/*

* Copyright (C) 2008, 2009 Apple Inc. All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

*

* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR

* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#include "config.h"

#if ENABLE(JIT)

#if USE(JSVALUE32_64)

#include "JIT.h"

#include "CodeBlock.h"

#include "JITInlineMethods.h"

#include "JITStubCall.h"

#include "JSArray.h"

#include "JSFunction.h"

#include "JSPropertyNameIterator.h"

#include "Interpreter.h"

#include "LinkBuffer.h"

#include "RepatchBuffer.h"

#include "ResultType.h"

#include "SamplingTool.h"

#ifndef NDEBUG

#include <stdio.h>

#endif

using namespace std;

namespace JSC {

void JIT::emit_op_put_by_index(Instruction* currentInstruction)

{

unsigned base = currentInstruction[1].u.operand;

unsigned property = currentInstruction[2].u.operand;

unsigned value = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_put_by_index);

stubCall.addArgument(base);

stubCall.addArgument(Imm32(property));

stubCall.addArgument(value);

stubCall.call();

}

void JIT::emit_op_put_getter(Instruction* currentInstruction)

{

unsigned base = currentInstruction[1].u.operand;

unsigned property = currentInstruction[2].u.operand;

unsigned function = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_put_getter);

stubCall.addArgument(base);

stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(property)));

stubCall.addArgument(function);

stubCall.call();

}

void JIT::emit_op_put_setter(Instruction* currentInstruction)

{

unsigned base = currentInstruction[1].u.operand;

unsigned property = currentInstruction[2].u.operand;

unsigned function = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_put_setter);

stubCall.addArgument(base);

stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(property)));

stubCall.addArgument(function);

stubCall.call();

}

void JIT::emit_op_del_by_id(Instruction* currentInstruction)

{

unsigned dst = currentInstruction[1].u.operand;

unsigned base = currentInstruction[2].u.operand;

unsigned property = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_del_by_id);

stubCall.addArgument(base);

stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(property)));

stubCall.call(dst);

}

#if !ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)

/* ------------------------------ BEGIN: !ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS) ------------------------------ */

// Treat these as nops - the call will be handed as a regular get_by_id/op_call pair.

void JIT::emit_op_method_check(Instruction*) {}

void JIT::emitSlow_op_method_check(Instruction*, Vector<SlowCaseEntry>::iterator&) { ASSERT_NOT_REACHED(); }

#if ENABLE(JIT_OPTIMIZE_METHOD_CALLS)

#error "JIT_OPTIMIZE_METHOD_CALLS requires JIT_OPTIMIZE_PROPERTY_ACCESS"

#endif

void JIT::emit_op_get_by_val(Instruction* currentInstruction)

{

unsigned dst = currentInstruction[1].u.operand;

unsigned base = currentInstruction[2].u.operand;

unsigned property = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_get_by_val);

stubCall.addArgument(base);

stubCall.addArgument(property);

stubCall.call(dst);

}

void JIT::emitSlow_op_get_by_val(Instruction*, Vector<SlowCaseEntry>::iterator&)

{

ASSERT_NOT_REACHED();

}

void JIT::emit_op_put_by_val(Instruction* currentInstruction)

{

unsigned base = currentInstruction[1].u.operand;

unsigned property = currentInstruction[2].u.operand;

unsigned value = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_put_by_val);

stubCall.addArgument(base);

stubCall.addArgument(property);

stubCall.addArgument(value);

stubCall.call();

}

void JIT::emitSlow_op_put_by_val(Instruction*, Vector<SlowCaseEntry>::iterator&)

{

ASSERT_NOT_REACHED();

}

void JIT::emit_op_get_by_id(Instruction* currentInstruction)

{

int dst = currentInstruction[1].u.operand;

int base = currentInstruction[2].u.operand;

int ident = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_get_by_id_generic);

stubCall.addArgument(base);

stubCall.addArgument(TrustedImmPtr(&(m_codeBlock->identifier(ident))));

stubCall.call(dst);

m_propertyAccessInstructionIndex++;

}

void JIT::emitSlow_op_get_by_id(Instruction*, Vector<SlowCaseEntry>::iterator&)

{

m_propertyAccessInstructionIndex++;

ASSERT_NOT_REACHED();

}

void JIT::emit_op_put_by_id(Instruction* currentInstruction)

{

int base = currentInstruction[1].u.operand;

int ident = currentInstruction[2].u.operand;

int value = currentInstruction[3].u.operand;

JITStubCall stubCall(this, cti_op_put_by_id_generic);

stubCall.addArgument(base);

stubCall.addArgument(TrustedImmPtr(&(m_codeBlock->identifier(ident))));

stubCall.addArgument(value);

stubCall.call();

m_propertyAccessInstructionIndex++;

}

void JIT::emitSlow_op_put_by_id(Instruction*, Vector<SlowCaseEntry>::iterator&)

{

m_propertyAccessInstructionIndex++;

ASSERT_NOT_REACHED();

}

#else // !ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)

/* ------------------------------ BEGIN: ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS) ------------------------------ */

#if ENABLE(JIT_OPTIMIZE_METHOD_CALLS)

void JIT::emit_op_method_check(Instruction* currentInstruction)

{

// Assert that the following instruction is a get_by_id.

