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JavaScriptCore-7601.1.46.3.tar.gz
[apple/javascriptcore.git] / jit / JITOpcodes32_64.cpp
index ccc0900326f1fa353ce4c5b2e5ddeca523d902da..8764cc2ccaa1fc00e5b5500a4ff025b4f44b534c 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2009, 2012, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
  *
  * Redistribution and use in source and binary forms, with or without
  */
 
 #include "config.h"
-#include "JIT.h"
 
-#if ENABLE(JIT) && USE(JSVALUE32_64)
+#if ENABLE(JIT)
+#if USE(JSVALUE32_64)
+#include "JIT.h"
 
-#include "JITInlineMethods.h"
-#include "JITStubCall.h"
+#include "CCallHelpers.h"
+#include "Debugger.h"
+#include "Exception.h"
+#include "JITInlines.h"
 #include "JSArray.h"
 #include "JSCell.h"
+#include "JSEnvironmentRecord.h"
 #include "JSFunction.h"
-#include "JSPropertyNameIterator.h"
+#include "JSNameScope.h"
+#include "JSPropertyNameEnumerator.h"
 #include "LinkBuffer.h"
+#include "MaxFrameExtentForSlowPathCall.h"
+#include "RepatchBuffer.h"
+#include "SlowPathCall.h"
+#include "TypeProfilerLog.h"
+#include "VirtualRegister.h"
 
 namespace JSC {
 
-void JIT::privateCompileCTIMachineTrampolines(RefPtr<ExecutablePool>* executablePool, JSGlobalData* globalData, TrampolineStructure *trampolines)
+JIT::CodeRef JIT::privateCompileCTINativeCall(VM* vm, NativeFunction func)
 {
-#if ENABLE(JIT_OPTIMIZE_MOD)
-    Label softModBegin = align();
-    softModulo();
-#endif
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    // (1) This function provides fast property access for string length
-    Label stringLengthBegin = align();
-
-    // regT0 holds payload, regT1 holds tag
-
-    Jump string_failureCases1 = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
-    Jump string_failureCases2 = branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr));
-
-    // Checks out okay! - get the length from the Ustring.
-    load32(Address(regT0, OBJECT_OFFSETOF(JSString, m_length)), regT2);
-
-    Jump string_failureCases3 = branch32(Above, regT2, Imm32(INT_MAX));
-    move(regT2, regT0);
-    move(Imm32(JSValue::Int32Tag), regT1);
-
-    ret();
-#endif
-
-    // (2) Trampolines for the slow cases of op_call / op_call_eval / op_construct.
-
-#if ENABLE(JIT_OPTIMIZE_CALL)
-    // VirtualCallLink Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    Label virtualCallLinkBegin = align();
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-
-    Jump isNativeFunc2 = branch32(Equal, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), Imm32(0));
-
-    Jump hasCodeBlock2 = branch32(GreaterThan, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), Imm32(0));
-    preserveReturnAddressAfterCall(regT3);
-    restoreArgumentReference();
-    Call callJSFunction2 = call();
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    emitGetJITStubArg(2, regT1); // argCount
-    restoreReturnAddressBeforeReturn(regT3);
-    hasCodeBlock2.link(this);
-
-    // Check argCount matches callee arity.
-    Jump arityCheckOkay2 = branch32(Equal, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), regT1);
-    preserveReturnAddressAfterCall(regT3);
-    emitPutJITStubArg(regT3, 1); // return address
-    restoreArgumentReference();
-    Call callArityCheck2 = call();
-    move(regT1, callFrameRegister);
-    emitGetJITStubArg(2, regT1); // argCount
-    restoreReturnAddressBeforeReturn(regT3);
-    arityCheckOkay2.link(this);
-
-    isNativeFunc2.link(this);
-
-    compileOpCallInitializeCallFrame();
-
-    preserveReturnAddressAfterCall(regT3);
-    emitPutJITStubArg(regT3, 1); // return address
-    restoreArgumentReference();
-    Call callLazyLinkCall = call();
-    restoreReturnAddressBeforeReturn(regT3);
-    jump(regT0);
-#endif // ENABLE(JIT_OPTIMIZE_CALL)
-
-    // VirtualCall Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    Label virtualCallBegin = align();
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-
-    Jump isNativeFunc3 = branch32(Equal, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), Imm32(0));
-
-    Jump hasCodeBlock3 = branch32(GreaterThan, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), Imm32(0));
-    preserveReturnAddressAfterCall(regT3);
-    restoreArgumentReference();
-    Call callJSFunction1 = call();
-    emitGetJITStubArg(2, regT1); // argCount
-    restoreReturnAddressBeforeReturn(regT3);
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    hasCodeBlock3.link(this);
-
-    // Check argCount matches callee arity.
-    Jump arityCheckOkay3 = branch32(Equal, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParameters)), regT1);
-    preserveReturnAddressAfterCall(regT3);
-    emitPutJITStubArg(regT3, 1); // return address
-    restoreArgumentReference();
-    Call callArityCheck1 = call();
-    move(regT1, callFrameRegister);
-    emitGetJITStubArg(2, regT1); // argCount
-    restoreReturnAddressBeforeReturn(regT3);
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    arityCheckOkay3.link(this);
-
-    isNativeFunc3.link(this);
+    Call nativeCall;
 
-    compileOpCallInitializeCallFrame();
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_jitCode)), regT0);
-    jump(regT0);
-
-#if CPU(X86) || CPU(ARM_TRADITIONAL)
-    Label nativeCallThunk = align();
-    preserveReturnAddressAfterCall(regT0);
-    emitPutToCallFrameHeader(regT0, RegisterFile::ReturnPC); // Push return address
-
-    // Load caller frame's scope chain into this callframe so that whatever we call can
-    // get to its global data.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT1);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT1);
-    emitPutToCallFrameHeader(regT1, RegisterFile::ScopeChain);
+    emitFunctionPrologue();
+    emitPutImmediateToCallFrameHeader(0, JSStack::CodeBlock);
+    storePtr(callFrameRegister, &m_vm->topCallFrame);
 
 #if CPU(X86)
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
-
-    /* We have two structs that we use to describe the stackframe we set up for our
-     * call to native code.  NativeCallFrameStructure describes the how we set up the stack
-     * in advance of the call.  NativeFunctionCalleeSignature describes the callframe
-     * as the native code expects it.  We do this as we are using the fastcall calling
-     * convention which results in the callee popping its arguments off the stack, but
-     * not the rest of the callframe so we need a nice way to ensure we increment the
-     * stack pointer by the right amount after the call.
-     */
-
-#if COMPILER(MSVC) || OS(LINUX)
-#if COMPILER(MSVC)
-#pragma pack(push)
-#pragma pack(4)
-#endif // COMPILER(MSVC)
-    struct NativeCallFrameStructure {
-        //  CallFrame* callFrame; // passed in EDX
-        JSObject* callee;
-        JSValue thisValue;
-        ArgList* argPointer;
-        ArgList args;
-        JSValue result;
-    };
-    struct NativeFunctionCalleeSignature {
-        JSObject* callee;
-        JSValue thisValue;
-        ArgList* argPointer;
-    };
-#if COMPILER(MSVC)
-#pragma pack(pop)
-#endif // COMPILER(MSVC)
-#else
-    struct NativeCallFrameStructure {
-        //  CallFrame* callFrame; // passed in ECX
-        //  JSObject* callee; // passed in EDX
-        JSValue thisValue;
-        ArgList* argPointer;
-        ArgList args;
-    };
-    struct NativeFunctionCalleeSignature {
-        JSValue thisValue;
-        ArgList* argPointer;
-    };
-#endif
-
-    const int NativeCallFrameSize = (sizeof(NativeCallFrameStructure) + 15) & ~15;
-    // Allocate system stack frame
-    subPtr(Imm32(NativeCallFrameSize), stackPointerRegister);
-
-    // Set up arguments
-    subPtr(Imm32(1), regT0); // Don't include 'this' in argcount
-
-    // push argcount
-    storePtr(regT0, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, args) + OBJECT_OFFSETOF(ArgList, m_argCount)));
-
-    // Calculate the start of the callframe header, and store in regT1
-    addPtr(Imm32(-RegisterFile::CallFrameHeaderSize * (int)sizeof(Register)), callFrameRegister, regT1);
-
-    // Calculate start of arguments as callframe header - sizeof(Register) * argcount (regT0)
-    mul32(Imm32(sizeof(Register)), regT0, regT0);
-    subPtr(regT0, regT1);
-    storePtr(regT1, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, args) + OBJECT_OFFSETOF(ArgList, m_args)));
+    // Calling convention:      f(ecx, edx, ...);
+    // Host function signature: f(ExecState*);
+    move(callFrameRegister, X86Registers::ecx);
 
-    // ArgList is passed by reference so is stackPointerRegister + 4 * sizeof(Register)
-    addPtr(Imm32(OBJECT_OFFSETOF(NativeCallFrameStructure, args)), stackPointerRegister, regT0);
-    storePtr(regT0, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, argPointer)));
+    subPtr(TrustedImm32(8), stackPointerRegister); // Align stack for call.
+    storePtr(X86Registers::ecx, Address(stackPointerRegister));
 
-    // regT1 currently points to the first argument, regT1 - sizeof(Register) points to 'this'
-    loadPtr(Address(regT1, -(int)sizeof(Register) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
-    loadPtr(Address(regT1, -(int)sizeof(Register) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT3);
-    storePtr(regT2, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, thisValue) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)));
-    storePtr(regT3, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, thisValue) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)));
+    // call the function
+    nativeCall = call();
 
-#if COMPILER(MSVC) || OS(LINUX)
-    // ArgList is passed by reference so is stackPointerRegister + 4 * sizeof(Register)
-    addPtr(Imm32(OBJECT_OFFSETOF(NativeCallFrameStructure, result)), stackPointerRegister, X86Registers::ecx);
+    addPtr(TrustedImm32(8), stackPointerRegister);
 
-    // Plant callee
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, X86Registers::eax);
-    storePtr(X86Registers::eax, Address(stackPointerRegister, OBJECT_OFFSETOF(NativeCallFrameStructure, callee)));
-
-    // Plant callframe
-    move(callFrameRegister, X86Registers::edx);
-
-    call(Address(X86Registers::eax, OBJECT_OFFSETOF(JSFunction, m_data)));
-
-    // JSValue is a non-POD type, so eax points to it
-    emitLoad(0, regT1, regT0, X86Registers::eax);
-#else
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, X86Registers::edx); // callee
-    move(callFrameRegister, X86Registers::ecx); // callFrame
-    call(Address(X86Registers::edx, OBJECT_OFFSETOF(JSFunction, m_data)));
+#elif CPU(ARM) || CPU(SH4) || CPU(MIPS)
+#if CPU(MIPS)
+    // Allocate stack space for (unused) 16 bytes (8-byte aligned) for 4 arguments.
+    subPtr(TrustedImm32(16), stackPointerRegister);
 #endif
 
