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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

  * vim: set ts=8 sts=4 et sw=4 tw=99:

  * This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef jit_x64_MacroAssembler_x64_h

 #define jit_x64_MacroAssembler_x64_h

 #include "jit/IonFrames.h"

 #include "jit/MoveResolver.h"

 #include "jit/shared/MacroAssembler-x86-shared.h"

 namespace js {

 namespace jit {

 struct ImmShiftedTag : public ImmWord

 {

     ImmShiftedTag(JSValueShiftedTag shtag)

       : ImmWord((uintptr_t)shtag)

     { }

     ImmShiftedTag(JSValueType type)

       : ImmWord(uintptr_t(JSValueShiftedTag(JSVAL_TYPE_TO_SHIFTED_TAG(type))))

     { }

 };

 struct ImmTag : public Imm32

 {

     ImmTag(JSValueTag tag)

       : Imm32(tag)

     { }

 };

 class MacroAssemblerX64 : public MacroAssemblerX86Shared

 {

     // Number of bytes the stack is adjusted inside a call to C. Calls to C may

     // not be nested.

     bool inCall_;

     uint32_t args_;

     uint32_t passedIntArgs_;

     uint32_t passedFloatArgs_;

     uint32_t stackForCall_;

     bool dynamicAlignment_;

     bool enoughMemory_;

     // These use SystemAllocPolicy since asm.js releases memory after each

     // function is compiled, and these need to live until after all functions

     // are compiled.

     struct Double {

         double value;

         NonAssertingLabel uses;

         Double(double value) : value(value) {}

     };

     Vector<Double, 0, SystemAllocPolicy> doubles_;

     typedef HashMap<double, size_t, DefaultHasher<double>, SystemAllocPolicy> DoubleMap;

     DoubleMap doubleMap_;

     struct Float {

         float value;

         NonAssertingLabel uses;

         Float(float value) : value(value) {}

     };

     Vector<Float, 0, SystemAllocPolicy> floats_;

     typedef HashMap<float, size_t, DefaultHasher<float>, SystemAllocPolicy> FloatMap;

     FloatMap floatMap_;

     void setupABICall(uint32_t arg);

   protected:

     MoveResolver moveResolver_;

   public:

     using MacroAssemblerX86Shared::call;

     using MacroAssemblerX86Shared::Push;

     using MacroAssemblerX86Shared::Pop;

     using MacroAssemblerX86Shared::callWithExitFrame;

     using MacroAssemblerX86Shared::branch32;

     using MacroAssemblerX86Shared::load32;

     using MacroAssemblerX86Shared::store32;

     MacroAssemblerX64()

       : inCall_(false),

         enoughMemory_(true)

     {

     }

     // The buffer is about to be linked, make sure any constant pools or excess

     // bookkeeping has been flushed to the instruction stream.

     void finish();

     bool oom() const {

         return MacroAssemblerX86Shared::oom() || !enoughMemory_;

     }

     /////////////////////////////////////////////////////////////////

     // X64 helpers.

     /////////////////////////////////////////////////////////////////

     void call(ImmWord target) {

         mov(target, rax);

         call(rax);

     }

     void call(ImmPtr target) {

         call(ImmWord(uintptr_t(target.value)));

     }

     void call(AsmJSImmPtr target) {

         mov(target, rax);

         call(rax);

     }

     void call(const CallSiteDesc &desc, AsmJSImmPtr target) {

         call(target);

         appendCallSite(desc);

     }

     void callExit(AsmJSImmPtr target, uint32_t stackArgBytes) {

         call(CallSiteDesc::Exit(), target);

     }

     // Refers to the upper 32 bits of a 64-bit Value operand.

     // On x86_64, the upper 32 bits do not necessarily only contain the type.

     Operand ToUpper32(Operand base) {

         switch (base.kind()) {

           case Operand::MEM_REG_DISP:

             return Operand(Register::FromCode(base.base()), base.disp() + 4);

           case Operand::MEM_SCALE:

             return Operand(Register::FromCode(base.base()), Register::FromCode(base.index()),

                            base.scale(), base.disp() + 4);

           default:

             MOZ_ASSUME_UNREACHABLE("unexpected operand kind");

         }

     }

     static inline Operand ToUpper32(const Address &address) {

         return Operand(address.base, address.offset + 4);

     }

     static inline Operand ToUpper32(const BaseIndex &address) {

         return Operand(address.base, address.index, address.scale, address.offset + 4);

     }

     uint32_t Upper32Of(JSValueShiftedTag tag) {

         union { // Implemented in this way to appease MSVC++.

             uint64_t tag;

             struct {

                 uint32_t lo32;

                 uint32_t hi32;

             } s;

         } e;

         e.tag = tag;

         return e.s.hi32;

     }

     JSValueShiftedTag GetShiftedTag(JSValueType type) {

         return (JSValueShiftedTag)JSVAL_TYPE_TO_SHIFTED_TAG(type);

     }

     /////////////////////////////////////////////////////////////////

     // X86/X64-common interface.

     /////////////////////////////////////////////////////////////////

     void storeValue(ValueOperand val, Operand dest) {

         movq(val.valueReg(), dest);

     }

     void storeValue(ValueOperand val, const Address &dest) {

         storeValue(val, Operand(dest));

     }

     template <typename T>

     void storeValue(JSValueType type, Register reg, const T &dest) {

         // Value types with 32-bit payloads can be emitted as two 32-bit moves.

         if (type == JSVAL_TYPE_INT32 || type == JSVAL_TYPE_BOOLEAN) {

             movl(reg, Operand(dest));

             movl(Imm32(Upper32Of(GetShiftedTag(type))), ToUpper32(Operand(dest)));

         } else {

             boxValue(type, reg, ScratchReg);

             movq(ScratchReg, Operand(dest));