ASSERT(m_interpreter->getOpcodeID((currentInstruction + OPCODE_LENGTH(op_method_check))->u.opcode) == op_get_by_id);

currentInstruction += OPCODE_LENGTH(op_method_check);

// Do the method check - check the object & its prototype's structure inline (this is the common case).

m_methodCallCompilationInfo.append(MethodCallCompilationInfo(m_propertyAccessInstructionIndex));

MethodCallCompilationInfo& info = m_methodCallCompilationInfo.last();

int dst = currentInstruction[1].u.operand;

int base = currentInstruction[2].u.operand;

emitLoad(base, regT1, regT0);

emitJumpSlowCaseIfNotJSCell(base, regT1);

BEGIN_UNINTERRUPTED_SEQUENCE(sequenceMethodCheck);

Jump structureCheck = branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), info.structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));

DataLabelPtr protoStructureToCompare, protoObj = moveWithPatch(TrustedImmPtr(0), regT2);

Jump protoStructureCheck = branchPtrWithPatch(NotEqual, Address(regT2, JSCell::structureOffset()), protoStructureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));

// This will be relinked to load the function without doing a load.

DataLabelPtr putFunction = moveWithPatch(TrustedImmPtr(0), regT0);

END_UNINTERRUPTED_SEQUENCE(sequenceMethodCheck);

move(TrustedImm32(JSValue::CellTag), regT1);

Jump match = jump();

ASSERT_JIT_OFFSET_UNUSED(protoObj, differenceBetween(info.structureToCompare, protoObj), patchOffsetMethodCheckProtoObj);

ASSERT_JIT_OFFSET(differenceBetween(info.structureToCompare, protoStructureToCompare), patchOffsetMethodCheckProtoStruct);

ASSERT_JIT_OFFSET_UNUSED(putFunction, differenceBetween(info.structureToCompare, putFunction), patchOffsetMethodCheckPutFunction);

// Link the failure cases here.

structureCheck.link(this);

protoStructureCheck.link(this);

// Do a regular(ish) get_by_id (the slow case will be link to

// cti_op_get_by_id_method_check instead of cti_op_get_by_id.

compileGetByIdHotPath();

match.link(this);

emitStore(dst, regT1, regT0);

map(m_bytecodeOffset + OPCODE_LENGTH(op_method_check), dst, regT1, regT0);

// We've already generated the following get_by_id, so make sure it's skipped over.

m_bytecodeOffset += OPCODE_LENGTH(op_get_by_id);

}

void JIT::emitSlow_op_method_check(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

currentInstruction += OPCODE_LENGTH(op_method_check);

int dst = currentInstruction[1].u.operand;

int base = currentInstruction[2].u.operand;

int ident = currentInstruction[3].u.operand;

compileGetByIdSlowCase(dst, base, &(m_codeBlock->identifier(ident)), iter, true);

// We've already generated the following get_by_id, so make sure it's skipped over.

m_bytecodeOffset += OPCODE_LENGTH(op_get_by_id);

}

#else //!ENABLE(JIT_OPTIMIZE_METHOD_CALLS)

// Treat these as nops - the call will be handed as a regular get_by_id/op_call pair.

void JIT::emit_op_method_check(Instruction*) {}

void JIT::emitSlow_op_method_check(Instruction*, Vector<SlowCaseEntry>::iterator&) { ASSERT_NOT_REACHED(); }

#endif

JIT::CodePtr JIT::stringGetByValStubGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

JSInterfaceJIT jit;

JumpList failures;

failures.append(jit.branchPtr(NotEqual, Address(regT0), TrustedImmPtr(globalData->jsStringVPtr)));

failures.append(jit.branchTest32(NonZero, Address(regT0, OBJECT_OFFSETOF(JSString, m_fiberCount))));

// Load string length to regT1, and start the process of loading the data pointer into regT0

jit.load32(Address(regT0, ThunkHelpers::jsStringLengthOffset()), regT1);

jit.loadPtr(Address(regT0, ThunkHelpers::jsStringValueOffset()), regT0);

jit.loadPtr(Address(regT0, ThunkHelpers::stringImplDataOffset()), regT0);

// Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large

failures.append(jit.branch32(AboveOrEqual, regT2, regT1));

// Load the character

jit.load16(BaseIndex(regT0, regT2, TimesTwo, 0), regT0);

failures.append(jit.branch32(AboveOrEqual, regT0, TrustedImm32(0x100)));

jit.move(TrustedImmPtr(globalData->smallStrings.singleCharacterStrings()), regT1);

jit.loadPtr(BaseIndex(regT1, regT0, ScalePtr, 0), regT0);

jit.move(TrustedImm32(JSValue::CellTag), regT1); // We null check regT0 on return so this is safe

jit.ret();

failures.link(&jit);

jit.move(TrustedImm32(0), regT0);

jit.ret();