-    // We've put a few temporaries on the stack in addition to the actual arguments
-    // so pull them off now
-    addPtr(Imm32(NativeCallFrameSize - sizeof(NativeFunctionCalleeSignature)), stackPointerRegister);
-
-#elif CPU(ARM_TRADITIONAL)
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
-
-    // Allocate stack space for our arglist
-    COMPILE_ASSERT((sizeof(ArgList) & 0x7) == 0 && sizeof(JSValue) == 8 && sizeof(Register) == 8, ArgList_should_by_8byte_aligned);
-    subPtr(Imm32(sizeof(ArgList)), stackPointerRegister);
-
-    // Set up arguments
-    subPtr(Imm32(1), regT0); // Don't include 'this' in argcount
-
-    // Push argcount
-    storePtr(regT0, Address(stackPointerRegister, OBJECT_OFFSETOF(ArgList, m_argCount)));
-
-    // Calculate the start of the callframe header, and store in regT1
-    move(callFrameRegister, regT1);
-    sub32(Imm32(RegisterFile::CallFrameHeaderSize * (int32_t)sizeof(Register)), regT1);
-
-    // Calculate start of arguments as callframe header - sizeof(Register) * argcount (regT1)
-    mul32(Imm32(sizeof(Register)), regT0, regT0);
-    subPtr(regT0, regT1);
-
-    // push pointer to arguments
-    storePtr(regT1, Address(stackPointerRegister, OBJECT_OFFSETOF(ArgList, m_args)));
+    // Calling convention is f(argumentGPR0, argumentGPR1, ...).
+    // Host function signature is f(ExecState*).
+    move(callFrameRegister, argumentGPR0);
 
-    // Argument passing method:
-    // r0 - points to return value
-    // r1 - callFrame
-    // r2 - callee
-    // stack: this(JSValue) and a pointer to ArgList
+    emitGetFromCallFrameHeaderPtr(JSStack::Callee, argumentGPR1);
+    loadPtr(Address(argumentGPR1, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
 
-#if OS(WINCE)
-    // Setup arg4:
-    push(stackPointerRegister);
-
-    // Setup arg3:
-    // regT1 currently points to the first argument, regT1-sizeof(Register) points to 'this'
-    load32(Address(regT1, -(int32_t)sizeof(void*) * 2), ARMRegisters::r3);
-    push(ARMRegisters::r3);
-    load32(Address(regT1, -(int32_t)sizeof(void*)), regT3);
-    storePtr(regT3, Address(stackPointerRegister));
-
-    // Setup arg2:
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT2);
-
-    // Setup arg1:
-    move(callFrameRegister, regT1);
-
-    // Setup arg0:
-    move(stackPointerRegister, regT0);
-
-    call(Address(regT2, OBJECT_OFFSETOF(JSFunction, m_data)));
-
-    load32(Address(stackPointerRegister, 0), regT0);
-    load32(Address(stackPointerRegister, 4), regT1);
-
-    addPtr(Imm32(sizeof(ArgList) + 8), stackPointerRegister);
-#else // OS(WINCE)
-    move(stackPointerRegister, regT3);
-    subPtr(Imm32(8), stackPointerRegister);
-    move(stackPointerRegister, regT0);
-    subPtr(Imm32(8 + 4 + 4 /* padding */), stackPointerRegister);
-
-    // Setup arg4:
-    storePtr(regT3, Address(stackPointerRegister, 8));
-
-    // Setup arg3:
-    // regT1 currently points to the first argument, regT1-sizeof(Register) points to 'this'
-    load32(Address(regT1, -(int32_t)sizeof(void*) * 2), regT3);
-    storePtr(regT3, Address(stackPointerRegister, 0));
-    load32(Address(regT1, -(int32_t)sizeof(void*)), regT3);
-    storePtr(regT3, Address(stackPointerRegister, 4));
-
-    // Setup arg2:
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT2);
-
-    // Setup arg1:
-    move(callFrameRegister, regT1);
-
-    call(Address(regT2, OBJECT_OFFSETOF(JSFunction, m_data)));
-
-    // Load return value
-    load32(Address(stackPointerRegister, 16), regT0);
-    load32(Address(stackPointerRegister, 20), regT1);
-
-    addPtr(Imm32(sizeof(ArgList) + 16 + 8), stackPointerRegister);
-#endif // OS(WINCE)
+    // call the function
+    nativeCall = call();
 
+#if CPU(MIPS)
+    // Restore stack space
+    addPtr(TrustedImm32(16), stackPointerRegister);
 #endif
 
-    // Check for an exception
-    move(ImmPtr(&globalData->exception), regT2);
-    Jump sawException = branch32(NotEqual, tagFor(0, regT2), Imm32(JSValue::EmptyValueTag));
-
-    // Grab the return address.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT3);
+    restoreReturnAddressBeforeReturn(regT3);
+#else
+#error "JIT not supported on this platform."
+    abortWithReason(JITNotSupported);
+#endif // CPU(X86)
 
-    // Restore our caller's "r".
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
+    // Check for an exception
+    Jump sawException = branch32(NotEqual, AbsoluteAddress(vm->addressOfException()), TrustedImm32(0));
 
+    emitFunctionEpilogue();
     // Return.
-    restoreReturnAddressBeforeReturn(regT3);
     ret();
 
     // Handle an exception
     sawException.link(this);
-    // Grab the return address.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
-    move(ImmPtr(&globalData->exceptionLocation), regT2);
-    storePtr(regT1, regT2);
-    move(ImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()), regT2);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
-    poke(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
-    restoreReturnAddressBeforeReturn(regT2);
-    ret();
 
-#elif ENABLE(JIT_OPTIMIZE_NATIVE_CALL)
-#error "JIT_OPTIMIZE_NATIVE_CALL not yet supported on this platform."
+    storePtr(callFrameRegister, &m_vm->topCallFrame);
+
+#if CPU(X86)
+    addPtr(TrustedImm32(-4), stackPointerRegister);
+    loadPtr(Address(callFrameRegister), X86Registers::ecx);
+    push(X86Registers::ecx);
 #else
-    UNUSED_PARAM(globalData);
-    breakpoint();
+    loadPtr(Address(callFrameRegister), argumentGPR0);
 #endif
+    move(TrustedImmPtr(FunctionPtr(operationVMHandleException).value()), regT3);
+    call(regT3);
 
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    Call string_failureCases1Call = makeTailRecursiveCall(string_failureCases1);
-    Call string_failureCases2Call = makeTailRecursiveCall(string_failureCases2);
-    Call string_failureCases3Call = makeTailRecursiveCall(string_failureCases3);
+#if CPU(X86)
+    addPtr(TrustedImm32(8), stackPointerRegister);
 #endif
 
-    // All trampolines constructed! copy the code, link up calls, and set the pointers on the Machine object.
-    LinkBuffer patchBuffer(this, m_globalData->executableAllocator.poolForSize(m_assembler.size()), 0);
-
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    patchBuffer.link(string_failureCases1Call, FunctionPtr(cti_op_get_by_id_string_fail));
-    patchBuffer.link(string_failureCases2Call, FunctionPtr(cti_op_get_by_id_string_fail));
-    patchBuffer.link(string_failureCases3Call, FunctionPtr(cti_op_get_by_id_string_fail));
-#endif
-    patchBuffer.link(callArityCheck1, FunctionPtr(cti_op_call_arityCheck));
-    patchBuffer.link(callJSFunction1, FunctionPtr(cti_op_call_JSFunction));
-#if ENABLE(JIT_OPTIMIZE_CALL)
-    patchBuffer.link(callArityCheck2, FunctionPtr(cti_op_call_arityCheck));
-    patchBuffer.link(callJSFunction2, FunctionPtr(cti_op_call_JSFunction));
-    patchBuffer.link(callLazyLinkCall, FunctionPtr(cti_vm_lazyLinkCall));
-#endif
+    jumpToExceptionHandler();
 
-    CodeRef finalCode = patchBuffer.finalizeCode();
-    *executablePool = finalCode.m_executablePool;
+    // All trampolines constructed! copy the code, link up calls, and set the pointers on the Machine object.
+    LinkBuffer patchBuffer(*m_vm, *this, GLOBAL_THUNK_ID);
 
-    trampolines->ctiVirtualCall = patchBuffer.trampolineAt(virtualCallBegin);
-#if ENABLE(JIT_OPTIMIZE_NATIVE_CALL)
-    trampolines->ctiNativeCallThunk = adoptRef(new NativeExecutable(JITCode(JITCode::HostFunction(patchBuffer.trampolineAt(nativeCallThunk)))));
-#endif
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    trampolines->ctiStringLengthTrampoline = patchBuffer.trampolineAt(stringLengthBegin);
-#else
-    UNUSED_PARAM(ctiStringLengthTrampoline);
-#endif
-#if ENABLE(JIT_OPTIMIZE_CALL)
-    trampolines->ctiVirtualCallLink = patchBuffer.trampolineAt(virtualCallLinkBegin);
-#else
-    UNUSED_PARAM(ctiVirtualCallLink);
-#endif
-#if ENABLE(JIT_OPTIMIZE_MOD)
-    trampolines->ctiSoftModulo = patchBuffer.trampolineAt(softModBegin);
-#endif
+    patchBuffer.link(nativeCall, FunctionPtr(func));
+    return FINALIZE_CODE(patchBuffer, ("JIT CTI native call"));
 }
 
 void JIT::emit_op_mov(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src = currentInstruction[2].u.operand;
-
+    int dst = currentInstruction[1].u.operand;
+    int src = currentInstruction[2].u.operand;
+    
     if (m_codeBlock->isConstantRegisterIndex(src))
         emitStore(dst, getConstantOperand(src));
     else {
         emitLoad(src, regT1, regT0);
         emitStore(dst, regT1, regT0);
-        map(m_bytecodeIndex + OPCODE_LENGTH(op_mov), dst, regT1, regT0);
     }
 }
 
 void JIT::emit_op_end(Instruction* currentInstruction)
 {
-    if (m_codeBlock->needsFullScopeChain())
-        JITStubCall(this, cti_op_end).call();
-    ASSERT(returnValueRegister != callFrameRegister);
+    ASSERT(returnValueGPR != callFrameRegister);
     emitLoad(currentInstruction[1].u.operand, regT1, regT0);
-    restoreReturnAddressBeforeReturn(Address(callFrameRegister, RegisterFile::ReturnPC * static_cast<int>(sizeof(Register))));
+    emitFunctionEpilogue();
     ret();
 }
 
@@ -447,217 +159,195 @@ void JIT::emit_op_jmp(Instruction* currentInstruction)
     addJump(jump(), target);
 }
 
-void JIT::emit_op_loop_if_lesseq(Instruction* currentInstruction)
+void JIT::emit_op_new_object(Instruction* currentInstruction)
 {
-    unsigned op1 = currentInstruction[1].u.operand;
-    unsigned op2 = currentInstruction[2].u.operand;
-    unsigned target = currentInstruction[3].u.operand;
-
-    emitTimeoutCheck();
+    Structure* structure = currentInstruction[3].u.objectAllocationProfile->structure();
+    size_t allocationSize = JSFinalObject::allocationSize(structure->inlineCapacity());
+    MarkedAllocator* allocator = &m_vm->heap.allocatorForObjectWithoutDestructor(allocationSize);
 
-    if (isOperandConstantImmediateInt(op1)) {
-        emitLoad(op2, regT1, regT0);
-        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
-        addJump(branch32(GreaterThanOrEqual, regT0, Imm32(getConstantOperand(op1).asInt32())), target);
-        return;
-    }
-
-    if (isOperandConstantImmediateInt(op2)) {
-        emitLoad(op1, regT1, regT0);
-        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
-        addJump(branch32(LessThanOrEqual, regT0, Imm32(getConstantOperand(op2).asInt32())), target);
-        return;
-    }
+    RegisterID resultReg = regT0;
+    RegisterID allocatorReg = regT1;
+    RegisterID scratchReg = regT2;
 
