/*
 * Copyright (C) 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"
#include "JIT.h"

#if ENABLE(JIT)

#include "JITInlineMethods.h"
#include "JITStubCall.h"
#include "JSArray.h"
#include "JSCell.h"

#define __ m_assembler.

namespace JSC {

void JIT::emit_op_mov(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src = currentInstruction[2].u.operand;

    if (m_codeBlock->isConstantRegisterIndex(src))
        emitStore(dst, getConstantOperand(src));
    else {
        emitLoad(src, regT1, regT0);
        emitStore(dst, regT1, regT0);
        map(m_bytecodeIndex + OPCODE_LENGTH(op_mov), dst, regT1, regT0);
    }
}

void JIT::emit_op_end(Instruction* currentInstruction)
{
    if (m_codeBlock->needsFullScopeChain())
        JITStubCall(this, cti_op_end).call();
    ASSERT(returnValueRegister != callFrameRegister);
    emitLoad(currentInstruction[1].u.operand, regT1, regT0);
    restoreReturnAddressBeforeReturn(Address(callFrameRegister, RegisterFile::ReturnPC * static_cast<int>(sizeof(Register))));
    ret();
}

void JIT::emit_op_jmp(Instruction* currentInstruction)
{
    unsigned target = currentInstruction[1].u.operand;
    addJump(jump(), target + 1);
}

void JIT::emit_op_loop(Instruction* currentInstruction)
{
    unsigned target = currentInstruction[1].u.operand;
    emitTimeoutCheck();
    addJump(jump(), target + 1);
}

void JIT::emit_op_loop_if_less(Instruction* currentInstruction)
{
    unsigned op1 = currentInstruction[1].u.operand;
    unsigned op2 = currentInstruction[2].u.operand;
    unsigned target = currentInstruction[3].u.operand;

    emitTimeoutCheck();

    if (isOperandConstantImmediateInt(op1)) {
        emitLoad(op2, regT1, regT0);
        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
        addJump(branch32(GreaterThan, regT0, Imm32(getConstantOperand(op1).asInt32())), target + 3);
        return;
    }
    
    if (isOperandConstantImmediateInt(op2)) {
        emitLoad(op1, regT1, regT0);
        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
        addJump(branch32(LessThan, regT0, Imm32(getConstantOperand(op2).asInt32())), target + 3);
        return;
    }

    emitLoad2(op1, regT1, regT0, op2, regT3, regT2);
    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
    addSlowCase(branch32(NotEqual, regT3, Imm32(JSValue::Int32Tag)));
    addJump(branch32(LessThan, regT0, regT2), target + 3);
}

void JIT::emitSlow_op_loop_if_less(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned op1 = currentInstruction[1].u.operand;
    unsigned op2 = currentInstruction[2].u.operand;
    unsigned target = currentInstruction[3].u.operand;

    if (!isOperandConstantImmediateInt(op1) && !isOperandConstantImmediateInt(op2))
        linkSlowCase(iter); // int32 check
    linkSlowCase(iter); // int32 check

    JITStubCall stubCall(this, cti_op_loop_if_less);
    stubCall.addArgument(op1);
    stubCall.addArgument(op2);
    stubCall.call();
    emitJumpSlowToHot(branchTest32(NonZero, regT0), target + 3);
}

void JIT::emit_op_loop_if_lesseq(Instruction* currentInstruction)
{
    unsigned op1 = currentInstruction[1].u.operand;
    unsigned op2 = currentInstruction[2].u.operand;
    unsigned target = currentInstruction[3].u.operand;

    emitTimeoutCheck();

    if (isOperandConstantImmediateInt(op1)) {
        emitLoad(op2, regT1, regT0);
        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
        addJump(branch32(GreaterThanOrEqual, regT0, Imm32(getConstantOperand(op1).asInt32())), target + 3);
        return;
    }

    if (isOperandConstantImmediateInt(op2)) {
        emitLoad(op1, regT1, regT0);
        addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
        addJump(branch32(LessThanOrEqual, regT0, Imm32(getConstantOperand(op2).asInt32())), target + 3);
        return;
    }

