
+        const QQmlTypeLoaderQmldirContent *qmldir = 0;
         if (!getQmldirContent(qmldirIdentifier, importUri, &qmldir, errors))
             return false;
 
@@ -1539,8 +1535,8 @@ bool QQmlImportsPrivate::updateQmldirContent(const QString &uri, const QString &
     QQmlImportNamespace *nameSpace = importNamespace(prefix);
     Q_ASSERT(nameSpace);
 
-    if (QQmlImportNamespace::Import *import = nameSpace->findImport(uri)) {
-        const QQmlTypeLoader::QmldirContent *qmldir = 0;
+    if (QQmlImportInstance *import = nameSpace->findImport(uri)) {
+        const QQmlTypeLoaderQmldirContent *qmldir = 0;
         if (!getQmldirContent(qmldirIdentifier, uri, &qmldir, errors))
             return false;
 
diff --git a/src/qml/qml/qqmlimport_p.h b/src/qml/qml/qqmlimport_p.h
index 0e7848730f..7c691a468c 100644
--- a/src/qml/qml/qqmlimport_p.h
+++ b/src/qml/qml/qqmlimport_p.h
@@ -68,6 +68,48 @@ class QQmlImportNamespace;
 class QQmlImportsPrivate;
 class QQmlImportDatabase;
 class QQmlTypeLoader;
+class QQmlTypeLoaderQmldirContent;
+
+struct QQmlImportInstance
+{
+    QString uri; // e.g. QtQuick
+    QString url; // the base path of the import
+    int majversion; // the major version imported
+    int minversion; // the minor version imported
+    bool isLibrary; // true means that this is not a file import
+    QQmlDirComponents qmlDirComponents; // a copy of the components listed in the qmldir
+    QQmlDirScripts qmlDirScripts; // a copy of the scripts in the qmldir
+
+    bool setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent *qmldir,
+                          QQmlImportNamespace *nameSpace, QList<QQmlError> *errors);
+
+    static QQmlDirScripts getVersionedScripts(const QQmlDirScripts &qmldirscripts, int vmaj, int vmin);
+
+    bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef &type,
+                     int *vmajor, int *vminor, QQmlType** type_return,
+                     QString *base = 0, bool *typeRecursionDetected = 0) const;
+};
+
+class QQmlImportNamespace
+{
+public:
+    QQmlImportNamespace() : nextNamespace(0) {}
+    ~QQmlImportNamespace() { qDeleteAll(imports); }
+
+    QList<QQmlImportInstance *> imports;
+
+    QQmlImportInstance *findImport(const QString &uri) const;
+
+    bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef& type,
+                     int *vmajor, int *vminor, QQmlType** type_return,
+                     QString *base = 0, QList<QQmlError> *errors = 0);
+
+    // Prefix when used as a qualified import.  Otherwise empty.
+    QHashedString prefix;
+
+    // Used by QQmlImportsPrivate::qualifiedSets
+    QQmlImportNamespace *nextNamespace;
+};
 
 class Q_QML_PRIVATE_EXPORT QQmlImports
 {
diff --git a/src/qml/qml/qqmlpropertycache.cpp b/src/qml/qml/qqmlpropertycache.cpp
index 562aa1c88a..88ce2fa1b9 100644
--- a/src/qml/qml/qqmlpropertycache.cpp
+++ b/src/qml/qml/qqmlpropertycache.cpp
@@ -76,7 +76,8 @@ public:
     int argumentsValid:1;
 
     QList<QByteArray> *names;
-    int arguments[0];
+
+    int arguments[1];
 };
 
 // Flags that do *NOT* depend on the property's QMetaProperty::userType() and thus are quick
@@ -919,7 +920,7 @@ static int EnumType(const QMetaObject *metaobj, const QByteArray &str, int type)
 QQmlPropertyCacheMethodArguments *QQmlPropertyCache::createArgumentsObject(int argc, const QList<QByteArray> &names)
 {
     typedef QQmlPropertyCacheMethodArguments A;
-    A *args = static_cast<A *>(malloc(sizeof(A) + (argc + 1) * sizeof(int)));
+    A *args = static_cast<A *>(malloc(sizeof(A) + (argc) * sizeof(int)));
     args->arguments[0] = argc;
     args->argumentsValid = false;
     args->signalParameterStringForJS = 0;
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 13ad02f7cb..f4f04e12c0 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -1362,7 +1362,7 @@ bool QQmlTypeLoader::Blob::updateQmldir(QQmlQmldirData *data, const QV4::Compile
     if (!importQualifier.isEmpty()) {
         // Does this library contain any qualified scripts?
         QUrl libraryUrl(qmldirUrl);
-        const QmldirContent *qmldir = typeLoader()->qmldirContent(qmldirIdentifier);
+        const QQmlTypeLoaderQmldirContent *qmldir = typeLoader()->qmldirContent(qmldirIdentifier);
         const auto qmldirScripts = qmldir->scripts();
         for (const QQmlDirParser::Script &script : qmldirScripts) {
             QUrl scriptUrl = libraryUrl.resolved(QUrl(script.fileName));
@@ -1410,7 +1410,7 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
             if (!importQualifier.isEmpty()) {
                 // Does this library contain any qualified scripts?
                 QUrl libraryUrl(qmldirUrl);
-                const QmldirContent *qmldir = typeLoader()->qmldirContent(qmldirFilePath);
+                const QQmlTypeLoaderQmldirContent *qmldir = typeLoader()->qmldirContent(qmldirFilePath);
                 const auto qmldirScripts = qmldir->scripts();
                 for (const QQmlDirParser::Script &script : qmldirScripts) {
                     QUrl scriptUrl = libraryUrl.resolved(QUrl(script.fileName));
@@ -1539,57 +1539,57 @@ bool QQmlTypeLoader::Blob::qmldirDataAvailable(QQmlQmldirData *data, QList<QQmlE
 }
 
 
-QQmlTypeLoader::QmldirContent::QmldirContent()
+QQmlTypeLoaderQmldirContent::QQmlTypeLoaderQmldirContent()
 {
 }
 
-bool QQmlTypeLoader::QmldirContent::hasError() const
+bool QQmlTypeLoaderQmldirContent::hasError() const
 {
     return m_parser.hasError();
 }
 
-QList<QQmlError> QQmlTypeLoader::QmldirContent::errors(const QString &uri) const
+QList<QQmlError> QQmlTypeLoaderQmldirContent::errors(const QString &uri) const
 {
     return m_parser.errors(uri);
 }
 
-QString QQmlTypeLoader::QmldirContent::typeNamespace() const
+QString QQmlTypeLoaderQmldirContent::typeNamespace() const
 {
     return m_parser.typeNamespace();
 }
 
-void QQmlTypeLoader::QmldirContent::setContent(const QString &location, const QString &content)
+void QQmlTypeLoaderQmldirContent::setContent(const QString &location, const QString &content)
 {
     m_location = location;
     m_parser.parse(content);
 }
 
-void QQmlTypeLoader::QmldirContent::setError(const QQmlError &error)
+void QQmlTypeLoaderQmldirContent::setError(const QQmlError &error)
 {
     m_parser.setError(error);
 }
 
-QQmlDirComponents QQmlTypeLoader::QmldirContent::components() const
+QQmlDirComponents QQmlTypeLoaderQmldirContent::components() const
 {
     return m_parser.components();
 }
 
-QQmlDirScripts QQmlTypeLoader::QmldirContent::scripts() const
+QQmlDirScripts QQmlTypeLoaderQmldirContent::scripts() const
 {
     return m_parser.scripts();
 }
 
-QQmlDirPlugins QQmlTypeLoader::QmldirContent::plugins() const
+QQmlDirPlugins QQmlTypeLoaderQmldirContent::plugins() const
 {
     return m_parser.plugins();
 }
 
-QString QQmlTypeLoader::QmldirContent::pluginLocation() const
+QString QQmlTypeLoaderQmldirContent::pluginLocation() const
 {
     return m_location;
 }
 
-bool QQmlTypeLoader::QmldirContent::designerSupported() const
+bool QQmlTypeLoaderQmldirContent::designerSupported() const
 {
     return m_parser.designerSupported();
 }
@@ -1861,13 +1861,13 @@ bool QQmlTypeLoader::directoryExists(const QString &path)
 
 
 /*!
-Return a QmldirContent for absoluteFilePath.  The QmldirContent may be cached.
+Return a QQmlTypeLoaderQmldirContent for absoluteFilePath.  The QQmlTypeLoaderQmldirContent may be cached.
 