-    emitLoad2(op1, regT1, regT0, op2, regT3, regT2);
-    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
-    addSlowCase(branch32(NotEqual, regT3, Imm32(JSValue::Int32Tag)));
-    addJump(branch32(LessThanOrEqual, regT0, regT2), target);
+    move(TrustedImmPtr(allocator), allocatorReg);
+    emitAllocateJSObject(allocatorReg, TrustedImmPtr(structure), resultReg, scratchReg);
+    emitStoreCell(currentInstruction[1].u.operand, resultReg);
 }
 
-void JIT::emitSlow_op_loop_if_lesseq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_new_object(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned op1 = currentInstruction[1].u.operand;
-    unsigned op2 = currentInstruction[2].u.operand;
-    unsigned target = currentInstruction[3].u.operand;
-
-    if (!isOperandConstantImmediateInt(op1) && !isOperandConstantImmediateInt(op2))
-        linkSlowCase(iter); // int32 check
-    linkSlowCase(iter); // int32 check
-
-    JITStubCall stubCall(this, cti_op_loop_if_lesseq);
-    stubCall.addArgument(op1);
-    stubCall.addArgument(op2);
-    stubCall.call();
-    emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
+    linkSlowCase(iter);
+    int dst = currentInstruction[1].u.operand;
+    Structure* structure = currentInstruction[3].u.objectAllocationProfile->structure();
+    callOperation(operationNewObject, structure);
+    emitStoreCell(dst, returnValueGPR);
 }
 
-void JIT::emit_op_new_object(Instruction* currentInstruction)
+void JIT::emit_op_check_has_instance(Instruction* currentInstruction)
 {
-    JITStubCall(this, cti_op_new_object).call(currentInstruction[1].u.operand);
+    int baseVal = currentInstruction[3].u.operand;
+
+    emitLoadPayload(baseVal, regT0);
+
+    // Check that baseVal is a cell.
+    emitJumpSlowCaseIfNotJSCell(baseVal);
+    
+    // Check that baseVal 'ImplementsHasInstance'.
+    addSlowCase(branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(ImplementsDefaultHasInstance)));
 }
 
 void JIT::emit_op_instanceof(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned value = currentInstruction[2].u.operand;
-    unsigned baseVal = currentInstruction[3].u.operand;
-    unsigned proto = currentInstruction[4].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    int proto = currentInstruction[3].u.operand;
 
     // Load the operands into registers.
     // We use regT0 for baseVal since we will be done with this first, and we can then use it for the result.
     emitLoadPayload(value, regT2);
-    emitLoadPayload(baseVal, regT0);
     emitLoadPayload(proto, regT1);
 
-    // Check that value, baseVal, and proto are cells.
+    // Check that proto are cells.  baseVal must be a cell - this is checked by op_check_has_instance.
     emitJumpSlowCaseIfNotJSCell(value);
-    emitJumpSlowCaseIfNotJSCell(baseVal);
     emitJumpSlowCaseIfNotJSCell(proto);
-
-    // Check that baseVal 'ImplementsDefaultHasInstance'.
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT0);
-    addSlowCase(branchTest8(Zero, Address(regT0, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(ImplementsDefaultHasInstance)));
+    
+    // Check that prototype is an object
+    addSlowCase(emitJumpIfCellNotObject(regT1));
 
     // Optimistically load the result true, and start looping.
     // Initially, regT1 still contains proto and regT2 still contains value.
     // As we loop regT2 will be updated with its prototype, recursively walking the prototype chain.
-    move(Imm32(JSValue::TrueTag), regT0);
+    move(TrustedImm32(1), regT0);
     Label loop(this);
 
     // Load the prototype of the cell in regT2.  If this is equal to regT1 - WIN!
     // Otherwise, check if we've hit null - if we have then drop out of the loop, if not go again.
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    load32(Address(regT2, OBJECT_OFFSETOF(Structure, m_prototype) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
+    loadPtr(Address(regT2, JSCell::structureIDOffset()), regT2);
+    load32(Address(regT2, Structure::prototypeOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
     Jump isInstance = branchPtr(Equal, regT2, regT1);
     branchTest32(NonZero, regT2).linkTo(loop, this);
 
     // We get here either by dropping out of the loop, or if value was not an Object.  Result is false.
-    move(Imm32(JSValue::FalseTag), regT0);
+    move(TrustedImm32(0), regT0);
 
     // isInstance jumps right down to here, to skip setting the result to false (it has already set true).
     isInstance.link(this);
     emitStoreBool(dst, regT0);
 }
 
-void JIT::emitSlow_op_instanceof(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_check_has_instance(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned value = currentInstruction[2].u.operand;
-    unsigned baseVal = currentInstruction[3].u.operand;
-    unsigned proto = currentInstruction[4].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    int baseVal = currentInstruction[3].u.operand;
 
-    linkSlowCaseIfNotJSCell(iter, value);
     linkSlowCaseIfNotJSCell(iter, baseVal);
-    linkSlowCaseIfNotJSCell(iter, proto);
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_instanceof);
-    stubCall.addArgument(value);
-    stubCall.addArgument(baseVal);
-    stubCall.addArgument(proto);
-    stubCall.call(dst);
-}
+    emitLoad(value, regT1, regT0);
+    emitLoad(baseVal, regT3, regT2);
+    callOperation(operationCheckHasInstance, dst, regT1, regT0, regT3, regT2);
 
-void JIT::emit_op_new_func(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_new_func);
-    stubCall.addArgument(ImmPtr(m_codeBlock->functionDecl(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
+    emitJumpSlowToHot(jump(), currentInstruction[4].u.operand);
 }
 
-void JIT::emit_op_get_global_var(Instruction* currentInstruction)
+void JIT::emitSlow_op_instanceof(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     int dst = currentInstruction[1].u.operand;
-    JSGlobalObject* globalObject = static_cast<JSGlobalObject*>(currentInstruction[2].u.jsCell);
-    ASSERT(globalObject->isGlobalObject());
-    int index = currentInstruction[3].u.operand;
+    int value = currentInstruction[2].u.operand;
+    int proto = currentInstruction[3].u.operand;
 
-    loadPtr(&globalObject->d()->registers, regT2);
+    linkSlowCaseIfNotJSCell(iter, value);
+    linkSlowCaseIfNotJSCell(iter, proto);
+    linkSlowCase(iter);
 
-    emitLoad(index, regT1, regT0, regT2);
-    emitStore(dst, regT1, regT0);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_get_global_var), dst, regT1, regT0);
+    emitLoad(value, regT1, regT0);
+    emitLoad(proto, regT3, regT2);
+    callOperation(operationInstanceOf, dst, regT1, regT0, regT3, regT2);
 }
 
-void JIT::emit_op_put_global_var(Instruction* currentInstruction)
+void JIT::emit_op_is_undefined(Instruction* currentInstruction)
 {
-    JSGlobalObject* globalObject = static_cast<JSGlobalObject*>(currentInstruction[1].u.jsCell);
-    ASSERT(globalObject->isGlobalObject());
-    int index = currentInstruction[2].u.operand;
-    int value = currentInstruction[3].u.operand;
-
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
     emitLoad(value, regT1, regT0);
-
-    loadPtr(&globalObject->d()->registers, regT2);
-    emitStore(index, regT1, regT0, regT2);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_put_global_var), value, regT1, regT0);
+    Jump isCell = branch32(Equal, regT1, TrustedImm32(JSValue::CellTag));
+
+    compare32(Equal, regT1, TrustedImm32(JSValue::UndefinedTag), regT0);
+    Jump done = jump();
+    
+    isCell.link(this);
+    Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    move(TrustedImm32(0), regT0);
+    Jump notMasqueradesAsUndefined = jump();
+    
+    isMasqueradesAsUndefined.link(this);
+    loadPtr(Address(regT0, JSCell::structureIDOffset()), regT1);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT1, Structure::globalObjectOffset()), regT1);
+    compare32(Equal, regT0, regT1, regT0);
+
+    notMasqueradesAsUndefined.link(this);
+    done.link(this);
+    emitStoreBool(dst, regT0);
 }
 
-void JIT::emit_op_get_scoped_var(Instruction* currentInstruction)
+void JIT::emit_op_is_boolean(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
-    int index = currentInstruction[2].u.operand;
-    int skip = currentInstruction[3].u.operand + m_codeBlock->needsFullScopeChain();
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
-    while (skip--)
-        loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
-
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, d)), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), regT2);
-
-    emitLoad(index, regT1, regT0, regT2);
-    emitStore(dst, regT1, regT0);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_get_scoped_var), dst, regT1, regT0);
+    int value = currentInstruction[2].u.operand;
+    
+    emitLoadTag(value, regT0);
+    compare32(Equal, regT0, TrustedImm32(JSValue::BooleanTag), regT0);
+    emitStoreBool(dst, regT0);
 }
 
-void JIT::emit_op_put_scoped_var(Instruction* currentInstruction)
+void JIT::emit_op_is_number(Instruction* currentInstruction)
 {
-    int index = currentInstruction[1].u.operand;
-    int skip = currentInstruction[2].u.operand + m_codeBlock->needsFullScopeChain();
-    int value = currentInstruction[3].u.operand;
-
-    emitLoad(value, regT1, regT0);
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
-    while (skip--)
-        loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);
-
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, d)), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), regT2);
-
-    emitStore(index, regT1, regT0, regT2);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_put_scoped_var), value, regT1, regT0);
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitLoadTag(value, regT0);
+    add32(TrustedImm32(1), regT0);
+    compare32(Below, regT0, TrustedImm32(JSValue::LowestTag + 1), regT0);
+    emitStoreBool(dst, regT0);
 }
 
-void JIT::emit_op_tear_off_activation(Instruction* currentInstruction)
+void JIT::emit_op_is_string(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_tear_off_activation);
-    stubCall.addArgument(currentInstruction[1].u.operand);
-    stubCall.call();
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitLoad(value, regT1, regT0);
+    Jump isNotCell = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
+    
+    compare8(Equal, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(StringType), regT0);
+    Jump done = jump();
+    
+    isNotCell.link(this);
+    move(TrustedImm32(0), regT0);
+    
+    done.link(this);
+    emitStoreBool(dst, regT0);
 }
 
-void JIT::emit_op_tear_off_arguments(Instruction*)
+void JIT::emit_op_is_object(Instruction* currentInstruction)
 {
-    JITStubCall(this, cti_op_tear_off_arguments).call();
-}
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
 
-void JIT::emit_op_new_array(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_new_array);
-    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
-    stubCall.call(currentInstruction[1].u.operand);
-}
+    emitLoad(value, regT1, regT0);
+    Jump isNotCell = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
 
-void JIT::emit_op_resolve(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve);
-    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
+    compare8(AboveOrEqual, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(ObjectType), regT0);
+    Jump done = jump();
+
+    isNotCell.link(this);
+    move(TrustedImm32(0), regT0);
+
+    done.link(this);
+    emitStoreBool(dst, regT0);
 }
 
 void JIT::emit_op_to_primitive(Instruction* currentInstruction)
@@ -667,297 +357,200 @@ void JIT::emit_op_to_primitive(Instruction* currentInstruction)
 
     emitLoad(src, regT1, regT0);
 