         }

     }

     template <typename T>

     void storeValue(const Value &val, const T &dest) {

         jsval_layout jv = JSVAL_TO_IMPL(val);

         if (val.isMarkable()) {

             movWithPatch(ImmWord(jv.asBits), ScratchReg);

             writeDataRelocation(val);

         } else {

             mov(ImmWord(jv.asBits), ScratchReg);

         }

         movq(ScratchReg, Operand(dest));

     }

     void storeValue(ValueOperand val, BaseIndex dest) {

         storeValue(val, Operand(dest));

     }

     void loadValue(Operand src, ValueOperand val) {

         movq(src, val.valueReg());

     }

     void loadValue(Address src, ValueOperand val) {

         loadValue(Operand(src), val);

     }

     void loadValue(const BaseIndex &src, ValueOperand val) {

         loadValue(Operand(src), val);

     }

     void tagValue(JSValueType type, Register payload, ValueOperand dest) {

         JS_ASSERT(dest.valueReg() != ScratchReg);

         if (payload != dest.valueReg())

             movq(payload, dest.valueReg());

         mov(ImmShiftedTag(type), ScratchReg);

         orq(ScratchReg, dest.valueReg());

     }

     void pushValue(ValueOperand val) {

         push(val.valueReg());

     }

     void Push(const ValueOperand &val) {

         pushValue(val);

         framePushed_ += sizeof(Value);

     }

     void popValue(ValueOperand val) {

         pop(val.valueReg());

     }

     void pushValue(const Value &val) {

         jsval_layout jv = JSVAL_TO_IMPL(val);

         push(ImmWord(jv.asBits));

     }

     void pushValue(JSValueType type, Register reg) {

         boxValue(type, reg, ScratchReg);

         push(ScratchReg);

     }

     void pushValue(const Address &addr) {

         push(Operand(addr));

     }

     void Pop(const ValueOperand &val) {

         popValue(val);

         framePushed_ -= sizeof(Value);

     }

     void moveValue(const Value &val, const Register &dest) {

         jsval_layout jv = JSVAL_TO_IMPL(val);

         movWithPatch(ImmWord(jv.asBits), dest);

         writeDataRelocation(val);

     }

     void moveValue(const Value &src, const ValueOperand &dest) {

         moveValue(src, dest.valueReg());

     }

     void moveValue(const ValueOperand &src, const ValueOperand &dest) {

         if (src.valueReg() != dest.valueReg())

             movq(src.valueReg(), dest.valueReg());

     }

     void boxValue(JSValueType type, Register src, Register dest) {

         JS_ASSERT(src != dest);

         JSValueShiftedTag tag = (JSValueShiftedTag)JSVAL_TYPE_TO_SHIFTED_TAG(type);

 #ifdef DEBUG

         if (type == JSVAL_TYPE_INT32 || type == JSVAL_TYPE_BOOLEAN) {

             Label upper32BitsZeroed;

             movePtr(ImmWord(UINT32_MAX), dest);

             branchPtr(Assembler::BelowOrEqual, src, dest, &upper32BitsZeroed);

             breakpoint();

             bind(&upper32BitsZeroed);

         }

 #endif

         mov(ImmShiftedTag(tag), dest);

         orq(src, dest);

     }

     Condition testUndefined(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_UNDEFINED));

         return cond;

     }

     Condition testInt32(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_INT32));

         return cond;

     }

     Condition testBoolean(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_BOOLEAN));

         return cond;

     }

     Condition testNull(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_NULL));

         return cond;

     }

     Condition testString(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_STRING));

         return cond;

     }

     Condition testObject(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_OBJECT));

         return cond;

     }

     Condition testDouble(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, Imm32(JSVAL_TAG_MAX_DOUBLE));

         return cond == Equal ? BelowOrEqual : Above;

     }

     Condition testNumber(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, Imm32(JSVAL_UPPER_INCL_TAG_OF_NUMBER_SET));

         return cond == Equal ? BelowOrEqual : Above;

     }

     Condition testGCThing(Condition cond, Register tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, Imm32(JSVAL_LOWER_INCL_TAG_OF_GCTHING_SET));

         return cond == Equal ? AboveOrEqual : Below;

     }

     Condition testMagic(Condition cond, const Register &tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_TAG_MAGIC));

         return cond;

     }

     Condition testError(Condition cond, const Register &tag) {

         return testMagic(cond, tag);

     }

     Condition testPrimitive(Condition cond, const Register &tag) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(tag, ImmTag(JSVAL_UPPER_EXCL_TAG_OF_PRIMITIVE_SET));

         return cond == Equal ? Below : AboveOrEqual;

     }

     Condition testUndefined(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testUndefined(cond, ScratchReg);

     }

     Condition testInt32(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testInt32(cond, ScratchReg);

     }

     Condition testBoolean(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testBoolean(cond, ScratchReg);

     }

     Condition testDouble(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testDouble(cond, ScratchReg);

     }

     Condition testNumber(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testNumber(cond, ScratchReg);

     }

     Condition testNull(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testNull(cond, ScratchReg);

     }

     Condition testString(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testString(cond, ScratchReg);

     }

     Condition testObject(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testObject(cond, ScratchReg);

     }

     Condition testGCThing(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testGCThing(cond, ScratchReg);

     }

     Condition testPrimitive(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testPrimitive(cond, ScratchReg);

     }

     Condition testUndefined(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testUndefined(cond, ScratchReg);

     }

     Condition testInt32(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testInt32(cond, ScratchReg);

     }

     Condition testBoolean(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testBoolean(cond, ScratchReg);

     }

     Condition testDouble(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testDouble(cond, ScratchReg);

     }

     Condition testNumber(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testNumber(cond, ScratchReg);

     }

     Condition testNull(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testNull(cond, ScratchReg);

     }

     Condition testString(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testString(cond, ScratchReg);

     }

     Condition testObject(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testObject(cond, ScratchReg);

     }

     Condition testPrimitive(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testPrimitive(cond, ScratchReg);

     }

     Condition testGCThing(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testGCThing(cond, ScratchReg);