    emitLoad2(op1, regT1, regT0, op2, regT3, regT2);
    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag)));
    addSlowCase(branch32(NotEqual, regT3, Imm32(JSValue::Int32Tag)));
    addJump(branch32(LessThanOrEqual, regT0, regT2), target + 3);
}

void JIT::emitSlow_op_loop_if_lesseq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned op1 = currentInstruction[1].u.operand;
    unsigned op2 = currentInstruction[2].u.operand;
    unsigned target = currentInstruction[3].u.operand;

    if (!isOperandConstantImmediateInt(op1) && !isOperandConstantImmediateInt(op2))
        linkSlowCase(iter); // int32 check
    linkSlowCase(iter); // int32 check

    JITStubCall stubCall(this, cti_op_loop_if_lesseq);
    stubCall.addArgument(op1);
    stubCall.addArgument(op2);
    stubCall.call();
    emitJumpSlowToHot(branchTest32(NonZero, regT0), target + 3);
}

void JIT::emit_op_new_object(Instruction* currentInstruction)
{
    JITStubCall(this, cti_op_new_object).call(currentInstruction[1].u.operand);
}

void JIT::emit_op_instanceof(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned value = currentInstruction[2].u.operand;
    unsigned baseVal = currentInstruction[3].u.operand;
    unsigned proto = currentInstruction[4].u.operand;

    // Load the operands (baseVal, proto, and value respectively) into registers.
    // We use regT0 for baseVal since we will be done with this first, and we can then use it for the result.
    emitLoadPayload(proto, regT1);
    emitLoadPayload(baseVal, regT0);
    emitLoadPayload(value, regT2);

    // Check that baseVal & proto are cells.
    emitJumpSlowCaseIfNotJSCell(proto);
    emitJumpSlowCaseIfNotJSCell(baseVal);

    // Check that baseVal is an object, that it 'ImplementsHasInstance' but that it does not 'OverridesHasInstance'.
    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT0);
    addSlowCase(branch32(NotEqual, Address(regT0, OBJECT_OFFSETOF(Structure, m_typeInfo.m_type)), Imm32(ObjectType))); // FIXME: Maybe remove this test.
    addSlowCase(branchTest32(Zero, Address(regT0, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(ImplementsHasInstance))); // FIXME: TOT checks ImplementsDefaultHasInstance.

    // If value is not an Object, return false.
    emitLoadTag(value, regT0);
    Jump valueIsImmediate = branch32(NotEqual, regT0, Imm32(JSValue::CellTag));
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSCell, m_structure)), regT0);
    Jump valueIsNotObject = branch32(NotEqual, Address(regT0, OBJECT_OFFSETOF(Structure, m_typeInfo.m_type)), Imm32(ObjectType)); // FIXME: Maybe remove this test.

    // Check proto is object.
    loadPtr(Address(regT1, OBJECT_OFFSETOF(JSCell, m_structure)), regT0);
    addSlowCase(branch32(NotEqual, Address(regT0, OBJECT_OFFSETOF(Structure, m_typeInfo.m_type)), Imm32(ObjectType)));

    // Optimistically load the result true, and start looping.
    // Initially, regT1 still contains proto and regT2 still contains value.
    // As we loop regT2 will be updated with its prototype, recursively walking the prototype chain.
    move(Imm32(JSValue::TrueTag), regT0);
    Label loop(this);

    // Load the prototype of the object in regT2.  If this is equal to regT1 - WIN!
    // Otherwise, check if we've hit null - if we have then drop out of the loop, if not go again.
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
    load32(Address(regT2, OBJECT_OFFSETOF(Structure, m_prototype) + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT2);
    Jump isInstance = branchPtr(Equal, regT2, regT1);
    branch32(NotEqual, regT2, Imm32(0), loop);

    // We get here either by dropping out of the loop, or if value was not an Object.  Result is false.
    valueIsImmediate.link(this);
    valueIsNotObject.link(this);
    move(Imm32(JSValue::FalseTag), regT0);