 \a filePath is a local file path.
 
 It can also be a remote path for a remote directory import, but it will have been cached by now in this case.
 */
-const QQmlTypeLoader::QmldirContent *QQmlTypeLoader::qmldirContent(const QString &filePathIn)
+const QQmlTypeLoaderQmldirContent *QQmlTypeLoader::qmldirContent(const QString &filePathIn)
 {
     QUrl url(filePathIn); //May already contain http scheme
     if (url.scheme() == QLatin1String("http") || url.scheme() == QLatin1String("https"))
@@ -1883,10 +1883,10 @@ const QQmlTypeLoader::QmldirContent *QQmlTypeLoader::qmldirContent(const QString
     else
         filePath = url.path();
 
-    QmldirContent *qmldir;
-    QmldirContent **val = m_importQmlDirCache.value(filePath);
+    QQmlTypeLoaderQmldirContent *qmldir;
+    QQmlTypeLoaderQmldirContent **val = m_importQmlDirCache.value(filePath);
     if (!val) {
-        qmldir = new QmldirContent;
+        qmldir = new QQmlTypeLoaderQmldirContent;
 
 #define ERROR(description) { QQmlError e; e.setDescription(description); qmldir->setError(e); }
 #define NOT_READABLE_ERROR QString(QLatin1String("module \"$$URI$$\" definition \"%1\" not readable"))
@@ -1916,12 +1916,12 @@ const QQmlTypeLoader::QmldirContent *QQmlTypeLoader::qmldirContent(const QString
 
 void QQmlTypeLoader::setQmldirContent(const QString &url, const QString &content)
 {
-    QmldirContent *qmldir;
-    QmldirContent **val = m_importQmlDirCache.value(url);
+    QQmlTypeLoaderQmldirContent *qmldir;
+    QQmlTypeLoaderQmldirContent **val = m_importQmlDirCache.value(url);
     if (val) {
         qmldir = *val;
     } else {
-        qmldir = new QmldirContent;
+        qmldir = new QQmlTypeLoaderQmldirContent;
         m_importQmlDirCache.insert(url, qmldir);
     }
 
@@ -2075,6 +2075,11 @@ bool QQmlTypeData::tryLoadFromDiskCache()
         }
     }
 
+    if (unit->data->flags & QV4::CompiledData::Unit::PendingTypeCompilation) {
+        restoreIR(unit);
+        return true;
+    }
+
     m_compiledData = unit;
 
     for (int i = 0, count = m_compiledData->objectCount(); i < count; ++i)
@@ -2397,6 +2402,15 @@ bool QQmlTypeData::loadFromSource()
     return true;
 }
 
+void QQmlTypeData::restoreIR(QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit)
+{
+    m_document.reset(new QmlIR::Document(isDebugging()));
+    QmlIR::IRLoader loader(unit->data, m_document.data());
+    loader.load();
+    m_document->javaScriptCompilationUnit = unit;
+    continueLoadFromIR();
+}
+
 void QQmlTypeData::continueLoadFromIR()
 {
     m_typeReferences.collectFromObjects(m_document->objects.constBegin(), m_document->objects.constEnd());
@@ -2602,7 +2616,7 @@ QQmlCompileError QQmlTypeData::buildTypeResolutionCaches(
         QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache
         ) const
 {
-    typeNameCache->adopt(new QQmlTypeNameCache);
+    typeNameCache->adopt(new QQmlTypeNameCache(m_importCache));
 
     for (const QString &ns: m_namespaces)
         (*typeNameCache)->add(ns);
@@ -2946,7 +2960,7 @@ void QQmlScriptBlob::done()
         }
     }
 
-    m_scriptData->typeNameCache = new QQmlTypeNameCache();
+    m_scriptData->typeNameCache = new QQmlTypeNameCache(m_importCache);
 
     QSet<QString> ns;
 
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 14141db180..915b1bcc4c 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -218,6 +218,34 @@ private:
 
 class QQmlTypeLoaderThread;
 
+class QQmlTypeLoaderQmldirContent
+{
+private:
+    friend class QQmlTypeLoader;
+    QQmlTypeLoaderQmldirContent();
+
+    void setContent(const QString &location, const QString &content);
+    void setError(const QQmlError &);
+
+public:
+    bool hasError() const;
+    QList<QQmlError> errors(const QString &uri) const;
+
+    QString typeNamespace() const;
+
+    QQmlDirComponents components() const;
+    QQmlDirScripts scripts() const;
+    QQmlDirPlugins plugins() const;
+
+    QString pluginLocation() const;
+
+    bool designerSupported() const;
+
+private:
+    QQmlDirParser m_parser;
+    QString m_location;
+};
+
 class Q_AUTOTEST_EXPORT QQmlTypeLoader
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlTypeLoader)
@@ -256,34 +284,6 @@ public:
         QList<QQmlQmldirData *> m_qmldirs;
     };
 
-    class QmldirContent
-    {
-    private:
-        friend class QQmlTypeLoader;
-        QmldirContent();
-
-        void setContent(const QString &location, const QString &content);
-        void setError(const QQmlError &);
-
-    public:
-        bool hasError() const;
-        QList<QQmlError> errors(const QString &uri) const;
-
-        QString typeNamespace() const;
-
-        QQmlDirComponents components() const;
-        QQmlDirScripts scripts() const;
-        QQmlDirPlugins plugins() const;
-
-        QString pluginLocation() const;
-
-        bool designerSupported() const;
-
-    private:
-        QQmlDirParser m_parser;
-        QString m_location;
-    };
-
     QQmlTypeLoader(QQmlEngine *);
     ~QQmlTypeLoader();
 
@@ -298,7 +298,7 @@ public:
     QString absoluteFilePath(const QString &path);
     bool directoryExists(const QString &path);
 
-    const QmldirContent *qmldirContent(const QString &filePath);
+    const QQmlTypeLoaderQmldirContent *qmldirContent(const QString &filePath);
     void setQmldirContent(const QString &filePath, const QString &content);
 
     void clearCache();
@@ -363,7 +363,7 @@ private:
     typedef QHash<QUrl, QQmlQmldirData *> QmldirCache;
     typedef QStringHash<bool> StringSet;
     typedef QStringHash<StringSet*> ImportDirCache;
-    typedef QStringHash<QmldirContent *> ImportQmlDirCache;
+    typedef QStringHash<QQmlTypeLoaderQmldirContent *> ImportQmlDirCache;
 
     QQmlEngine *m_engine;
     QQmlTypeLoaderThread *m_thread;
@@ -446,6 +446,7 @@ protected:
 private:
     bool tryLoadFromDiskCache();
     bool loadFromSource();
+    void restoreIR(QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit);
     void continueLoadFromIR();
     void resolveTypes();
     QQmlCompileError buildTypeResolutionCaches(
diff --git a/src/qml/qml/qqmltypenamecache.cpp b/src/qml/qml/qqmltypenamecache.cpp
index c2098bc9a1..c8e2b92c29 100644
--- a/src/qml/qml/qqmltypenamecache.cpp
+++ b/src/qml/qml/qqmltypenamecache.cpp
@@ -43,7 +43,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QQmlTypeNameCache::QQmlTypeNameCache()
+QQmlTypeNameCache::QQmlTypeNameCache(const QQmlImports &importCache)
+    : m_imports(importCache)
 {
 }
 
@@ -70,6 +71,7 @@ void QQmlTypeNameCache::add(const QHashedString &name, int importedScriptIndex,
 {
     Import import;
     import.scriptIndex = importedScriptIndex;
+    import.m_qualifier = name;
 
     if (nameSpace.length() != 0) {
         Import *i = m_namedImports.value(nameSpace);
@@ -94,6 +96,18 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name)
     if (!result.isValid())
         result = query(m_anonymousCompositeSingletons, name);
 