     }

     Condition testMagic(Condition cond, const Address &src) {

         splitTag(src, ScratchReg);

         return testMagic(cond, ScratchReg);

     }

     Condition testUndefined(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testUndefined(cond, ScratchReg);

     }

     Condition testNull(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testNull(cond, ScratchReg);

     }

     Condition testBoolean(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testBoolean(cond, ScratchReg);

     }

     Condition testString(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testString(cond, ScratchReg);

     }

     Condition testInt32(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testInt32(cond, ScratchReg);

     }

     Condition testObject(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testObject(cond, ScratchReg);

     }

     Condition testDouble(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testDouble(cond, ScratchReg);

     }

     Condition testMagic(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testMagic(cond, ScratchReg);

     }

     Condition testGCThing(Condition cond, const BaseIndex &src) {

         splitTag(src, ScratchReg);

         return testGCThing(cond, ScratchReg);

     }

     Condition isMagic(Condition cond, const ValueOperand &src, JSWhyMagic why) {

         uint64_t magic = MagicValue(why).asRawBits();

         cmpPtr(src.valueReg(), ImmWord(magic));

         return cond;

     }

     void cmpPtr(const Register &lhs, const ImmWord rhs) {

         JS_ASSERT(lhs != ScratchReg);

         mov(rhs, ScratchReg);

         cmpq(lhs, ScratchReg);

     }

     void cmpPtr(const Register &lhs, const ImmPtr rhs) {

         cmpPtr(lhs, ImmWord(uintptr_t(rhs.value)));

     }

     void cmpPtr(const Register &lhs, const ImmGCPtr rhs) {

         JS_ASSERT(lhs != ScratchReg);

         movq(rhs, ScratchReg);

         cmpq(lhs, ScratchReg);

     }

     void cmpPtr(const Register &lhs, const Imm32 rhs) {

         cmpq(lhs, rhs);

     }

     void cmpPtr(const Operand &lhs, const ImmGCPtr rhs) {

         movq(rhs, ScratchReg);

         cmpq(lhs, ScratchReg);

     }

     void cmpPtr(const Operand &lhs, const ImmWord rhs) {

         if ((intptr_t)rhs.value <= INT32_MAX && (intptr_t)rhs.value >= INT32_MIN) {

             cmpq(lhs, Imm32((int32_t)rhs.value));

         } else {

             mov(rhs, ScratchReg);

             cmpq(lhs, ScratchReg);

         }

     }

     void cmpPtr(const Operand &lhs, const ImmPtr rhs) {

         cmpPtr(lhs, ImmWord(uintptr_t(rhs.value)));

     }

     void cmpPtr(const Address &lhs, const ImmGCPtr rhs) {

         cmpPtr(Operand(lhs), rhs);

     }

     void cmpPtr(const Address &lhs, const ImmWord rhs) {

         cmpPtr(Operand(lhs), rhs);

     }

     void cmpPtr(const Address &lhs, const ImmPtr rhs) {

         cmpPtr(lhs, ImmWord(uintptr_t(rhs.value)));

     }

     void cmpPtr(const Operand &lhs, const Register &rhs) {

         cmpq(lhs, rhs);

     }

     void cmpPtr(const Operand &lhs, const Imm32 rhs) {

         cmpq(lhs, rhs);

     }

     void cmpPtr(const Address &lhs, const Register &rhs) {

         cmpPtr(Operand(lhs), rhs);

     }

     void cmpPtr(const Register &lhs, const Register &rhs) {

         return cmpq(lhs, rhs);

     }

     void testPtr(const Register &lhs, const Register &rhs) {

         testq(lhs, rhs);

     }

     template <typename T1, typename T2>

     void cmpPtrSet(Assembler::Condition cond, T1 lhs, T2 rhs, const Register &dest)

     {

         cmpPtr(lhs, rhs);

         emitSet(cond, dest);

     }

     /////////////////////////////////////////////////////////////////

     // Common interface.

     /////////////////////////////////////////////////////////////////

     void reserveStack(uint32_t amount) {

         if (amount)

             subq(Imm32(amount), StackPointer);

         framePushed_ += amount;

     }

     void freeStack(uint32_t amount) {

         JS_ASSERT(amount <= framePushed_);

         if (amount)

             addq(Imm32(amount), StackPointer);

         framePushed_ -= amount;

     }

     void freeStack(Register amount) {

         addq(amount, StackPointer);

     }

     void addPtr(const Register &src, const Register &dest) {

         addq(src, dest);

     }

     void addPtr(Imm32 imm, const Register &dest) {

         addq(imm, dest);

     }

     void addPtr(Imm32 imm, const Address &dest) {

         addq(imm, Operand(dest));

     }

     void addPtr(Imm32 imm, const Operand &dest) {

         addq(imm, dest);

     }

     void addPtr(ImmWord imm, const Register &dest) {

         JS_ASSERT(dest != ScratchReg);

         if ((intptr_t)imm.value <= INT32_MAX && (intptr_t)imm.value >= INT32_MIN) {

             addq(Imm32((int32_t)imm.value), dest);

         } else {

             mov(imm, ScratchReg);

             addq(ScratchReg, dest);

         }

     }

     void addPtr(ImmPtr imm, const Register &dest) {

         addPtr(ImmWord(uintptr_t(imm.value)), dest);

     }

     void addPtr(const Address &src, const Register &dest) {

         addq(Operand(src), dest);

     }

     void subPtr(Imm32 imm, const Register &dest) {

         subq(imm, dest);

     }

     void subPtr(const Register &src, const Register &dest) {

         subq(src, dest);

     }

     void subPtr(const Address &addr, const Register &dest) {

         subq(Operand(addr), dest);

     }

     void subPtr(const Register &src, const Address &dest) {

         subq(src, Operand(dest));

     }

     void branch32(Condition cond, const AbsoluteAddress &lhs, Imm32 rhs, Label *label) {

         if (JSC::X86Assembler::isAddressImmediate(lhs.addr)) {

             branch32(cond, Operand(lhs), rhs, label);