    // isInstance jumps right down to here, to skip setting the result to false (it has already set true).
    isInstance.link(this);
    emitStoreBool(dst, regT0);
}

void JIT::emitSlow_op_instanceof(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned value = currentInstruction[2].u.operand;
    unsigned baseVal = currentInstruction[3].u.operand;
    unsigned proto = currentInstruction[4].u.operand;

    linkSlowCaseIfNotJSCell(iter, baseVal);
    linkSlowCaseIfNotJSCell(iter, proto);
    linkSlowCase(iter);
    linkSlowCase(iter);
    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_instanceof);
    stubCall.addArgument(value);
    stubCall.addArgument(baseVal);
    stubCall.addArgument(proto);
    stubCall.call(dst);
}

void JIT::emit_op_new_func(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_new_func);
    stubCall.addArgument(ImmPtr(m_codeBlock->function(currentInstruction[2].u.operand)));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_get_global_var(Instruction* currentInstruction)
{
    int dst = currentInstruction[1].u.operand;
    JSGlobalObject* globalObject = static_cast<JSGlobalObject*>(currentInstruction[2].u.jsCell);
    ASSERT(globalObject->isGlobalObject());
    int index = currentInstruction[3].u.operand;

    loadPtr(&globalObject->d()->registers, regT2);

    emitLoad(index, regT1, regT0, regT2);
    emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_get_global_var), dst, regT1, regT0);
}

void JIT::emit_op_put_global_var(Instruction* currentInstruction)
{
    JSGlobalObject* globalObject = static_cast<JSGlobalObject*>(currentInstruction[1].u.jsCell);
    ASSERT(globalObject->isGlobalObject());
    int index = currentInstruction[2].u.operand;
    int value = currentInstruction[3].u.operand;

    emitLoad(value, regT1, regT0);

    loadPtr(&globalObject->d()->registers, regT2);
    emitStore(index, regT1, regT0, regT2);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_put_global_var), value, regT1, regT0);
}

void JIT::emit_op_get_scoped_var(Instruction* currentInstruction)
{
    int dst = currentInstruction[1].u.operand;
    int index = currentInstruction[2].u.operand;
    int skip = currentInstruction[3].u.operand + m_codeBlock->needsFullScopeChain();

    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
    while (skip--)
        loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);

    loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, d)), regT2);
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), regT2);

    emitLoad(index, regT1, regT0, regT2);
    emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_get_scoped_var), dst, regT1, regT0);
}

void JIT::emit_op_put_scoped_var(Instruction* currentInstruction)
{
    int index = currentInstruction[1].u.operand;
    int skip = currentInstruction[2].u.operand + m_codeBlock->needsFullScopeChain();
    int value = currentInstruction[3].u.operand;

    emitLoad(value, regT1, regT0);

    emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT2);
    while (skip--)
        loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, next)), regT2);

    loadPtr(Address(regT2, OBJECT_OFFSETOF(ScopeChainNode, object)), regT2);
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject, d)), regT2);
    loadPtr(Address(regT2, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), regT2);

    emitStore(index, regT1, regT0, regT2);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_put_scoped_var), value, regT1, regT0);
}

void JIT::emit_op_tear_off_activation(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_tear_off_activation);
    stubCall.addArgument(currentInstruction[1].u.operand);
    stubCall.call();
}

void JIT::emit_op_tear_off_arguments(Instruction*)
{
    JITStubCall(this, cti_op_tear_off_arguments).call();
}

void JIT::emit_op_new_array(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_new_array);
    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_resolve(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_resolve);
    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_to_primitive(Instruction* currentInstruction)
{
    int dst = currentInstruction[1].u.operand;
    int src = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);

    Jump isImm = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));
    addSlowCase(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
    isImm.link(this);

    if (dst != src)
        emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_to_primitive), dst, regT1, regT0);
}

void JIT::emitSlow_op_to_primitive(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    int dst = currentInstruction[1].u.operand;