-    Jump isImm = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
-    addSlowCase(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
+    Jump isImm = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
+    addSlowCase(emitJumpIfCellObject(regT0));
     isImm.link(this);
 
     if (dst != src)
         emitStore(dst, regT1, regT0);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_to_primitive), dst, regT1, regT0);
 }
 
 void JIT::emitSlow_op_to_primitive(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    int dst = currentInstruction[1].u.operand;
-
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_to_primitive);
-    stubCall.addArgument(regT1, regT0);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_primitive);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_strcat(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_strcat);
-    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_resolve_base(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve_base);
-    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_resolve_skip(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve_skip);
-    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand + m_codeBlock->needsFullScopeChain()));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_resolve_global(Instruction* currentInstruction, bool dynamic)
-{
-    // FIXME: Optimize to use patching instead of so many memory accesses.
-
-    unsigned dst = currentInstruction[1].u.operand;
-    void* globalObject = currentInstruction[2].u.jsCell;
-
-    unsigned currentIndex = m_globalResolveInfoIndex++;
-    void* structureAddress = &(m_codeBlock->globalResolveInfo(currentIndex).structure);
-    void* offsetAddr = &(m_codeBlock->globalResolveInfo(currentIndex).offset);
-
-    // Verify structure.
-    move(ImmPtr(globalObject), regT0);
-    loadPtr(structureAddress, regT1);
-    addSlowCase(branchPtr(NotEqual, regT1, Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure))));
-
-    // Load property.
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSGlobalObject, m_externalStorage)), regT2);
-    load32(offsetAddr, regT3);
-    load32(BaseIndex(regT2, regT3, TimesEight), regT0); // payload
-    load32(BaseIndex(regT2, regT3, TimesEight, 4), regT1); // tag
-    emitStore(dst, regT1, regT0);
-    map(m_bytecodeIndex + dynamic ? OPCODE_LENGTH(op_resolve_global_dynamic) : OPCODE_LENGTH(op_resolve_global), dst, regT1, regT0);
-}
-
-void JIT::emitSlow_op_resolve_global(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    unsigned dst = currentInstruction[1].u.operand;
-    void* globalObject = currentInstruction[2].u.jsCell;
-    Identifier* ident = &m_codeBlock->identifier(currentInstruction[3].u.operand);
-
-    unsigned currentIndex = m_globalResolveInfoIndex++;
-
-    linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_resolve_global);
-    stubCall.addArgument(ImmPtr(globalObject));
-    stubCall.addArgument(ImmPtr(ident));
-    stubCall.addArgument(Imm32(currentIndex));
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_strcat);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_not(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src = currentInstruction[2].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src = currentInstruction[2].u.operand;
 
     emitLoadTag(src, regT0);
 
-    xor32(Imm32(JSValue::FalseTag), regT0);
-    addSlowCase(branchTest32(NonZero, regT0, Imm32(~1)));
-    xor32(Imm32(JSValue::TrueTag), regT0);
+    emitLoad(src, regT1, regT0);
+    addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::BooleanTag)));
+    xor32(TrustedImm32(1), regT0);
 
     emitStoreBool(dst, regT0, (dst == src));
 }
 
 void JIT::emitSlow_op_not(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src = currentInstruction[2].u.operand;
-
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_not);
-    stubCall.addArgument(src);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_not);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_jfalse(Instruction* currentInstruction)
 {
-    unsigned cond = currentInstruction[1].u.operand;
+    int cond = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     emitLoad(cond, regT1, regT0);
 
-    Jump isTrue = branch32(Equal, regT1, Imm32(JSValue::TrueTag));
-    addJump(branch32(Equal, regT1, Imm32(JSValue::FalseTag)), target);
-
-    Jump isNotInteger = branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag));
-    Jump isTrue2 = branch32(NotEqual, regT0, Imm32(0));
-    addJump(jump(), target);
-
-    if (supportsFloatingPoint()) {
-        isNotInteger.link(this);
-
-        addSlowCase(branch32(Above, regT1, Imm32(JSValue::LowestTag)));
-
-        emitLoadDouble(cond, fpRegT0);
-        addJump(branchDoubleZeroOrNaN(fpRegT0, fpRegT1), target);
-    } else
-        addSlowCase(isNotInteger);
-
-    isTrue.link(this);
-    isTrue2.link(this);
+    ASSERT((JSValue::BooleanTag + 1 == JSValue::Int32Tag) && !(JSValue::Int32Tag + 1));
+    addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::BooleanTag)));
+    addJump(branchTest32(Zero, regT0), target);
 }
 
 void JIT::emitSlow_op_jfalse(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned cond = currentInstruction[1].u.operand;
+    int cond = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_jtrue);
-    stubCall.addArgument(cond);
-    stubCall.call();
-    emitJumpSlowToHot(branchTest32(Zero, regT0), target); // Inverted.
+
+    if (supportsFloatingPoint()) {
+        // regT1 contains the tag from the hot path.
+        Jump notNumber = branch32(Above, regT1, TrustedImm32(JSValue::LowestTag));
+
+        emitLoadDouble(cond, fpRegT0);
+        emitJumpSlowToHot(branchDoubleZeroOrNaN(fpRegT0, fpRegT1), target);
+        emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_jfalse));
+
+        notNumber.link(this);
+    }
+
+    callOperation(operationConvertJSValueToBoolean, regT1, regT0);
+    emitJumpSlowToHot(branchTest32(Zero, returnValueGPR), target); // Inverted.
 }
 
 void JIT::emit_op_jtrue(Instruction* currentInstruction)
 {
-    unsigned cond = currentInstruction[1].u.operand;
+    int cond = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     emitLoad(cond, regT1, regT0);
 
-    Jump isFalse = branch32(Equal, regT1, Imm32(JSValue::FalseTag));
-    addJump(branch32(Equal, regT1, Imm32(JSValue::TrueTag)), target);
-
-    Jump isNotInteger = branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag));
-    Jump isFalse2 = branch32(Equal, regT0, Imm32(0));
-    addJump(jump(), target);
-
-    if (supportsFloatingPoint()) {
-        isNotInteger.link(this);
-
-        addSlowCase(branch32(Above, regT1, Imm32(JSValue::LowestTag)));
-
-        emitLoadDouble(cond, fpRegT0);
-        addJump(branchDoubleNonZero(fpRegT0, fpRegT1), target);
-    } else
-        addSlowCase(isNotInteger);
-
-    isFalse.link(this);
-    isFalse2.link(this);
+    ASSERT((JSValue::BooleanTag + 1 == JSValue::Int32Tag) && !(JSValue::Int32Tag + 1));
+    addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::BooleanTag)));
+    addJump(branchTest32(NonZero, regT0), target);
 }
 
 void JIT::emitSlow_op_jtrue(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned cond = currentInstruction[1].u.operand;
+    int cond = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_jtrue);
-    stubCall.addArgument(cond);
-    stubCall.call();
-    emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
+
+    if (supportsFloatingPoint()) {
+        // regT1 contains the tag from the hot path.
+        Jump notNumber = branch32(Above, regT1, TrustedImm32(JSValue::LowestTag));
+
+        emitLoadDouble(cond, fpRegT0);
+        emitJumpSlowToHot(branchDoubleNonZero(fpRegT0, fpRegT1), target);
+        emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_jtrue));
+
+        notNumber.link(this);
+    }
+
+    callOperation(operationConvertJSValueToBoolean, regT1, regT0);
+    emitJumpSlowToHot(branchTest32(NonZero, returnValueGPR), target);
 }
 
 void JIT::emit_op_jeq_null(Instruction* currentInstruction)
 {
-    unsigned src = currentInstruction[1].u.operand;
+    int src = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     emitLoad(src, regT1, regT0);
 
-    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
-
-    // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    addJump(branchTest8(NonZero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined)), target);
+    Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
 
-    Jump wasNotImmediate = jump();
+    Jump isNotMasqueradesAsUndefined = branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    loadPtr(Address(regT0, JSCell::structureIDOffset()), regT2);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    addJump(branchPtr(Equal, Address(regT2, Structure::globalObjectOffset()), regT0), target);
+    Jump masqueradesGlobalObjectIsForeign = jump();
 
     // Now handle the immediate cases - undefined & null
     isImmediate.link(this);
+    ASSERT((JSValue::UndefinedTag + 1 == JSValue::NullTag) && (JSValue::NullTag & 0x1));
+    or32(TrustedImm32(1), regT1);
+    addJump(branch32(Equal, regT1, TrustedImm32(JSValue::NullTag)), target);
 
-    set32(Equal, regT1, Imm32(JSValue::NullTag), regT2);
-    set32(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
-    or32(regT2, regT1);
-
-    addJump(branchTest32(NonZero, regT1), target);
-
-    wasNotImmediate.link(this);
+    isNotMasqueradesAsUndefined.link(this);
+    masqueradesGlobalObjectIsForeign.link(this);
 }
 
 void JIT::emit_op_jneq_null(Instruction* currentInstruction)
 {
-    unsigned src = currentInstruction[1].u.operand;
+    int src = currentInstruction[1].u.operand;
     unsigned target = currentInstruction[2].u.operand;
 
     emitLoad(src, regT1, regT0);
 
-    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
-
-    // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    addJump(branchTest8(Zero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined)), target);
+    Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
 
+    addJump(branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
+    loadPtr(Address(regT0, JSCell::structureIDOffset()), regT2);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    addJump(branchPtr(NotEqual, Address(regT2, Structure::globalObjectOffset()), regT0), target);
     Jump wasNotImmediate = jump();
 
     // Now handle the immediate cases - undefined & null
     isImmediate.link(this);
 
-    set32(Equal, regT1, Imm32(JSValue::NullTag), regT2);
-    set32(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
-    or32(regT2, regT1);
-
-    addJump(branchTest32(Zero, regT1), target);
+    ASSERT((JSValue::UndefinedTag + 1 == JSValue::NullTag) && (JSValue::NullTag & 0x1));
+    or32(TrustedImm32(1), regT1);
+    addJump(branch32(NotEqual, regT1, TrustedImm32(JSValue::NullTag)), target);
 
     wasNotImmediate.link(this);
 }
 
 void JIT::emit_op_jneq_ptr(Instruction* currentInstruction)
 {
-    unsigned src = currentInstruction[1].u.operand;
-    JSCell* ptr = currentInstruction[2].u.jsCell;
+    int src = currentInstruction[1].u.operand;
+    Special::Pointer ptr = currentInstruction[2].u.specialPointer;
     unsigned target = currentInstruction[3].u.operand;
 
     emitLoad(src, regT1, regT0);
-    addJump(branch32(NotEqual, regT1, Imm32(JSValue::CellTag)), target);
-    addJump(branchPtr(NotEqual, regT0, ImmPtr(ptr)), target);
-}
-
-void JIT::emit_op_jsr(Instruction* currentInstruction)
-{
-    int retAddrDst = currentInstruction[1].u.operand;
-    int target = currentInstruction[2].u.operand;
-    DataLabelPtr storeLocation = storePtrWithPatch(ImmPtr(0), Address(callFrameRegister, sizeof(Register) * retAddrDst));
-    addJump(jump(), target);
-    m_jsrSites.append(JSRInfo(storeLocation, label()));
-}
-
-void JIT::emit_op_sret(Instruction* currentInstruction)
-{
-    jump(Address(callFrameRegister, sizeof(Register) * currentInstruction[1].u.operand));
+    addJump(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)), target);
+    addJump(branchPtr(NotEqual, regT0, TrustedImmPtr(actualPointerFor(m_codeBlock, ptr))), target);
 }
 
 void JIT::emit_op_eq(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
-    unsigned src2 = currentInstruction[3].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src1 = currentInstruction[2].u.operand;
+    int src2 = currentInstruction[3].u.operand;
 
     emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
     addSlowCase(branch32(NotEqual, regT1, regT3));
-    addSlowCase(branch32(Equal, regT1, Imm32(JSValue::CellTag)));
-    addSlowCase(branch32(Below, regT1, Imm32(JSValue::LowestTag)));
+    addSlowCase(branch32(Equal, regT1, TrustedImm32(JSValue::CellTag)));
+    addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::LowestTag)));
 