         } else {

             mov(ImmPtr(lhs.addr), ScratchReg);

             branch32(cond, Address(ScratchReg, 0), rhs, label);

         }

     }

     void branch32(Condition cond, const AbsoluteAddress &lhs, Register rhs, Label *label) {

         if (JSC::X86Assembler::isAddressImmediate(lhs.addr)) {

             branch32(cond, Operand(lhs), rhs, label);

         } else {

             mov(ImmPtr(lhs.addr), ScratchReg);

             branch32(cond, Address(ScratchReg, 0), rhs, label);

         }

     }

     // Specialization for AbsoluteAddress.

     void branchPtr(Condition cond, const AbsoluteAddress &addr, const Register &ptr, Label *label) {

         JS_ASSERT(ptr != ScratchReg);

         if (JSC::X86Assembler::isAddressImmediate(addr.addr)) {

             branchPtr(cond, Operand(addr), ptr, label);

         } else {

             mov(ImmPtr(addr.addr), ScratchReg);

             branchPtr(cond, Operand(ScratchReg, 0x0), ptr, label);

         }

     }

     void branchPtr(Condition cond, const AsmJSAbsoluteAddress &addr, const Register &ptr, Label *label) {

         JS_ASSERT(ptr != ScratchReg);

         mov(AsmJSImmPtr(addr.kind()), ScratchReg);

         branchPtr(cond, Operand(ScratchReg, 0x0), ptr, label);

     }

     void branchPrivatePtr(Condition cond, Address lhs, ImmPtr ptr, Label *label) {

         branchPtr(cond, lhs, ImmWord(uintptr_t(ptr.value) >> 1), label);

     }

     void branchPrivatePtr(Condition cond, Address lhs, Register ptr, Label *label) {

         if (ptr != ScratchReg)

             movePtr(ptr, ScratchReg);

         rshiftPtr(Imm32(1), ScratchReg);

         branchPtr(cond, lhs, ScratchReg, label);

     }

     template <typename T, typename S>

     void branchPtr(Condition cond, T lhs, S ptr, Label *label) {

         cmpPtr(Operand(lhs), ptr);

         j(cond, label);

     }

     CodeOffsetJump jumpWithPatch(RepatchLabel *label) {

         JmpSrc src = jmpSrc(label);

         return CodeOffsetJump(size(), addPatchableJump(src, Relocation::HARDCODED));

     }

     CodeOffsetJump jumpWithPatch(RepatchLabel *label, Condition cond) {

         JmpSrc src = jSrc(cond, label);

         return CodeOffsetJump(size(), addPatchableJump(src, Relocation::HARDCODED));

     }

     template <typename S, typename T>

     CodeOffsetJump branchPtrWithPatch(Condition cond, S lhs, T ptr, RepatchLabel *label) {

         cmpPtr(lhs, ptr);

         return jumpWithPatch(label, cond);

     }

     void branchPtr(Condition cond, Register lhs, Register rhs, Label *label) {

         cmpPtr(lhs, rhs);

         j(cond, label);

     }

     void branchTestPtr(Condition cond, Register lhs, Register rhs, Label *label) {

         testq(lhs, rhs);

         j(cond, label);

     }

     void branchTestPtr(Condition cond, Register lhs, Imm32 imm, Label *label) {

         testq(lhs, imm);

         j(cond, label);

     }

     void branchTestPtr(Condition cond, const Address &lhs, Imm32 imm, Label *label) {

         testq(Operand(lhs), imm);

         j(cond, label);

     }

     void decBranchPtr(Condition cond, const Register &lhs, Imm32 imm, Label *label) {

         subPtr(imm, lhs);

         j(cond, label);

     }

     void movePtr(const Register &src, const Register &dest) {

         movq(src, dest);

     }

     void movePtr(const Register &src, const Operand &dest) {

         movq(src, dest);

     }

     void movePtr(ImmWord imm, Register dest) {

         mov(imm, dest);

     }

     void movePtr(ImmPtr imm, Register dest) {

         mov(imm, dest);

     }

     void movePtr(AsmJSImmPtr imm, const Register &dest) {

         mov(imm, dest);

     }

     void movePtr(ImmGCPtr imm, Register dest) {

         movq(imm, dest);

     }

     void loadPtr(const AbsoluteAddress &address, Register dest) {

         if (JSC::X86Assembler::isAddressImmediate(address.addr)) {

             movq(Operand(address), dest);

         } else {

             mov(ImmPtr(address.addr), ScratchReg);

             loadPtr(Address(ScratchReg, 0x0), dest);

         }

     }

     void loadPtr(const Address &address, Register dest) {

         movq(Operand(address), dest);

     }

     void loadPtr(const Operand &src, Register dest) {

         movq(src, dest);

     }

     void loadPtr(const BaseIndex &src, Register dest) {

         movq(Operand(src), dest);

     }

     void loadPrivate(const Address &src, Register dest) {

         loadPtr(src, dest);

         shlq(Imm32(1), dest);

     }

     void load32(const AbsoluteAddress &address, Register dest) {

         if (JSC::X86Assembler::isAddressImmediate(address.addr)) {

             movl(Operand(address), dest);

         } else {

             mov(ImmPtr(address.addr), ScratchReg);

             load32(Address(ScratchReg, 0x0), dest);

         }

     }

     void storePtr(ImmWord imm, const Address &address) {

         if ((intptr_t)imm.value <= INT32_MAX && (intptr_t)imm.value >= INT32_MIN) {

             movq(Imm32((int32_t)imm.value), Operand(address));

         } else {

             mov(imm, ScratchReg);

             movq(ScratchReg, Operand(address));

         }

     }

     void storePtr(ImmPtr imm, const Address &address) {

         storePtr(ImmWord(uintptr_t(imm.value)), address);