    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_to_primitive);
    stubCall.addArgument(regT1, regT0);
    stubCall.call(dst);
}

void JIT::emit_op_strcat(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_strcat);
    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_loop_if_true(Instruction* currentInstruction)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    emitTimeoutCheck();

    emitLoad(cond, regT1, regT0);

    Jump isNotInteger = branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag));
    addJump(branch32(NotEqual, regT0, Imm32(0)), target + 2);
    Jump isNotZero = jump();

    isNotInteger.link(this);

    addJump(branch32(Equal, regT1, Imm32(JSValue::TrueTag)), target + 2);
    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::FalseTag)));

    isNotZero.link(this);
}

void JIT::emitSlow_op_loop_if_true(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_jtrue);
    stubCall.addArgument(cond);
    stubCall.call();
    emitJumpSlowToHot(branchTest32(NonZero, regT0), target + 2);
}

void JIT::emit_op_resolve_base(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_resolve_base);
    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_resolve_skip(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_resolve_skip);
    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
    stubCall.addArgument(Imm32(currentInstruction[3].u.operand + m_codeBlock->needsFullScopeChain()));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_resolve_global(Instruction* currentInstruction)
{
    // FIXME: Optimize to use patching instead of so many memory accesses.

    unsigned dst = currentInstruction[1].u.operand;
    void* globalObject = currentInstruction[2].u.jsCell;
    
    unsigned currentIndex = m_globalResolveInfoIndex++;
    void* structureAddress = &(m_codeBlock->globalResolveInfo(currentIndex).structure);
    void* offsetAddr = &(m_codeBlock->globalResolveInfo(currentIndex).offset);

    // Verify structure.
    move(ImmPtr(globalObject), regT0);
    loadPtr(structureAddress, regT1);
    addSlowCase(branchPtr(NotEqual, regT1, Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure))));

    // Load property.
    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSGlobalObject, m_externalStorage)), regT2);
    load32(offsetAddr, regT3);
    load32(BaseIndex(regT2, regT3, TimesEight), regT0); // payload
    load32(BaseIndex(regT2, regT3, TimesEight, 4), regT1); // tag
    emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_resolve_global), dst, regT1, regT0);
}

void JIT::emitSlow_op_resolve_global(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    void* globalObject = currentInstruction[2].u.jsCell;
    Identifier* ident = &m_codeBlock->identifier(currentInstruction[3].u.operand);

    unsigned currentIndex = m_globalResolveInfoIndex++;

    linkSlowCase(iter);
    JITStubCall stubCall(this, cti_op_resolve_global);
    stubCall.addArgument(ImmPtr(globalObject));
    stubCall.addArgument(ImmPtr(ident));
    stubCall.addArgument(Imm32(currentIndex));
    stubCall.call(dst);
}

void JIT::emit_op_not(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src = currentInstruction[2].u.operand;

    emitLoadTag(src, regT0);

    xor32(Imm32(JSValue::FalseTag), regT0);
    addSlowCase(branchTest32(NonZero, regT0, Imm32(~1)));
    xor32(Imm32(JSValue::TrueTag), regT0);

    emitStoreBool(dst, regT0, (dst == src));
}

void JIT::emitSlow_op_not(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src = currentInstruction[2].u.operand;

    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_not);
    stubCall.addArgument(src);
    stubCall.call(dst);
}

void JIT::emit_op_jfalse(Instruction* currentInstruction)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    emitLoad(cond, regT1, regT0);

    Jump isTrue = branch32(Equal, regT1, Imm32(JSValue::TrueTag));
    addJump(branch32(Equal, regT1, Imm32(JSValue::FalseTag)), target + 2);

