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JavaScriptCore-7600.1.4.15.12.tar.gz
[apple/javascriptcore.git] / jit / JITOpcodes.cpp
index 4cdd35aa96f48ef84057ad301b7672438b53c9ff..25a843fcbade8e0dcf41b3b5285ad84da89c500e 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2009, 2012, 2013 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 "JIT.h"
 
 #include "Arguments.h"
-#include "JITInlineMethods.h"
-#include "JITStubCall.h"
+#include "CopiedSpaceInlines.h"
+#include "Debugger.h"
+#include "Heap.h"
+#include "JITInlines.h"
 #include "JSArray.h"
 #include "JSCell.h"
 #include "JSFunction.h"
 #include "JSPropertyNameIterator.h"
-#include "LinkBuffer.h"
+#include "MaxFrameExtentForSlowPathCall.h"
+#include "SlowPathCall.h"
+#include "VirtualRegister.h"
 
 namespace JSC {
 
 #if USE(JSVALUE64)
 
-void JIT::privateCompileCTIMachineTrampolines(RefPtr<ExecutablePool>* executablePool, JSGlobalData* globalData, TrampolineStructure *trampolines)
+JIT::CodeRef JIT::privateCompileCTINativeCall(VM* vm, NativeFunction)
 {
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    // (2) The second function provides fast property access for string length
-    Label stringLengthBegin = align();
-
-    // Check eax is a string
-    Jump string_failureCases1 = emitJumpIfNotJSCell(regT0);
-    Jump string_failureCases2 = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr));
-
-    // Checks out okay! - get the length from the Ustring.
-    load32(Address(regT0, OBJECT_OFFSETOF(JSString, m_length)), regT0);
-
-    Jump string_failureCases3 = branch32(LessThan, regT0, TrustedImm32(0));
-
-    // regT0 contains a 64 bit value (is positive, is zero extended) so we don't need sign extend here.
-    emitFastArithIntToImmNoCheck(regT0, regT0);
-    
-    ret();
-#endif
-
-    // (3) Trampolines for the slow cases of op_call / op_call_eval / op_construct.
-    COMPILE_ASSERT(sizeof(CodeType) == 4, CodeTypeEnumMustBe32Bit);
-
-    // VirtualCallLink Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    JumpList callLinkFailures;
-    Label virtualCallLinkBegin = align();
-    compileOpCallInitializeCallFrame();
-    preserveReturnAddressAfterCall(regT3);
-    emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
-    restoreArgumentReference();
-    Call callLazyLinkCall = call();
-    callLinkFailures.append(branchTestPtr(Zero, regT0));
-    restoreReturnAddressBeforeReturn(regT3);
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
-    jump(regT0);
-
-    // VirtualConstructLink Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    Label virtualConstructLinkBegin = align();
-    compileOpCallInitializeCallFrame();
-    preserveReturnAddressAfterCall(regT3);
-    emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
-    restoreArgumentReference();
-    Call callLazyLinkConstruct = call();
-    callLinkFailures.append(branchTestPtr(Zero, regT0));
-    restoreReturnAddressBeforeReturn(regT3);
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
-    jump(regT0);
-
-    // VirtualCall Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    Label virtualCallBegin = align();
-    compileOpCallInitializeCallFrame();
-
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-
-    Jump hasCodeBlock3 = branch32(GreaterThanOrEqual, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParametersForCall)), TrustedImm32(0));
-    preserveReturnAddressAfterCall(regT3);
-    restoreArgumentReference();
-    Call callCompileCall = call();
-    callLinkFailures.append(branchTestPtr(Zero, regT0));
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
-    restoreReturnAddressBeforeReturn(regT3);
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    hasCodeBlock3.link(this);
-
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_jitCodeForCallWithArityCheck)), regT0);
-    jump(regT0);
-
-    // VirtualConstruct Trampoline
-    // regT0 holds callee, regT1 holds argCount.  regT2 will hold the FunctionExecutable.
-    Label virtualConstructBegin = align();
-    compileOpCallInitializeCallFrame();
-
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-
-    Jump hasCodeBlock4 = branch32(GreaterThanOrEqual, Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_numParametersForConstruct)), TrustedImm32(0));
-    preserveReturnAddressAfterCall(regT3);
-    restoreArgumentReference();
-    Call callCompileConstruct = call();
-    callLinkFailures.append(branchTestPtr(Zero, regT0));
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT1);
-    restoreReturnAddressBeforeReturn(regT3);
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    hasCodeBlock4.link(this);
-
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(FunctionExecutable, m_jitCodeForConstructWithArityCheck)), regT0);
-    jump(regT0);
-    
-    // If the parser fails we want to be able to be able to keep going,
-    // So we handle this as a parse failure.
-    callLinkFailures.link(this);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
-    restoreReturnAddressBeforeReturn(regT1);
-    move(TrustedImmPtr(&globalData->exceptionLocation), regT2);
-    storePtr(regT1, regT2);
-    poke(callFrameRegister, 1 + OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
-    poke(TrustedImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()));
-    ret();
-
-    // NativeCall Trampoline
-    Label nativeCallThunk = privateCompileCTINativeCall(globalData);    
-    Label nativeConstructThunk = privateCompileCTINativeCall(globalData, true);    
-
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    Call string_failureCases1Call = makeTailRecursiveCall(string_failureCases1);
-    Call string_failureCases2Call = makeTailRecursiveCall(string_failureCases2);
-    Call string_failureCases3Call = makeTailRecursiveCall(string_failureCases3);
-#endif
-
-    // All trampolines constructed! copy the code, link up calls, and set the pointers on the Machine object.
-    LinkBuffer patchBuffer(*m_globalData, this, m_globalData->executableAllocator);
-
-#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
-#if ENABLE(JIT_OPTIMIZE_CALL)
-    patchBuffer.link(callLazyLinkCall, FunctionPtr(cti_vm_lazyLinkCall));
-    patchBuffer.link(callLazyLinkConstruct, FunctionPtr(cti_vm_lazyLinkConstruct));
-#endif
-    patchBuffer.link(callCompileCall, FunctionPtr(cti_op_call_jitCompile));
-    patchBuffer.link(callCompileConstruct, FunctionPtr(cti_op_construct_jitCompile));
-
-    CodeRef finalCode = patchBuffer.finalizeCode();
-    *executablePool = finalCode.m_executablePool;
-
-    trampolines->ctiVirtualCallLink = patchBuffer.trampolineAt(virtualCallLinkBegin);
-    trampolines->ctiVirtualConstructLink = patchBuffer.trampolineAt(virtualConstructLinkBegin);
-    trampolines->ctiVirtualCall = patchBuffer.trampolineAt(virtualCallBegin);
-    trampolines->ctiVirtualConstruct = patchBuffer.trampolineAt(virtualConstructBegin);
-    trampolines->ctiNativeCall = patchBuffer.trampolineAt(nativeCallThunk);
-    trampolines->ctiNativeConstruct = patchBuffer.trampolineAt(nativeConstructThunk);
-#if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
-    trampolines->ctiStringLengthTrampoline = patchBuffer.trampolineAt(stringLengthBegin);
-#endif
+    return vm->getCTIStub(nativeCallGenerator);
 }
 
-JIT::Label JIT::privateCompileCTINativeCall(JSGlobalData* globalData, bool isConstruct)
+void JIT::emit_op_mov(Instruction* currentInstruction)
 {
-    int executableOffsetToFunction = isConstruct ? OBJECT_OFFSETOF(NativeExecutable, m_constructor) : OBJECT_OFFSETOF(NativeExecutable, m_function);
-
-    Label nativeCallThunk = align();
-    
-    emitPutImmediateToCallFrameHeader(0, RegisterFile::CodeBlock);
-
-#if CPU(X86_64)
-    // Load caller frame's scope chain into this callframe so that whatever we call can
-    // get to its global data.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
-    emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
-
-    peek(regT1);
-    emitPutToCallFrameHeader(regT1, RegisterFile::ReturnPC);
-
-    // Calling convention:      f(edi, esi, edx, ecx, ...);
-    // Host function signature: f(ExecState*);
-    move(callFrameRegister, X86Registers::edi);
-
-    subPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister); // Align stack after call.
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, X86Registers::esi);
-    loadPtr(Address(X86Registers::esi, OBJECT_OFFSETOF(JSFunction, m_executable)), X86Registers::r9);
-    move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
-    call(Address(X86Registers::r9, executableOffsetToFunction));
-
-    addPtr(TrustedImm32(16 - sizeof(void*)), stackPointerRegister);
-
-#elif CPU(ARM)
-    // Load caller frame's scope chain into this callframe so that whatever we call can
-    // get to its global data.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT2);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT2);
-    emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
-
-    preserveReturnAddressAfterCall(regT3); // Callee preserved
-    emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
-
-    // Calling convention:      f(r0 == regT0, r1 == regT1, ...);
-    // Host function signature: f(ExecState*);
-    move(callFrameRegister, ARMRegisters::r0);
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, ARMRegisters::r1);
-    move(regT2, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
-    loadPtr(Address(ARMRegisters::r1, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    call(Address(regT2, executableOffsetToFunction));
-
-    restoreReturnAddressBeforeReturn(regT3);
-
-#elif CPU(MIPS)
-    // Load caller frame's scope chain into this callframe so that whatever we call can
-    // get to its global data.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, regT0);
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1, regT0);
-    emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
-
-    preserveReturnAddressAfterCall(regT3); // Callee preserved
-    emitPutToCallFrameHeader(regT3, RegisterFile::ReturnPC);
-
-    // Calling convention:      f(a0, a1, a2, a3);
-    // Host function signature: f(ExecState*);
-
-    // Allocate stack space for 16 bytes (8-byte aligned)
-    // 16 bytes (unused) for 4 arguments
-    subPtr(TrustedImm32(16), stackPointerRegister);
-
-    // Setup arg0
-    move(callFrameRegister, MIPSRegisters::a0);
-
-    // Call
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, MIPSRegisters::a2);
-    loadPtr(Address(MIPSRegisters::a2, OBJECT_OFFSETOF(JSFunction, m_executable)), regT2);
-    move(regT0, callFrameRegister); // Eagerly restore caller frame register to avoid loading from stack.
-    call(Address(regT2, executableOffsetToFunction));
-
-    // Restore stack space
-    addPtr(TrustedImm32(16), stackPointerRegister);
-
-    restoreReturnAddressBeforeReturn(regT3);
-
-#elif ENABLE(JIT_OPTIMIZE_NATIVE_CALL)
-#error "JIT_OPTIMIZE_NATIVE_CALL not yet supported on this platform."
-#else
-    UNUSED_PARAM(executableOffsetToFunction);
-    breakpoint();
-#endif
-
-    // Check for an exception
-    loadPtr(&(globalData->exception), regT2);
-    Jump exceptionHandler = branchTestPtr(NonZero, regT2);
-
-    // Return.
-    ret();
-
-    // Handle an exception
-    exceptionHandler.link(this);
-
-    // Grab the return address.
-    preserveReturnAddressAfterCall(regT1);
-
-    move(TrustedImmPtr(&globalData->exceptionLocation), regT2);
-    storePtr(regT1, regT2);
-    poke(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof(void*));
-
-    // Set the return address.
-    move(TrustedImmPtr(FunctionPtr(ctiVMThrowTrampoline).value()), regT1);
-    restoreReturnAddressBeforeReturn(regT1);
-
-    ret();
-
-    return nativeCallThunk;
-}
+    int dst = currentInstruction[1].u.operand;
+    int src = currentInstruction[2].u.operand;
 