LinkBuffer patchBuffer(&jit, pool);

return patchBuffer.finalizeCode().m_code;

}

void JIT::emit_op_get_by_val(Instruction* currentInstruction)

{

unsigned dst = currentInstruction[1].u.operand;

unsigned base = currentInstruction[2].u.operand;

unsigned property = currentInstruction[3].u.operand;

emitLoad2(base, regT1, regT0, property, regT3, regT2);

addSlowCase(branch32(NotEqual, regT3, TrustedImm32(JSValue::Int32Tag)));

emitJumpSlowCaseIfNotJSCell(base, regT1);

addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr)));

loadPtr(Address(regT0, JSArray::storageOffset()), regT3);

addSlowCase(branch32(AboveOrEqual, regT2, Address(regT0, JSArray::vectorLengthOffset())));

load32(BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(ArrayStorage, m_vector[0]) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1); // tag

load32(BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(ArrayStorage, m_vector[0]) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0); // payload

addSlowCase(branch32(Equal, regT1, TrustedImm32(JSValue::EmptyValueTag)));

emitStore(dst, regT1, regT0);

map(m_bytecodeOffset + OPCODE_LENGTH(op_get_by_val), dst, regT1, regT0);

}

void JIT::emitSlow_op_get_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

unsigned dst = currentInstruction[1].u.operand;

unsigned base = currentInstruction[2].u.operand;

unsigned property = currentInstruction[3].u.operand;

linkSlowCase(iter); // property int32 check

linkSlowCaseIfNotJSCell(iter, base); // base cell check

Jump nonCell = jump();

linkSlowCase(iter); // base array check

Jump notString = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr));

emitNakedCall(m_globalData->getCTIStub(stringGetByValStubGenerator));

Jump failed = branchTestPtr(Zero, regT0);

emitStore(dst, regT1, regT0);

emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_get_by_val));

failed.link(this);

notString.link(this);

nonCell.link(this);

linkSlowCase(iter); // vector length check

linkSlowCase(iter); // empty value

JITStubCall stubCall(this, cti_op_get_by_val);

stubCall.addArgument(base);

stubCall.addArgument(property);

stubCall.call(dst);

}

void JIT::emit_op_put_by_val(Instruction* currentInstruction)

{

unsigned base = currentInstruction[1].u.operand;

unsigned property = currentInstruction[2].u.operand;

unsigned value = currentInstruction[3].u.operand;

emitLoad2(base, regT1, regT0, property, regT3, regT2);

addSlowCase(branch32(NotEqual, regT3, TrustedImm32(JSValue::Int32Tag)));

emitJumpSlowCaseIfNotJSCell(base, regT1);

addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr)));

addSlowCase(branch32(AboveOrEqual, regT2, Address(regT0, JSArray::vectorLengthOffset())));

loadPtr(Address(regT0, JSArray::storageOffset()), regT3);

Jump empty = branch32(Equal, BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(ArrayStorage, m_vector[0]) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), TrustedImm32(JSValue::EmptyValueTag));

Label storeResult(this);

emitLoad(value, regT1, regT0);

store32(regT0, BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(ArrayStorage, m_vector[0]) + OBJECT_OFFSETOF(JSValue, u.asBits.payload))); // payload

store32(regT1, BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(ArrayStorage, m_vector[0]) + OBJECT_OFFSETOF(JSValue, u.asBits.tag))); // tag

Jump end = jump();

empty.link(this);

add32(TrustedImm32(1), Address(regT3, OBJECT_OFFSETOF(ArrayStorage, m_numValuesInVector)));

branch32(Below, regT2, Address(regT3, OBJECT_OFFSETOF(ArrayStorage, m_length))).linkTo(storeResult, this);

add32(TrustedImm32(1), regT2, regT0);

store32(regT0, Address(regT3, OBJECT_OFFSETOF(ArrayStorage, m_length)));

jump().linkTo(storeResult, this);

end.link(this);

}

void JIT::emitSlow_op_put_by_val(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

JITStubCall stubPutByValCall(this, cti_op_put_by_val);

stubPutByValCall.addArgument(base);

stubPutByValCall.addArgument(property);

stubPutByValCall.addArgument(value);

stubPutByValCall.call();

}

void JIT::emit_op_get_by_id(Instruction* currentInstruction)

{

int dst = currentInstruction[1].u.operand;

int base = currentInstruction[2].u.operand;

emitLoad(base, regT1, regT0);

emitJumpSlowCaseIfNotJSCell(base, regT1);

compileGetByIdHotPath();

emitStore(dst, regT1, regT0);

map(m_bytecodeOffset + OPCODE_LENGTH(op_get_by_id), dst, regT1, regT0);

}

void JIT::compileGetByIdHotPath()

{

// As for put_by_id, get_by_id requires the offset of the Structure and the offset of the access to be patched.