    Jump isNotInteger = branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag));
    Jump isTrue2 = branch32(NotEqual, regT0, Imm32(0));
    addJump(jump(), target + 2);

    isNotInteger.link(this);

    addSlowCase(branch32(Above, regT1, Imm32(JSValue::LowestTag)));

    zeroDouble(fpRegT0);
    emitLoadDouble(cond, fpRegT1);
    addJump(branchDouble(DoubleEqual, fpRegT0, fpRegT1), target + 2);
    
    isTrue.link(this);
    isTrue2.link(this);
}

void JIT::emitSlow_op_jfalse(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    linkSlowCase(iter);
    JITStubCall stubCall(this, cti_op_jtrue);
    stubCall.addArgument(cond);
    stubCall.call();
    emitJumpSlowToHot(branchTest32(Zero, regT0), target + 2); // Inverted.
}

void JIT::emit_op_jtrue(Instruction* currentInstruction)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    emitLoad(cond, regT1, regT0);

    Jump isFalse = branch32(Equal, regT1, Imm32(JSValue::FalseTag));
    addJump(branch32(Equal, regT1, Imm32(JSValue::TrueTag)), target + 2);

    Jump isNotInteger = branch32(NotEqual, regT1, Imm32(JSValue::Int32Tag));
    Jump isFalse2 = branch32(Equal, regT0, Imm32(0));
    addJump(jump(), target + 2);

    isNotInteger.link(this);

    addSlowCase(branch32(Above, regT1, Imm32(JSValue::LowestTag)));

    zeroDouble(fpRegT0);
    emitLoadDouble(cond, fpRegT1);
    addJump(branchDouble(DoubleNotEqual, fpRegT0, fpRegT1), target + 2);
    
    isFalse.link(this);
    isFalse2.link(this);
}

void JIT::emitSlow_op_jtrue(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned cond = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    linkSlowCase(iter);
    JITStubCall stubCall(this, cti_op_jtrue);
    stubCall.addArgument(cond);
    stubCall.call();
    emitJumpSlowToHot(branchTest32(NonZero, regT0), target + 2);
}

void JIT::emit_op_jeq_null(Instruction* currentInstruction)
{
    unsigned src = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);

    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));

    // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
    addJump(branchTest32(NonZero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined)), target + 2);

    Jump wasNotImmediate = jump();

    // Now handle the immediate cases - undefined & null
    isImmediate.link(this);

    set32(Equal, regT1, Imm32(JSValue::NullTag), regT2);
    set32(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
    or32(regT2, regT1);

    addJump(branchTest32(NonZero, regT1), target + 2);

    wasNotImmediate.link(this);
}

void JIT::emit_op_jneq_null(Instruction* currentInstruction)
{
    unsigned src = currentInstruction[1].u.operand;
    unsigned target = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);

    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));

    // First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.
    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
    addJump(branchTest32(Zero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined)), target + 2);

    Jump wasNotImmediate = jump();

    // Now handle the immediate cases - undefined & null
    isImmediate.link(this);

    set32(Equal, regT1, Imm32(JSValue::NullTag), regT2);
    set32(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
    or32(regT2, regT1);

    addJump(branchTest32(Zero, regT1), target + 2);

    wasNotImmediate.link(this);
}

void JIT::emit_op_jneq_ptr(Instruction* currentInstruction)
{
    unsigned src = currentInstruction[1].u.operand;
    JSCell* ptr = currentInstruction[2].u.jsCell;
    unsigned target = currentInstruction[3].u.operand;

    emitLoad(src, regT1, regT0);
    addJump(branch32(NotEqual, regT1, Imm32(JSValue::CellTag)), target + 3);
    addJump(branchPtr(NotEqual, regT0, ImmPtr(ptr)), target + 3);
}

void JIT::emit_op_jsr(Instruction* currentInstruction)
{
    int retAddrDst = currentInstruction[1].u.operand;
    int target = currentInstruction[2].u.operand;
    DataLabelPtr storeLocation = storePtrWithPatch(ImmPtr(0), Address(callFrameRegister, sizeof(Register) * retAddrDst));
    addJump(jump(), target + 2);
    m_jsrSites.append(JSRInfo(storeLocation, label()));
}

void JIT::emit_op_sret(Instruction* currentInstruction)
{
    jump(Address(callFrameRegister, sizeof(Register) * currentInstruction[1].u.operand));
}