+    if (!result.isValid()) {
+        // Look up anonymous types from the imports of this document
+        QQmlImportNamespace *typeNamespace = 0;
+        QList<QQmlError> errors;
+        QQmlType *t = 0;
+        bool typeFound = m_imports.resolveType(name, &t, 0, 0, &typeNamespace, &errors);
+        if (typeFound) {
+            return Result(t);
+        }
+
+    }
+
     return result;
 }
 
@@ -109,6 +123,20 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name,
     if (!result.isValid())
         result = query(i->compositeSingletons, name);
 
+    if (!result.isValid()) {
+        // Look up types from the imports of this document
+        // ### it would be nice if QQmlImports allowed us to resolve a namespace
+        // first, and then types on it.
+        QString qualifiedTypeName = i->m_qualifier + QLatin1Char('.') + name.toString();
+        QQmlImportNamespace *typeNamespace = 0;
+        QList<QQmlError> errors;
+        QQmlType *t = 0;
+        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, 0, 0, &typeNamespace, &errors);
+        if (typeFound) {
+            return Result(t);
+        }
+    }
+
     return result;
 }
 
@@ -122,6 +150,19 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name) cons
     if (!result.isValid())
         result = query(m_anonymousCompositeSingletons, name);
 
+    if (!result.isValid()) {
+        // Look up anonymous types from the imports of this document
+        QString typeName = name->toQStringNoThrow();
+        QQmlImportNamespace *typeNamespace = 0;
+        QList<QQmlError> errors;
+        QQmlType *t = 0;
+        bool typeFound = m_imports.resolveType(typeName, &t, 0, 0, &typeNamespace, &errors);
+        if (typeFound) {
+            return Result(t);
+        }
+
+    }
+
     return result;
 }
 
@@ -143,6 +184,20 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name, cons
     if (!r.isValid())
         r = query(i->compositeSingletons, name);
 
+    if (!r.isValid()) {
+        // Look up types from the imports of this document
+        // ### it would be nice if QQmlImports allowed us to resolve a namespace
+        // first, and then types on it.
+        QString qualifiedTypeName = i->m_qualifier + QLatin1Char('.') + name->toQStringNoThrow();
+        QQmlImportNamespace *typeNamespace = 0;
+        QList<QQmlError> errors;
+        QQmlType *t = 0;
+        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, 0, 0, &typeNamespace, &errors);
+        if (typeFound) {
+            return Result(t);
+        }
+    }
+
     return r;
 }
 
diff --git a/src/qml/qml/qqmltypenamecache_p.h b/src/qml/qml/qqmltypenamecache_p.h
index 8a387bed5f..7cdcbe91b6 100644
--- a/src/qml/qml/qqmltypenamecache_p.h
+++ b/src/qml/qml/qqmltypenamecache_p.h
@@ -56,6 +56,7 @@
 #include "qqmlmetatype_p.h"
 
 #include <private/qhashedstring_p.h>
+#include <private/qqmlimport_p.h>
 
 #include <QtCore/qvector.h>
 
@@ -66,7 +67,7 @@ class QQmlEngine;
 class QQmlTypeNameCache : public QQmlRefCount
 {
 public:
-    QQmlTypeNameCache();
+    QQmlTypeNameCache(const QQmlImports &imports);
     virtual ~QQmlTypeNameCache();
 
     inline bool isEmpty() const;
@@ -105,6 +106,9 @@ private:
 
         // Or, imported compositeSingletons
         QStringHash<QUrl> compositeSingletons;
+
+        // The qualifier of this import
+        QString m_qualifier;
     };
 
     template<typename Key>
@@ -112,6 +116,7 @@ private:
     {
         Import *i = imports.value(key);
         if (i) {
+            Q_ASSERT(!i->m_qualifier.isEmpty());
             if (i->scriptIndex != -1) {
                 return Result(i->scriptIndex);
             } else {
@@ -151,6 +156,7 @@ private:
     QMap<const Import *, QStringHash<Import> > m_namespacedImports;
     QVector<QQmlTypeModuleVersion> m_anonymousImports;
     QStringHash<QUrl> m_anonymousCompositeSingletons;
+    QQmlImports m_imports;
 };
 
 QQmlTypeNameCache::Result::Result()
diff --git a/src/qmldevtools/qmldevtools.pro b/src/qmldevtools/qmldevtools.pro
index acd5c9729b..ec5d73044f 100644
--- a/src/qmldevtools/qmldevtools.pro
+++ b/src/qmldevtools/qmldevtools.pro
@@ -18,5 +18,6 @@ include(../qml/parser/parser.pri)
 include(../qml/jsruntime/jsruntime.pri)
 include(../qml/compiler/compiler.pri)
 include(../qml/memory/memory.pri)
+include(../qml/jit/jit.pri)
 
 load(qt_module)
diff --git a/src/quick/items/qquickitemgrabresult.cpp b/src/quick/items/qquickitemgrabresult.cpp
index 07c2cb607c..12bcd43076 100644
--- a/src/quick/items/qquickitemgrabresult.cpp
+++ b/src/quick/items/qquickitemgrabresult.cpp
@@ -75,7 +75,7 @@ public:
 
     void ensureImageInCache() const {
         if (url.isEmpty() && !image.isNull()) {
-            url.setScheme(QStringLiteral("ItemGrabber"));
+            url.setScheme(QQuickPixmap::itemGrabberScheme);
             url.setPath(QVariant::fromValue(item.data()).toString());
             static uint counter = 0;
             url.setFragment(QString::number(++counter));
diff --git a/src/quick/items/qquicktext.cpp b/src/quick/items/qquicktext.cpp
index 965fb0102f..1720377046 100644
--- a/src/quick/items/qquicktext.cpp
+++ b/src/quick/items/qquicktext.cpp
@@ -74,7 +74,7 @@ Q_DECLARE_LOGGING_CATEGORY(DBG_HOVER_TRACE)
 const QChar QQuickTextPrivate::elideChar = QChar(0x2026);
 
 QQuickTextPrivate::QQuickTextPrivate()
-    : elideLayout(0), textLine(0), lineWidth(0)
+    : fontInfo(font), elideLayout(0), textLine(0), lineWidth(0)
     , color(0xFF000000), linkColor(0xFF0000FF), styleColor(0xFF000000)
     , lineCount(1), multilengthEos(-1)
     , elideMode(QQuickText::ElideNone), hAlign(QQuickText::AlignLeft), vAlign(QQuickText::AlignTop)
@@ -1018,6 +1018,17 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const baseline)
     implicitWidthValid = true;
     implicitHeightValid = true;
 
+    QFontInfo scaledFontInfo(scaledFont);
+    if (fontInfo.weight() != scaledFontInfo.weight()
+            || fontInfo.pixelSize() != scaledFontInfo.pixelSize()
+            || fontInfo.italic() != scaledFontInfo.italic()
+            || !qFuzzyCompare(fontInfo.pointSizeF(), scaledFontInfo.pointSizeF())
+            || fontInfo.family() != scaledFontInfo.family()
+            || fontInfo.styleName() != scaledFontInfo.styleName()) {
+        fontInfo = scaledFontInfo;
+        emit q->fontInfoChanged();
+    }
+
     if (eos != multilengthEos)
         truncated = true;
 
@@ -2974,4 +2985,80 @@ void QQuickText::resetBottomPadding()
     d->setBottomPadding(0, true);
 }
 