-    set8(Equal, regT0, regT2, regT0);
-    or32(Imm32(JSValue::FalseTag), regT0);
+    compare32(Equal, regT0, regT2, regT0);
 
     emitStoreBool(dst, regT0);
 }
 
 void JIT::emitSlow_op_eq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned op1 = currentInstruction[2].u.operand;
-    unsigned op2 = currentInstruction[3].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int op1 = currentInstruction[2].u.operand;
+    int op2 = currentInstruction[3].u.operand;
 
     JumpList storeResult;
     JumpList genericCase;
@@ -965,49 +558,43 @@ void JIT::emitSlow_op_eq(Instruction* currentInstruction, Vector<SlowCaseEntry>:
     genericCase.append(getSlowCase(iter)); // tags not equal
 
     linkSlowCase(iter); // tags equal and JSCell
-    genericCase.append(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
-    genericCase.append(branchPtr(NotEqual, Address(regT2), ImmPtr(m_globalData->jsStringVPtr)));
+    genericCase.append(branchPtr(NotEqual, Address(regT0, JSCell::structureIDOffset()), TrustedImmPtr(m_vm->stringStructure.get())));
+    genericCase.append(branchPtr(NotEqual, Address(regT2, JSCell::structureIDOffset()), TrustedImmPtr(m_vm->stringStructure.get())));
 
     // String case.
-    JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
-    stubCallEqStrings.addArgument(regT0);
-    stubCallEqStrings.addArgument(regT2);
-    stubCallEqStrings.call();
+    callOperation(operationCompareStringEq, regT0, regT2);
     storeResult.append(jump());
 
     // Generic case.
     genericCase.append(getSlowCase(iter)); // doubles
     genericCase.link(this);
-    JITStubCall stubCallEq(this, cti_op_eq);
-    stubCallEq.addArgument(op1);
-    stubCallEq.addArgument(op2);
-    stubCallEq.call(regT0);
+    emitLoad(op1, regT1, regT0);
+    emitLoad(op2, regT3, regT2);
+    callOperation(operationCompareEq, regT1, regT0, regT3, regT2);
 
     storeResult.link(this);
-    or32(Imm32(JSValue::FalseTag), regT0);
-    emitStoreBool(dst, regT0);
+    emitStoreBool(dst, returnValueGPR);
 }
 
 void JIT::emit_op_neq(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
-    unsigned src2 = currentInstruction[3].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src1 = currentInstruction[2].u.operand;
+    int src2 = currentInstruction[3].u.operand;
 
     emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
     addSlowCase(branch32(NotEqual, regT1, regT3));
-    addSlowCase(branch32(Equal, regT1, Imm32(JSValue::CellTag)));
-    addSlowCase(branch32(Below, regT1, Imm32(JSValue::LowestTag)));
+    addSlowCase(branch32(Equal, regT1, TrustedImm32(JSValue::CellTag)));
+    addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::LowestTag)));
 
-    set8(NotEqual, regT0, regT2, regT0);
-    or32(Imm32(JSValue::FalseTag), regT0);
+    compare32(NotEqual, regT0, regT2, regT0);
 
     emitStoreBool(dst, regT0);
 }
 
 void JIT::emitSlow_op_neq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
+    int dst = currentInstruction[1].u.operand;
 
     JumpList storeResult;
     JumpList genericCase;
@@ -1015,52 +602,47 @@ void JIT::emitSlow_op_neq(Instruction* currentInstruction, Vector<SlowCaseEntry>
     genericCase.append(getSlowCase(iter)); // tags not equal
 
     linkSlowCase(iter); // tags equal and JSCell
-    genericCase.append(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
-    genericCase.append(branchPtr(NotEqual, Address(regT2), ImmPtr(m_globalData->jsStringVPtr)));
+    genericCase.append(branchPtr(NotEqual, Address(regT0, JSCell::structureIDOffset()), TrustedImmPtr(m_vm->stringStructure.get())));
+    genericCase.append(branchPtr(NotEqual, Address(regT2, JSCell::structureIDOffset()), TrustedImmPtr(m_vm->stringStructure.get())));
 
     // String case.
-    JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
-    stubCallEqStrings.addArgument(regT0);
-    stubCallEqStrings.addArgument(regT2);
-    stubCallEqStrings.call(regT0);
+    callOperation(operationCompareStringEq, regT0, regT2);
     storeResult.append(jump());
 
     // Generic case.
     genericCase.append(getSlowCase(iter)); // doubles
     genericCase.link(this);
-    JITStubCall stubCallEq(this, cti_op_eq);
-    stubCallEq.addArgument(regT1, regT0);
-    stubCallEq.addArgument(regT3, regT2);
-    stubCallEq.call(regT0);
+    callOperation(operationCompareEq, regT1, regT0, regT3, regT2);
 
     storeResult.link(this);
-    xor32(Imm32(0x1), regT0);
-    or32(Imm32(JSValue::FalseTag), regT0);
-    emitStoreBool(dst, regT0);
+    xor32(TrustedImm32(0x1), returnValueGPR);
+    emitStoreBool(dst, returnValueGPR);
 }
 
 void JIT::compileOpStrictEq(Instruction* currentInstruction, CompileOpStrictEqType type)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
-    unsigned src2 = currentInstruction[3].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src1 = currentInstruction[2].u.operand;
+    int src2 = currentInstruction[3].u.operand;
 
-    emitLoadTag(src1, regT0);
-    emitLoadTag(src2, regT1);
+    emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
 
-    // Jump to a slow case if either operand is double, or if both operands are
-    // cells and/or Int32s.
-    move(regT0, regT2);
-    and32(regT1, regT2);
-    addSlowCase(branch32(Below, regT2, Imm32(JSValue::LowestTag)));
-    addSlowCase(branch32(AboveOrEqual, regT2, Imm32(JSValue::CellTag)));
+    // Bail if the tags differ, or are double.
+    addSlowCase(branch32(NotEqual, regT1, regT3));
+    addSlowCase(branch32(Below, regT1, TrustedImm32(JSValue::LowestTag)));
+
+    // Jump to a slow case if both are strings or symbols (non object).
+    Jump notCell = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
+    Jump firstIsObject = emitJumpIfCellObject(regT0);
+    addSlowCase(emitJumpIfCellNotObject(regT2));
+    notCell.link(this);
+    firstIsObject.link(this);
 
+    // Simply compare the payloads.
     if (type == OpStrictEq)
-        set8(Equal, regT0, regT1, regT0);
+        compare32(Equal, regT0, regT2, regT0);
     else
-        set8(NotEqual, regT0, regT1, regT0);
-
-    or32(Imm32(JSValue::FalseTag), regT0);
+        compare32(NotEqual, regT0, regT2, regT0);
 
     emitStoreBool(dst, regT0);
 }
@@ -1072,17 +654,12 @@ void JIT::emit_op_stricteq(Instruction* currentInstruction)
 
 void JIT::emitSlow_op_stricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
-    unsigned src2 = currentInstruction[3].u.operand;
-
+    linkSlowCase(iter);
     linkSlowCase(iter);
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_stricteq);
-    stubCall.addArgument(src1);
-    stubCall.addArgument(src2);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_stricteq);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_nstricteq(Instruction* currentInstruction)
@@ -1092,438 +669,643 @@ void JIT::emit_op_nstricteq(Instruction* currentInstruction)
 
 void JIT::emitSlow_op_nstricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
-    unsigned src2 = currentInstruction[3].u.operand;
-
+    linkSlowCase(iter);
     linkSlowCase(iter);
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_nstricteq);
-    stubCall.addArgument(src1);
-    stubCall.addArgument(src2);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_nstricteq);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_eq_null(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src = currentInstruction[2].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src = currentInstruction[2].u.operand;
 
     emitLoad(src, regT1, regT0);
-    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
+    Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
 
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT1);
-    setTest8(NonZero, Address(regT1, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined), regT1);
+    Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    move(TrustedImm32(0), regT1);
+    Jump wasNotMasqueradesAsUndefined = jump();
 
+    isMasqueradesAsUndefined.link(this);
+    loadPtr(Address(regT0, JSCell::structureIDOffset()), regT2);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT2, Structure::globalObjectOffset()), regT2);
+    compare32(Equal, regT0, regT2, regT1);
     Jump wasNotImmediate = jump();
 
     isImmediate.link(this);
 
-    set8(Equal, regT1, Imm32(JSValue::NullTag), regT2);
-    set8(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
+    compare32(Equal, regT1, TrustedImm32(JSValue::NullTag), regT2);
+    compare32(Equal, regT1, TrustedImm32(JSValue::UndefinedTag), regT1);
     or32(regT2, regT1);
 
     wasNotImmediate.link(this);
-
-    or32(Imm32(JSValue::FalseTag), regT1);
+    wasNotMasqueradesAsUndefined.link(this);
 
     emitStoreBool(dst, regT1);
 }
 
 void JIT::emit_op_neq_null(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src = currentInstruction[2].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src = currentInstruction[2].u.operand;
 
     emitLoad(src, regT1, regT0);
-    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
+    Jump isImmediate = branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag));
 
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT1);
-    setTest8(Zero, Address(regT1, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined), regT1);
+    Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    move(TrustedImm32(1), regT1);
+    Jump wasNotMasqueradesAsUndefined = jump();
 
+    isMasqueradesAsUndefined.link(this);
+    loadPtr(Address(regT0, JSCell::structureIDOffset()), regT2);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT2, Structure::globalObjectOffset()), regT2);
+    compare32(NotEqual, regT0, regT2, regT1);
     Jump wasNotImmediate = jump();
 
     isImmediate.link(this);
 
-    set8(NotEqual, regT1, Imm32(JSValue::NullTag), regT2);
-    set8(NotEqual, regT1, Imm32(JSValue::UndefinedTag), regT1);
+    compare32(NotEqual, regT1, TrustedImm32(JSValue::NullTag), regT2);
+    compare32(NotEqual, regT1, TrustedImm32(JSValue::UndefinedTag), regT1);
     and32(regT2, regT1);
 
     wasNotImmediate.link(this);
-
-    or32(Imm32(JSValue::FalseTag), regT1);
+    wasNotMasqueradesAsUndefined.link(this);
 
     emitStoreBool(dst, regT1);
 }
 
-void JIT::emit_op_resolve_with_base(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve_with_base);
-    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[3].u.operand)));
-    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
-    stubCall.call(currentInstruction[2].u.operand);
-}
-
-void JIT::emit_op_new_func_exp(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_new_func_exp);
-    stubCall.addArgument(ImmPtr(m_codeBlock->functionExpr(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
 void JIT::emit_op_throw(Instruction* currentInstruction)
 {
-    unsigned exception = currentInstruction[1].u.operand;
-    JITStubCall stubCall(this, cti_op_throw);
-    stubCall.addArgument(exception);
-    stubCall.call();
-
-#ifndef NDEBUG
-    // cti_op_throw always changes it's return address,
-    // this point in the code should never be reached.
-    breakpoint();
-#endif
+    ASSERT(regT0 == returnValueGPR);
+    emitLoad(currentInstruction[1].u.operand, regT1, regT0);
+    callOperationNoExceptionCheck(operationThrow, regT1, regT0);
+    jumpToExceptionHandler();
 }
 