-JIT::CodePtr JIT::privateCompileCTINativeCall(PassRefPtr<ExecutablePool>, JSGlobalData* globalData, NativeFunction)
-{
-    return globalData->jitStubs->ctiNativeCall();
+    emitGetVirtualRegister(src, regT0);
+    emitPutVirtualRegister(dst);
 }
 
-void JIT::emit_op_mov(Instruction* currentInstruction)
+void JIT::emit_op_captured_mov(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
     int src = currentInstruction[2].u.operand;
 
-    if (m_codeBlock->isConstantRegisterIndex(src)) {
-        storePtr(ImmPtr(JSValue::encode(getConstantOperand(src))), Address(callFrameRegister, dst * sizeof(Register)));
-        if (dst == m_lastResultBytecodeRegister)
-            killLastResultRegister();
-    } else if ((src == m_lastResultBytecodeRegister) || (dst == m_lastResultBytecodeRegister)) {
-        // If either the src or dst is the cached register go though
-        // get/put registers to make sure we track this correctly.
-        emitGetVirtualRegister(src, regT0);
-        emitPutVirtualRegister(dst);
-    } else {
-        // Perform the copy via regT1; do not disturb any mapping in regT0.
-        loadPtr(Address(callFrameRegister, src * sizeof(Register)), regT1);
-        storePtr(regT1, Address(callFrameRegister, dst * sizeof(Register)));
-    }
+    emitGetVirtualRegister(src, regT0);
+    emitNotifyWrite(regT0, regT1, currentInstruction[3].u.watchpointSet);
+    emitPutVirtualRegister(dst);
 }
 
 void JIT::emit_op_end(Instruction* currentInstruction)
 {
-    ASSERT(returnValueRegister != callFrameRegister);
-    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueRegister);
-    restoreReturnAddressBeforeReturn(Address(callFrameRegister, RegisterFile::ReturnPC * static_cast<int>(sizeof(Register))));
+    RELEASE_ASSERT(returnValueGPR != callFrameRegister);
+    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueGPR);
+    emitFunctionEpilogue();
     ret();
 }
 
@@ -339,34 +83,33 @@ 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)
 {
-    emitTimeoutCheck();
+    Structure* structure = currentInstruction[3].u.objectAllocationProfile->structure();
+    size_t allocationSize = JSFinalObject::allocationSize(structure->inlineCapacity());
+    MarkedAllocator* allocator = &m_vm->heap.allocatorForObjectWithoutDestructor(allocationSize);
 
-    unsigned op1 = currentInstruction[1].u.operand;
-    unsigned op2 = currentInstruction[2].u.operand;
-    unsigned target = currentInstruction[3].u.operand;
-    if (isOperandConstantImmediateInt(op2)) {
-        emitGetVirtualRegister(op1, regT0);
-        emitJumpSlowCaseIfNotImmediateInteger(regT0);
-        int32_t op2imm = getConstantOperandImmediateInt(op2);
-        addJump(branch32(LessThanOrEqual, regT0, Imm32(op2imm)), target);
-    } else {
-        emitGetVirtualRegisters(op1, regT0, op2, regT1);
-        emitJumpSlowCaseIfNotImmediateInteger(regT0);
-        emitJumpSlowCaseIfNotImmediateInteger(regT1);
-        addJump(branch32(LessThanOrEqual, regT0, regT1), target);
-    }
+    RegisterID resultReg = regT0;
+    RegisterID allocatorReg = regT1;
+    RegisterID scratchReg = regT2;
+
+    move(TrustedImmPtr(allocator), allocatorReg);
+    emitAllocateJSObject(allocatorReg, TrustedImmPtr(structure), resultReg, scratchReg);
+    emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
-void JIT::emit_op_new_object(Instruction* currentInstruction)
+void JIT::emitSlow_op_new_object(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    JITStubCall(this, cti_op_new_object).call(currentInstruction[1].u.operand);
+    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_check_has_instance(Instruction* currentInstruction)
 {
-    unsigned baseVal = currentInstruction[1].u.operand;
+    int baseVal = currentInstruction[3].u.operand;
 
     emitGetVirtualRegister(baseVal, regT0);
 
@@ -374,21 +117,18 @@ void JIT::emit_op_check_has_instance(Instruction* currentInstruction)
     emitJumpSlowCaseIfNotJSCell(regT0, baseVal);
 
     // Check that baseVal 'ImplementsHasInstance'.
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT0);
-    addSlowCase(branchTest8(Zero, Address(regT0, Structure::typeInfoFlagsOffset()), TrustedImm32(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 (baseVal, proto, and value respectively) into registers.
     // We use regT0 for baseVal since we will be done with this first, and we can then use it for the result.
     emitGetVirtualRegister(value, regT2);
-    emitGetVirtualRegister(baseVal, regT0);
     emitGetVirtualRegister(proto, regT1);
 
     // Check that proto are cells.  baseVal must be a cell - this is checked by op_check_has_instance.
@@ -396,207 +136,159 @@ void JIT::emit_op_instanceof(Instruction* currentInstruction)
     emitJumpSlowCaseIfNotJSCell(regT1, proto);
 
     // Check that prototype is an object
-    loadPtr(Address(regT1, JSCell::structureOffset()), regT3);
-    addSlowCase(branch8(NotEqual, Address(regT3, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType)));
+    addSlowCase(emitJumpIfCellNotObject(regT1));
     
-    // Fixme: this check is only needed because the JSC API allows HasInstance to be overridden; we should deprecate this.
-    // Check that baseVal 'ImplementsDefaultHasInstance'.
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT0);
-    addSlowCase(branchTest8(Zero, Address(regT0, Structure::typeInfoFlagsOffset()), TrustedImm32(ImplementsDefaultHasInstance)));
-
     // 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(TrustedImmPtr(JSValue::encode(jsBoolean(true))), regT0);
+    move(TrustedImm64(JSValue::encode(jsBoolean(true))), regT0);
     Label loop(this);
 
     // Load the prototype of the object 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, JSCell::structureOffset()), regT2);
-    loadPtr(Address(regT2, Structure::prototypeOffset()), regT2);
+    emitLoadStructure(regT2, regT2, regT3);
+    load64(Address(regT2, Structure::prototypeOffset()), regT2);
     Jump isInstance = branchPtr(Equal, regT2, regT1);
     emitJumpIfJSCell(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(TrustedImmPtr(JSValue::encode(jsBoolean(false))), regT0);
+    move(TrustedImm64(JSValue::encode(jsBoolean(false))), regT0);
 
     // isInstance jumps right down to here, to skip setting the result to false (it has already set true).
     isInstance.link(this);
     emitPutVirtualRegister(dst);
 }
 
-void JIT::emit_op_call(Instruction* currentInstruction)
-{
-    compileOpCall(op_call, currentInstruction, m_callLinkInfoIndex++);
-}
-
-void JIT::emit_op_call_eval(Instruction* currentInstruction)
-{
-    compileOpCall(op_call_eval, currentInstruction, m_callLinkInfoIndex++);
-}
-
-void JIT::emit_op_call_varargs(Instruction* currentInstruction)
-{
-    compileOpCallVarargs(currentInstruction);
-}
-
-void JIT::emit_op_construct(Instruction* currentInstruction)
+void JIT::emit_op_is_undefined(Instruction* currentInstruction)
 {
-    compileOpCall(op_construct, currentInstruction, m_callLinkInfoIndex++);
-}
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitGetVirtualRegister(value, regT0);
+    Jump isCell = emitJumpIfJSCell(regT0);
 
-void JIT::emit_op_get_global_var(Instruction* currentInstruction)
-{
-    JSVariableObject* globalObject = m_codeBlock->globalObject();
-    loadPtr(&globalObject->m_registers, regT0);
-    loadPtr(Address(regT0, currentInstruction[2].u.operand * sizeof(Register)), regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
+    compare64(Equal, regT0, TrustedImm32(ValueUndefined), 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);
+    emitLoadStructure(regT0, regT1, regT2);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT1, Structure::globalObjectOffset()), regT1);
+    comparePtr(Equal, regT0, regT1, regT0);
+
+    notMasqueradesAsUndefined.link(this);
+    done.link(this);
+    emitTagAsBoolImmediate(regT0);
+    emitPutVirtualRegister(dst);
 }
 
-void JIT::emit_op_put_global_var(Instruction* currentInstruction)
+void JIT::emit_op_is_boolean(Instruction* currentInstruction)
 {
-    emitGetVirtualRegister(currentInstruction[2].u.operand, regT1);
-    JSVariableObject* globalObject = m_codeBlock->globalObject();
-    loadPtr(&globalObject->m_registers, regT0);
-    storePtr(regT1, Address(regT0, currentInstruction[1].u.operand * sizeof(Register)));
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitGetVirtualRegister(value, regT0);
+    xor64(TrustedImm32(static_cast<int32_t>(ValueFalse)), regT0);
+    test64(Zero, regT0, TrustedImm32(static_cast<int32_t>(~1)), regT0);
+    emitTagAsBoolImmediate(regT0);
+    emitPutVirtualRegister(dst);
 }
 