     }

     void storePtr(ImmGCPtr imm, const Address &address) {

         movq(imm, ScratchReg);

         movq(ScratchReg, Operand(address));

     }

     void storePtr(Register src, const Address &address) {

         movq(src, Operand(address));

     }

     void storePtr(Register src, const Operand &dest) {

         movq(src, dest);

     }

     void storePtr(const Register &src, const AbsoluteAddress &address) {

         if (JSC::X86Assembler::isAddressImmediate(address.addr)) {

             movq(src, Operand(address));

         } else {

             mov(ImmPtr(address.addr), ScratchReg);

             storePtr(src, Address(ScratchReg, 0x0));

         }

     }

     void store32(const Register &src, const AbsoluteAddress &address) {

         if (JSC::X86Assembler::isAddressImmediate(address.addr)) {

             movl(src, Operand(address));

         } else {

             mov(ImmPtr(address.addr), ScratchReg);

             store32(src, Address(ScratchReg, 0x0));

         }

     }

     void rshiftPtr(Imm32 imm, Register dest) {

         shrq(imm, dest);

     }

     void lshiftPtr(Imm32 imm, Register dest) {

         shlq(imm, dest);

     }

     void xorPtr(Imm32 imm, Register dest) {

         xorq(imm, dest);

     }

     void xorPtr(Register src, Register dest) {

         xorq(src, dest);

     }

     void orPtr(Imm32 imm, Register dest) {

         orq(imm, dest);

     }

     void orPtr(Register src, Register dest) {

         orq(src, dest);

     }

     void andPtr(Imm32 imm, Register dest) {

         andq(imm, dest);

     }

     void andPtr(Register src, Register dest) {

         andq(src, dest);

     }

     void splitTag(Register src, Register dest) {

         if (src != dest)

             movq(src, dest);

         shrq(Imm32(JSVAL_TAG_SHIFT), dest);

     }

     void splitTag(const ValueOperand &operand, const Register &dest) {

         splitTag(operand.valueReg(), dest);

     }

     void splitTag(const Operand &operand, const Register &dest) {

         movq(operand, dest);

         shrq(Imm32(JSVAL_TAG_SHIFT), dest);

     }

     void splitTag(const Address &operand, const Register &dest) {

         splitTag(Operand(operand), dest);

     }

     void splitTag(const BaseIndex &operand, const Register &dest) {

         splitTag(Operand(operand), dest);

     }

     // Extracts the tag of a value and places it in ScratchReg.

     Register splitTagForTest(const ValueOperand &value) {

         splitTag(value, ScratchReg);

         return ScratchReg;

     }

     void cmpTag(const ValueOperand &operand, ImmTag tag) {

         Register reg = splitTagForTest(operand);

         cmpl(reg, tag);

     }

     void branchTestUndefined(Condition cond, Register tag, Label *label) {

         cond = testUndefined(cond, tag);

         j(cond, label);

     }

     void branchTestInt32(Condition cond, Register tag, Label *label) {

         cond = testInt32(cond, tag);

         j(cond, label);

     }

     void branchTestDouble(Condition cond, Register tag, Label *label) {

         cond = testDouble(cond, tag);

         j(cond, label);

     }

     void branchTestBoolean(Condition cond, Register tag, Label *label) {

         cond = testBoolean(cond, tag);

         j(cond, label);

     }

     void branchTestNull(Condition cond, Register tag, Label *label) {

         cond = testNull(cond, tag);

         j(cond, label);

     }

     void branchTestString(Condition cond, Register tag, Label *label) {

         cond = testString(cond, tag);

         j(cond, label);

     }

     void branchTestObject(Condition cond, Register tag, Label *label) {

         cond = testObject(cond, tag);

         j(cond, label);

     }

     void branchTestNumber(Condition cond, Register tag, Label *label) {

         cond = testNumber(cond, tag);

         j(cond, label);

     }

     // x64 can test for certain types directly from memory when the payload

     // of the type is limited to 32 bits. This avoids loading into a register,

     // accesses half as much memory, and removes a right-shift.

     void branchTestUndefined(Condition cond, const Operand &operand, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(ToUpper32(operand), Imm32(Upper32Of(GetShiftedTag(JSVAL_TYPE_UNDEFINED))));

         j(cond, label);

     }

     void branchTestUndefined(Condition cond, const Address &address, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         branchTestUndefined(cond, Operand(address), label);

     }

     void branchTestInt32(Condition cond, const Operand &operand, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(ToUpper32(operand), Imm32(Upper32Of(GetShiftedTag(JSVAL_TYPE_INT32))));

         j(cond, label);

     }

     void branchTestInt32(Condition cond, const Address &address, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         branchTestInt32(cond, Operand(address), label);

     }

     void branchTestDouble(Condition cond, const Operand &operand, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         splitTag(operand, ScratchReg);

         branchTestDouble(cond, ScratchReg, label);

     }

     void branchTestDouble(Condition cond, const Address &address, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         branchTestDouble(cond, Operand(address), label);

     }

     void branchTestBoolean(Condition cond, const Operand &operand, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(ToUpper32(operand), Imm32(Upper32Of(GetShiftedTag(JSVAL_TYPE_BOOLEAN))));

         j(cond, label);

     }

     void branchTestNull(Condition cond, const Operand &operand, Label *label) {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         cmpl(ToUpper32(operand), Imm32(Upper32Of(GetShiftedTag(JSVAL_TYPE_NULL))));

         j(cond, label);

     }

     // Perform a type-test on a full Value loaded into a register.