// Additionally, for get_by_id we need patch the offset of the branch to the slow case (we patch this to jump

// to array-length / prototype access tranpolines, and finally we also the the property-map access offset as a label

// to jump back to if one of these trampolies finds a match.

BEGIN_UNINTERRUPTED_SEQUENCE(sequenceGetByIdHotPath);

Label hotPathBegin(this);

m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex].hotPathBegin = hotPathBegin;

m_propertyAccessInstructionIndex++;

DataLabelPtr structureToCompare;

Jump structureCheck = branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));

addSlowCase(structureCheck);

ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureToCompare), patchOffsetGetByIdStructure);

ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureCheck), patchOffsetGetByIdBranchToSlowCase);

loadPtr(Address(regT0, OBJECT_OFFSETOF(JSObject, m_propertyStorage)), regT2);

DataLabel32 displacementLabel1 = loadPtrWithAddressOffsetPatch(Address(regT2, patchGetByIdDefaultOffset), regT0); // payload

ASSERT_JIT_OFFSET_UNUSED(displacementLabel1, differenceBetween(hotPathBegin, displacementLabel1), patchOffsetGetByIdPropertyMapOffset1);

DataLabel32 displacementLabel2 = loadPtrWithAddressOffsetPatch(Address(regT2, patchGetByIdDefaultOffset), regT1); // tag

ASSERT_JIT_OFFSET_UNUSED(displacementLabel2, differenceBetween(hotPathBegin, displacementLabel2), patchOffsetGetByIdPropertyMapOffset2);

Label putResult(this);

ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, putResult), patchOffsetGetByIdPutResult);

END_UNINTERRUPTED_SEQUENCE(sequenceGetByIdHotPath);

}

void JIT::emitSlow_op_get_by_id(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

int dst = currentInstruction[1].u.operand;

int base = currentInstruction[2].u.operand;

int ident = currentInstruction[3].u.operand;

compileGetByIdSlowCase(dst, base, &(m_codeBlock->identifier(ident)), iter);

}

void JIT::compileGetByIdSlowCase(int dst, int base, Identifier* ident, Vector<SlowCaseEntry>::iterator& iter, bool isMethodCheck)

{

// As for the hot path of get_by_id, above, we ensure that we can use an architecture specific offset

// so that we only need track one pointer into the slow case code - we track a pointer to the location

// of the call (which we can use to look up the patch information), but should a array-length or

// prototype access trampoline fail we want to bail out back to here. To do so we can subtract back

// the distance from the call to the head of the slow case.

linkSlowCaseIfNotJSCell(iter, base);

linkSlowCase(iter);

BEGIN_UNINTERRUPTED_SEQUENCE(sequenceGetByIdSlowCase);

#ifndef NDEBUG

Label coldPathBegin(this);

#endif

JITStubCall stubCall(this, isMethodCheck ? cti_op_get_by_id_method_check : cti_op_get_by_id);

stubCall.addArgument(regT1, regT0);

stubCall.addArgument(TrustedImmPtr(ident));

Call call = stubCall.call(dst);

END_UNINTERRUPTED_SEQUENCE_FOR_PUT(sequenceGetByIdSlowCase, dst);

ASSERT_JIT_OFFSET(differenceBetween(coldPathBegin, call), patchOffsetGetByIdSlowCaseCall);

// Track the location of the call; this will be used to recover patch information.

m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex].callReturnLocation = call;

m_propertyAccessInstructionIndex++;

}

void JIT::emit_op_put_by_id(Instruction* currentInstruction)

{

// In order to be able to patch both the Structure, and the object offset, we store one pointer,

// to just after the arguments have been loaded into registers 'hotPathBegin', and we generate code

// such that the Structure & offset are always at the same distance from this.

int base = currentInstruction[1].u.operand;

int value = currentInstruction[3].u.operand;

emitLoad2(base, regT1, regT0, value, regT3, regT2);

emitJumpSlowCaseIfNotJSCell(base, regT1);

BEGIN_UNINTERRUPTED_SEQUENCE(sequencePutById);

Label hotPathBegin(this);

m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex].hotPathBegin = hotPathBegin;

m_propertyAccessInstructionIndex++;

// It is important that the following instruction plants a 32bit immediate, in order that it can be patched over.

