Decode instructions into registers

Don't use the old instruction structures in the VME anymore,
instead directly decode into scoped registers.

Change-Id: Ie03ebad98050ebfd9eb9cc7e9273e5db92884a89
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 38 insertions, 6 deletions

diff --git a/src/qml/compiler/qv4bytecodegenerator.cpp b/src/qml/compiler/qv4bytecodegenerator.cpp
index 3c28f6a719..1d4e91bdf6 100644
--- a/src/qml/compiler/qv4bytecodegenerator.cpp
+++ b/src/qml/compiler/qv4bytecodegenerator.cpp
@@ -97,7 +97,7 @@ void BytecodeGenerator::finalize(Compiler::Context *context)
         int offset = instructionOffsets.at(j.instructionIndex) + j.offset;
 //        qDebug() << "offset data is at" << offset;
         char *c = code.data() + offset;
-        int linkedInstructionOffset = instructionOffsets.at(linkedInstruction) - offset;
+        int linkedInstructionOffset = instructionOffsets.at(linkedInstruction) - instructionOffsets.at(j.instructionIndex + 1);
 //        qDebug() << "linked instruction" << linkedInstruction << "at " << instructionOffsets.at(linkedInstruction);
         memcpy(c, &linkedInstructionOffset, sizeof(int));
     }
diff --git a/src/qml/compiler/qv4bytecodegenerator_p.h b/src/qml/compiler/qv4bytecodegenerator_p.h
index a0255b2059..594c97790b 100644
--- a/src/qml/compiler/qv4bytecodegenerator_p.h
+++ b/src/qml/compiler/qv4bytecodegenerator_p.h
@@ -149,7 +149,7 @@ public:
     void addInstruction(const InstrData<InstrT> &data)
     {
         Instr genericInstr;
-        genericInstr.Common.instructionType = static_cast<Instr::Type>(InstrT);
+        genericInstr.Common.instructionType = InstrT;
         InstrMeta<InstrT>::setDataNoCommon(genericInstr, data);
         addInstructionHelper(InstrMeta<InstrT>::Size, genericInstr);
     }
@@ -229,7 +229,7 @@ public:
     Jump addJumpInstruction(const InstrData<InstrT> &data)
     {
         Instr genericInstr;
-        genericInstr.Common.instructionType = static_cast<Instr::Type>(InstrT);
+        genericInstr.Common.instructionType = InstrT;
         InstrMeta<InstrT>::setDataNoCommon(genericInstr, data);
         return Jump(this, addInstructionHelper(InstrMeta<InstrT>::Size, genericInstr), offsetof(InstrData<InstrT>, offset));
     }
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index ec4e99c4bf..ba52fc5f9a 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -86,7 +86,7 @@ static QString toString(QV4::ReturnedValue v)
 template<typename T>
 size_t absoluteInstructionOffset(const char *codeStart, const T &instr)
 {
-    return reinterpret_cast<const char *>(&instr) - codeStart + offsetof(T, offset) + instr.offset;
+    return reinterpret_cast<const char *>(&instr) - codeStart + sizeof(T) + instr.offset;
 }
 
 #define MOTH_BEGIN_INSTR(I) \
@@ -126,7 +126,7 @@ void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int star
             lastLine = line;
         else
             line = -1;
-        switch (genericInstr->Common.instructionType) {
+        switch (Instr::Type(genericInstr->Common.instructionType)) {
 
         MOTH_BEGIN_INSTR(LoadReg)
             d << StackSlot::createRegister(instr.reg).dump(nFormals);
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index 529584f1dd..6af80689a6 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -297,7 +297,7 @@ QT_BEGIN_NAMESPACE
 
 #define MOTH_INSTR_ALIGN_MASK (Q_ALIGNOF(QV4::Moth::Instr) - 1)
 
-#define MOTH_INSTR_HEADER union { Instr::Type instructionType; quint64 _dummy; };
+#define MOTH_INSTR_HEADER int instructionType;
 
 #define MOTH_INSTR_ENUM(I)  I,
 #define MOTH_INSTR_SIZE(I) ((sizeof(QV4::Moth::Instr::instr_##I) + MOTH_INSTR_ALIGN_MASK) & ~MOTH_INSTR_ALIGN_MASK)
@@ -340,6 +340,38 @@ QT_BEGIN_NAMESPACE
     instr_##name name;
 
 
+#define MOTH_DECODE_ARG(arg, type, offset) \
+    arg = reinterpret_cast<const type *>(code)[offset]
+#define MOTH_ADJUST_CODE(type, nargs) \
+    code += nargs*sizeof(type)
+
+#define MOTH_DECODE_INSTRUCTION(name, nargs, ...) \
+        MOTH_DEFINE_ARGS(nargs, __VA_ARGS__) \
+    op_int_##name: \
+        MOTH_DECODE_ARGS(name, int, nargs, __VA_ARGS__) \
+        MOTH_ADJUST_CODE(int, nargs); \
+
+#define MOTH_DECODE_ARGS(name, type, nargs, ...) \
+    MOTH_DECODE_ARGS##nargs(name, type, __VA_ARGS__)
+
+#define MOTH_DECODE_ARGS0(name, type, dummy)
+#define MOTH_DECODE_ARGS1(name, type, arg) \
+        MOTH_DECODE_ARG(arg, type, 0);
+#define MOTH_DECODE_ARGS2(name, type, arg1, arg2) \
+        MOTH_DECODE_ARGS1(name, type, arg1); \
+        MOTH_DECODE_ARG(arg2, type, 1);
+#define MOTH_DECODE_ARGS3(name, type, arg1, arg2, arg3) \
+        MOTH_DECODE_ARGS2(name, type, arg1, arg2); \
+        MOTH_DECODE_ARG(arg3, type, 2);
+#define MOTH_DECODE_ARGS4(name, type, arg1, arg2, arg3, arg4) \
+        MOTH_DECODE_ARGS3(name, type, arg1, arg2, arg3); \
+        MOTH_DECODE_ARG(arg4, type, 3);
+
+#define MOTH_DISPATCH() \
+    int instr = *reinterpret_cast<const int *>(code); \
+    code += 4; \
+    goto *jumpTable[instr];
+
 namespace QV4 {
 namespace Moth {