-void JIT::emit_op_get_scoped_var(Instruction* currentInstruction)
+void JIT::emit_op_is_number(Instruction* currentInstruction)
 {
-    int skip = currentInstruction[3].u.operand;
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT0);
-    bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
-    ASSERT(skip || !checkTopLevel);
-    if (checkTopLevel && skip--) {
-        Jump activationNotCreated;
-        if (checkTopLevel)
-            activationNotCreated = branchTestPtr(Zero, addressFor(m_codeBlock->activationRegister()));
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
-        activationNotCreated.link(this);
-    }
-    while (skip--)
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
-
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, object)), regT0);
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSVariableObject, m_registers)), regT0);
-    loadPtr(Address(regT0, currentInstruction[2].u.operand * sizeof(Register)), regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitGetVirtualRegister(value, regT0);
+    test64(NonZero, regT0, tagTypeNumberRegister, regT0);
+    emitTagAsBoolImmediate(regT0);
+    emitPutVirtualRegister(dst);
 }
 
-void JIT::emit_op_put_scoped_var(Instruction* currentInstruction)
+void JIT::emit_op_is_string(Instruction* currentInstruction)
 {
-    int skip = currentInstruction[2].u.operand;
-
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1);
-    emitGetVirtualRegister(currentInstruction[3].u.operand, regT0);
-    bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
-    ASSERT(skip || !checkTopLevel);
-    if (checkTopLevel && skip--) {
-        Jump activationNotCreated;
-        if (checkTopLevel)
-            activationNotCreated = branchTestPtr(Zero, addressFor(m_codeBlock->activationRegister()));
-        loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, next)), regT1);
-        activationNotCreated.link(this);
-    }
-    while (skip--)
-        loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, next)), regT1);
-
-    loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, object)), regT1);
-    loadPtr(Address(regT1, OBJECT_OFFSETOF(JSVariableObject, m_registers)), regT1);
-    storePtr(regT0, Address(regT1, currentInstruction[1].u.operand * sizeof(Register)));
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    
+    emitGetVirtualRegister(value, regT0);
+    Jump isNotCell = emitJumpIfNotJSCell(regT0);
+    
+    compare8(Equal, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(StringType), regT0);
+    emitTagAsBoolImmediate(regT0);
+    Jump done = jump();
+    
+    isNotCell.link(this);
+    move(TrustedImm32(ValueFalse), regT0);
+    
+    done.link(this);
+    emitPutVirtualRegister(dst);
 }
 
 void JIT::emit_op_tear_off_activation(Instruction* currentInstruction)
 {
-    unsigned activation = currentInstruction[1].u.operand;
-    unsigned arguments = currentInstruction[2].u.operand;
-    Jump activationCreated = branchTestPtr(NonZero, addressFor(activation));
-    Jump argumentsNotCreated = branchTestPtr(Zero, addressFor(arguments));
-    activationCreated.link(this);
-    JITStubCall stubCall(this, cti_op_tear_off_activation);
-    stubCall.addArgument(activation, regT2);
-    stubCall.addArgument(unmodifiedArgumentsRegister(arguments), regT2);
-    stubCall.call();
-    argumentsNotCreated.link(this);
+    int activation = currentInstruction[1].u.operand;
+    Jump activationNotCreated = branchTest64(Zero, addressFor(activation));
+    emitGetVirtualRegister(activation, regT0);
+    callOperation(operationTearOffActivation, regT0);
+    activationNotCreated.link(this);
 }
 
 void JIT::emit_op_tear_off_arguments(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
+    int arguments = currentInstruction[1].u.operand;
+    int activation = currentInstruction[2].u.operand;
 
-    Jump argsNotCreated = branchTestPtr(Zero, Address(callFrameRegister, sizeof(Register) * (unmodifiedArgumentsRegister(dst))));
-    JITStubCall stubCall(this, cti_op_tear_off_arguments);
-    stubCall.addArgument(unmodifiedArgumentsRegister(dst), regT2);
-    stubCall.call();
+    Jump argsNotCreated = branchTest64(Zero, Address(callFrameRegister, sizeof(Register) * (unmodifiedArgumentsRegister(VirtualRegister(arguments)).offset())));
+    emitGetVirtualRegister(unmodifiedArgumentsRegister(VirtualRegister(arguments)).offset(), regT0);
+    emitGetVirtualRegister(activation, regT1);
+    callOperation(operationTearOffArguments, regT0, regT1);
     argsNotCreated.link(this);
 }
 
 void JIT::emit_op_ret(Instruction* currentInstruction)
 {
     ASSERT(callFrameRegister != regT1);
-    ASSERT(regT1 != returnValueRegister);
-    ASSERT(returnValueRegister != callFrameRegister);
+    ASSERT(regT1 != returnValueGPR);
+    ASSERT(returnValueGPR != callFrameRegister);
 
     // Return the result in %eax.
-    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueRegister);
-
-    // Grab the return address.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
+    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueGPR);
 
-    // Restore our caller's "r".
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
-
-    // Return.
-    restoreReturnAddressBeforeReturn(regT1);
+    checkStackPointerAlignment();
+    emitFunctionEpilogue();
     ret();
 }
 
 void JIT::emit_op_ret_object_or_this(Instruction* currentInstruction)
 {
     ASSERT(callFrameRegister != regT1);
-    ASSERT(regT1 != returnValueRegister);
-    ASSERT(returnValueRegister != callFrameRegister);
+    ASSERT(regT1 != returnValueGPR);
+    ASSERT(returnValueGPR != callFrameRegister);
 
     // Return the result in %eax.
-    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueRegister);
-    Jump notJSCell = emitJumpIfNotJSCell(returnValueRegister);
-    loadPtr(Address(returnValueRegister, JSCell::structureOffset()), regT2);
-    Jump notObject = branch8(NotEqual, Address(regT2, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType));
-
-    // Grab the return address.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
-
-    // Restore our caller's "r".
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
+    emitGetVirtualRegister(currentInstruction[1].u.operand, returnValueGPR);
+    Jump notJSCell = emitJumpIfNotJSCell(returnValueGPR);
+    Jump notObject = emitJumpIfCellNotObject(returnValueGPR);
 
     // Return.
-    restoreReturnAddressBeforeReturn(regT1);
+    emitFunctionEpilogue();
     ret();
 
     // Return 'this' in %eax.
     notJSCell.link(this);
     notObject.link(this);
-    emitGetVirtualRegister(currentInstruction[2].u.operand, returnValueRegister);
-
-    // Grab the return address.
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, regT1);
-
-    // Restore our caller's "r".
-    emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, callFrameRegister);
+    emitGetVirtualRegister(currentInstruction[2].u.operand, returnValueGPR);
 
     // Return.
-    restoreReturnAddressBeforeReturn(regT1);
+    emitFunctionEpilogue();
     ret();
 }
 
-void JIT::emit_op_resolve(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve);
-    stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
 void JIT::emit_op_to_primitive(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
@@ -605,7 +297,9 @@ void JIT::emit_op_to_primitive(Instruction* currentInstruction)
     emitGetVirtualRegister(src, regT0);
     
     Jump isImm = emitJumpIfNotJSCell(regT0);
-    addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr)));
+    addSlowCase(branchStructure(NotEqual, 
+        Address(regT0, JSCell::structureIDOffset()), 
+        m_vm->stringStructure.get()));
     isImm.link(this);
 
     if (dst != src)
@@ -615,69 +309,8 @@ void JIT::emit_op_to_primitive(Instruction* currentInstruction)
 
 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, currentInstruction[3].u.operand ? cti_op_resolve_base_strict_put : cti_op_resolve_base);
-    stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_ensure_property_exists(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_ensure_property_exists);
-    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
-    stubCall.addArgument(TrustedImmPtr(&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(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_resolve_global(Instruction* currentInstruction, bool)
-{
-    // Fast case
-    void* globalObject = m_codeBlock->globalObject();
-    unsigned currentIndex = m_globalResolveInfoIndex++;
-    GlobalResolveInfo* resolveInfoAddress = &(m_codeBlock->globalResolveInfo(currentIndex));
-
-    // Check Structure of global object
-    move(TrustedImmPtr(globalObject), regT0);
-    move(TrustedImmPtr(resolveInfoAddress), regT2);
-    loadPtr(Address(regT2, OBJECT_OFFSETOF(GlobalResolveInfo, structure)), regT1);
-    addSlowCase(branchPtr(NotEqual, regT1, Address(regT0, JSCell::structureOffset()))); // Structures don't match
-
-    // Load cached property
-    // Assume that the global object always uses external storage.
-    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSGlobalObject, m_propertyStorage)), regT0);
-    load32(Address(regT2, OBJECT_OFFSETOF(GlobalResolveInfo, offset)), regT1);
-    loadPtr(BaseIndex(regT0, regT1, ScalePtr), regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
-}
-
-void JIT::emitSlow_op_resolve_global(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    unsigned dst = currentInstruction[1].u.operand;
-    Identifier* ident = &m_codeBlock->identifier(currentInstruction[2].u.operand);
-    
-    unsigned currentIndex = m_globalResolveInfoIndex++;
-    
-    linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_resolve_global);
-    stubCall.addArgument(TrustedImmPtr(ident));
-    stubCall.addArgument(Imm32(currentIndex));
-    stubCall.addArgument(regT0);
-    stubCall.call(dst);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_strcat);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_not(Instruction* currentInstruction)
@@ -687,9 +320,9 @@ void JIT::emit_op_not(Instruction* currentInstruction)
     // Invert against JSValue(false); if the value was tagged as a boolean, then all bits will be
     // clear other than the low bit (which will be 0 or 1 for false or true inputs respectively).
     // Then invert against JSValue(true), which will add the tag back in, and flip the low bit.
-    xorPtr(TrustedImm32(static_cast<int32_t>(ValueFalse)), regT0);
+    xor64(TrustedImm32(static_cast<int32_t>(ValueFalse)), regT0);
     addSlowCase(branchTestPtr(NonZero, regT0, TrustedImm32(static_cast<int32_t>(~1))));
-    xorPtr(TrustedImm32(static_cast<int32_t>(ValueTrue)), regT0);
+    xor64(TrustedImm32(static_cast<int32_t>(ValueTrue)), regT0);
 
     emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
@@ -699,80 +332,69 @@ void JIT::emit_op_jfalse(Instruction* currentInstruction)
     unsigned target = currentInstruction[2].u.operand;
     emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
 