     // Clobbers the ScratchReg.

     void branchTestUndefined(Condition cond, const ValueOperand &src, Label *label) {

         cond = testUndefined(cond, src);

         j(cond, label);

     }

     void branchTestInt32(Condition cond, const ValueOperand &src, Label *label) {

         splitTag(src, ScratchReg);

         branchTestInt32(cond, ScratchReg, label);

     }

     void branchTestBoolean(Condition cond, const ValueOperand &src, Label *label) {

         splitTag(src, ScratchReg);

         branchTestBoolean(cond, ScratchReg, label);

     }

     void branchTestDouble(Condition cond, const ValueOperand &src, Label *label) {

         cond = testDouble(cond, src);

         j(cond, label);

     }

     void branchTestNull(Condition cond, const ValueOperand &src, Label *label) {

         cond = testNull(cond, src);

         j(cond, label);

     }

     void branchTestString(Condition cond, const ValueOperand &src, Label *label) {

         cond = testString(cond, src);

         j(cond, label);

     }

     void branchTestObject(Condition cond, const ValueOperand &src, Label *label) {

         cond = testObject(cond, src);

         j(cond, label);

     }

     void branchTestNumber(Condition cond, const ValueOperand &src, Label *label) {

         cond = testNumber(cond, src);

         j(cond, label);

     }

     // Perform a type-test on a Value addressed by BaseIndex.

     // Clobbers the ScratchReg.

     void branchTestUndefined(Condition cond, const BaseIndex &address, Label *label) {

         cond = testUndefined(cond, address);

         j(cond, label);

     }

     void branchTestInt32(Condition cond, const BaseIndex &address, Label *label) {

         splitTag(address, ScratchReg);

         branchTestInt32(cond, ScratchReg, label);

     }

     void branchTestBoolean(Condition cond, const BaseIndex &address, Label *label) {

         splitTag(address, ScratchReg);

         branchTestBoolean(cond, ScratchReg, label);

     }

     void branchTestDouble(Condition cond, const BaseIndex &address, Label *label) {

         cond = testDouble(cond, address);

         j(cond, label);

     }

     void branchTestNull(Condition cond, const BaseIndex &address, Label *label) {

         cond = testNull(cond, address);

         j(cond, label);

     }

     void branchTestString(Condition cond, const BaseIndex &address, Label *label) {

         cond = testString(cond, address);

         j(cond, label);

     }

     void branchTestObject(Condition cond, const BaseIndex &address, Label *label) {

         cond = testObject(cond, address);

         j(cond, label);

     }

     template <typename T>

     void branchTestGCThing(Condition cond, const T &src, Label *label) {

         cond = testGCThing(cond, src);

         j(cond, label);

     }

     template <typename T>

     void branchTestPrimitive(Condition cond, const T &t, Label *label) {

         cond = testPrimitive(cond, t);

         j(cond, label);

     }

     template <typename T>

     void branchTestMagic(Condition cond, const T &t, Label *label) {

         cond = testMagic(cond, t);

         j(cond, label);

     }

     void branchTestMagicValue(Condition cond, const ValueOperand &val, JSWhyMagic why,

                               Label *label)

     {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         // Test for magic

         Label notmagic;

         Condition testCond = testMagic(cond, val);

         j(InvertCondition(testCond), &notmagic);

         // Test magic value

         unboxMagic(val, ScratchReg);

         branch32(cond, ScratchReg, Imm32(static_cast<int32_t>(why)), label);

         bind(&notmagic);

     }

     Condition testMagic(Condition cond, const ValueOperand &src) {

         splitTag(src, ScratchReg);

         return testMagic(cond, ScratchReg);

     }

     Condition testError(Condition cond, const ValueOperand &src) {

         return testMagic(cond, src);

     }

     void branchTestValue(Condition cond, const ValueOperand &value, const Value &v, Label *label) {

         JS_ASSERT(value.valueReg() != ScratchReg);

         moveValue(v, ScratchReg);

         cmpq(value.valueReg(), ScratchReg);

         j(cond, label);

     }

     void branchTestValue(Condition cond, const Address &valaddr, const ValueOperand &value,

                          Label *label)

     {

         JS_ASSERT(cond == Equal || cond == NotEqual);

         branchPtr(cond, valaddr, value.valueReg(), label);

     }

     void testNullSet(Condition cond, const ValueOperand &value, Register dest) {

         cond = testNull(cond, value);

         emitSet(cond, dest);

     }

     void testUndefinedSet(Condition cond, const ValueOperand &value, Register dest) {

         cond = testUndefined(cond, value);

         emitSet(cond, dest);

     }

     void boxDouble(const FloatRegister &src, const ValueOperand &dest) {

         movq(src, dest.valueReg());

     }

     void boxNonDouble(JSValueType type, const Register &src, const ValueOperand &dest) {

         JS_ASSERT(src != dest.valueReg());

         boxValue(type, src, dest.valueReg());

     }

     // Note that the |dest| register here may be ScratchReg, so we shouldn't

     // use it.

     void unboxInt32(const ValueOperand &src, const Register &dest) {

         movl(src.valueReg(), dest);

     }

     void unboxInt32(const Operand &src, const Register &dest) {

         movl(src, dest);

     }

     void unboxInt32(const Address &src, const Register &dest) {

         unboxInt32(Operand(src), dest);

     }

     void unboxDouble(const Address &src, const FloatRegister &dest) {

         loadDouble(Operand(src), dest);

     }

     void unboxArgObjMagic(const ValueOperand &src, const Register &dest) {

         unboxArgObjMagic(Operand(src.valueReg()), dest);

     }

     void unboxArgObjMagic(const Operand &src, const Register &dest) {

         mov(ImmWord(0), dest);

     }

     void unboxArgObjMagic(const Address &src, const Register &dest) {

         unboxArgObjMagic(Operand(src), dest);

     }

     void unboxBoolean(const ValueOperand &src, const Register &dest) {

         movl(src.valueReg(), dest);

     }

     void unboxBoolean(const Operand &src, const Register &dest) {

         movl(src, dest);

     }

     void unboxBoolean(const Address &src, const Register &dest) {

         unboxBoolean(Operand(src), dest);

     }

     void unboxMagic(const ValueOperand &src, const Register &dest) {

         movl(src.valueReg(), dest);

     }

     void unboxDouble(const ValueOperand &src, const FloatRegister &dest) {

         movq(src.valueReg(), dest);