DataLabelPtr structureToCompare;

addSlowCase(branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure))));

ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureToCompare), patchOffsetPutByIdStructure);

loadPtr(Address(regT0, OBJECT_OFFSETOF(JSObject, m_propertyStorage)), regT0);

DataLabel32 displacementLabel1 = storePtrWithAddressOffsetPatch(regT2, Address(regT0, patchGetByIdDefaultOffset)); // payload

DataLabel32 displacementLabel2 = storePtrWithAddressOffsetPatch(regT3, Address(regT0, patchGetByIdDefaultOffset)); // tag

END_UNINTERRUPTED_SEQUENCE(sequencePutById);

ASSERT_JIT_OFFSET_UNUSED(displacementLabel1, differenceBetween(hotPathBegin, displacementLabel1), patchOffsetPutByIdPropertyMapOffset1);

ASSERT_JIT_OFFSET_UNUSED(displacementLabel2, differenceBetween(hotPathBegin, displacementLabel2), patchOffsetPutByIdPropertyMapOffset2);

}

void JIT::emitSlow_op_put_by_id(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

int base = currentInstruction[1].u.operand;

int ident = currentInstruction[2].u.operand;

int direct = currentInstruction[8].u.operand;

linkSlowCaseIfNotJSCell(iter, base);

linkSlowCase(iter);

JITStubCall stubCall(this, direct ? cti_op_put_by_id_direct : cti_op_put_by_id);

stubCall.addArgument(regT1, regT0);

stubCall.addArgument(TrustedImmPtr(&(m_codeBlock->identifier(ident))));

stubCall.addArgument(regT3, regT2);

Call call = stubCall.call();

// Track the location of the call; this will be used to recover patch information.

m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex].callReturnLocation = call;

m_propertyAccessInstructionIndex++;

}

// Compile a store into an object's property storage. May overwrite base.

void JIT::compilePutDirectOffset(RegisterID base, RegisterID valueTag, RegisterID valuePayload, Structure* structure, size_t cachedOffset)

{

int offset = cachedOffset;

if (structure->isUsingInlineStorage())

offset += JSObject::offsetOfInlineStorage() / sizeof(Register);

else

loadPtr(Address(base, OBJECT_OFFSETOF(JSObject, m_propertyStorage)), base);

emitStore(offset, valueTag, valuePayload, base);

}

// Compile a load from an object's property storage. May overwrite base.

void JIT::compileGetDirectOffset(RegisterID base, RegisterID resultTag, RegisterID resultPayload, Structure* structure, size_t cachedOffset)

{

int offset = cachedOffset;

if (structure->isUsingInlineStorage()) {

offset += JSObject::offsetOfInlineStorage() / sizeof(Register);

emitLoad(offset, resultTag, resultPayload, base);

} else {

RegisterID temp = resultPayload;

loadPtr(Address(base, OBJECT_OFFSETOF(JSObject, m_propertyStorage)), temp);

emitLoad(offset, resultTag, resultPayload, temp);

}

}

void JIT::compileGetDirectOffset(JSObject* base, RegisterID resultTag, RegisterID resultPayload, size_t cachedOffset)

{

load32(reinterpret_cast<char*>(&base->m_propertyStorage[cachedOffset]) + OBJECT_OFFSETOF(JSValue, u.asBits.payload), resultPayload);

load32(reinterpret_cast<char*>(&base->m_propertyStorage[cachedOffset]) + OBJECT_OFFSETOF(JSValue, u.asBits.tag), resultTag);

}

void JIT::privateCompilePutByIdTransition(StructureStubInfo* stubInfo, Structure* oldStructure, Structure* newStructure, size_t cachedOffset, StructureChain* chain, ReturnAddressPtr returnAddress, bool direct)

{

// It is assumed that regT0 contains the basePayload and regT1 contains the baseTag. The value can be found on the stack.

JumpList failureCases;

failureCases.append(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));

failureCases.append(branchPtr(NotEqual, Address(regT0, JSCell::structureOffset()), TrustedImmPtr(oldStructure)));

testPrototype(oldStructure->storedPrototype(), failureCases);

if (!direct) {

// Verify that nothing in the prototype chain has a setter for this property.

for (WriteBarrier<Structure>* it = chain->head(); *it; ++it)

testPrototype((*it)->storedPrototype(), failureCases);

}

// Reallocate property storage if needed.

Call callTarget;

bool willNeedStorageRealloc = oldStructure->propertyStorageCapacity() != newStructure->propertyStorageCapacity();

if (willNeedStorageRealloc) {

// This trampoline was called to like a JIT stub; before we can can call again we need to

// remove the return address from the stack, to prevent the stack from becoming misaligned.

preserveReturnAddressAfterCall(regT3);

JITStubCall stubCall(this, cti_op_put_by_id_transition_realloc);

stubCall.skipArgument(); // base

stubCall.skipArgument(); // ident

stubCall.skipArgument(); // value

stubCall.addArgument(TrustedImm32(oldStructure->propertyStorageCapacity()));

stubCall.addArgument(TrustedImm32(newStructure->propertyStorageCapacity()));

stubCall.call(regT0);

restoreReturnAddressBeforeReturn(regT3);

}

storePtrWithWriteBarrier(TrustedImmPtr(newStructure), regT0, Address(regT0, JSCell::structureOffset()));

#if CPU(MIPS) || CPU(SH4)

// For MIPS, we don't add sizeof(void*) to the stack offset.

load32(Address(stackPointerRegister, OBJECT_OFFSETOF(JITStackFrame, args[2]) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT3);

load32(Address(stackPointerRegister, OBJECT_OFFSETOF(JITStackFrame, args[2]) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT2);