-void JIT::emit_op_get_pnames(Instruction* currentInstruction)
+void JIT::emit_op_push_with_scope(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
-    int base = currentInstruction[2].u.operand;
-    int i = currentInstruction[3].u.operand;
-    int size = currentInstruction[4].u.operand;
-    int breakTarget = currentInstruction[5].u.operand;
-
-    JumpList isNotObject;
-
-    emitLoad(base, regT1, regT0);
-    if (!m_codeBlock->isKnownNotImmediate(base))
-        isNotObject.append(branch32(NotEqual, regT1, Imm32(JSValue::CellTag)));
-    if (base != m_codeBlock->thisRegister()) {
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-        isNotObject.append(branch8(NotEqual, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_type)), Imm32(ObjectType)));
-    }
-
-    // We could inline the case where you have a valid cache, but
-    // this call doesn't seem to be hot.
-    Label isObject(this);
-    JITStubCall getPnamesStubCall(this, cti_op_get_pnames);
-    getPnamesStubCall.addArgument(regT0);
-    getPnamesStubCall.call(dst);
-    load32(Address(regT0, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStringsSize)), regT3);
-    store32(Imm32(0), addressFor(i));
-    store32(regT3, addressFor(size));
-    Jump end = jump();
-
-    isNotObject.link(this);
-    addJump(branch32(Equal, regT1, Imm32(JSValue::NullTag)), breakTarget);
-    addJump(branch32(Equal, regT1, Imm32(JSValue::UndefinedTag)), breakTarget);
-    JITStubCall toObjectStubCall(this, cti_to_object);
-    toObjectStubCall.addArgument(regT1, regT0);
-    toObjectStubCall.call(base);
-    jump().linkTo(isObject, this);
+    emitLoad(currentInstruction[2].u.operand, regT1, regT0);
+    callOperation(operationPushWithScope, dst, regT1, regT0);
+}
 
-    end.link(this);
+void JIT::emit_op_pop_scope(Instruction* currentInstruction)
+{
+    int scope = currentInstruction[1].u.operand;
+    callOperation(operationPopScope, scope);
 }
 
-void JIT::emit_op_next_pname(Instruction* currentInstruction)
+void JIT::emit_op_to_number(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
-    int base = currentInstruction[2].u.operand;
-    int i = currentInstruction[3].u.operand;
-    int size = currentInstruction[4].u.operand;
-    int it = currentInstruction[5].u.operand;
-    int target = currentInstruction[6].u.operand;
-
-    JumpList callHasProperty;
-
-    Label begin(this);
-    load32(addressFor(i), regT0);
-    Jump end = branch32(Equal, regT0, addressFor(size));
-
-    // Grab key @ i
-    loadPtr(addressFor(it), regT1);
-    loadPtr(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStrings)), regT2);
-    load32(BaseIndex(regT2, regT0, TimesEight), regT2);
-    store32(Imm32(JSValue::CellTag), tagFor(dst));
-    store32(regT2, payloadFor(dst));
-
-    // Increment i
-    add32(Imm32(1), regT0);
-    store32(regT0, addressFor(i));
-
-    // Verify that i is valid:
-    loadPtr(addressFor(base), regT0);
-
-    // Test base's structure
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    callHasProperty.append(branchPtr(NotEqual, regT2, Address(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedStructure)))));
-
-    // Test base's prototype chain
-    loadPtr(Address(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedPrototypeChain))), regT3);
-    loadPtr(Address(regT3, OBJECT_OFFSETOF(StructureChain, m_vector)), regT3);
-    addJump(branchTestPtr(Zero, Address(regT3)), target);
-
-    Label checkPrototype(this);
-    callHasProperty.append(branch32(Equal, Address(regT2, OBJECT_OFFSETOF(Structure, m_prototype) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), Imm32(JSValue::NullTag)));
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(Structure, m_prototype) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    callHasProperty.append(branchPtr(NotEqual, regT2, Address(regT3)));
-    addPtr(Imm32(sizeof(Structure*)), regT3);
-    branchTestPtr(NonZero, Address(regT3)).linkTo(checkPrototype, this);
-
-    // Continue loop.
-    addJump(jump(), target);
+    int src = currentInstruction[2].u.operand;
 
-    // Slow case: Ask the object if i is valid.
-    callHasProperty.link(this);
-    loadPtr(addressFor(dst), regT1);
-    JITStubCall stubCall(this, cti_has_property);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call();
+    emitLoad(src, regT1, regT0);
 
-    // Test for valid key.
-    addJump(branchTest32(NonZero, regT0), target);
-    jump().linkTo(begin, this);
+    Jump isInt32 = branch32(Equal, regT1, TrustedImm32(JSValue::Int32Tag));
+    addSlowCase(branch32(AboveOrEqual, regT1, TrustedImm32(JSValue::LowestTag)));
+    isInt32.link(this);
 
-    // End of loop.
-    end.link(this);
+    if (src != dst)
+        emitStore(dst, regT1, regT0);
 }
 
-void JIT::emit_op_push_scope(Instruction* currentInstruction)
+void JIT::emitSlow_op_to_number(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    JITStubCall stubCall(this, cti_op_push_scope);
-    stubCall.addArgument(currentInstruction[1].u.operand);
-    stubCall.call(currentInstruction[1].u.operand);
-}
+    linkSlowCase(iter);
 
-void JIT::emit_op_pop_scope(Instruction*)
-{
-    JITStubCall(this, cti_op_pop_scope).call();
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_number);
+    slowPathCall.call();
 }
 
-void JIT::emit_op_to_jsnumber(Instruction* currentInstruction)
+void JIT::emit_op_to_string(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
     int src = currentInstruction[2].u.operand;
 
     emitLoad(src, regT1, regT0);
 
-    Jump isInt32 = branch32(Equal, regT1, Imm32(JSValue::Int32Tag));
-    addSlowCase(branch32(AboveOrEqual, regT1, Imm32(JSValue::EmptyValueTag)));
-    isInt32.link(this);
+    addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));
+    addSlowCase(branch8(NotEqual, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(StringType)));
 
     if (src != dst)
         emitStore(dst, regT1, regT0);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_to_jsnumber), dst, regT1, regT0);
 }
 
-void JIT::emitSlow_op_to_jsnumber(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_to_string(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    int dst = currentInstruction[1].u.operand;
-
-    linkSlowCase(iter);
+    linkSlowCase(iter); // Not JSCell.
+    linkSlowCase(iter); // Not JSString.
 
-    JITStubCall stubCall(this, cti_op_to_jsnumber);
-    stubCall.addArgument(regT1, regT0);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_string);
+    slowPathCall.call();
 }
 
-void JIT::emit_op_push_new_scope(Instruction* currentInstruction)
+void JIT::emit_op_push_name_scope(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_push_new_scope);
-    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.addArgument(currentInstruction[3].u.operand);
-    stubCall.call(currentInstruction[1].u.operand);
+    int dst = currentInstruction[1].u.operand;
+    emitLoad(currentInstruction[2].u.operand, regT1, regT0);
+    if (currentInstruction[4].u.operand == JSNameScope::CatchScope) {
+        callOperation(operationPushCatchScope, dst, jsCast<SymbolTable*>(getConstantOperand(currentInstruction[3].u.operand)), regT1, regT0);
+        return;
+    }
+
+    RELEASE_ASSERT(currentInstruction[4].u.operand == JSNameScope::FunctionNameScope);
+    callOperation(operationPushFunctionNameScope, dst, jsCast<SymbolTable*>(getConstantOperand(currentInstruction[3].u.operand)), regT1, regT0);
 }
 
 void JIT::emit_op_catch(Instruction* currentInstruction)
 {
-    unsigned exception = currentInstruction[1].u.operand;
+    move(TrustedImmPtr(m_vm), regT3);
+    // operationThrow returns the callFrame for the handler.
+    load32(Address(regT3, VM::callFrameForThrowOffset()), callFrameRegister);
+    load32(Address(regT3, VM::vmEntryFrameForThrowOffset()), regT0);
+    store32(regT0, Address(regT3, VM::topVMEntryFrameOffset()));
 
-    // This opcode only executes after a return from cti_op_throw.
+    addPtr(TrustedImm32(stackPointerOffsetFor(codeBlock()) * sizeof(Register)), callFrameRegister, stackPointerRegister);
 
-    // cti_op_throw may have taken us to a call frame further up the stack; reload
-    // the call frame pointer to adjust.
-    peek(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
+    // Now store the exception returned by operationThrow.
+    load32(Address(regT3, VM::exceptionOffset()), regT2);
+    move(TrustedImm32(JSValue::CellTag), regT1);
 
-    // Now store the exception returned by cti_op_throw.
-    emitStore(exception, regT1, regT0);
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_catch), exception, regT1, regT0);
-}
+    store32(TrustedImm32(0), Address(regT3, VM::exceptionOffset()));
 
-void JIT::emit_op_jmp_scopes(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_jmp_scopes);
-    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
-    stubCall.call();
-    addJump(jump(), currentInstruction[2].u.operand);
+    unsigned exception = currentInstruction[1].u.operand;
+    emitStore(exception, regT1, regT2);
+
+    load32(Address(regT2, Exception::valueOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
+    load32(Address(regT2, Exception::valueOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
+
+    unsigned thrownValue = currentInstruction[2].u.operand;
+    emitStore(thrownValue, regT1, regT0);
 }
 
 void JIT::emit_op_switch_imm(Instruction* currentInstruction)
 {
-    unsigned tableIndex = currentInstruction[1].u.operand;
+    size_t tableIndex = currentInstruction[1].u.operand;
     unsigned defaultOffset = currentInstruction[2].u.operand;
     unsigned scrutinee = currentInstruction[3].u.operand;
 
     // create jump table for switch destinations, track this switch statement.
-    SimpleJumpTable* jumpTable = &m_codeBlock->immediateSwitchJumpTable(tableIndex);
-    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset, SwitchRecord::Immediate));
-    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
+    SimpleJumpTable* jumpTable = &m_codeBlock->switchJumpTable(tableIndex);
+    m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Immediate));
+    jumpTable->ensureCTITable();
 
-    JITStubCall stubCall(this, cti_op_switch_imm);
-    stubCall.addArgument(scrutinee);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitLoad(scrutinee, regT1, regT0);
+    callOperation(operationSwitchImmWithUnknownKeyType, regT1, regT0, tableIndex);
+    jump(returnValueGPR);
 }
 
 void JIT::emit_op_switch_char(Instruction* currentInstruction)
 {
-    unsigned tableIndex = currentInstruction[1].u.operand;
+    size_t tableIndex = currentInstruction[1].u.operand;
     unsigned defaultOffset = currentInstruction[2].u.operand;
     unsigned scrutinee = currentInstruction[3].u.operand;
 
     // create jump table for switch destinations, track this switch statement.
-    SimpleJumpTable* jumpTable = &m_codeBlock->characterSwitchJumpTable(tableIndex);
-    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset, SwitchRecord::Character));
-    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
+    SimpleJumpTable* jumpTable = &m_codeBlock->switchJumpTable(tableIndex);
+    m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Character));
+    jumpTable->ensureCTITable();
 
-    JITStubCall stubCall(this, cti_op_switch_char);
-    stubCall.addArgument(scrutinee);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitLoad(scrutinee, regT1, regT0);
+    callOperation(operationSwitchCharWithUnknownKeyType, regT1, regT0, tableIndex);
+    jump(returnValueGPR);
 }
 
 void JIT::emit_op_switch_string(Instruction* currentInstruction)
 {
-    unsigned tableIndex = currentInstruction[1].u.operand;
+    size_t tableIndex = currentInstruction[1].u.operand;
     unsigned defaultOffset = currentInstruction[2].u.operand;
     unsigned scrutinee = currentInstruction[3].u.operand;
 
     // create jump table for switch destinations, track this switch statement.
     StringJumpTable* jumpTable = &m_codeBlock->stringSwitchJumpTable(tableIndex);
-    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset));
+    m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset));
 