     }

     void unboxPrivate(const ValueOperand &src, const Register dest) {

         movq(src.valueReg(), dest);

         shlq(Imm32(1), dest);

     }

     void notBoolean(const ValueOperand &val) {

         xorq(Imm32(1), val.valueReg());

     }

     // Unbox any non-double value into dest. Prefer unboxInt32 or unboxBoolean

     // instead if the source type is known.

     void unboxNonDouble(const ValueOperand &src, const Register &dest) {

         // In a non-trivial coupling, we're not permitted to use ScratchReg when

         // src and dest are different registers, because of how extractObject is

         // implemented.

         if (src.valueReg() == dest) {

             mov(ImmWord(JSVAL_PAYLOAD_MASK), ScratchReg);

             andq(ScratchReg, dest);

         } else {

             mov(ImmWord(JSVAL_PAYLOAD_MASK), dest);

             andq(src.valueReg(), dest);

         }

     }

     void unboxNonDouble(const Operand &src, const Register &dest) {

         // Explicitly permits |dest| to be used in |src|.

         JS_ASSERT(dest != ScratchReg);

         mov(ImmWord(JSVAL_PAYLOAD_MASK), ScratchReg);

         movq(src, dest);

         andq(ScratchReg, dest);

     }

     void unboxString(const ValueOperand &src, const Register &dest) { unboxNonDouble(src, dest); }

     void unboxString(const Operand &src, const Register &dest) { unboxNonDouble(src, dest); }

     void unboxObject(const ValueOperand &src, const Register &dest) { unboxNonDouble(src, dest); }

     void unboxObject(const Operand &src, const Register &dest) { unboxNonDouble(src, dest); }

     // Extended unboxing API. If the payload is already in a register, returns

     // that register. Otherwise, provides a move to the given scratch register,

     // and returns that.

     Register extractObject(const Address &address, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         loadPtr(address, ScratchReg);

         // We have a special coupling with unboxObject. As long as the registers

         // aren't equal, it doesn't use ScratchReg.

         unboxObject(ValueOperand(ScratchReg), scratch);

         return scratch;

     }

     Register extractObject(const ValueOperand &value, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         unboxObject(value, scratch);

         return scratch;

     }

     Register extractInt32(const ValueOperand &value, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         unboxInt32(value, scratch);

         return scratch;

     }

     Register extractBoolean(const ValueOperand &value, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         unboxBoolean(value, scratch);

         return scratch;

     }

     Register extractTag(const Address &address, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         loadPtr(address, scratch);

         splitTag(scratch, scratch);

         return scratch;

     }

     Register extractTag(const ValueOperand &value, Register scratch) {

         JS_ASSERT(scratch != ScratchReg);

         splitTag(value, scratch);

         return scratch;

     }

     void unboxValue(const ValueOperand &src, AnyRegister dest) {

         if (dest.isFloat()) {

             Label notInt32, end;

             branchTestInt32(Assembler::NotEqual, src, &notInt32);

             convertInt32ToDouble(src.valueReg(), dest.fpu());

             jump(&end);

             bind(&notInt32);

             unboxDouble(src, dest.fpu());

             bind(&end);

         } else {

             unboxNonDouble(src, dest.gpr());

         }

     }

     // These two functions use the low 32-bits of the full value register.

     void boolValueToDouble(const ValueOperand &operand, const FloatRegister &dest) {

         convertInt32ToDouble(operand.valueReg(), dest);

     }

     void int32ValueToDouble(const ValueOperand &operand, const FloatRegister &dest) {

         convertInt32ToDouble(operand.valueReg(), dest);

     }

     void boolValueToFloat32(const ValueOperand &operand, const FloatRegister &dest) {

         convertInt32ToFloat32(operand.valueReg(), dest);

     }

     void int32ValueToFloat32(const ValueOperand &operand, const FloatRegister &dest) {

         convertInt32ToFloat32(operand.valueReg(), dest);

     }

     void loadConstantDouble(double d, const FloatRegister &dest);

     void loadConstantFloat32(float f, const FloatRegister &dest);

     void branchTruncateDouble(const FloatRegister &src, const Register &dest, Label *fail) {

         cvttsd2sq(src, dest);

         // cvttsd2sq returns 0x8000000000000000 on failure. Test for it by

         // subtracting 1 and testing overflow (this avoids the need to

         // materialize that value in a register).

         cmpq(dest, Imm32(1));

         j(Assembler::Overflow, fail);

         movl(dest, dest); // Zero upper 32-bits.

     }

     void branchTruncateFloat32(const FloatRegister &src, const Register &dest, Label *fail) {

         cvttss2sq(src, dest);

         // Same trick as for Doubles

         cmpq(dest, Imm32(1));

         j(Assembler::Overflow, fail);

         movl(dest, dest); // Zero upper 32-bits.

     }

     Condition testInt32Truthy(bool truthy, const ValueOperand &operand) {

         testl(operand.valueReg(), operand.valueReg());

         return truthy ? NonZero : Zero;

     }

     void branchTestInt32Truthy(bool truthy, const ValueOperand &operand, Label *label) {

         Condition cond = testInt32Truthy(truthy, operand);

         j(cond, label);

     }

     void branchTestBooleanTruthy(bool truthy, const ValueOperand &operand, Label *label) {

         testl(operand.valueReg(), operand.valueReg());

         j(truthy ? NonZero : Zero, label);

     }

     Condition testStringTruthy(bool truthy, const ValueOperand &value) {

         unboxString(value, ScratchReg);

         Operand lengthAndFlags(ScratchReg, JSString::offsetOfLengthAndFlags());

         testq(lengthAndFlags, Imm32(-1 << JSString::LENGTH_SHIFT));

         return truthy ? Assembler::NonZero : Assembler::Zero;

     }

     void branchTestStringTruthy(bool truthy, const ValueOperand &value, Label *label) {