+/*!
+    \qmlproperty string QtQuick::Text::fontInfo.family
+    \since 5.9
+
+    The family name of the font that has been resolved for the current font
+    and fontSizeMode.
+*/
+
+/*!
+    \qmlproperty string QtQuick::Text::fontInfo.styleName
+    \since 5.9
+
+    The style name of the font info that has been resolved for the current font
+    and fontSizeMode.
+*/
+
+/*!
+    \qmlproperty bool QtQuick::Text::fontInfo.bold
+    \since 5.9
+
+    The bold state of the font info that has been resolved for the current font
+    and fontSizeMode. This is true if the weight of the resolved font is bold or higher.
+*/
+
+/*!
+    \qmlproperty int QtQuick::Text::fontInfo.weight
+    \since 5.9
+
+    The weight of the font info that has been resolved for the current font
+    and fontSizeMode.
+*/
+
+/*!
+    \qmlproperty bool QtQuick::Text::fontInfo.italic
+    \since 5.9
+
+    The italic state of the font info that has been resolved for the current font
+    and fontSizeMode.
+*/
+
+/*!
+    \qmlproperty real QtQuick::Text::fontInfo.pointSize
+    \since 5.9
+
+    The pointSize of the font info that has been resolved for the current font
+    and fontSizeMode.
+*/
+
+/*!
+    \qmlproperty string QtQuick::Text::fontInfo.pixelSize
+    \since 5.9
+
+    The pixel size of the font info that has been resolved for the current font
+    and fontSizeMode.
+*/
+QJSValue QQuickText::fontInfo() const
+{
+    Q_D(const QQuickText);
+
+    QJSEngine *engine = qjsEngine(this);
+    if (!engine) {
+        qmlWarning(this) << "fontInfo: item has no JS engine";
+        return QJSValue();
+    }
+
+    QJSValue value = engine->newObject();
+    value.setProperty(QStringLiteral("family"), d->fontInfo.family());
+    value.setProperty(QStringLiteral("styleName"), d->fontInfo.styleName());
+    value.setProperty(QStringLiteral("bold"), d->fontInfo.bold());
+    value.setProperty(QStringLiteral("weight"), d->fontInfo.weight());
+    value.setProperty(QStringLiteral("italic"), d->fontInfo.italic());
+    value.setProperty(QStringLiteral("pointSize"), d->fontInfo.pointSizeF());
+    value.setProperty(QStringLiteral("pixelSize"), d->fontInfo.pixelSize());
+    return value;
+}
+
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquicktext_p.h b/src/quick/items/qquicktext_p.h
index c3d3906e7e..b190738cfb 100644
--- a/src/quick/items/qquicktext_p.h
+++ b/src/quick/items/qquicktext_p.h
@@ -98,6 +98,8 @@ class Q_QUICK_PRIVATE_EXPORT QQuickText : public QQuickImplicitSizeItem
     Q_PROPERTY(qreal rightPadding READ rightPadding WRITE setRightPadding RESET resetRightPadding NOTIFY rightPaddingChanged REVISION 6)
     Q_PROPERTY(qreal bottomPadding READ bottomPadding WRITE setBottomPadding RESET resetBottomPadding NOTIFY bottomPaddingChanged REVISION 6)
 
+    Q_PROPERTY(QJSValue fontInfo READ fontInfo NOTIFY fontInfoChanged REVISION 9)
+
 public:
     QQuickText(QQuickItem *parent=0);
     ~QQuickText();
@@ -248,6 +250,8 @@ public:
     void setBottomPadding(qreal padding);
     void resetBottomPadding();
 
+    QJSValue fontInfo() const;
+
 Q_SIGNALS:
     void textChanged(const QString &text);
     void linkActivated(const QString &link);
@@ -280,6 +284,7 @@ Q_SIGNALS:
     Q_REVISION(6) void leftPaddingChanged();
     Q_REVISION(6) void rightPaddingChanged();
     Q_REVISION(6) void bottomPaddingChanged();
+    Q_REVISION(9) void fontInfoChanged();
 
 protected:
     QQuickText(QQuickTextPrivate &dd, QQuickItem *parent = 0);
diff --git a/src/quick/items/qquicktext_p_p.h b/src/quick/items/qquicktext_p_p.h
index 0669bcf115..6456750359 100644
--- a/src/quick/items/qquicktext_p_p.h
+++ b/src/quick/items/qquicktext_p_p.h
@@ -122,6 +122,7 @@ public:
     QString text;
     QFont font;
     QFont sourceFont;
+    QFontInfo fontInfo;
 
     QTextLayout layout;
     QTextLayout *elideLayout;
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 83aff5e07e..6897240fbd 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -454,8 +454,13 @@ void QQuickWindowPrivate::renderSceneGraph(const QSize &size)
             fboId = renderTargetId;
             renderer->setDeviceRect(rect);
             renderer->setViewportRect(rect);
-            renderer->setProjectionMatrixToRect(QRect(QPoint(0, 0), rect.size()));
-            renderer->setDevicePixelRatio(1);
+            if (QQuickRenderControl::renderWindowFor(q)) {
+                renderer->setProjectionMatrixToRect(QRect(QPoint(0, 0), size));
+                renderer->setDevicePixelRatio(devicePixelRatio);
+            } else {
+                renderer->setProjectionMatrixToRect(QRect(QPoint(0, 0), rect.size()));
+                renderer->setDevicePixelRatio(1);
+            }
         } else {
             QRect rect(QPoint(0, 0), devicePixelRatio * size);
             renderer->setDeviceRect(rect);
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
index 322192944b..2c0f8667e8 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
@@ -440,9 +440,7 @@ struct Batch
     mutable uint uploadedThisFrame : 1; // solely for debugging purposes
 
     Buffer vbo;
-#ifdef QSG_SEPARATE_INDEX_BUFFER
     Buffer ibo;
-#endif
 
     QDataBuffer<DrawSet> drawSets;
 };
@@ -744,9 +742,7 @@ private:
     ClipType m_currentClipType;
 
     QDataBuffer<char> m_vertexUploadPool;
-#ifdef QSG_SEPARATE_INDEX_BUFFER
     QDataBuffer<char> m_indexUploadPool;
-#endif
     // For minimal OpenGL core profile support
     QOpenGLVertexArrayObject *m_vao;
 
@@ -766,10 +762,7 @@ Batch *Renderer::newBatch()
         m_batchPool.resize(size - 1);
     } else {
         b = new Batch();
-        memset(&b->vbo, 0, sizeof(Buffer));
-#ifdef QSG_SEPARATE_INDEX_BUFFER
-        memset(&b->ibo, 0, sizeof(Buffer));
-#endif
+        memset(&b->vbo, 0, sizeof(Buffer) * 2); // Clear VBO & IBO
     }
     b->init();
     return b;
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index 6b9db105e7..2f5d5790ee 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -88,6 +88,7 @@ class QSGRectangleNode;
 class QSGImageNode;
 class QSGNinePatchNode;
 class QSGSpriteNode;
+class QSGRenderContext;
 
 Q_DECLARE_LOGGING_CATEGORY(QSG_LOG_TIME_RENDERLOOP)
 Q_DECLARE_LOGGING_CATEGORY(QSG_LOG_TIME_COMPILATION)
@@ -98,6 +99,54 @@ Q_DECLARE_LOGGING_CATEGORY(QSG_LOG_TIME_RENDERER)
 Q_DECLARE_LOGGING_CATEGORY(QSG_LOG_INFO)
 Q_DECLARE_LOGGING_CATEGORY(QSG_LOG_RENDERLOOP)
 
+class Q_QUICK_PRIVATE_EXPORT QSGContext : public QObject
+{
+    Q_OBJECT
+
+public:
+    enum AntialiasingMethod {
+        UndecidedAntialiasing,
+        VertexAntialiasing,
+        MsaaAntialiasing
+    };
+
+    explicit QSGContext(QObject *parent = 0);
+    virtual ~QSGContext();
+
+    virtual void renderContextInitialized(QSGRenderContext *renderContext);
+    virtual void renderContextInvalidated(QSGRenderContext *renderContext);
+    virtual QSGRenderContext *createRenderContext() = 0;
+
+    QSGInternalRectangleNode *createInternalRectangleNode(const QRectF &rect, const QColor &c);
+    virtual QSGInternalRectangleNode *createInternalRectangleNode() = 0;
+    virtual QSGInternalImageNode *createInternalImageNode() = 0;
+    virtual QSGPainterNode *createPainterNode(QQuickPaintedItem *item) = 0;
+    virtual QSGGlyphNode *createGlyphNode(QSGRenderContext *rc, bool preferNativeGlyphNode) = 0;
+    virtual QSGLayer *createLayer(QSGRenderContext *renderContext) = 0;
+    virtual QSGGuiThreadShaderEffectManager *createGuiThreadShaderEffectManager();
+    virtual QSGShaderEffectNode *createShaderEffectNode(QSGRenderContext *renderContext,
+                                                        QSGGuiThreadShaderEffectManager *mgr);
+#if QT_CONFIG(quick_sprite)
+    virtual QSGSpriteNode *createSpriteNode() = 0;
+#endif
+    virtual QAnimationDriver *createAnimationDriver(QObject *parent);
+
+    virtual QSize minimumFBOSize() const;
+    virtual QSurfaceFormat defaultSurfaceFormat() const = 0;
+
+    virtual QSGRendererInterface *rendererInterface(QSGRenderContext *renderContext);
+
+    virtual QSGRectangleNode *createRectangleNode() = 0;
+    virtual QSGImageNode *createImageNode() = 0;
+    virtual QSGNinePatchNode *createNinePatchNode() = 0;
+
+    static QSGContext *createDefaultContext();
+    static QQuickTextureFactory *createTextureFactoryFromImage(const QImage &image);
+    static QSGRenderLoop *createWindowManager();
+
+    static void setBackend(const QString &backend);
+};
+
 class Q_QUICK_PRIVATE_EXPORT QSGRenderContext : public QObject
 {
     Q_OBJECT
@@ -150,55 +199,6 @@ protected:
     QSet<QFontEngine *> m_fontEnginesToClean;
 };
 