-    addJump(branchPtr(Equal, regT0, TrustedImmPtr(JSValue::encode(jsNumber(0)))), target);
+    addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsNumber(0)))), target);
     Jump isNonZero = emitJumpIfImmediateInteger(regT0);
 
-    addJump(branchPtr(Equal, regT0, TrustedImmPtr(JSValue::encode(jsBoolean(false)))), target);
-    addSlowCase(branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(jsBoolean(true)))));
+    addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsBoolean(false)))), target);
+    addSlowCase(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(jsBoolean(true)))));
 
     isNonZero.link(this);
 }
 
 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;
 
     emitGetVirtualRegister(src, regT0);
     Jump isImmediate = emitJumpIfNotJSCell(regT0);
 
     // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-    addJump(branchTest8(NonZero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
-    Jump wasNotImmediate = jump();
+    Jump isNotMasqueradesAsUndefined = branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    emitLoadStructure(regT0, regT2, regT1);
+    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);
-    andPtr(TrustedImm32(~TagBitUndefined), regT0);
-    addJump(branchPtr(Equal, regT0, TrustedImmPtr(JSValue::encode(jsNull()))), target);            
+    and64(TrustedImm32(~TagBitUndefined), regT0);
+    addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsNull()))), 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;
 
     emitGetVirtualRegister(src, regT0);
     Jump isImmediate = emitJumpIfNotJSCell(regT0);
 
     // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-    addJump(branchTest8(Zero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
+    addJump(branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);
+    emitLoadStructure(regT0, regT2, regT1);
+    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);
-    andPtr(TrustedImm32(~TagBitUndefined), regT0);
-    addJump(branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(jsNull()))), target);            
+    and64(TrustedImm32(~TagBitUndefined), regT0);
+    addJump(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(jsNull()))), target);            
 
     wasNotImmediate.link(this);
 }
 
 void JIT::emit_op_jneq_ptr(Instruction* currentInstruction)
 {
-    unsigned src = currentInstruction[1].u.operand;
-    JSCell* ptr = currentInstruction[2].u.jsCell.get();
+    int src = currentInstruction[1].u.operand;
+    Special::Pointer ptr = currentInstruction[2].u.specialPointer;
     unsigned target = currentInstruction[3].u.operand;
     
     emitGetVirtualRegister(src, regT0);
-    addJump(branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(JSValue(ptr)))), target);            
-}
-
-void JIT::emit_op_jsr(Instruction* currentInstruction)
-{
-    int retAddrDst = currentInstruction[1].u.operand;
-    int target = currentInstruction[2].u.operand;
-    DataLabelPtr storeLocation = storePtrWithPatch(TrustedImmPtr(0), Address(callFrameRegister, sizeof(Register) * retAddrDst));
-    addJump(jump(), target);
-    m_jsrSites.append(JSRInfo(storeLocation, label()));
-    killLastResultRegister();
-}
-
-void JIT::emit_op_sret(Instruction* currentInstruction)
-{
-    jump(Address(callFrameRegister, sizeof(Register) * currentInstruction[1].u.operand));
-    killLastResultRegister();
+    addJump(branchPtr(NotEqual, regT0, TrustedImmPtr(actualPointerFor(m_codeBlock, ptr))), target);
 }
 
 void JIT::emit_op_eq(Instruction* currentInstruction)
@@ -784,40 +406,16 @@ void JIT::emit_op_eq(Instruction* currentInstruction)
     emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
-void JIT::emit_op_bitnot(Instruction* currentInstruction)
-{
-    emitGetVirtualRegister(currentInstruction[2].u.operand, regT0);
-    emitJumpSlowCaseIfNotImmediateInteger(regT0);
-    not32(regT0);
-    emitFastArithIntToImmNoCheck(regT0, regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
-}
-
-void JIT::emit_op_resolve_with_base(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_resolve_with_base);
-    stubCall.addArgument(TrustedImmPtr(&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(TrustedImmPtr(m_codeBlock->functionExpr(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
 void JIT::emit_op_jtrue(Instruction* currentInstruction)
 {
     unsigned target = currentInstruction[2].u.operand;
     emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
 
-    Jump isZero = branchPtr(Equal, regT0, TrustedImmPtr(JSValue::encode(jsNumber(0))));
+    Jump isZero = branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsNumber(0))));
     addJump(emitJumpIfImmediateInteger(regT0), target);
 
-    addJump(branchPtr(Equal, regT0, TrustedImmPtr(JSValue::encode(jsBoolean(true)))), target);
-    addSlowCase(branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(jsBoolean(false)))));
+    addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsBoolean(true)))), target);
+    addSlowCase(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(jsBoolean(false)))));
 
     isZero.link(this);
 }
@@ -837,7 +435,7 @@ void JIT::emit_op_bitxor(Instruction* currentInstruction)
 {
     emitGetVirtualRegisters(currentInstruction[2].u.operand, regT0, currentInstruction[3].u.operand, regT1);
     emitJumpSlowCaseIfNotImmediateIntegers(regT0, regT1, regT2);
-    xorPtr(regT1, regT0);
+    xor64(regT1, regT0);
     emitFastArithReTagImmediate(regT0, regT0);
     emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
@@ -846,21 +444,16 @@ void JIT::emit_op_bitor(Instruction* currentInstruction)
 {
     emitGetVirtualRegisters(currentInstruction[2].u.operand, regT0, currentInstruction[3].u.operand, regT1);
     emitJumpSlowCaseIfNotImmediateIntegers(regT0, regT1, regT2);
-    orPtr(regT1, regT0);
+    or64(regT1, regT0);
     emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
 void JIT::emit_op_throw(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_throw);
-    stubCall.addArgument(currentInstruction[1].u.operand, regT2);
-    stubCall.call();
-    ASSERT(regT0 == returnValueRegister);
-#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);
+    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
+    callOperationNoExceptionCheck(operationThrow, regT0);
+    jumpToExceptionHandler();
 }
 
 void JIT::emit_op_get_pnames(Instruction* currentInstruction)
@@ -876,19 +469,16 @@ void JIT::emit_op_get_pnames(Instruction* currentInstruction)
     emitGetVirtualRegister(base, regT0);
     if (!m_codeBlock->isKnownNotImmediate(base))
         isNotObject.append(emitJumpIfNotJSCell(regT0));
-    if (base != m_codeBlock->thisRegister() || m_codeBlock->isStrictMode()) {
-        loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-        isNotObject.append(branch8(NotEqual, Address(regT2, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType)));
-    }
+    if (base != m_codeBlock->thisRegister().offset() || m_codeBlock->isStrictMode())
+        isNotObject.append(emitJumpIfCellNotObject(regT0));
 
     // 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);
+    callOperation(operationGetPNames, regT0);
+    emitStoreCell(dst, returnValueGPR);
     load32(Address(regT0, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStringsSize)), regT3);
-    storePtr(tagTypeNumberRegister, payloadFor(i));
+    store64(tagTypeNumberRegister, addressFor(i));
     store32(TrustedImm32(Int32Tag), intTagFor(size));
     store32(regT3, intPayloadFor(size));
     Jump end = jump();
@@ -897,10 +487,7 @@ void JIT::emit_op_get_pnames(Instruction* currentInstruction)
     move(regT0, regT1);
     and32(TrustedImm32(~TagBitUndefined), regT1);
     addJump(branch32(Equal, regT1, TrustedImm32(ValueNull)), breakTarget);
-
-    JITStubCall toObjectStubCall(this, cti_to_object);
-    toObjectStubCall.addArgument(regT0);
-    toObjectStubCall.call(base);
+    callOperation(operationToObject, base, regT0);
     jump().linkTo(isObject, this);
     
     end.link(this);
@@ -925,7 +512,7 @@ void JIT::emit_op_next_pname(Instruction* currentInstruction)
     loadPtr(addressFor(it), regT1);
     loadPtr(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_jsStrings)), regT2);
 
-    loadPtr(BaseIndex(regT2, regT0, TimesEight), regT2);
+    load64(BaseIndex(regT2, regT0, TimesEight), regT2);
 
     emitPutVirtualRegister(dst, regT2);
 
@@ -937,7 +524,7 @@ void JIT::emit_op_next_pname(Instruction* currentInstruction)
     emitGetVirtualRegister(base, regT0);
 
     // Test base's structure
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
+    emitLoadStructure(regT0, regT2, regT3);
     callHasProperty.append(branchPtr(NotEqual, regT2, Address(Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedStructure)))));
 
     // Test base's prototype chain
@@ -946,9 +533,9 @@ void JIT::emit_op_next_pname(Instruction* currentInstruction)
     addJump(branchTestPtr(Zero, Address(regT3)), target);
 
     Label checkPrototype(this);
-    loadPtr(Address(regT2, Structure::prototypeOffset()), regT2);
+    load64(Address(regT2, Structure::prototypeOffset()), regT2);
     callHasProperty.append(emitJumpIfNotJSCell(regT2));
-    loadPtr(Address(regT2, JSCell::structureOffset()), regT2);
+    emitLoadStructure(regT2, regT2, regT1);
     callHasProperty.append(branchPtr(NotEqual, regT2, Address(regT3)));
     addPtr(TrustedImm32(sizeof(Structure*)), regT3);
     branchTestPtr(NonZero, Address(regT3)).linkTo(checkPrototype, this);
@@ -959,10 +546,7 @@ void JIT::emit_op_next_pname(Instruction* currentInstruction)
     // Slow case: Ask the object if i is valid.
     callHasProperty.link(this);
     emitGetVirtualRegister(dst, regT1);
-    JITStubCall stubCall(this, cti_has_property);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call();
+    callOperation(operationHasProperty, regT0, regT1);
 
     // Test for valid key.
     addJump(branchTest32(NonZero, regT0), target);
@@ -972,36 +556,43 @@ void JIT::emit_op_next_pname(Instruction* currentInstruction)
     end.link(this);
 }
 