void JIT::emit_op_eq(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src1 = currentInstruction[2].u.operand;
    unsigned src2 = currentInstruction[3].u.operand;
    
    emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
    addSlowCase(branch32(NotEqual, regT1, regT3));
    addSlowCase(branch32(Equal, regT1, Imm32(JSValue::CellTag)));
    addSlowCase(branch32(Below, regT1, Imm32(JSValue::LowestTag)));

    set8(Equal, regT0, regT2, regT0);
    or32(Imm32(JSValue::FalseTag), regT0);

    emitStoreBool(dst, regT0);
}

void JIT::emitSlow_op_eq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned op1 = currentInstruction[2].u.operand;
    unsigned op2 = currentInstruction[3].u.operand;
    
    JumpList storeResult;
    JumpList genericCase;
    
    genericCase.append(getSlowCase(iter)); // tags not equal

    linkSlowCase(iter); // tags equal and JSCell
    genericCase.append(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
    genericCase.append(branchPtr(NotEqual, Address(regT2), ImmPtr(m_globalData->jsStringVPtr)));

    // String case.
    JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
    stubCallEqStrings.addArgument(regT0);
    stubCallEqStrings.addArgument(regT2);
    stubCallEqStrings.call();
    storeResult.append(jump());

    // Generic case.
    genericCase.append(getSlowCase(iter)); // doubles
    genericCase.link(this);
    JITStubCall stubCallEq(this, cti_op_eq);
    stubCallEq.addArgument(op1);
    stubCallEq.addArgument(op2);
    stubCallEq.call(regT0);

    storeResult.link(this);
    or32(Imm32(JSValue::FalseTag), regT0);
    emitStoreBool(dst, regT0);
}

void JIT::emit_op_neq(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src1 = currentInstruction[2].u.operand;
    unsigned src2 = currentInstruction[3].u.operand;
    
    emitLoad2(src1, regT1, regT0, src2, regT3, regT2);
    addSlowCase(branch32(NotEqual, regT1, regT3));
    addSlowCase(branch32(Equal, regT1, Imm32(JSValue::CellTag)));
    addSlowCase(branch32(Below, regT1, Imm32(JSValue::LowestTag)));

    set8(NotEqual, regT0, regT2, regT0);
    or32(Imm32(JSValue::FalseTag), regT0);

    emitStoreBool(dst, regT0);
}

void JIT::emitSlow_op_neq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    
    JumpList storeResult;
    JumpList genericCase;
    
    genericCase.append(getSlowCase(iter)); // tags not equal

    linkSlowCase(iter); // tags equal and JSCell
    genericCase.append(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
    genericCase.append(branchPtr(NotEqual, Address(regT2), ImmPtr(m_globalData->jsStringVPtr)));

    // String case.
    JITStubCall stubCallEqStrings(this, cti_op_eq_strings);
    stubCallEqStrings.addArgument(regT0);
    stubCallEqStrings.addArgument(regT2);
    stubCallEqStrings.call(regT0);
    storeResult.append(jump());

    // Generic case.
    genericCase.append(getSlowCase(iter)); // doubles
    genericCase.link(this);
    JITStubCall stubCallEq(this, cti_op_eq);
    stubCallEq.addArgument(regT1, regT0);
    stubCallEq.addArgument(regT3, regT2);
    stubCallEq.call(regT0);

    storeResult.link(this);
    xor32(Imm32(0x1), regT0);
    or32(Imm32(JSValue::FalseTag), regT0);
    emitStoreBool(dst, regT0);
}

void JIT::compileOpStrictEq(Instruction* currentInstruction, CompileOpStrictEqType type)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src1 = currentInstruction[2].u.operand;
    unsigned src2 = currentInstruction[3].u.operand;

    emitLoadTag(src1, regT0);
    emitLoadTag(src2, regT1);