-
-class Q_QUICK_PRIVATE_EXPORT QSGContext : public QObject
-{
-    Q_OBJECT
-
-public:
-    enum AntialiasingMethod {
-        UndecidedAntialiasing,
-        VertexAntialiasing,
-        MsaaAntialiasing
-    };
-
-    explicit QSGContext(QObject *parent = 0);
-    virtual ~QSGContext();
-
-    virtual void renderContextInitialized(QSGRenderContext *renderContext);
-    virtual void renderContextInvalidated(QSGRenderContext *renderContext);
-    virtual QSGRenderContext *createRenderContext() = 0;
-
-    QSGInternalRectangleNode *createInternalRectangleNode(const QRectF &rect, const QColor &c);
-    virtual QSGInternalRectangleNode *createInternalRectangleNode() = 0;
-    virtual QSGInternalImageNode *createInternalImageNode() = 0;
-    virtual QSGPainterNode *createPainterNode(QQuickPaintedItem *item) = 0;
-    virtual QSGGlyphNode *createGlyphNode(QSGRenderContext *rc, bool preferNativeGlyphNode) = 0;
-    virtual QSGLayer *createLayer(QSGRenderContext *renderContext) = 0;
-    virtual QSGGuiThreadShaderEffectManager *createGuiThreadShaderEffectManager();
-    virtual QSGShaderEffectNode *createShaderEffectNode(QSGRenderContext *renderContext,
-                                                        QSGGuiThreadShaderEffectManager *mgr);
-#if QT_CONFIG(quick_sprite)
-    virtual QSGSpriteNode *createSpriteNode() = 0;
-#endif
-    virtual QAnimationDriver *createAnimationDriver(QObject *parent);
-
-    virtual QSize minimumFBOSize() const;
-    virtual QSurfaceFormat defaultSurfaceFormat() const = 0;
-
-    virtual QSGRendererInterface *rendererInterface(QSGRenderContext *renderContext);
-
-    virtual QSGRectangleNode *createRectangleNode() = 0;
-    virtual QSGImageNode *createImageNode() = 0;
-    virtual QSGNinePatchNode *createNinePatchNode() = 0;
-
-    static QSGContext *createDefaultContext();
-    static QQuickTextureFactory *createTextureFactoryFromImage(const QImage &image);
-    static QSGRenderLoop *createWindowManager();
-
-    static void setBackend(const QString &backend);
-};
-
 QT_END_NAMESPACE
 
 #endif // QSGCONTEXT_H
diff --git a/src/quick/scenegraph/scenegraph.pri b/src/quick/scenegraph/scenegraph.pri
index edf4aa08c5..38c3b8dd85 100644
--- a/src/quick/scenegraph/scenegraph.pri
+++ b/src/quick/scenegraph/scenegraph.pri
@@ -1,4 +1,4 @@
-# DEFINES += QSG_SEPARATE_INDEX_BUFFER
+DEFINES += QSG_SEPARATE_INDEX_BUFFER
 # DEFINES += QSG_DISTANCEFIELD_CACHE_DEBUG
 
 # Core API
diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index 1c6b2afb54..be6d4d18bd 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -84,6 +84,7 @@
 
 QT_BEGIN_NAMESPACE
 
+const QLatin1String QQuickPixmap::itemGrabberScheme = QLatin1String("itemgrabber");
 
 #ifndef QT_NO_DEBUG
 static const bool qsg_leak_check = !qEnvironmentVariableIsEmpty("QML_LEAK_CHECK");
@@ -1462,8 +1463,15 @@ void QQuickPixmap::load(QQmlEngine *engine, const QUrl &url, const QSize &reques
     QHash<QQuickPixmapKey, QQuickPixmapData *>::Iterator iter = store->m_cache.end();
 
     // If Cache is disabled, the pixmap will always be loaded, even if there is an existing
-    // cached version.
-    if (options & QQuickPixmap::Cache)
+    // cached version. Unless it's an itemgrabber url, since the cache is used to pass
+    // the result between QQuickItemGrabResult and QQuickImage.
+    if (url.scheme() == itemGrabberScheme) {
+        QSize dummy;
+        if (requestSize != dummy)
+            qWarning() << "Ignoring sourceSize request for image url that came from grabToImage. Use the targetSize parameter of the grabToImage() function instead.";
+        const QQuickPixmapKey grabberKey = { &url, &dummy, QQuickImageProviderOptions() };
+        iter = store->m_cache.find(grabberKey);
+    } else if (options & QQuickPixmap::Cache)
         iter = store->m_cache.find(key);
 
     if (iter == store->m_cache.end()) {
diff --git a/src/quick/util/qquickpixmapcache_p.h b/src/quick/util/qquickpixmapcache_p.h
index f7cdfa7d07..a867771755 100644
--- a/src/quick/util/qquickpixmapcache_p.h
+++ b/src/quick/util/qquickpixmapcache_p.h
@@ -177,6 +177,8 @@ public:
     static void purgeCache();
     static bool isCached(const QUrl &url, const QSize &requestSize);
 
+    static const QLatin1String itemGrabberScheme;
+
 private:
     Q_DISABLE_COPY(QQuickPixmap)
     QQuickPixmapData *d;
diff --git a/src/src.pro b/src/src.pro
index 21925c9330..c2a58c3757 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -21,5 +21,3 @@ SUBDIRS += \
     qmldevtools
 
 qtConfig(localserver):!contains(QT_CONFIG, no-qml-debug): SUBDIRS += qmldebug
-
-qmldevtools.CONFIG = host_build
diff --git a/tests/auto/auto.pro b/tests/auto/auto.pro
index f25742fb14..1e80f1bf65 100644
--- a/tests/auto/auto.pro
+++ b/tests/auto/auto.pro
@@ -18,6 +18,4 @@ qtHaveModule(gui):qtConfig(opengl(es1|es2)?) {
 # console applications not supported
 uikit: SUBDIRS -= qmltest
 
-qmldevtools.CONFIG = host_build
-
 installed_cmake.depends = cmake
diff --git a/tests/auto/qml/qml.pro b/tests/auto/qml/qml.pro
index 68a2eace19..04e4b04114 100644
--- a/tests/auto/qml/qml.pro
+++ b/tests/auto/qml/qml.pro
@@ -73,7 +73,7 @@ qtHaveModule(widgets) {
 SUBDIRS += $$PUBLICTESTS \
     qqmlextensionplugin
 SUBDIRS += $$METATYPETESTS
-!uikit:!winrt { # no QProcess on uikit/winrt
+!qtConfig(process) {
     !contains(QT_CONFIG, no-qml-debug): SUBDIRS += debugger
     SUBDIRS += qmllint qmlplugindump
 }
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 89dac33671..1f0248c258 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -333,6 +334,8 @@ private slots:
     void stringify_qtbug_50592();
     void instanceof_data();
     void instanceof();
+    void constkw_data();
+    void constkw();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -8183,6 +8186,60 @@ void tst_qqmlecmascript::instanceof()
     }
 }
 