-void JIT::emit_op_push_scope(Instruction* currentInstruction)
+void JIT::emit_op_push_with_scope(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_push_scope);
-    stubCall.addArgument(currentInstruction[1].u.operand, regT2);
-    stubCall.call(currentInstruction[1].u.operand);
+    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
+    callOperation(operationPushWithScope, regT0);
 }
 
 void JIT::emit_op_pop_scope(Instruction*)
 {
-    JITStubCall(this, cti_op_pop_scope).call();
+    callOperation(operationPopScope);
 }
 
 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;
 
     emitGetVirtualRegisters(src1, regT0, src2, regT1);
-
-    // Jump to a slow case if either operand is a number, or if both are JSCell*s.
+    
+    // Jump slow if both are cells (to cover strings).
     move(regT0, regT2);
-    orPtr(regT1, regT2);
+    or64(regT1, regT2);
     addSlowCase(emitJumpIfJSCell(regT2));
-    addSlowCase(emitJumpIfImmediateNumber(regT2));
+    
+    // Jump slow if either is a double. First test if it's an integer, which is fine, and then test
+    // if it's a double.
+    Jump leftOK = emitJumpIfImmediateInteger(regT0);
+    addSlowCase(emitJumpIfImmediateNumber(regT0));
+    leftOK.link(this);
+    Jump rightOK = emitJumpIfImmediateInteger(regT1);
+    addSlowCase(emitJumpIfImmediateNumber(regT1));
+    rightOK.link(this);
 
     if (type == OpStrictEq)
-        compare32(Equal, regT1, regT0, regT0);
+        compare64(Equal, regT1, regT0, regT0);
     else
-        compare32(NotEqual, regT1, regT0, regT0);
+        compare64(NotEqual, regT1, regT0, regT0);
     emitTagAsBoolImmediate(regT0);
 
     emitPutVirtualRegister(dst);
@@ -1017,87 +608,74 @@ void JIT::emit_op_nstricteq(Instruction* currentInstruction)
     compileOpStrictEq(currentInstruction, OpNStrictEq);
 }
 
-void JIT::emit_op_to_jsnumber(Instruction* currentInstruction)
+void JIT::emit_op_to_number(Instruction* currentInstruction)
 {
     int srcVReg = currentInstruction[2].u.operand;
     emitGetVirtualRegister(srcVReg, regT0);
     
-    Jump wasImmediate = emitJumpIfImmediateInteger(regT0);
-
-    emitJumpSlowCaseIfNotJSCell(regT0, srcVReg);
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-    addSlowCase(branch8(NotEqual, Address(regT2, Structure::typeInfoTypeOffset()), TrustedImm32(NumberType)));
-    
-    wasImmediate.link(this);
+    addSlowCase(emitJumpIfNotImmediateNumber(regT0));
 
     emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
-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(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
-    stubCall.addArgument(currentInstruction[3].u.operand, regT2);
-    stubCall.call(currentInstruction[1].u.operand);
+    emitGetVirtualRegister(currentInstruction[2].u.operand, regT0);
+    callOperation(operationPushNameScope, &m_codeBlock->identifier(currentInstruction[1].u.operand), regT0, currentInstruction[3].u.operand);
 }
 
 void JIT::emit_op_catch(Instruction* currentInstruction)
 {
-    killLastResultRegister(); // FIXME: Implicitly treat op_catch as a labeled statement, and remove this line of code.
-    move(regT0, callFrameRegister);
-    peek(regT3, OBJECT_OFFSETOF(struct JITStackFrame, globalData) / sizeof(void*));
-    loadPtr(Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception)), regT0);
-    storePtr(TrustedImmPtr(JSValue::encode(JSValue())), Address(regT3, OBJECT_OFFSETOF(JSGlobalData, exception)));
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
-}
+    // Gotta restore the tag registers. We could be throwing from FTL, which may
+    // clobber them.
+    move(TrustedImm64(TagTypeNumber), tagTypeNumberRegister);
+    move(TrustedImm64(TagMask), tagMaskRegister);
+    
+    move(TrustedImmPtr(m_vm), regT3);
+    load64(Address(regT3, VM::callFrameForThrowOffset()), callFrameRegister);
 
-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);
+    addPtr(TrustedImm32(stackPointerOffsetFor(codeBlock()) * sizeof(Register)), callFrameRegister, stackPointerRegister);
+
+    load64(Address(regT3, VM::exceptionOffset()), regT0);
+    store64(TrustedImm64(JSValue::encode(JSValue())), Address(regT3, VM::exceptionOffset()));
+    emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
 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);
+    SimpleJumpTable* jumpTable = &m_codeBlock->switchJumpTable(tableIndex);
     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Immediate));
-    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
+    jumpTable->ensureCTITable();
 
-    JITStubCall stubCall(this, cti_op_switch_imm);
-    stubCall.addArgument(scrutinee, regT2);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitGetVirtualRegister(scrutinee, regT0);
+    callOperation(operationSwitchImmWithUnknownKeyType, 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);
+    SimpleJumpTable* jumpTable = &m_codeBlock->switchJumpTable(tableIndex);
     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset, SwitchRecord::Character));
-    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());
+    jumpTable->ensureCTITable();
 
-    JITStubCall stubCall(this, cti_op_switch_char);
-    stubCall.addArgument(scrutinee, regT2);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitGetVirtualRegister(scrutinee, regT0);
+    callOperation(operationSwitchCharWithUnknownKeyType, 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;
 
@@ -1105,53 +683,51 @@ void JIT::emit_op_switch_string(Instruction* currentInstruction)
     StringJumpTable* jumpTable = &m_codeBlock->stringSwitchJumpTable(tableIndex);
     m_switches.append(SwitchRecord(jumpTable, m_bytecodeOffset, defaultOffset));
 
-    JITStubCall stubCall(this, cti_op_switch_string);
-    stubCall.addArgument(scrutinee, regT2);
-    stubCall.addArgument(Imm32(tableIndex));
-    stubCall.call();
-    jump(regT0);
+    emitGetVirtualRegister(scrutinee, regT0);
+    callOperation(operationSwitchStringWithUnknownKeyType, regT0, tableIndex);
+    jump(returnValueGPR);
 }
 
-void JIT::emit_op_throw_reference_error(Instruction* currentInstruction)
+void JIT::emit_op_throw_static_error(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_throw_reference_error);
-    stubCall.addArgument(ImmPtr(JSValue::encode(m_codeBlock->getConstant(currentInstruction[1].u.operand))));
-    stubCall.call();
+    move(TrustedImm64(JSValue::encode(m_codeBlock->getConstant(currentInstruction[1].u.operand))), regT0);
+    callOperation(operationThrowStaticError, 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_eq_null(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src1 = currentInstruction[2].u.operand;
 
     emitGetVirtualRegister(src1, regT0);
     Jump isImmediate = emitJumpIfNotJSCell(regT0);
 
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-    test8(NonZero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined), regT0);
+    Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    move(TrustedImm32(0), regT0);
+    Jump wasNotMasqueradesAsUndefined = jump();
 
+    isMasqueradesAsUndefined.link(this);
+    emitLoadStructure(regT0, regT2, regT1);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT2, Structure::globalObjectOffset()), regT2);
+    comparePtr(Equal, regT0, regT2, regT0);
     Jump wasNotImmediate = jump();
 
     isImmediate.link(this);
 
-    andPtr(TrustedImm32(~TagBitUndefined), regT0);
-    comparePtr(Equal, regT0, TrustedImm32(ValueNull), regT0);
+    and64(TrustedImm32(~TagBitUndefined), regT0);
+    compare64(Equal, regT0, TrustedImm32(ValueNull), regT0);
 
     wasNotImmediate.link(this);
+    wasNotMasqueradesAsUndefined.link(this);
 
     emitTagAsBoolImmediate(regT0);
     emitPutVirtualRegister(dst);
@@ -1160,23 +736,30 @@ void JIT::emit_op_eq_null(Instruction* currentInstruction)
 
 void JIT::emit_op_neq_null(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned src1 = currentInstruction[2].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int src1 = currentInstruction[2].u.operand;
 
     emitGetVirtualRegister(src1, regT0);
     Jump isImmediate = emitJumpIfNotJSCell(regT0);
 
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
-    test8(Zero, Address(regT2, Structure::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined), regT0);
+    Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));
+    move(TrustedImm32(1), regT0);
+    Jump wasNotMasqueradesAsUndefined = jump();
 
+    isMasqueradesAsUndefined.link(this);
+    emitLoadStructure(regT0, regT2, regT1);
+    move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);
+    loadPtr(Address(regT2, Structure::globalObjectOffset()), regT2);
+    comparePtr(NotEqual, regT0, regT2, regT0);
     Jump wasNotImmediate = jump();
 
     isImmediate.link(this);
 
-    andPtr(TrustedImm32(~TagBitUndefined), regT0);
-    comparePtr(NotEqual, regT0, TrustedImm32(ValueNull), regT0);
+    and64(TrustedImm32(~TagBitUndefined), regT0);
+    compare64(NotEqual, regT0, TrustedImm32(ValueNull), regT0);
 
     wasNotImmediate.link(this);
+    wasNotMasqueradesAsUndefined.link(this);
 
     emitTagAsBoolImmediate(regT0);
     emitPutVirtualRegister(dst);
@@ -1189,334 +772,256 @@ void JIT::emit_op_enter(Instruction*)
     // object lifetime and increasing GC pressure.
     size_t count = m_codeBlock->m_numVars;
     for (size_t j = 0; j < count; ++j)
-        emitInitRegister(j);
+        emitInitRegister(virtualRegisterForLocal(j).offset());
+
+    emitWriteBarrier(m_codeBlock->ownerExecutable());
 
+    emitEnterOptimizationCheck();
 }
 
 void JIT::emit_op_create_activation(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
+    int dst = currentInstruction[1].u.operand;
     