    // Jump to a slow case if either operand is double, or if both operands are
    // cells and/or Int32s.
    move(regT0, regT2);
    and32(regT1, regT2);
    addSlowCase(branch32(Below, regT2, Imm32(JSValue::LowestTag)));
    addSlowCase(branch32(AboveOrEqual, regT2, Imm32(JSValue::CellTag)));

    if (type == OpStrictEq)
        set8(Equal, regT0, regT1, regT0);
    else
        set8(NotEqual, regT0, regT1, regT0);

    or32(Imm32(JSValue::FalseTag), regT0);

    emitStoreBool(dst, regT0);
}

void JIT::emit_op_stricteq(Instruction* currentInstruction)
{
    compileOpStrictEq(currentInstruction, OpStrictEq);
}

void JIT::emitSlow_op_stricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src1 = currentInstruction[2].u.operand;
    unsigned src2 = currentInstruction[3].u.operand;

    linkSlowCase(iter);
    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_stricteq);
    stubCall.addArgument(src1);
    stubCall.addArgument(src2);
    stubCall.call(dst);
}

void JIT::emit_op_nstricteq(Instruction* currentInstruction)
{
    compileOpStrictEq(currentInstruction, OpNStrictEq);
}

void JIT::emitSlow_op_nstricteq(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src1 = currentInstruction[2].u.operand;
    unsigned src2 = currentInstruction[3].u.operand;

    linkSlowCase(iter);
    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_nstricteq);
    stubCall.addArgument(src1);
    stubCall.addArgument(src2);
    stubCall.call(dst);
}

void JIT::emit_op_eq_null(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);
    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));

    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT1);
    setTest8(NonZero, Address(regT1, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined), regT1);

    Jump wasNotImmediate = jump();

    isImmediate.link(this);

    set8(Equal, regT1, Imm32(JSValue::NullTag), regT2);
    set8(Equal, regT1, Imm32(JSValue::UndefinedTag), regT1);
    or32(regT2, regT1);

    wasNotImmediate.link(this);

    or32(Imm32(JSValue::FalseTag), regT1);

    emitStoreBool(dst, regT1);
}

void JIT::emit_op_neq_null(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned src = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);
    Jump isImmediate = branch32(NotEqual, regT1, Imm32(JSValue::CellTag));

    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT1);
    setTest8(Zero, Address(regT1, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(MasqueradesAsUndefined), regT1);

    Jump wasNotImmediate = jump();

    isImmediate.link(this);

    set8(NotEqual, regT1, Imm32(JSValue::NullTag), regT2);
    set8(NotEqual, regT1, Imm32(JSValue::UndefinedTag), regT1);
    and32(regT2, regT1);

    wasNotImmediate.link(this);

    or32(Imm32(JSValue::FalseTag), regT1);

    emitStoreBool(dst, regT1);
}

void JIT::emit_op_resolve_with_base(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_resolve_with_base);
    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[3].u.operand)));
    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
    stubCall.call(currentInstruction[2].u.operand);
}

void JIT::emit_op_new_func_exp(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_new_func_exp);
    stubCall.addArgument(ImmPtr(m_codeBlock->functionExpression(currentInstruction[2].u.operand)));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_new_regexp(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_new_regexp);
    stubCall.addArgument(ImmPtr(m_codeBlock->regexp(currentInstruction[2].u.operand)));
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_throw(Instruction* currentInstruction)
{
    unsigned exception = currentInstruction[1].u.operand;
    JITStubCall stubCall(this, cti_op_throw);
    stubCall.addArgument(exception);
    stubCall.call();

#ifndef NDEBUG
    // cti_op_throw always changes it's return address,
    // this point in the code should never be reached.
    breakpoint();
#endif
}

void JIT::emit_op_next_pname(Instruction* currentInstruction)
{
    int dst = currentInstruction[1].u.operand;
    int iter = currentInstruction[2].u.operand;
    int target = currentInstruction[3].u.operand;

    load32(Address(callFrameRegister, (iter * sizeof(Register))), regT0);

    JITStubCall stubCall(this, cti_op_next_pname);
    stubCall.addArgument(regT0);
    stubCall.call();