#else

load32(Address(stackPointerRegister, OBJECT_OFFSETOF(JITStackFrame, args[2]) + sizeof(void*) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT3);

load32(Address(stackPointerRegister, OBJECT_OFFSETOF(JITStackFrame, args[2]) + sizeof(void*) + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT2);

#endif

// Write the value

compilePutDirectOffset(regT0, regT2, regT3, newStructure, cachedOffset);

ret();

ASSERT(!failureCases.empty());

failureCases.link(this);

restoreArgumentReferenceForTrampoline();

Call failureCall = tailRecursiveCall();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

patchBuffer.link(failureCall, FunctionPtr(direct ? cti_op_put_by_id_direct_fail : cti_op_put_by_id_fail));

if (willNeedStorageRealloc) {

ASSERT(m_calls.size() == 1);

patchBuffer.link(m_calls[0].from, FunctionPtr(cti_op_put_by_id_transition_realloc));

}

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

stubInfo->stubRoutine = entryLabel;

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relinkCallerToTrampoline(returnAddress, entryLabel);

}

void JIT::patchGetByIdSelf(CodeBlock* codeBlock, StructureStubInfo* stubInfo, Structure* structure, size_t cachedOffset, ReturnAddressPtr returnAddress)

{

RepatchBuffer repatchBuffer(codeBlock);

// We don't want to patch more than once - in future go to cti_op_get_by_id_generic.

// Should probably go to JITStubs::cti_op_get_by_id_fail, but that doesn't do anything interesting right now.

repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_self_fail));

int offset = sizeof(JSValue) * cachedOffset;

// Patch the offset into the propoerty map to load from, then patch the Structure to look for.

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetGetByIdStructure), structure);

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabel32AtOffset(patchOffsetGetByIdPropertyMapOffset1), offset + OBJECT_OFFSETOF(JSValue, u.asBits.payload)); // payload

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabel32AtOffset(patchOffsetGetByIdPropertyMapOffset2), offset + OBJECT_OFFSETOF(JSValue, u.asBits.tag)); // tag

}

void JIT::patchMethodCallProto(JSGlobalData& globalData, CodeBlock* codeBlock, MethodCallLinkInfo& methodCallLinkInfo, JSFunction* callee, Structure* structure, JSObject* proto, ReturnAddressPtr returnAddress)

{

RepatchBuffer repatchBuffer(codeBlock);

ASSERT(!methodCallLinkInfo.cachedStructure);

methodCallLinkInfo.cachedStructure.set(globalData, codeBlock->ownerExecutable(), structure);

Structure* prototypeStructure = proto->structure();

methodCallLinkInfo.cachedPrototypeStructure.set(globalData, codeBlock->ownerExecutable(), prototypeStructure);

repatchBuffer.repatch(methodCallLinkInfo.structureLabel, structure);

repatchBuffer.repatch(methodCallLinkInfo.structureLabel.dataLabelPtrAtOffset(patchOffsetMethodCheckProtoObj), proto);

repatchBuffer.repatch(methodCallLinkInfo.structureLabel.dataLabelPtrAtOffset(patchOffsetMethodCheckProtoStruct), prototypeStructure);

repatchBuffer.repatch(methodCallLinkInfo.structureLabel.dataLabelPtrAtOffset(patchOffsetMethodCheckPutFunction), callee);

repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id));

}

void JIT::patchPutByIdReplace(CodeBlock* codeBlock, StructureStubInfo* stubInfo, Structure* structure, size_t cachedOffset, ReturnAddressPtr returnAddress, bool direct)

{

RepatchBuffer repatchBuffer(codeBlock);

// We don't want to patch more than once - in future go to cti_op_put_by_id_generic.

// Should probably go to cti_op_put_by_id_fail, but that doesn't do anything interesting right now.

repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(direct ? cti_op_put_by_id_direct_generic : cti_op_put_by_id_generic));

int offset = sizeof(JSValue) * cachedOffset;

// Patch the offset into the propoerty map to load from, then patch the Structure to look for.

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetPutByIdStructure), structure);

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabel32AtOffset(patchOffsetPutByIdPropertyMapOffset1), offset + OBJECT_OFFSETOF(JSValue, u.asBits.payload)); // payload

repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabel32AtOffset(patchOffsetPutByIdPropertyMapOffset2), offset + OBJECT_OFFSETOF(JSValue, u.asBits.tag)); // tag

}

void JIT::privateCompilePatchGetArrayLength(ReturnAddressPtr returnAddress)

{

StructureStubInfo* stubInfo = &m_codeBlock->getStubInfo(returnAddress);

// regT0 holds a JSCell*

// Check for array

Jump failureCases1 = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr));

// Checks out okay! - get the length from the storage

loadPtr(Address(regT0, JSArray::storageOffset()), regT2);

load32(Address(regT2, OBJECT_OFFSETOF(ArrayStorage, m_length)), regT2);

Jump failureCases2 = branch32(Above, regT2, TrustedImm32(INT_MAX));

move(regT2, regT0);

move(TrustedImm32(JSValue::Int32Tag), regT1);

Jump success = jump();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

// Use the patch information to link the failure cases back to the original slow case routine.