-    Jump activationCreated = branchTestPtr(NonZero, Address(callFrameRegister, sizeof(Register) * dst));
-    JITStubCall(this, cti_op_push_activation).call(currentInstruction[1].u.operand);
-    emitPutVirtualRegister(dst);
+    Jump activationCreated = branchTest64(NonZero, Address(callFrameRegister, sizeof(Register) * dst));
+    callOperation(operationCreateActivation, 0);
+    emitStoreCell(dst, returnValueGPR);
     activationCreated.link(this);
 }
 
 void JIT::emit_op_create_arguments(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
+    int dst = currentInstruction[1].u.operand;
+
+    Jump argsCreated = branchTest64(NonZero, Address(callFrameRegister, sizeof(Register) * dst));
+
+    callOperation(operationCreateArguments);
+    emitStoreCell(dst, returnValueGPR);
+    emitStoreCell(unmodifiedArgumentsRegister(VirtualRegister(dst)), returnValueGPR);
 
-    Jump argsCreated = branchTestPtr(NonZero, Address(callFrameRegister, sizeof(Register) * dst));
-    if (m_codeBlock->m_numParameters == 1)
-        JITStubCall(this, cti_op_create_arguments_no_params).call();
-    else
-        JITStubCall(this, cti_op_create_arguments).call();
-    emitPutVirtualRegister(dst);
-    emitPutVirtualRegister(unmodifiedArgumentsRegister(dst));
     argsCreated.link(this);
 }
 
 void JIT::emit_op_init_lazy_reg(Instruction* currentInstruction)
 {
-    unsigned dst = currentInstruction[1].u.operand;
+    int dst = currentInstruction[1].u.operand;
 
-    storePtr(TrustedImmPtr(0), Address(callFrameRegister, sizeof(Register) * dst));
+    store64(TrustedImm64((int64_t)0), Address(callFrameRegister, sizeof(Register) * dst));
 }
 
-void JIT::emit_op_convert_this(Instruction* currentInstruction)
+void JIT::emit_op_to_this(Instruction* currentInstruction)
 {
-    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
+    WriteBarrierBase<Structure>* cachedStructure = &currentInstruction[2].u.structure;
+    emitGetVirtualRegister(currentInstruction[1].u.operand, regT1);
 
-    emitJumpSlowCaseIfNotJSCell(regT0);
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT1);
-    addSlowCase(branchTest8(NonZero, Address(regT1, Structure::typeInfoFlagsOffset()), TrustedImm32(NeedsThisConversion)));
-}
+    emitJumpSlowCaseIfNotJSCell(regT1);
 
-void JIT::emit_op_convert_this_strict(Instruction* currentInstruction)
-{
-    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
-    Jump notNull = branchTestPtr(NonZero, regT0);
-    move(TrustedImmPtr(JSValue::encode(jsNull())), regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand, regT0);
-    Jump setThis = jump();
-    notNull.link(this);
-    Jump isImmediate = emitJumpIfNotJSCell(regT0);
-    loadPtr(Address(regT0, JSCell::structureOffset()), regT1);
-    Jump notAnObject = branch8(NotEqual, Address(regT1, Structure::typeInfoTypeOffset()), TrustedImm32(ObjectType));
-    addSlowCase(branchTest8(NonZero, Address(regT1, Structure::typeInfoFlagsOffset()), TrustedImm32(NeedsThisConversion)));
-    isImmediate.link(this);
-    notAnObject.link(this);
-    setThis.link(this);
+    addSlowCase(branch8(NotEqual, Address(regT1, JSCell::typeInfoTypeOffset()), TrustedImm32(FinalObjectType)));
+    loadPtr(cachedStructure, regT2);
+    addSlowCase(branchTestPtr(Zero, regT2));
+    load32(Address(regT2, Structure::structureIDOffset()), regT2);
+    addSlowCase(branch32(NotEqual, Address(regT1, JSCell::structureIDOffset()), regT2));
 }
 
 void JIT::emit_op_get_callee(Instruction* currentInstruction)
 {
-    unsigned result = currentInstruction[1].u.operand;
-    emitGetFromCallFrameHeaderPtr(RegisterFile::Callee, regT0);
+    int result = currentInstruction[1].u.operand;
+    WriteBarrierBase<JSCell>* cachedFunction = &currentInstruction[2].u.jsCell;
+    emitGetFromCallFrameHeaderPtr(JSStack::Callee, regT0);
+
+    loadPtr(cachedFunction, regT2);
+    addSlowCase(branchPtr(NotEqual, regT0, regT2));
+
     emitPutVirtualRegister(result);
 }
 
+void JIT::emitSlow_op_get_callee(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+{
+    linkSlowCase(iter);
+
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_get_callee);
+    slowPathCall.call();
+}
+
 void JIT::emit_op_create_this(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_create_this);
-    stubCall.addArgument(currentInstruction[2].u.operand, regT1);
-    stubCall.call(currentInstruction[1].u.operand);
+    int callee = currentInstruction[2].u.operand;
+    RegisterID calleeReg = regT0;
+    RegisterID resultReg = regT0;
+    RegisterID allocatorReg = regT1;
+    RegisterID structureReg = regT2;
+    RegisterID scratchReg = regT3;
+
+    emitGetVirtualRegister(callee, calleeReg);
+    loadPtr(Address(calleeReg, JSFunction::offsetOfAllocationProfile() + ObjectAllocationProfile::offsetOfAllocator()), allocatorReg);
+    loadPtr(Address(calleeReg, JSFunction::offsetOfAllocationProfile() + ObjectAllocationProfile::offsetOfStructure()), structureReg);
+    addSlowCase(branchTestPtr(Zero, allocatorReg));
+
+    emitAllocateJSObject(allocatorReg, structureReg, resultReg, scratchReg);
+    emitPutVirtualRegister(currentInstruction[1].u.operand);
 }
 
-void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
+void JIT::emitSlow_op_create_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    peek(regT1, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
-    Jump noProfiler = branchTestPtr(Zero, Address(regT1));
+    linkSlowCase(iter); // doesn't have an allocation profile
+    linkSlowCase(iter); // allocation failed
 
-    JITStubCall stubCall(this, cti_op_profile_will_call);
-    stubCall.addArgument(currentInstruction[1].u.operand, regT1);
-    stubCall.call();
-    noProfiler.link(this);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_create_this);
+    slowPathCall.call();
+}
 
+void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
+{
+    Jump profilerDone = branchTestPtr(Zero, AbsoluteAddress(m_vm->enabledProfilerAddress()));
+    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
+    callOperation(operationProfileWillCall, regT0);
+    profilerDone.link(this);
 }
 
 void JIT::emit_op_profile_did_call(Instruction* currentInstruction)
 {
-    peek(regT1, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof(void*));
-    Jump noProfiler = branchTestPtr(Zero, Address(regT1));
-
-    JITStubCall stubCall(this, cti_op_profile_did_call);
-    stubCall.addArgument(currentInstruction[1].u.operand, regT1);
-    stubCall.call();
-    noProfiler.link(this);
+    Jump profilerDone = branchTestPtr(Zero, AbsoluteAddress(m_vm->enabledProfilerAddress()));
+    emitGetVirtualRegister(currentInstruction[1].u.operand, regT0);
+    callOperation(operationProfileDidCall, regT0);
+    profilerDone.link(this);
 }
 
 
 // Slow cases
 
-void JIT::emitSlow_op_convert_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_to_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_convert_this);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emitSlow_op_convert_this_strict(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_convert_this_strict);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emitSlow_op_to_primitive(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_to_primitive);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
-}
-
-void JIT::emitSlow_op_loop_if_lesseq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    unsigned op2 = currentInstruction[2].u.operand;
-    unsigned target = currentInstruction[3].u.operand;
-    if (isOperandConstantImmediateInt(op2)) {
-        linkSlowCase(iter);
-        JITStubCall stubCall(this, cti_op_loop_if_lesseq);
-        stubCall.addArgument(regT0);
-        stubCall.addArgument(currentInstruction[2].u.operand, regT2);
-        stubCall.call();
-        emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
-    } else {
-        linkSlowCase(iter);
-        linkSlowCase(iter);
-        JITStubCall stubCall(this, cti_op_loop_if_lesseq);
-        stubCall.addArgument(regT0);
-        stubCall.addArgument(regT1);
-        stubCall.call();
-        emitJumpSlowToHot(branchTest32(NonZero, regT0), target);
-    }
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_this);
+    slowPathCall.call();
 }
 
-void JIT::emitSlow_op_put_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_to_primitive(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned base = currentInstruction[1].u.operand;
-    unsigned property = currentInstruction[2].u.operand;
-    unsigned value = currentInstruction[3].u.operand;
-
-    linkSlowCase(iter); // property int32 check
-    linkSlowCaseIfNotJSCell(iter, base); // base cell check
-    linkSlowCase(iter); // base not array check
-    linkSlowCase(iter); // in vector check
+    linkSlowCase(iter);
 
-    JITStubCall stubPutByValCall(this, cti_op_put_by_val);
-    stubPutByValCall.addArgument(regT0);
-    stubPutByValCall.addArgument(property, regT2);
-    stubPutByValCall.addArgument(value, regT2);
-    stubPutByValCall.call();
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_primitive);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_not(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    xorPtr(TrustedImm32(static_cast<int32_t>(ValueFalse)), regT0);
-    JITStubCall stubCall(this, cti_op_not);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
+    
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_not);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_jfalse(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_jtrue);
-    stubCall.addArgument(regT0);
-    stubCall.call();
-    emitJumpSlowToHot(branchTest32(Zero, regT0), currentInstruction[2].u.operand); // inverted!
-}
-
-void JIT::emitSlow_op_bitnot(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_bitnot);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
+    callOperation(operationConvertJSValueToBoolean, regT0);
+    emitJumpSlowToHot(branchTest32(Zero, returnValueGPR), currentInstruction[2].u.operand); // inverted!
 }
 
 void JIT::emitSlow_op_jtrue(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_jtrue);
-    stubCall.addArgument(regT0);
-    stubCall.call();
-    emitJumpSlowToHot(branchTest32(NonZero, regT0), currentInstruction[2].u.operand);
+    callOperation(operationConvertJSValueToBoolean, regT0);
+    emitJumpSlowToHot(branchTest32(NonZero, returnValueGPR), currentInstruction[2].u.operand);
 }
 