+void tst_qqmlecmascript::constkw_data()
+{
+    QTest::addColumn<QString>("sourceCode");
+    QTest::addColumn<bool>("exceptionExpected");
+    QTest::addColumn<QVariant>("expectedValue");
+
+    QTest::newRow("simpleconst")
+        << "const v = 5\n"
+           "v\n"
+        << false
+        << QVariant(5);
+    QTest::newRow("twoconst")
+        << "const v = 5, i = 10\n"
+           "v + i\n"
+        << false
+        << QVariant(15);
+    QTest::newRow("constandvar")
+        << "const v = 5\n"
+           "var i = 20\n"
+           "v + i\n"
+        << false
+        << QVariant(25);
+
+    // error cases
+    QTest::newRow("const-no-initializer")
+        << "const v\n"
+        << true
+        << QVariant("SyntaxError: Missing initializer in const declaration");
+    QTest::newRow("const-no-initializer-comma")
+        << "const v = 1, i\n"
+        << true
+        << QVariant("SyntaxError: Missing initializer in const declaration");
+}
+
+void tst_qqmlecmascript::constkw()
+{
+    QFETCH(QString, sourceCode);
+    QFETCH(bool, exceptionExpected);
+    QFETCH(QVariant, expectedValue);
+
+    QJSEngine engine;
+    QJSValue ret = engine.evaluate(sourceCode);
+
+    if (!exceptionExpected) {
+        QVERIFY2(!ret.isError(), qPrintable(ret.toString()));
+        QCOMPARE(ret.toVariant(), expectedValue);
+    } else {
+        QVERIFY2(ret.isError(), qPrintable(ret.toString()));
+        QCOMPARE(ret.toString(), expectedValue.toString());
+    }
+}
+
+
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"
diff --git a/tests/auto/qml/qqmllanguage/data/compositeTypeByName_anon_qmldir.qml b/tests/auto/qml/qqmllanguage/data/compositeTypeByName_anon_qmldir.qml
new file mode 100644
index 0000000000..5ffdc26096
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/compositeTypeByName_anon_qmldir.qml
@@ -0,0 +1,9 @@
+import QtQuick 2.6
+import "simpleimportByName"
+
+Item {
+    Component.onCompleted: {
+        console.warn(SimpleType)
+    }
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/compositeTypeByName_named_qmldir.qml b/tests/auto/qml/qqmllanguage/data/compositeTypeByName_named_qmldir.qml
new file mode 100644
index 0000000000..c446eae84c
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/compositeTypeByName_named_qmldir.qml
@@ -0,0 +1,9 @@
+import QtQuick 2.6
+import "simpleimportByName" as ImportName
+
+Item {
+    Component.onCompleted: {
+        console.warn(ImportName.SimpleType)
+    }
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/quickTypeByName_anon.qml b/tests/auto/qml/qqmllanguage/data/quickTypeByName_anon.qml
new file mode 100644
index 0000000000..abe750db33
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/quickTypeByName_anon.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.6
+
+Item {
+    Component.onCompleted: {
+        console.warn(Item)
+    }
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/quickTypeByName_named.qml b/tests/auto/qml/qqmllanguage/data/quickTypeByName_named.qml
new file mode 100644
index 0000000000..397d4f42f0
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/quickTypeByName_named.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.6 as Quick
+
+Quick.Item {
+    Quick.Component.onCompleted: {
+        console.warn(Quick.Item)
+    }
+}
+
diff --git a/tests/auto/qml/qqmllanguage/data/simpleimportByName/SimpleType.qml b/tests/auto/qml/qqmllanguage/data/simpleimportByName/SimpleType.qml
new file mode 100644
index 0000000000..4772dde8f0
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/simpleimportByName/SimpleType.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.6
+
+MouseArea {
+}
diff --git a/tests/auto/qml/qqmllanguage/data/simpleimportByName/qmldir b/tests/auto/qml/qqmllanguage/data/simpleimportByName/qmldir
new file mode 100644
index 0000000000..80df37d0e6
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/simpleimportByName/qmldir
@@ -0,0 +1 @@
+SimpleType 1.0 SimpleType.qml
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index f586f7d429..c0500afddd 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -257,6 +257,9 @@ private slots:
     void defaultListProperty();
     void namespacedPropertyTypes();
 
+    void qmlTypeCanBeResolvedByName_data();
+    void qmlTypeCanBeResolvedByName();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -4250,6 +4253,32 @@ void tst_qqmllanguage::namespacedPropertyTypes()
     QVERIFY(!o.isNull());
 }
 
+void tst_qqmllanguage::qmlTypeCanBeResolvedByName_data()
+{
+    QTest::addColumn<QUrl>("componentUrl");
+
+    // Built-in C++ types
+    QTest::newRow("C++ - Anonymous") << testFileUrl("quickTypeByName_anon.qml");
+    QTest::newRow("C++ - Named") << testFileUrl("quickTypeByName_named.qml");
+
+    // Composite types with a qmldir
+    QTest::newRow("QML - Anonymous - qmldir") << testFileUrl("compositeTypeByName_anon_qmldir.qml");
+    QTest::newRow("QML - Named - qmldir") << testFileUrl("compositeTypeByName_named_qmldir.qml");
+}
+
+void tst_qqmllanguage::qmlTypeCanBeResolvedByName()
+{
+    QFETCH(QUrl, componentUrl);
+
+    QQmlEngine engine;
+    QQmlComponent component(&engine, componentUrl);
+    VERIFY_ERRORS(0);
+    QTest::ignoreMessage(QtMsgType::QtWarningMsg, "[object Object]"); // a bit crude, but it will do
+
+    QScopedPointer<QObject> o(component.create());
+    QVERIFY(!o.isNull());
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"
diff --git a/tests/auto/qmltest/BLACKLIST b/tests/auto/qmltest/BLACKLIST
index fd796fcdb4..c38347b42a 100644
--- a/tests/auto/qmltest/BLACKLIST
+++ b/tests/auto/qmltest/BLACKLIST
@@ -9,5 +9,3 @@ linux
 linux
 [ListView::test_listInteractiveCurrentIndexEnforce]
 linux
-[mouserelease::test_mouseDrag]
-rhel-7.2
diff --git a/tests/auto/qmltest/events/tst_drag.qml b/tests/auto/qmltest/events/tst_drag.qml
index ffdc94167c..ae77247a41 100644
--- a/tests/auto/qmltest/events/tst_drag.qml
+++ b/tests/auto/qmltest/events/tst_drag.qml
@@ -117,9 +117,9 @@ Rectangle{
         name:"mouserelease"
         when:windowShown
         function test_mouseDrag() {
-            mouseDrag(container, 10, 10, 20, 30);
-            compare(container.x, 20 - util.dragThreshold - 1);
-            compare(container.y, 30 - util.dragThreshold - 1);
+            mouseDrag(container, 10, 10, util.dragThreshold * 2, util.dragThreshold * 3);
+            compare(container.x, util.dragThreshold - 1);
+            compare(container.y, util.dragThreshold * 2 - 1);
         }
 
         function test_doSomethingWhileDragging() {
diff --git a/tests/auto/qmltest/itemgrabber/tst_itemgrabber.qml b/tests/auto/qmltest/itemgrabber/tst_itemgrabber.qml
index 022e98a202..a80814d6de 100644
--- a/tests/auto/qmltest/itemgrabber/tst_itemgrabber.qml
+++ b/tests/auto/qmltest/itemgrabber/tst_itemgrabber.qml
@@ -37,8 +37,9 @@ Item {
     TestCase {
         id: testCase
         name: "item-grabber"
-        when: imageOnDisk.ready && imageOnDiskSmall.ready && imageInCache.ready && imageInCacheSmall.ready
-        function test_endresult() {
+        when: imageOnDisk.ready && imageOnDiskSmall.ready
+
+        function test_endresult_disk() {
             var image = grabImage(root);
 