CodeLocationLabel slowCaseBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);

patchBuffer.link(failureCases1, slowCaseBegin);

patchBuffer.link(failureCases2, slowCaseBegin);

// On success return back to the hot patch code, at a point it will perform the store to dest for us.

patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));

// Track the stub we have created so that it will be deleted later.

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

stubInfo->stubRoutine = entryLabel;

// Finally patch the jump to slow case back in the hot path to jump here instead.

CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relink(jumpLocation, entryLabel);

// We don't want to patch more than once - in future go to cti_op_put_by_id_generic.

repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_array_fail));

}

void JIT::privateCompileGetByIdProto(StructureStubInfo* stubInfo, Structure* structure, Structure* prototypeStructure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, ReturnAddressPtr returnAddress, CallFrame* callFrame)

{

// regT0 holds a JSCell*

// The prototype object definitely exists (if this stub exists the CodeBlock is referencing a Structure that is

// referencing the prototype object - let's speculatively load it's table nice and early!)

JSObject* protoObject = asObject(structure->prototypeForLookup(callFrame));

Jump failureCases1 = checkStructure(regT0, structure);

// Check the prototype object's Structure had not changed.

move(TrustedImmPtr(protoObject), regT3);

Jump failureCases2 = branchPtr(NotEqual, Address(regT3, JSCell::structureOffset()), TrustedImmPtr(prototypeStructure));

bool needsStubLink = false;

// Checks out okay!

if (slot.cachedPropertyType() == PropertySlot::Getter) {

needsStubLink = true;

compileGetDirectOffset(protoObject, regT2, regT1, cachedOffset);

JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);

stubCall.addArgument(regT1);

stubCall.addArgument(regT0);

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else if (slot.cachedPropertyType() == PropertySlot::Custom) {

needsStubLink = true;

JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);

stubCall.addArgument(TrustedImmPtr(protoObject));

stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));

stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else

compileGetDirectOffset(protoObject, regT1, regT0, cachedOffset);

Jump success = jump();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

// Use the patch information to link the failure cases back to the original slow case routine.

CodeLocationLabel slowCaseBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);

patchBuffer.link(failureCases1, slowCaseBegin);

patchBuffer.link(failureCases2, slowCaseBegin);

// On success return back to the hot patch code, at a point it will perform the store to dest for us.

patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));

if (needsStubLink) {

for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {

if (iter->to)

patchBuffer.link(iter->from, FunctionPtr(iter->to));

}

}

// Track the stub we have created so that it will be deleted later.

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

stubInfo->stubRoutine = entryLabel;

// Finally patch the jump to slow case back in the hot path to jump here instead.

CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relink(jumpLocation, entryLabel);

// We don't want to patch more than once - in future go to cti_op_put_by_id_generic.

repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_proto_list));

}

void JIT::privateCompileGetByIdSelfList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* polymorphicStructures, int currentIndex, Structure* structure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset)

{

// regT0 holds a JSCell*

Jump failureCase = checkStructure(regT0, structure);

bool needsStubLink = false;

if (slot.cachedPropertyType() == PropertySlot::Getter) {

needsStubLink = true;

compileGetDirectOffset(regT0, regT2, regT1, structure, cachedOffset);

JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);

stubCall.addArgument(regT1);

stubCall.addArgument(regT0);

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else if (slot.cachedPropertyType() == PropertySlot::Custom) {

needsStubLink = true;

JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);

stubCall.addArgument(regT0);

stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));

stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else

compileGetDirectOffset(regT0, regT1, regT0, structure, cachedOffset);

Jump success = jump();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

if (needsStubLink) {

for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {

if (iter->to)

patchBuffer.link(iter->from, FunctionPtr(iter->to));

}

}

// Use the patch information to link the failure cases back to the original slow case routine.

CodeLocationLabel lastProtoBegin = polymorphicStructures->list[currentIndex - 1].stubRoutine;

if (!lastProtoBegin)

lastProtoBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);

patchBuffer.link(failureCase, lastProtoBegin);

// On success return back to the hot patch code, at a point it will perform the store to dest for us.

patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

polymorphicStructures->list[currentIndex].set(*m_globalData, m_codeBlock->ownerExecutable(), entryLabel, structure);

// Finally patch the jump to slow case back in the hot path to jump here instead.

CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relink(jumpLocation, entryLabel);

}

void JIT::privateCompileGetByIdProtoList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* prototypeStructures, int currentIndex, Structure* structure, Structure* prototypeStructure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, CallFrame* callFrame)

{

// regT0 holds a JSCell*

// The prototype object definitely exists (if this stub exists the CodeBlock is referencing a Structure that is

// referencing the prototype object - let's speculatively load it's table nice and early!)