 void JIT::emitSlow_op_bitxor(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_bitxor);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call(currentInstruction[1].u.operand);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_bitxor);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_bitor(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_bitor);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call(currentInstruction[1].u.operand);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_bitor);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_eq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_eq);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call();
-    emitTagAsBoolImmediate(regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
+    callOperation(operationCompareEq, regT0, regT1);
+    emitTagAsBoolImmediate(returnValueGPR);
+    emitPutVirtualRegister(currentInstruction[1].u.operand, returnValueGPR);
 }
 
 void JIT::emitSlow_op_neq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_eq);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call();
+    callOperation(operationCompareEq, regT0, regT1);
     xor32(TrustedImm32(0x1), regT0);
-    emitTagAsBoolImmediate(regT0);
-    emitPutVirtualRegister(currentInstruction[1].u.operand);
+    emitTagAsBoolImmediate(returnValueGPR);
+    emitPutVirtualRegister(currentInstruction[1].u.operand, returnValueGPR);
 }
 
 void JIT::emitSlow_op_stricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_stricteq);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call(currentInstruction[1].u.operand);
+    linkSlowCase(iter);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_stricteq);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_nstricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_nstricteq);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(regT1);
-    stubCall.call(currentInstruction[1].u.operand);
+    linkSlowCase(iter);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_nstricteq);
+    slowPathCall.call();
 }
 
 void JIT::emitSlow_op_check_has_instance(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned baseVal = currentInstruction[1].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int value = currentInstruction[2].u.operand;
+    int baseVal = currentInstruction[3].u.operand;
 
     linkSlowCaseIfNotJSCell(iter, baseVal);
     linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_check_has_instance);
-    stubCall.addArgument(baseVal, regT2);
-    stubCall.call();
+    emitGetVirtualRegister(value, regT0);
+    emitGetVirtualRegister(baseVal, regT1);
+    callOperation(operationCheckHasInstance, dst, regT0, regT1);
+
+    emitJumpSlowToHot(jump(), currentInstruction[4].u.operand);
 }
 
 void JIT::emitSlow_op_instanceof(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 proto = currentInstruction[3].u.operand;
 
     linkSlowCaseIfNotJSCell(iter, value);
     linkSlowCaseIfNotJSCell(iter, proto);
     linkSlowCase(iter);
-    linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_instanceof);
-    stubCall.addArgument(value, regT2);
-    stubCall.addArgument(baseVal, regT2);
-    stubCall.addArgument(proto, regT2);
-    stubCall.call(dst);
-}
-
-void JIT::emitSlow_op_call(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    compileOpCallSlowCase(currentInstruction, iter, m_callLinkInfoIndex++, op_call);
-}
-
-void JIT::emitSlow_op_call_eval(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    compileOpCallSlowCase(currentInstruction, iter, m_callLinkInfoIndex++, op_call_eval);
-}
-
-void JIT::emitSlow_op_call_varargs(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    compileOpCallVarargsSlowCase(currentInstruction, iter);
-}
-
-void JIT::emitSlow_op_construct(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
-{
-    compileOpCallSlowCase(currentInstruction, iter, m_callLinkInfoIndex++, op_construct);
+    emitGetVirtualRegister(value, regT0);
+    emitGetVirtualRegister(proto, regT1);
+    callOperation(operationInstanceOf, dst, regT0, regT1);
 }
 
-void JIT::emitSlow_op_to_jsnumber(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emitSlow_op_to_number(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    linkSlowCaseIfNotJSCell(iter, currentInstruction[2].u.operand);
     linkSlowCase(iter);
 
-    JITStubCall stubCall(this, cti_op_to_jsnumber);
-    stubCall.addArgument(regT0);
-    stubCall.call(currentInstruction[1].u.operand);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_to_number);
+    slowPathCall.call();
 }
 
 void JIT::emit_op_get_arguments_length(Instruction* currentInstruction)
 {
     int dst = currentInstruction[1].u.operand;
     int argumentsRegister = currentInstruction[2].u.operand;
-    addSlowCase(branchTestPtr(NonZero, addressFor(argumentsRegister)));
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
+    addSlowCase(branchTest64(NonZero, addressFor(argumentsRegister)));
+    emitGetFromCallFrameHeader32(JSStack::ArgumentCount, regT0);
     sub32(TrustedImm32(1), regT0);
     emitFastArithReTagImmediate(regT0, regT0);
     emitPutVirtualRegister(dst, regT0);
@@ -1525,15 +1030,9 @@ void JIT::emit_op_get_arguments_length(Instruction* currentInstruction)
 void JIT::emitSlow_op_get_arguments_length(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
     linkSlowCase(iter);
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned base = currentInstruction[2].u.operand;
-    Identifier* ident = &(m_codeBlock->identifier(currentInstruction[3].u.operand));
-    
-    emitGetVirtualRegister(base, regT0);
-    JITStubCall stubCall(this, cti_op_get_by_id_generic);
-    stubCall.addArgument(regT0);
-    stubCall.addArgument(TrustedImmPtr(ident));
-    stubCall.call(dst);
+    int dst = currentInstruction[1].u.operand;
+    int base = currentInstruction[2].u.operand;
+    callOperation(operationGetArgumentsLength, dst, base);
 }
 
 void JIT::emit_op_get_argument_by_val(Instruction* currentInstruction)
@@ -1541,182 +1040,99 @@ void JIT::emit_op_get_argument_by_val(Instruction* currentInstruction)
     int dst = currentInstruction[1].u.operand;
     int argumentsRegister = currentInstruction[2].u.operand;
     int property = currentInstruction[3].u.operand;
-    addSlowCase(branchTestPtr(NonZero, addressFor(argumentsRegister)));
+    addSlowCase(branchTest64(NonZero, addressFor(argumentsRegister)));
     emitGetVirtualRegister(property, regT1);
     addSlowCase(emitJumpIfNotImmediateInteger(regT1));
     add32(TrustedImm32(1), regT1);
     // regT1 now contains the integer index of the argument we want, including this
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT2);
+    emitGetFromCallFrameHeader32(JSStack::ArgumentCount, regT2);
     addSlowCase(branch32(AboveOrEqual, regT1, regT2));
-    
-    Jump skipOutofLineParams;
-    int numArgs = m_codeBlock->m_numParameters;
-    if (numArgs) {
-        Jump notInInPlaceArgs = branch32(AboveOrEqual, regT1, Imm32(numArgs));
-        addPtr(Imm32(static_cast<unsigned>(-(RegisterFile::CallFrameHeaderSize + numArgs) * sizeof(Register))), callFrameRegister, regT0);
-        loadPtr(BaseIndex(regT0, regT1, TimesEight, 0), regT0);
-        skipOutofLineParams = jump();
-        notInInPlaceArgs.link(this);
-    }
-    
-    addPtr(Imm32(static_cast<unsigned>(-(RegisterFile::CallFrameHeaderSize + numArgs) * sizeof(Register))), callFrameRegister, regT0);
-    mul32(TrustedImm32(sizeof(Register)), regT2, regT2);
-    subPtr(regT2, regT0);
-    loadPtr(BaseIndex(regT0, regT1, TimesEight, 0), regT0);
-    if (numArgs)
-        skipOutofLineParams.link(this);
+
+    signExtend32ToPtr(regT1, regT1);
+    load64(BaseIndex(callFrameRegister, regT1, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))), regT0);
+    emitValueProfilingSite();
     emitPutVirtualRegister(dst, regT0);
 }
 
 void JIT::emitSlow_op_get_argument_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    unsigned arguments = currentInstruction[2].u.operand;
-    unsigned property = currentInstruction[3].u.operand;
+    int dst = currentInstruction[1].u.operand;
+    int arguments = currentInstruction[2].u.operand;
+    int property = currentInstruction[3].u.operand;
     
     linkSlowCase(iter);
     Jump skipArgumentsCreation = jump();
     
     linkSlowCase(iter);
     linkSlowCase(iter);
-    if (m_codeBlock->m_numParameters == 1)
-        JITStubCall(this, cti_op_create_arguments_no_params).call();
-    else
-        JITStubCall(this, cti_op_create_arguments).call();
-    emitPutVirtualRegister(arguments);
-    emitPutVirtualRegister(unmodifiedArgumentsRegister(arguments));
+    callOperation(operationCreateArguments);
+    emitStoreCell(arguments, returnValueGPR);
+    emitStoreCell(unmodifiedArgumentsRegister(VirtualRegister(arguments)), returnValueGPR);
     
     skipArgumentsCreation.link(this);
-    JITStubCall stubCall(this, cti_op_get_by_val);
-    stubCall.addArgument(arguments, regT2);
-    stubCall.addArgument(property, regT2);
-    stubCall.call(dst);
+    emitGetVirtualRegister(arguments, regT0);
+    emitGetVirtualRegister(property, regT1);
+    callOperation(WithProfile, operationGetByValGeneric, dst, regT0, regT1);
 }
 
 #endif // USE(JSVALUE64)
 
-void JIT::emit_op_resolve_global_dynamic(Instruction* currentInstruction)
+void JIT::emit_op_touch_entry(Instruction* currentInstruction)
 {
-    int skip = currentInstruction[5].u.operand;
-    
-    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT0);
+    if (m_codeBlock->symbolTable()->m_functionEnteredOnce.hasBeenInvalidated())
+        return;
     
-    bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
-    ASSERT(skip || !checkTopLevel);
-    if (checkTopLevel && skip--) {
-        Jump activationNotCreated;
-        if (checkTopLevel)
-            activationNotCreated = branchTestPtr(Zero, addressFor(m_codeBlock->activationRegister()));
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, object)), regT1);
-        addSlowCase(checkStructure(regT1, m_globalData->activationStructure.get()));
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
-        activationNotCreated.link(this);
-    }
-    while (skip--) {
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, object)), regT1);
-        addSlowCase(checkStructure(regT1, m_globalData->activationStructure.get()));
-        loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
-    }
-    emit_op_resolve_global(currentInstruction, true);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_touch_entry);
+    slowPathCall.call();
 }
 