             // imageOnDisk at (0, 0) - (100x100)
@@ -52,6 +53,40 @@ Item {
             compare(imageOnDiskSmall.height, 50);
             verify(image.pixel(100, 0) === Qt.rgba(1, 0, 0, 1));
             verify(image.pixel(149, 49) === Qt.rgba(0, 0, 1, 1));
+        }
+
+        function test_endresult_cache_data() {
+            return [
+                { cache: true, sourceSize: Qt.size(-1, -1), fillMode: Image.Stretch },
+                { cache: true, sourceSize: Qt.size(-1, -1), fillMode: Image.PreserveAspectFit },
+                { cache: true, sourceSize: Qt.size(-1, -1), fillMode: Image.PreserveAspectCrop },
+                { cache: true, sourceSize: Qt.size(10, 10), fillMode: Image.Stretch },
+                { cache: true, sourceSize: Qt.size(10, 10), fillMode: Image.PreserveAspectFit },
+                { cache: true, sourceSize: Qt.size(10, 10), fillMode: Image.PreserveAspectCrop },
+                { cache: false, sourceSize: Qt.size(-1, -1), fillMode: Image.Stretch },
+                { cache: false, sourceSize: Qt.size(-1, -1), fillMode: Image.PreserveAspectFit },
+                { cache: false, sourceSize: Qt.size(-1, -1), fillMode: Image.PreserveAspectCrop },
+                { cache: false, sourceSize: Qt.size(10, 10), fillMode: Image.Stretch },
+                { cache: false, sourceSize: Qt.size(10, 10), fillMode: Image.PreserveAspectFit },
+                { cache: false, sourceSize: Qt.size(10, 10), fillMode: Image.PreserveAspectCrop },
+            ];
+        }
+
+        function test_endresult_cache(data) {
+            imageInCache.cache = data.cache;
+            imageInCache.sourceSize = data.sourceSize;
+            imageInCache.fillMode = data.fillMode;
+            imageInCacheSmall.cache = data.cache;
+            imageInCacheSmall.sourceSize = data.sourceSize;
+            imageInCacheSmall.fillMode = data.fillMode;
+
+            box.grabToImage(imageInCache.handleGrab);
+            box.grabToImage(imageInCacheSmall.handleGrab, Qt.size(50, 50));
+
+            tryCompare(imageInCache, "ready", true);
+            tryCompare(imageInCacheSmall, "ready", true);
+
+            var image = grabImage(root);
 
             // imageInCache at (0, 100) - 100x100
             compare(imageInCache.width, 100);
@@ -72,8 +107,6 @@ Item {
         onWindowShownChanged: {
             box.grabToImage(imageOnDisk.handleGrab);
             box.grabToImage(imageOnDiskSmall.handleGrab, Qt.size(50, 50));
-            box.grabToImage(imageInCache.handleGrab);
-            box.grabToImage(imageInCacheSmall.handleGrab, Qt.size(50, 50));
         }
 
     }
diff --git a/tests/auto/quick/qquicktext/data/fontInfo.qml b/tests/auto/quick/qquicktext/data/fontInfo.qml
new file mode 100644
index 0000000000..25f924029f
--- /dev/null
+++ b/tests/auto/quick/qquicktext/data/fontInfo.qml
@@ -0,0 +1,24 @@
+import QtQuick 2.9
+
+Item {
+    Text {
+        id: main
+        objectName: "main"
+        width: 500
+        height: 500
+        text: "Meaningless text"
+        font.pixelSize: 1000
+        fontSizeMode: Text.Fit
+    }
+
+    Text {
+        objectName: "copy"
+        text: main.text
+        width: main.width
+        height: main.height
+
+        font.family: main.fontInfo.family
+        font.pixelSize: main.fontInfo.pixelSize
+    }
+}
+
diff --git a/tests/auto/quick/qquicktext/tst_qquicktext.cpp b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
index 034ea4aec8..f741062d42 100644
--- a/tests/auto/quick/qquicktext/tst_qquicktext.cpp
+++ b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
@@ -154,6 +154,8 @@ private slots:
     void hAlignWidthDependsOnImplicitWidth_data();
     void hAlignWidthDependsOnImplicitWidth();
 
+    void fontInfo();
+
 private:
     QStringList standard;
     QStringList richText;
@@ -4253,6 +4255,23 @@ void tst_qquicktext::hAlignWidthDependsOnImplicitWidth()
     QCOMPARE(numberOfNonWhitePixels(0, rectX - 1, image), 0);
 }
 
+void tst_qquicktext::fontInfo()
+{
+    QQmlComponent component(&engine, testFile("fontInfo.qml"));
+
+    QScopedPointer<QObject> object(component.create());
+    QObject *root = object.data();
+
+    QQuickText *main = root->findChild<QQuickText *>("main");
+    QVERIFY(main);
+    QCOMPARE(main->font().pixelSize(), 1000);
+
+    QQuickText *copy = root->findChild<QQuickText *>("copy");
+    QVERIFY(copy);
+    QCOMPARE(copy->font().family(), QFontInfo(QFont()).family());
+    QVERIFY(copy->font().pixelSize() < 1000);
+}
+
 QTEST_MAIN(tst_qquicktext)
 