-    JITStubCall stubCall(this, cti_op_switch_string);
-    stubCall.addArgument(scrutinee);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitLoad(scrutinee, regT1, regT0);
+    callOperation(operationSwitchStringWithUnknownKeyType, regT1, regT0, tableIndex);
+    jump(returnValueGPR);
 }
 
-void JIT::emit_op_new_error(Instruction* currentInstruction)
+void JIT::emit_op_throw_static_error(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned type = currentInstruction[2].u.operand;
-    unsigned message = currentInstruction[3].u.operand;
-
-    JITStubCall stubCall(this, cti_op_new_error);
-    stubCall.addArgument(Imm32(type));
-    stubCall.addArgument(m_codeBlock->getConstant(message));
-    stubCall.addArgument(Imm32(m_bytecodeIndex));
-    stubCall.call(dst);
+    emitLoad(m_codeBlock->getConstant(currentInstruction[1].u.operand), regT1, regT0);
+    callOperation(operationThrowStaticError, regT1, regT0, currentInstruction[2].u.operand);
 }
 
 void JIT::emit_op_debug(Instruction* currentInstruction)
 {
-#if ENABLE(DEBUG_WITH_BREAKPOINT)
-    UNUSED_PARAM(currentInstruction);
-    breakpoint();
-#else
-    JITStubCall stubCall(this, cti_op_debug);
-    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
-    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
-    stubCall.call();
-#endif
+    load32(codeBlock()->debuggerRequestsAddress(), regT0);
+    Jump noDebuggerRequests = branchTest32(Zero, regT0);
+    callOperation(operationDebug, currentInstruction[1].u.operand);
+    noDebuggerRequests.link(this);
 }
 
 
-void JIT::emit_op_enter(Instruction*)
+void JIT::emit_op_enter(Instruction* currentInstruction)
 {
+    emitEnterOptimizationCheck();
+    
     // Even though JIT code doesn't use them, we initialize our constant
     // registers to zap stale pointers, to avoid unnecessarily prolonging
     // object lifetime and increasing GC pressure.
     for (int i = 0; i < m_codeBlock->m_numVars; ++i)
-        emitStore(i, jsUndefined());
+        emitStore(virtualRegisterForLocal(i).offset(), jsUndefined());
+
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_enter);
+    slowPathCall.call();
 }
 
-void JIT::emit_op_enter_with_activation(Instruction* currentInstruction)
+void JIT::emit_op_create_lexical_environment(Instruction* currentInstruction)
 {
-    emit_op_enter(currentInstruction);
+    int lexicalEnvironment = currentInstruction[1].u.operand;
+    int scope = currentInstruction[2].u.operand;
 
-    JITStubCall(this, cti_op_push_activation).call(currentInstruction[1].u.operand);
+    emitLoadPayload(currentInstruction[2].u.operand, regT0);
+    callOperation(operationCreateActivation, regT0);
+    emitStoreCell(lexicalEnvironment, returnValueGPR);
+    emitStoreCell(scope, returnValueGPR);
 }
 
-void JIT::emit_op_create_arguments(Instruction*)
+void JIT::emit_op_get_scope(Instruction* currentInstruction)
 {
-    Jump argsCreated = branch32(NotEqual, tagFor(RegisterFile::ArgumentsRegister, callFrameRegister), Imm32(JSValue::EmptyValueTag));
-
-    // If we get here the arguments pointer is a null cell - i.e. arguments need lazy creation.
-    if (m_codeBlock->m_numParameters == 1)
-        JITStubCall(this, cti_op_create_arguments_no_params).call();
-    else
-        JITStubCall(this, cti_op_create_arguments).call();
-
-    argsCreated.link(this);
+    int dst = currentInstruction[1].u.operand;
+    emitGetFromCallFrameHeaderPtr(JSStack::Callee, regT0);
+    loadPtr(Address(regT0, JSFunction::offsetOfScopeChain()), regT0);
+    emitStoreCell(dst, regT0);
 }
 
-void JIT::emit_op_init_arguments(Instruction*)
+void JIT::emit_op_create_this(Instruction* currentInstruction)
 {
-    emitStore(RegisterFile::ArgumentsRegister, JSValue(), callFrameRegister);
+    int callee = currentInstruction[2].u.operand;
+    WriteBarrierBase<JSCell>* cachedFunction = &currentInstruction[4].u.jsCell;
+    RegisterID calleeReg = regT0;
+    RegisterID rareDataReg = regT4;
+    RegisterID resultReg = regT0;
+    RegisterID allocatorReg = regT1;
+    RegisterID structureReg = regT2;
+    RegisterID cachedFunctionReg = regT4;
+    RegisterID scratchReg = regT3;
+
+    emitLoadPayload(callee, calleeReg);
+    loadPtr(Address(calleeReg, JSFunction::offsetOfRareData()), rareDataReg);
+    addSlowCase(branchTestPtr(Zero, rareDataReg));
+    loadPtr(Address(rareDataReg, FunctionRareData::offsetOfAllocationProfile() + ObjectAllocationProfile::offsetOfAllocator()), allocatorReg);
+    loadPtr(Address(rareDataReg, FunctionRareData::offsetOfAllocationProfile() + ObjectAllocationProfile::offsetOfStructure()), structureReg);
+    addSlowCase(branchTestPtr(Zero, allocatorReg));
+
+    loadPtr(cachedFunction, cachedFunctionReg);
+    Jump hasSeenMultipleCallees = branchPtr(Equal, cachedFunctionReg, TrustedImmPtr(JSCell::seenMultipleCalleeObjects()));
+    addSlowCase(branchPtr(NotEqual, calleeReg, cachedFunctionReg));
+    hasSeenMultipleCallees.link(this);
+
+    emitAllocateJSObject(allocatorReg, structureReg, resultReg, scratchReg);
+    emitStoreCell(currentInstruction[1].u.operand, resultReg);
 }
 
-void JIT::emit_op_convert_this(Instruction* currentInstruction)
+void JIT::emitSlow_op_create_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned thisRegister = currentInstruction[1].u.operand;
+    linkSlowCase(iter); // doesn't have rare data
+    linkSlowCase(iter); // doesn't have an allocation profile
+    linkSlowCase(iter); // allocation failed
+    linkSlowCase(iter); // cached function didn't match
 
-    emitLoad(thisRegister, regT1, regT0);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_create_this);
+    slowPathCall.call();
+}
 
-    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::CellTag)));
+void JIT::emit_op_to_this(Instruction* currentInstruction)
+{
+    WriteBarrierBase<Structure>* cachedStructure = &currentInstruction[2].u.structure;
+    int thisRegister = currentInstruction[1].u.operand;
 
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
-    addSlowCase(branchTest8(NonZero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(NeedsThisConversion)));
+    emitLoad(thisRegister, regT3, regT2);
 
-    map(m_bytecodeIndex + OPCODE_LENGTH(op_convert_this), thisRegister, regT1, regT0);
+    addSlowCase(branch32(NotEqual, regT3, TrustedImm32(JSValue::CellTag)));
+    addSlowCase(branch8(NotEqual, Address(regT2, JSCell::typeInfoTypeOffset()), TrustedImm32(FinalObjectType)));
+    loadPtr(Address(regT2, JSCell::structureIDOffset()), regT0);
+    loadPtr(cachedStructure, regT2);
+    addSlowCase(branchPtr(NotEqual, regT0, regT2));
 }
 
-void JIT::emitSlow_op_convert_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_to_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned thisRegister = currentInstruction[1].u.operand;
-
     linkSlowCase(iter);
     linkSlowCase(iter);
+    linkSlowCase(iter);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_this);
+    slowPathCall.call();
+}
 
-    JITStubCall stubCall(this, cti_op_convert_this);
-    stubCall.addArgument(regT1, regT0);
-    stubCall.call(thisRegister);
+void JIT::emit_op_check_tdz(Instruction* currentInstruction)
+{
+    emitLoadTag(currentInstruction[1].u.operand, regT0);
+    addSlowCase(branch32(Equal, regT0, TrustedImm32(JSValue::EmptyValueTag)));
 }
 
-void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
+void JIT::emitSlow_op_check_tdz(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
-    Jump noProfiler = branchTestPtr(Zero, Address(regT2));
+    linkSlowCase(iter);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_throw_tdz_error);
+    slowPathCall.call();
+}
 
-    JITStubCall stubCall(this, cti_op_profile_will_call);
-    stubCall.addArgument(currentInstruction[1].u.operand);
-    stubCall.call();
-    noProfiler.link(this);
+void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
+{
+    load32(m_vm->enabledProfilerAddress(), regT0);
+    Jump profilerDone = branchTestPtr(Zero, regT0);
+    emitLoad(currentInstruction[1].u.operand, regT1, regT0);
+    callOperation(operationProfileWillCall, regT1, regT0);
+    profilerDone.link(this);
 }
 
 void JIT::emit_op_profile_did_call(Instruction* currentInstruction)
 {
-    peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
-    Jump noProfiler = branchTestPtr(Zero, Address(regT2));
+    load32(m_vm->enabledProfilerAddress(), regT0);
+    Jump profilerDone = branchTestPtr(Zero, regT0);
+    emitLoad(currentInstruction[1].u.operand, regT1, regT0);
+    callOperation(operationProfileDidCall, regT1, regT0);
+    profilerDone.link(this);
+}
+
+void JIT::emit_op_has_structure_property(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int base = currentInstruction[2].u.operand;
+    int enumerator = currentInstruction[4].u.operand;
+
+    emitLoadPayload(base, regT0);
+    emitJumpSlowCaseIfNotJSCell(base);
 
-    JITStubCall stubCall(this, cti_op_profile_did_call);
-    stubCall.addArgument(currentInstruction[1].u.operand);
-    stubCall.call();
-    noProfiler.link(this);
+    emitLoadPayload(enumerator, regT1);
+
+    load32(Address(regT0, JSCell::structureIDOffset()), regT0);
+    addSlowCase(branch32(NotEqual, regT0, Address(regT1, JSPropertyNameEnumerator::cachedStructureIDOffset())));
+    
+    move(TrustedImm32(1), regT0);
+    emitStoreBool(dst, regT0);
 }
 