         Condition cond = testStringTruthy(truthy, value);

         j(cond, label);

     }

     void loadInt32OrDouble(const Operand &operand, const FloatRegister &dest) {

         Label notInt32, end;

         branchTestInt32(Assembler::NotEqual, operand, &notInt32);

         convertInt32ToDouble(operand, dest);

         jump(&end);

         bind(&notInt32);

         loadDouble(operand, dest);

         bind(&end);

     }

     template <typename T>

     void loadUnboxedValue(const T &src, MIRType type, AnyRegister dest) {

         if (dest.isFloat())

             loadInt32OrDouble(Operand(src), dest.fpu());

         else if (type == MIRType_Int32 || type == MIRType_Boolean)

             movl(Operand(src), dest.gpr());

         else

             unboxNonDouble(Operand(src), dest.gpr());

     }

     void loadInstructionPointerAfterCall(const Register &dest) {

         loadPtr(Address(StackPointer, 0x0), dest);

     }

     void convertUInt32ToDouble(const Register &src, const FloatRegister &dest) {

         cvtsq2sd(src, dest);

     }

     void convertUInt32ToFloat32(const Register &src, const FloatRegister &dest) {

         cvtsq2ss(src, dest);

     }

     void inc64(AbsoluteAddress dest) {

         if (JSC::X86Assembler::isAddressImmediate(dest.addr)) {

             addPtr(Imm32(1), Operand(dest));

         } else {

             mov(ImmPtr(dest.addr), ScratchReg);

             addPtr(Imm32(1), Address(ScratchReg, 0));

         }

     }

     // If source is a double, load it into dest. If source is int32,

     // convert it to double. Else, branch to failure.

     void ensureDouble(const ValueOperand &source, FloatRegister dest, Label *failure) {

         Label isDouble, done;

         Register tag = splitTagForTest(source);

         branchTestDouble(Assembler::Equal, tag, &isDouble);

         branchTestInt32(Assembler::NotEqual, tag, failure);

         unboxInt32(source, ScratchReg);

         convertInt32ToDouble(ScratchReg, dest);

         jump(&done);

         bind(&isDouble);

         unboxDouble(source, dest);

         bind(&done);

     }

     // Setup a call to C/C++ code, given the number of general arguments it

     // takes. Note that this only supports cdecl.

     //

     // In order for alignment to work correctly, the MacroAssembler must have a

     // consistent view of the stack displacement. It is okay to call "push"

     // manually, however, if the stack alignment were to change, the macro

     // assembler should be notified before starting a call.

     void setupAlignedABICall(uint32_t args);

     // Sets up an ABI call for when the alignment is not known. This may need a

     // scratch register.

     void setupUnalignedABICall(uint32_t args, const Register &scratch);

     // Arguments must be assigned to a C/C++ call in order. They are moved

     // in parallel immediately before performing the call. This process may

     // temporarily use more stack, in which case esp-relative addresses will be

     // automatically adjusted. It is extremely important that esp-relative

     // addresses are computed *after* setupABICall(). Furthermore, no

     // operations should be emitted while setting arguments.

     void passABIArg(const MoveOperand &from, MoveOp::Type type);

     void passABIArg(const Register &reg);

     void passABIArg(const FloatRegister &reg, MoveOp::Type type);

   private:

     void callWithABIPre(uint32_t *stackAdjust);

     void callWithABIPost(uint32_t stackAdjust, MoveOp::Type result);

   public:

     // Emits a call to a C/C++ function, resolving all argument moves.

     void callWithABI(void *fun, MoveOp::Type result = MoveOp::GENERAL);

     void callWithABI(AsmJSImmPtr imm, MoveOp::Type result = MoveOp::GENERAL);

     void callWithABI(Address fun, MoveOp::Type result = MoveOp::GENERAL);

     void handleFailureWithHandler(void *handler);

     void handleFailureWithHandlerTail();

     void makeFrameDescriptor(Register frameSizeReg, FrameType type) {

         shlq(Imm32(FRAMESIZE_SHIFT), frameSizeReg);

         orq(Imm32(type), frameSizeReg);

     }

     // Save an exit frame (which must be aligned to the stack pointer) to

     // ThreadData::ionTop of the main thread.

     void linkExitFrame() {

         storePtr(StackPointer,

                  AbsoluteAddress(GetIonContext()->runtime->addressOfIonTop()));

     }

     void callWithExitFrame(JitCode *target, Register dynStack) {

         addPtr(Imm32(framePushed()), dynStack);

         makeFrameDescriptor(dynStack, JitFrame_IonJS);

         Push(dynStack);

         call(target);

     }

     // Save an exit frame to the thread data of the current thread, given a

     // register that holds a PerThreadData *.

     void linkParallelExitFrame(const Register &pt) {

         storePtr(StackPointer, Address(pt, offsetof(PerThreadData, ionTop)));

     }

     // See CodeGeneratorX64 calls to noteAsmJSGlobalAccess.

     void patchAsmJSGlobalAccess(CodeOffsetLabel patchAt, uint8_t *code, uint8_t *globalData,

                                 unsigned globalDataOffset)

     {

         uint8_t *nextInsn = code + patchAt.offset();

         JS_ASSERT(nextInsn <= globalData);

         uint8_t *target = globalData + globalDataOffset;

         ((int32_t *)nextInsn)[-1] = target - nextInsn;

     }

     void memIntToValue(Address Source, Address Dest) {

         load32(Source, ScratchReg);

         storeValue(JSVAL_TYPE_INT32, ScratchReg, Dest);

     }

 #ifdef JSGC_GENERATIONAL

     void branchPtrInNurseryRange(Register ptr, Register temp, Label *label);

     void branchValueIsNurseryObject(ValueOperand value, Register temp, Label *label);

 #endif

 };

 typedef MacroAssemblerX64 MacroAssemblerSpecific;

 } // namespace jit

 } // namespace js

 #endif /* jit_x64_MacroAssembler_x64_h */