 #include "tst_qquicktext.moc"
diff --git a/tools/qmlcachegen/qmlcache.prf b/tools/qmlcachegen/qmlcache.prf
new file mode 100644
index 0000000000..fed9f0d2f3
--- /dev/null
+++ b/tools/qmlcachegen/qmlcache.prf
@@ -0,0 +1,12 @@
+qtPrepareTool(QML_CACHEGEN, qmlcachegen)
+
+!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}
+qmlcachegen.name = Generate QML Cache ${QMAKE_FILE_IN}
+qmlcachegen.variable_out = AUX_QML_FILES
+
+QMAKE_EXTRA_COMPILERS += qmlcachegen
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
new file mode 100644
index 0000000000..4b902eda0f
--- /dev/null
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -0,0 +1,309 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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 <QCoreApplication>
+#include <QStringList>
+#include <QCommandLineParser>
+#include <QFile>
+#include <QFileInfo>
+#include <QDateTime>
+
+#include <private/qqmlirbuilder_p.h>
+#include <private/qv4isel_moth_p.h>
+#include <private/qqmljsparser_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);
+} }
+
+QT_END_NAMESPACE
+
+struct Error
+{
+    QString message;
+    void print();
+    Error augment(const QString &contextErrorMessage) const;
+};
+
+void Error::print()
+{
+    fprintf(stderr, "%s\n", qPrintable(message));
+}
+
+Error Error::augment(const QString &contextErrorMessage) const
+{
+    Error augmented;
+    augmented.message = contextErrorMessage + message;
+    return augmented;
+}
+
+QString diagnosticErrorMessage(const QString &fileName, const QQmlJS::DiagnosticMessage &m)
+{
+    QString message;
+    message = fileName + QLatin1Char(':') + QString::number(m.loc.startLine) + QLatin1Char(':');
+    if (m.loc.startColumn > 0)
+        message += QString::number(m.loc.startColumn) + QLatin1Char(':');
+
+    if (m.isError())
+        message += QLatin1String(" error: ");
+    else
+        message += QLatin1String(" warning: ");
+    message += m.message;
+    return message;
+}
+
+static bool compileQmlFile(const QString &inputFileName, QV4::EvalISelFactory *iselFactory, Error *error)
+{
+    QmlIR::Document irDocument(/*debugMode*/false);
+
+    QString sourceCode;
+    {
+        QFile f(inputFileName);
+        if (!f.open(QIODevice::ReadOnly)) {
+            error->message = QLatin1String("Error opening ") + inputFileName + QLatin1Char(':') + f.errorString();
+            return false;
+        }
+        sourceCode = QString::fromUtf8(f.readAll());
+        if (f.error() != QFileDevice::NoError) {
+            error->message = QLatin1String("Error reading from ") + inputFileName + QLatin1Char(':') + f.errorString();
+            return false;
+        }
+        irDocument.jsModule.sourceTimeStamp = QFileInfo(f).lastModified().toMSecsSinceEpoch();
+    }
+
+    {
+        QSet<QString> illegalNames; // ####
+        QmlIR::IRBuilder irBuilder(illegalNames);
+        if (!irBuilder.generateFromQml(sourceCode, inputFileName, &irDocument)) {
+            for (const QQmlJS::DiagnosticMessage &parseError: qAsConst(irBuilder.errors)) {
+                if (!error->message.isEmpty())
+                    error->message += QLatin1Char('\n');
+                error->message += diagnosticErrorMessage(inputFileName, parseError);
+            }
+            return false;
+        }
+    }
+
+    {
+        QmlIR::JSCodeGen v4CodeGen(inputFileName, 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;
+            QList<QmlIR::CompiledFunctionOrExpression> functionsToCompile;
+            for (QmlIR::CompiledFunctionOrExpression *foe = object->functionsAndExpressions->first; foe; foe = foe->next) {
+                foe->disableAcceleratedLookups = true;
+                functionsToCompile << *foe;
+            }
+            const QVector<int> runtimeFunctionIndices = v4CodeGen.generateJSCodeForFunctionsAndBindings(functionsToCompile);
+            QList<QQmlJS::DiagnosticMessage> jsErrors = v4CodeGen.errors();
+            if (!jsErrors.isEmpty()) {
+                for (const QQmlJS::DiagnosticMessage &e: qAsConst(jsErrors)) {
+                    if (!error->message.isEmpty())
+                        error->message += QLatin1Char('\n');
+                    error->message += diagnosticErrorMessage(inputFileName, e);
+                }
+                return false;
+            }
+
+            QQmlJS::MemoryPool *pool = irDocument.jsParserEngine.pool();
+            object->runtimeFunctionIndices.allocate(pool, runtimeFunctionIndices);
+        }
+
+        QmlIR::QmlUnitGenerator generator;
+
+        // ### translation binding simplification
+
+        QScopedPointer<QV4::EvalInstructionSelection> isel(iselFactory->create(/*engine*/nullptr, /*executable allocator*/nullptr, &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);
+        unit->flags |= QV4::CompiledData::Unit::StaticData;
+        unit->flags |= QV4::CompiledData::Unit::PendingTypeCompilation;
+        irDocument.javaScriptCompilationUnit->data = unit;
+
+        if (!irDocument.javaScriptCompilationUnit->saveToDisk(inputFileName, &error->message))
+            return false;
+
+        free(unit);
+    }
+    return true;
+}
+
+static bool compileJSFile(const QString &inputFileName, QV4::EvalISelFactory *iselFactory, Error *error)
+{
+    QmlIR::Document irDocument(/*debugMode*/false);
+
+    QString sourceCode;
+    {
+        QFile f(inputFileName);
+        if (!f.open(QIODevice::ReadOnly)) {
+            error->message = QLatin1String("Error opening ") + inputFileName + QLatin1Char(':') + f.errorString();
+            return false;
+        }
+        sourceCode = QString::fromUtf8(f.readAll());
+        if (f.error() != QFileDevice::NoError) {
+            error->message = QLatin1String("Error reading from ") + inputFileName + QLatin1Char(':') + f.errorString();
+            return false;
+        }
+        irDocument.jsModule.sourceTimeStamp = QFileInfo(f).lastModified().toMSecsSinceEpoch();
+    }
+
+    QQmlJS::Engine *engine = &irDocument.jsParserEngine;
+    QmlIR::ScriptDirectivesCollector directivesCollector(engine, &irDocument.jsGenerator);
+    QQmlJS::Directives *oldDirs = engine->directives();
+    engine->setDirectives(&directivesCollector);
+
+    QQmlJS::AST::Program *program = nullptr;
+
+    {
+        QQmlJS::Lexer lexer(engine);
+         lexer.setCode(sourceCode, /*line*/1, /*parseAsBinding*/false);
+         QQmlJS::Parser parser(engine);
+
+         bool parsed = parser.parseProgram();
+
+         for (const QQmlJS::DiagnosticMessage &parseError: parser.diagnosticMessages()) {
+             if (!error->message.isEmpty())
+                 error->message += QLatin1Char('\n');
+             error->message += diagnosticErrorMessage(inputFileName, parseError);
+         }
+
+         if (!parsed) {
+             engine->setDirectives(oldDirs);
+             return false;
+         }
+
+         program = QQmlJS::AST::cast<QQmlJS::AST::Program*>(parser.rootNode());
+         if (!program) {
+             lexer.setCode(QStringLiteral("undefined;"), 1, false);
+             parsed = parser.parseProgram();
+             Q_ASSERT(parsed);
+             program = QQmlJS::AST::cast<QQmlJS::AST::Program*>(parser.rootNode());
+             Q_ASSERT(program);
+         }
+    }
+
+    {
+        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);
+        QList<QQmlJS::DiagnosticMessage> jsErrors = v4CodeGen.errors();
+        if (!jsErrors.isEmpty()) {
+            for (const QQmlJS::DiagnosticMessage &e: qAsConst(jsErrors)) {
+                if (!error->message.isEmpty())
+                    error->message += QLatin1Char('\n');
+                error->message += diagnosticErrorMessage(inputFileName, e);
+            }
+            engine->setDirectives(oldDirs);
+            return false;
+        }
+
+        QmlIR::QmlUnitGenerator generator;
+
+        // ### translation binding simplification
+
+        QScopedPointer<QV4::EvalInstructionSelection> isel(iselFactory->create(/*engine*/nullptr, /*executable allocator*/nullptr, &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);
+        unit->flags |= QV4::CompiledData::Unit::StaticData;
+        irDocument.javaScriptCompilationUnit->data = unit;
+
+        if (!irDocument.javaScriptCompilationUnit->saveToDisk(inputFileName, &error->message)) {
+            engine->setDirectives(oldDirs);
+            return false;
+        }
+
+        free(unit);
+    }
+    engine->setDirectives(oldDirs);
+    return true;
+}
+
+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);
+
+    QCoreApplication app(argc, argv);
+    QCoreApplication::setApplicationName(QStringLiteral("qmlcachegen"));
+    QCoreApplication::setApplicationVersion(QLatin1String(QT_VERSION_STR));
+
+    QCommandLineParser parser;
+    parser.addHelpOption();
+    parser.addVersionOption();
+
+    QCommandLineOption targetArchitectureOption(QStringLiteral("target-architecture"), QCoreApplication::translate("main", "Target architecture"), QCoreApplication::translate("main", "architecture"));
+    parser.addOption(targetArchitectureOption);
+
+    parser.addPositionalArgument(QStringLiteral("[qml file]"),
+            QStringLiteral("QML source file to generate cache for."));
+
+    parser.process(app);
+
+    const QStringList sources = parser.positionalArguments();
+    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 (!isel)
+        isel.reset(new QV4::Moth::ISelFactory);
+
+    Error error;
+
+    if (inputFile.endsWith(QLatin1String(".qml"))) {
+        if (!compileQmlFile(inputFile, isel.data(), &error)) {
+            error.augment(QLatin1String("Error compiling qml file: ")).print();
+            return EXIT_FAILURE;
+        }
+    } else if (inputFile.endsWith(QLatin1String(".js"))) {
+        if (!compileJSFile(inputFile, isel.data(), &error)) {
+            error.augment(QLatin1String("Error compiling qml file: ")).print();
+            return EXIT_FAILURE;
+        }
+    } else {
+        fprintf(stderr, "Ignoring %s input file as it is not QML source code - maybe remove from QML_FILES?\n", qPrintable(inputFile));    }
+
+
+    return EXIT_SUCCESS;
+}
diff --git a/tools/qmlcachegen/qmlcachegen.pro b/tools/qmlcachegen/qmlcachegen.pro
new file mode 100644
index 0000000000..81783d0396
--- /dev/null
+++ b/tools/qmlcachegen/qmlcachegen.pro
@@ -0,0 +1,24 @@
+option(host_build)
+
+QT = qmldevtools-private
+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
+
+load(qt_tool)
diff --git a/tools/qmljs/qmljs.cpp b/tools/qmljs/qmljs.cpp
index 54e1b6cea8..4d0f9d278f 100644
--- a/tools/qmljs/qmljs.cpp
+++ b/tools/qmljs/qmljs.cpp
@@ -141,7 +141,7 @@ int main(int argc, char *argv[])
 #endif
 #ifdef V4_ENABLE_JIT
         } else {
-            iSelFactory = new QV4::JIT::ISelFactory;
+            iSelFactory = new QV4::JIT::ISelFactory<>;
 #endif // V4_ENABLE_JIT
         }
 
diff --git a/tools/tools.pro b/tools/tools.pro
index 3952ec4b01..f3988a909a 100644
--- a/tools/tools.pro
+++ b/tools/tools.pro
@@ -4,9 +4,6 @@ SUBDIRS += \
     qmlmin \
     qmlimportscanner
 
-qmlmin.CONFIG = host_build
-qmlimportscanner.CONFIG = host_build
-
 !android|android_app {
     SUBDIRS += \
         qml \