+void JIT::privateCompileHasIndexedProperty(ByValInfo* byValInfo, ReturnAddressPtr returnAddress, JITArrayMode arrayMode)
+{
+    Instruction* currentInstruction = m_codeBlock->instructions().begin() + byValInfo->bytecodeIndex;
+    
+    PatchableJump badType;
+    
+    // FIXME: Add support for other types like TypedArrays and Arguments.
+    // See https://bugs.webkit.org/show_bug.cgi?id=135033 and https://bugs.webkit.org/show_bug.cgi?id=135034.
+    JumpList slowCases = emitLoadForArrayMode(currentInstruction, arrayMode, badType);
+    move(TrustedImm32(1), regT0);
+    Jump done = jump();
+
+    LinkBuffer patchBuffer(*m_vm, *this, m_codeBlock);
+    
+    patchBuffer.link(badType, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(returnAddress.value())).labelAtOffset(byValInfo->returnAddressToSlowPath));
+    patchBuffer.link(slowCases, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(returnAddress.value())).labelAtOffset(byValInfo->returnAddressToSlowPath));
+    
+    patchBuffer.link(done, byValInfo->badTypeJump.labelAtOffset(byValInfo->badTypeJumpToDone));
+    
+    byValInfo->stubRoutine = FINALIZE_CODE_FOR_STUB(
+        m_codeBlock, patchBuffer,
+        ("Baseline has_indexed_property stub for %s, return point %p", toCString(*m_codeBlock).data(), returnAddress.value()));
+    
+    RepatchBuffer repatchBuffer(m_codeBlock);
+    repatchBuffer.relink(byValInfo->badTypeJump, CodeLocationLabel(byValInfo->stubRoutine->code().code()));
+    repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(operationHasIndexedPropertyGeneric));
+}
+
+void JIT::emit_op_has_indexed_property(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int base = currentInstruction[2].u.operand;
+    int property = currentInstruction[3].u.operand;
+    ArrayProfile* profile = currentInstruction[4].u.arrayProfile;
+    
+    emitLoadPayload(base, regT0);
+    emitJumpSlowCaseIfNotJSCell(base);
+
+    emitLoadPayload(property, regT1);
+
+    // This is technically incorrect - we're zero-extending an int32. On the hot path this doesn't matter.
+    // We check the value as if it was a uint32 against the m_vectorLength - which will always fail if
+    // number was signed since m_vectorLength is always less than intmax (since the total allocation
+    // size is always less than 4Gb). As such zero extending will have been correct (and extending the value
+    // to 64-bits is necessary since it's used in the address calculation. We zero extend rather than sign
+    // extending since it makes it easier to re-tag the value in the slow case.
+    zeroExtend32ToPtr(regT1, regT1);
+
+    emitArrayProfilingSiteWithCell(regT0, regT2, profile);
+    and32(TrustedImm32(IndexingShapeMask), regT2);
+
+    JITArrayMode mode = chooseArrayMode(profile);
+    PatchableJump badType;
+
+    // FIXME: Add support for other types like TypedArrays and Arguments.
+    // See https://bugs.webkit.org/show_bug.cgi?id=135033 and https://bugs.webkit.org/show_bug.cgi?id=135034.
+    JumpList slowCases = emitLoadForArrayMode(currentInstruction, mode, badType);
+    move(TrustedImm32(1), regT0);
+
+    addSlowCase(badType);
+    addSlowCase(slowCases);
+    
+    Label done = label();
+    
+    emitStoreBool(dst, regT0);
+    
+    m_byValCompilationInfo.append(ByValCompilationInfo(m_bytecodeOffset, badType, mode, done));
+}
+
+void JIT::emitSlow_op_has_indexed_property(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+{
+    int dst = currentInstruction[1].u.operand;
+    int base = currentInstruction[2].u.operand;
+    int property = currentInstruction[3].u.operand;
+    ArrayProfile* profile = currentInstruction[4].u.arrayProfile;
+    
+    linkSlowCaseIfNotJSCell(iter, base); // base cell check
+    linkSlowCase(iter); // base array check
+    linkSlowCase(iter); // vector length check
+    linkSlowCase(iter); // empty value
+
+    Label slowPath = label();
+    
+    emitLoad(base, regT1, regT0);
+    emitLoad(property, regT3, regT2);
+    Call call = callOperation(operationHasIndexedPropertyDefault, dst, regT1, regT0, regT3, regT2, profile);
+
+    m_byValCompilationInfo[m_byValInstructionIndex].slowPathTarget = slowPath;
+    m_byValCompilationInfo[m_byValInstructionIndex].returnAddress = call;
+    m_byValInstructionIndex++;
 }
 
-#endif // ENABLE(JIT) && USE(JSVALUE32_64)
+void JIT::emit_op_get_direct_pname(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int base = currentInstruction[2].u.operand;
+    int index = currentInstruction[4].u.operand;
+    int enumerator = currentInstruction[5].u.operand;
+
+    // Check that base is a cell
+    emitLoadPayload(base, regT0);
+    emitJumpSlowCaseIfNotJSCell(base);
+
+    // Check the structure
+    emitLoadPayload(enumerator, regT1);
+    load32(Address(regT0, JSCell::structureIDOffset()), regT2);
+    addSlowCase(branch32(NotEqual, regT2, Address(regT1, JSPropertyNameEnumerator::cachedStructureIDOffset())));
+
+    // Compute the offset
+    emitLoadPayload(index, regT2);
+    // If index is less than the enumerator's cached inline storage, then it's an inline access
+    Jump outOfLineAccess = branch32(AboveOrEqual, regT2, Address(regT1, JSPropertyNameEnumerator::cachedInlineCapacityOffset()));
+    addPtr(TrustedImm32(JSObject::offsetOfInlineStorage()), regT0);
+    load32(BaseIndex(regT0, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
+    load32(BaseIndex(regT0, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
+    
+    Jump done = jump();
+
+    // Otherwise it's out of line
+    outOfLineAccess.link(this);
+    loadPtr(Address(regT0, JSObject::butterflyOffset()), regT0);
+    sub32(Address(regT1, JSPropertyNameEnumerator::cachedInlineCapacityOffset()), regT2);
+    neg32(regT2);
+    int32_t offsetOfFirstProperty = static_cast<int32_t>(offsetInButterfly(firstOutOfLineOffset)) * sizeof(EncodedJSValue);
+    load32(BaseIndex(regT0, regT2, TimesEight, offsetOfFirstProperty + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
+    load32(BaseIndex(regT0, regT2, TimesEight, offsetOfFirstProperty + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
+    
+    done.link(this);
+    emitValueProfilingSite();
+    emitStore(dst, regT1, regT0);
+}
+
+void JIT::emitSlow_op_get_direct_pname(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+{
+    int base = currentInstruction[2].u.operand;
+    linkSlowCaseIfNotJSCell(iter, base);
+    linkSlowCase(iter);
+
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_get_direct_pname);
+    slowPathCall.call();
+}
+
+void JIT::emit_op_enumerator_structure_pname(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int enumerator = currentInstruction[2].u.operand;
+    int index = currentInstruction[3].u.operand;
+
+    emitLoadPayload(index, regT0);
+    emitLoadPayload(enumerator, regT1);
+    Jump inBounds = branch32(Below, regT0, Address(regT1, JSPropertyNameEnumerator::endStructurePropertyIndexOffset()));
+
+    move(TrustedImm32(JSValue::NullTag), regT2);
+    move(TrustedImm32(0), regT0);
+
+    Jump done = jump();
+    inBounds.link(this);
+
+    loadPtr(Address(regT1, JSPropertyNameEnumerator::cachedPropertyNamesVectorOffset()), regT1);
+    loadPtr(BaseIndex(regT1, regT0, timesPtr()), regT0);
+    move(TrustedImm32(JSValue::CellTag), regT2);
+
+    done.link(this);
+    emitStore(dst, regT2, regT0);
+}
+
+void JIT::emit_op_enumerator_generic_pname(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int enumerator = currentInstruction[2].u.operand;
+    int index = currentInstruction[3].u.operand;
+
+    emitLoadPayload(index, regT0);
+    emitLoadPayload(enumerator, regT1);
+    Jump inBounds = branch32(Below, regT0, Address(regT1, JSPropertyNameEnumerator::endGenericPropertyIndexOffset()));
+
+    move(TrustedImm32(JSValue::NullTag), regT2);
+    move(TrustedImm32(0), regT0);
+
+    Jump done = jump();
+    inBounds.link(this);
+
+    loadPtr(Address(regT1, JSPropertyNameEnumerator::cachedPropertyNamesVectorOffset()), regT1);
+    loadPtr(BaseIndex(regT1, regT0, timesPtr()), regT0);
+    move(TrustedImm32(JSValue::CellTag), regT2);
+    
+    done.link(this);
+    emitStore(dst, regT2, regT0);
+}
+
+void JIT::emit_op_profile_type(Instruction* currentInstruction)
+{
+    TypeLocation* cachedTypeLocation = currentInstruction[2].u.location;
+    int valueToProfile = currentInstruction[1].u.operand;
+
+    // Load payload in T0. Load tag in T3.
+    emitLoadPayload(valueToProfile, regT0);
+    emitLoadTag(valueToProfile, regT3);
+
+    JumpList jumpToEnd;
+
+    // Compile in a predictive type check, if possible, to see if we can skip writing to the log.
+    // These typechecks are inlined to match those of the 32-bit JSValue type checks.
+    if (cachedTypeLocation->m_lastSeenType == TypeUndefined)
+        jumpToEnd.append(branch32(Equal, regT3, TrustedImm32(JSValue::UndefinedTag)));
+    else if (cachedTypeLocation->m_lastSeenType == TypeNull)
+        jumpToEnd.append(branch32(Equal, regT3, TrustedImm32(JSValue::NullTag)));
+    else if (cachedTypeLocation->m_lastSeenType == TypeBoolean)
+        jumpToEnd.append(branch32(Equal, regT3, TrustedImm32(JSValue::BooleanTag)));
+    else if (cachedTypeLocation->m_lastSeenType == TypeMachineInt)
+        jumpToEnd.append(branch32(Equal, regT3, TrustedImm32(JSValue::Int32Tag)));
+    else if (cachedTypeLocation->m_lastSeenType == TypeNumber) {
+        jumpToEnd.append(branch32(Below, regT3, TrustedImm32(JSValue::LowestTag)));
+        jumpToEnd.append(branch32(Equal, regT3, TrustedImm32(JSValue::Int32Tag)));
+    } else if (cachedTypeLocation->m_lastSeenType == TypeString) {
+        Jump isNotCell = branch32(NotEqual, regT3, TrustedImm32(JSValue::CellTag));
+        jumpToEnd.append(branch8(Equal, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(StringType)));
+        isNotCell.link(this);
+    }
+
+    // Load the type profiling log into T2.
+    TypeProfilerLog* cachedTypeProfilerLog = m_vm->typeProfilerLog();
+    move(TrustedImmPtr(cachedTypeProfilerLog), regT2);
+
+    // Load the next log entry into T1.
+    loadPtr(Address(regT2, TypeProfilerLog::currentLogEntryOffset()), regT1);
+
+    // Store the JSValue onto the log entry.
+    store32(regT0, Address(regT1, TypeProfilerLog::LogEntry::valueOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.payload)));
+    store32(regT3, Address(regT1, TypeProfilerLog::LogEntry::valueOffset() + OBJECT_OFFSETOF(JSValue, u.asBits.tag)));
+
+    // Store the structureID of the cell if argument is a cell, otherwise, store 0 on the log entry.
+    Jump notCell = branch32(NotEqual, regT3, TrustedImm32(JSValue::CellTag));
+    load32(Address(regT0, JSCell::structureIDOffset()), regT0);
+    store32(regT0, Address(regT1, TypeProfilerLog::LogEntry::structureIDOffset()));
+    Jump skipNotCell = jump();
+    notCell.link(this);
+    store32(TrustedImm32(0), Address(regT1, TypeProfilerLog::LogEntry::structureIDOffset()));
+    skipNotCell.link(this);
+
+    // Store the typeLocation on the log entry.
+    move(TrustedImmPtr(cachedTypeLocation), regT0);
+    store32(regT0, Address(regT1, TypeProfilerLog::LogEntry::locationOffset()));
+
+    // Increment the current log entry.
+    addPtr(TrustedImm32(sizeof(TypeProfilerLog::LogEntry)), regT1);
+    store32(regT1, Address(regT2, TypeProfilerLog::currentLogEntryOffset()));
+    jumpToEnd.append(branchPtr(NotEqual, regT1, TrustedImmPtr(cachedTypeProfilerLog->logEndPtr())));
+    // Clear the log if we're at the end of the log.
+    callOperation(operationProcessTypeProfilerLog);
+
+    jumpToEnd.link(this);
+}
+
+} // namespace JSC
+
+#endif // USE(JSVALUE32_64)
+#endif // ENABLE(JIT)