JSObject* protoObject = asObject(structure->prototypeForLookup(callFrame));

// Check eax is an object of the right Structure.

Jump failureCases1 = checkStructure(regT0, structure);

// Check the prototype object's Structure had not changed.

move(TrustedImmPtr(protoObject), regT3);

Jump failureCases2 = branchPtr(NotEqual, Address(regT3, JSCell::structureOffset()), TrustedImmPtr(prototypeStructure));

bool needsStubLink = false;

if (slot.cachedPropertyType() == PropertySlot::Getter) {

needsStubLink = true;

compileGetDirectOffset(protoObject, regT2, regT1, cachedOffset);

JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);

stubCall.addArgument(regT1);

stubCall.addArgument(regT0);

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else if (slot.cachedPropertyType() == PropertySlot::Custom) {

needsStubLink = true;

JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);

stubCall.addArgument(TrustedImmPtr(protoObject));

stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));

stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else

compileGetDirectOffset(protoObject, regT1, regT0, cachedOffset);

Jump success = jump();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

if (needsStubLink) {

for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {

if (iter->to)

patchBuffer.link(iter->from, FunctionPtr(iter->to));

}

}

// Use the patch information to link the failure cases back to the original slow case routine.

CodeLocationLabel lastProtoBegin = prototypeStructures->list[currentIndex - 1].stubRoutine;

patchBuffer.link(failureCases1, lastProtoBegin);

patchBuffer.link(failureCases2, lastProtoBegin);

// On success return back to the hot patch code, at a point it will perform the store to dest for us.

patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

prototypeStructures->list[currentIndex].set(callFrame->globalData(), m_codeBlock->ownerExecutable(), entryLabel, structure, prototypeStructure);

// Finally patch the jump to slow case back in the hot path to jump here instead.

CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relink(jumpLocation, entryLabel);

}

void JIT::privateCompileGetByIdChainList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* prototypeStructures, int currentIndex, Structure* structure, StructureChain* chain, size_t count, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, CallFrame* callFrame)

{

// regT0 holds a JSCell*

ASSERT(count);

JumpList bucketsOfFail;

// Check eax is an object of the right Structure.

bucketsOfFail.append(checkStructure(regT0, structure));

Structure* currStructure = structure;

WriteBarrier<Structure>* it = chain->head();

JSObject* protoObject = 0;

for (unsigned i = 0; i < count; ++i, ++it) {

protoObject = asObject(currStructure->prototypeForLookup(callFrame));

currStructure = it->get();

testPrototype(protoObject, bucketsOfFail);

}

ASSERT(protoObject);

bool needsStubLink = false;

if (slot.cachedPropertyType() == PropertySlot::Getter) {

needsStubLink = true;

compileGetDirectOffset(protoObject, regT2, regT1, cachedOffset);

JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);

stubCall.addArgument(regT1);

stubCall.addArgument(regT0);

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else if (slot.cachedPropertyType() == PropertySlot::Custom) {

needsStubLink = true;

JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);

stubCall.addArgument(TrustedImmPtr(protoObject));

stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));

stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));

stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));

stubCall.call();

} else

compileGetDirectOffset(protoObject, regT1, regT0, cachedOffset);

Jump success = jump();

LinkBuffer patchBuffer(this, m_codeBlock->executablePool());

if (needsStubLink) {

for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {

if (iter->to)

patchBuffer.link(iter->from, FunctionPtr(iter->to));

}

}

// Use the patch information to link the failure cases back to the original slow case routine.

CodeLocationLabel lastProtoBegin = prototypeStructures->list[currentIndex - 1].stubRoutine;

patchBuffer.link(bucketsOfFail, lastProtoBegin);

// On success return back to the hot patch code, at a point it will perform the store to dest for us.

patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));

CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();

// Track the stub we have created so that it will be deleted later.

prototypeStructures->list[currentIndex].set(callFrame->globalData(), m_codeBlock->ownerExecutable(), entryLabel, structure, chain);

// Finally patch the jump to slow case back in the hot path to jump here instead.

CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);

RepatchBuffer repatchBuffer(m_codeBlock);

repatchBuffer.relink(jumpLocation, entryLabel);

}

void JIT::privateCompileGetByIdChain(StructureStubInfo* stubInfo, Structure* structure, StructureChain* chain, size_t count, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, ReturnAddressPtr returnAddress, CallFrame* callFrame)

{

// regT0 holds a JSCell*

ASSERT(count);

JumpList bucketsOfFail;

// Check eax is an object of the right Structure.

bucketsOfFail.append(checkStructure(regT0, structure));

Structure* currStructure = structure;

WriteBarrier<Structure>* it = chain->head();

JSObject* protoObject = 0;

for (unsigned i = 0; i < count; ++i, ++it) {

protoObject = asObject(currStructure->prototypeForLookup(callFrame));

currStructure = it->get();

testPrototype(protoObject, bucketsOfFail);

}