-void JIT::emitSlow_op_resolve_global_dynamic(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emit_op_loop_hint(Instruction*)
 {
-    unsigned dst = currentInstruction[1].u.operand;
-    Identifier* ident = &m_codeBlock->identifier(currentInstruction[2].u.operand);
-    int skip = currentInstruction[5].u.operand;
-    while (skip--)
-        linkSlowCase(iter);
-    JITStubCall resolveStubCall(this, cti_op_resolve);
-    resolveStubCall.addArgument(TrustedImmPtr(ident));
-    resolveStubCall.call(dst);
-    emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_resolve_global_dynamic));
-    
-    unsigned currentIndex = m_globalResolveInfoIndex++;
-    
-    linkSlowCase(iter); // We managed to skip all the nodes in the scope chain, but the cache missed.
-    JITStubCall stubCall(this, cti_op_resolve_global);
-    stubCall.addArgument(TrustedImmPtr(ident));
-    stubCall.addArgument(Imm32(currentIndex));
-    stubCall.addArgument(regT0);
-    stubCall.call(dst);
-}
+    // Emit the JIT optimization check: 
+    if (canBeOptimized()) {
+        addSlowCase(branchAdd32(PositiveOrZero, TrustedImm32(Options::executionCounterIncrementForLoop()),
+            AbsoluteAddress(m_codeBlock->addressOfJITExecuteCounter())));
+    }
 
-void JIT::emit_op_new_regexp(Instruction* currentInstruction)
-{
-    JITStubCall stubCall(this, cti_op_new_regexp);
-    stubCall.addArgument(TrustedImmPtr(m_codeBlock->regexp(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
+    // Emit the watchdog timer check:
+    if (m_vm->watchdog && m_vm->watchdog->isEnabled())
+        addSlowCase(branchTest8(NonZero, AbsoluteAddress(m_vm->watchdog->timerDidFireAddress())));
 }
 
-void JIT::emit_op_load_varargs(Instruction* currentInstruction)
+void JIT::emitSlow_op_loop_hint(Instruction*, Vector<SlowCaseEntry>::iterator& iter)
 {
-    int argCountDst = currentInstruction[1].u.operand;
-    int argsOffset = currentInstruction[2].u.operand;
-    int registerOffset = currentInstruction[3].u.operand;
-    ASSERT(argsOffset <= registerOffset);
-    
-    int expectedParams = m_codeBlock->m_numParameters - 1;
-    // Don't do inline copying if we aren't guaranteed to have a single stream
-    // of arguments
-    if (expectedParams) {
-        JITStubCall stubCall(this, cti_op_load_varargs);
-        stubCall.addArgument(Imm32(argsOffset));
-        stubCall.call();
-        // Stores a naked int32 in the register file.
-        store32(returnValueRegister, Address(callFrameRegister, argCountDst * sizeof(Register)));
-        return;
+#if ENABLE(DFG_JIT)
+    // Emit the slow path for the JIT optimization check:
+    if (canBeOptimized()) {
+        linkSlowCase(iter);
+        
+        callOperation(operationOptimize, m_bytecodeOffset);
+        Jump noOptimizedEntry = branchTestPtr(Zero, returnValueGPR);
+        if (!ASSERT_DISABLED) {
+            Jump ok = branchPtr(MacroAssembler::Above, regT0, TrustedImmPtr(bitwise_cast<void*>(static_cast<intptr_t>(1000))));
+            abortWithReason(JITUnreasonableLoopHintJumpTarget);
+            ok.link(this);
+        }
+        jump(returnValueGPR);
+        noOptimizedEntry.link(this);
+
+        emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_loop_hint));
     }
-
-#if USE(JSVALUE32_64)
-    addSlowCase(branch32(NotEqual, tagFor(argsOffset), TrustedImm32(JSValue::EmptyValueTag)));
-#else
-    addSlowCase(branchTestPtr(NonZero, addressFor(argsOffset)));
 #endif
-    // Load arg count into regT0
-    emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
-    store32(TrustedImm32(Int32Tag), intTagFor(argCountDst));
-    store32(regT0, intPayloadFor(argCountDst));
-    Jump endBranch = branch32(Equal, regT0, TrustedImm32(1));
-
-    mul32(TrustedImm32(sizeof(Register)), regT0, regT3);
-    addPtr(TrustedImm32(static_cast<unsigned>(sizeof(Register) - RegisterFile::CallFrameHeaderSize * sizeof(Register))), callFrameRegister, regT1);
-    subPtr(regT3, regT1); // regT1 is now the start of the out of line arguments
-    addPtr(Imm32(argsOffset * sizeof(Register)), callFrameRegister, regT2); // regT2 is the target buffer
-    
-    // Bounds check the registerfile
-    addPtr(regT2, regT3);
-    addPtr(Imm32((registerOffset - argsOffset) * sizeof(Register)), regT3);
-    addSlowCase(branchPtr(Below, AbsoluteAddress(m_globalData->interpreter->registerFile().addressOfEnd()), regT3));
 
-    sub32(TrustedImm32(1), regT0);
-    Label loopStart = label();
-    loadPtr(BaseIndex(regT1, regT0, TimesEight, static_cast<unsigned>(0 - 2 * sizeof(Register))), regT3);
-    storePtr(regT3, BaseIndex(regT2, regT0, TimesEight, static_cast<unsigned>(0 - sizeof(Register))));
-#if USE(JSVALUE32_64)
-    loadPtr(BaseIndex(regT1, regT0, TimesEight, static_cast<unsigned>(sizeof(void*) - 2 * sizeof(Register))), regT3);
-    storePtr(regT3, BaseIndex(regT2, regT0, TimesEight, static_cast<unsigned>(sizeof(void*) - sizeof(Register))));
-#endif
-    branchSubPtr(NonZero, TrustedImm32(1), regT0).linkTo(loopStart, this);
-    endBranch.link(this);
+    // Emit the slow path of the watchdog timer check:
+    if (m_vm->watchdog && m_vm->watchdog->isEnabled()) {
+        linkSlowCase(iter);
+        callOperation(operationHandleWatchdogTimer);
+
+        emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_loop_hint));
+    }
+
 }
 
-void JIT::emitSlow_op_load_varargs(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+void JIT::emit_op_new_regexp(Instruction* currentInstruction)
 {
-    int argCountDst = currentInstruction[1].u.operand;
-    int argsOffset = currentInstruction[2].u.operand;
-    int expectedParams = m_codeBlock->m_numParameters - 1;
-    if (expectedParams)
-        return;
-    
-    linkSlowCase(iter);
-    linkSlowCase(iter);
-    JITStubCall stubCall(this, cti_op_load_varargs);
-    stubCall.addArgument(Imm32(argsOffset));
-    stubCall.call();
-    
-    store32(TrustedImm32(Int32Tag), intTagFor(argCountDst));
-    store32(returnValueRegister, intPayloadFor(argCountDst));
+    callOperation(operationNewRegexp, currentInstruction[1].u.operand, m_codeBlock->regexp(currentInstruction[2].u.operand));
 }
 
 void JIT::emit_op_new_func(Instruction* currentInstruction)
@@ -1727,30 +1143,75 @@ void JIT::emit_op_new_func(Instruction* currentInstruction)
 #if USE(JSVALUE32_64)
         lazyJump = branch32(NotEqual, tagFor(dst), TrustedImm32(JSValue::EmptyValueTag));
 #else
-        lazyJump = branchTestPtr(NonZero, addressFor(dst));
+        lazyJump = branchTest64(NonZero, addressFor(dst));
 #endif
     }
-    JITStubCall stubCall(this, cti_op_new_func);
-    stubCall.addArgument(TrustedImmPtr(m_codeBlock->functionDecl(currentInstruction[2].u.operand)));
-    stubCall.call(currentInstruction[1].u.operand);
+
+    FunctionExecutable* funcExec = m_codeBlock->functionDecl(currentInstruction[2].u.operand);
+    callOperation(operationNewFunction, dst, funcExec);
+
     if (currentInstruction[3].u.operand)
         lazyJump.link(this);
 }
 
+void JIT::emit_op_new_captured_func(Instruction* currentInstruction)
+{
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_new_captured_func);
+    slowPathCall.call();
+}
+
+void JIT::emit_op_new_func_exp(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    FunctionExecutable* funcExpr = m_codeBlock->functionExpr(currentInstruction[2].u.operand);
+    callOperation(operationNewFunction, dst, funcExpr);
+}
+
 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);
+    int dst = currentInstruction[1].u.operand;
+    int valuesIndex = currentInstruction[2].u.operand;
+    int size = currentInstruction[3].u.operand;
+    addPtr(TrustedImm32(valuesIndex * sizeof(Register)), callFrameRegister, regT0);
+    callOperation(operationNewArrayWithProfile, dst,
+        currentInstruction[4].u.arrayAllocationProfile, regT0, size);
+}
+
+void JIT::emit_op_new_array_with_size(Instruction* currentInstruction)
+{
+    int dst = currentInstruction[1].u.operand;
+    int sizeIndex = currentInstruction[2].u.operand;
+#if USE(JSVALUE64)
+    emitGetVirtualRegister(sizeIndex, regT0);
+    callOperation(operationNewArrayWithSizeAndProfile, dst,
+        currentInstruction[3].u.arrayAllocationProfile, regT0);
+#else
+    emitLoad(sizeIndex, regT1, regT0);
+    callOperation(operationNewArrayWithSizeAndProfile, dst,
+        currentInstruction[3].u.arrayAllocationProfile, regT1, regT0);
+#endif
 }
 
 void JIT::emit_op_new_array_buffer(Instruction* currentInstruction)
 {
-    JITStubCall stubCall(this, cti_op_new_array_buffer);
-    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
-    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
-    stubCall.call(currentInstruction[1].u.operand);
+    int dst = currentInstruction[1].u.operand;
+    int valuesIndex = currentInstruction[2].u.operand;
+    int size = currentInstruction[3].u.operand;
+    const JSValue* values = codeBlock()->constantBuffer(valuesIndex);
+    callOperation(operationNewArrayBufferWithProfile, dst, currentInstruction[4].u.arrayAllocationProfile, values, size);
+}
+
+void JIT::emitSlow_op_captured_mov(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
+{
+    VariableWatchpointSet* set = currentInstruction[3].u.watchpointSet;
+    if (!set || set->state() == IsInvalidated)
+        return;
+#if USE(JSVALUE32_64)
+    linkSlowCase(iter);
+#endif
+    linkSlowCase(iter);
+    JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_captured_mov);
+    slowPathCall.call();
 }
 
 } // namespace JSC