    Jump endOfIter = branchTestPtr(Zero, regT0);
    emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_next_pname), dst, regT1, regT0);
    addJump(jump(), target + 3);
    endOfIter.link(this);
}

void JIT::emit_op_push_scope(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_push_scope);
    stubCall.addArgument(currentInstruction[1].u.operand);
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_pop_scope(Instruction*)
{
    JITStubCall(this, cti_op_pop_scope).call();
}

void JIT::emit_op_to_jsnumber(Instruction* currentInstruction)
{
    int dst = currentInstruction[1].u.operand;
    int src = currentInstruction[2].u.operand;

    emitLoad(src, regT1, regT0);

    Jump isInt32 = branch32(Equal, regT1, Imm32(JSValue::Int32Tag));
    addSlowCase(branch32(AboveOrEqual, regT1, Imm32(JSValue::DeletedValueTag)));
    isInt32.link(this);

    if (src != dst)
        emitStore(dst, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_to_jsnumber), dst, regT1, regT0);
}

void JIT::emitSlow_op_to_jsnumber(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    int dst = currentInstruction[1].u.operand;

    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_to_jsnumber);
    stubCall.addArgument(regT1, regT0);
    stubCall.call(dst);
}

void JIT::emit_op_push_new_scope(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_push_new_scope);
    stubCall.addArgument(ImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
    stubCall.addArgument(currentInstruction[3].u.operand);
    stubCall.call(currentInstruction[1].u.operand);
}

void JIT::emit_op_catch(Instruction* currentInstruction)
{
    unsigned exception = currentInstruction[1].u.operand;

    // This opcode only executes after a return from cti_op_throw.

    // cti_op_throw may have taken us to a call frame further up the stack; reload
    // the call frame pointer to adjust.
    peek(callFrameRegister, OBJECT_OFFSETOF(struct JITStackFrame, callFrame) / sizeof (void*));

    // Now store the exception returned by cti_op_throw.
    emitStore(exception, regT1, regT0);
    map(m_bytecodeIndex + OPCODE_LENGTH(op_catch), exception, regT1, regT0);
}

void JIT::emit_op_jmp_scopes(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_jmp_scopes);
    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
    stubCall.call();
    addJump(jump(), currentInstruction[2].u.operand + 2);
}

void JIT::emit_op_switch_imm(Instruction* currentInstruction)
{
    unsigned tableIndex = currentInstruction[1].u.operand;
    unsigned defaultOffset = currentInstruction[2].u.operand;
    unsigned scrutinee = currentInstruction[3].u.operand;

    // create jump table for switch destinations, track this switch statement.
    SimpleJumpTable* jumpTable = &m_codeBlock->immediateSwitchJumpTable(tableIndex);
    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset, SwitchRecord::Immediate));
    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());

    JITStubCall stubCall(this, cti_op_switch_imm);
    stubCall.addArgument(scrutinee);
    stubCall.addArgument(Imm32(tableIndex));
    stubCall.call();
    jump(regT0);
}

void JIT::emit_op_switch_char(Instruction* currentInstruction)
{
    unsigned tableIndex = currentInstruction[1].u.operand;
    unsigned defaultOffset = currentInstruction[2].u.operand;
    unsigned scrutinee = currentInstruction[3].u.operand;

    // create jump table for switch destinations, track this switch statement.
    SimpleJumpTable* jumpTable = &m_codeBlock->characterSwitchJumpTable(tableIndex);
    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset, SwitchRecord::Character));
    jumpTable->ctiOffsets.grow(jumpTable->branchOffsets.size());

    JITStubCall stubCall(this, cti_op_switch_char);
    stubCall.addArgument(scrutinee);
    stubCall.addArgument(Imm32(tableIndex));
    stubCall.call();
    jump(regT0);
}

void JIT::emit_op_switch_string(Instruction* currentInstruction)
{
    unsigned tableIndex = currentInstruction[1].u.operand;
    unsigned defaultOffset = currentInstruction[2].u.operand;
    unsigned scrutinee = currentInstruction[3].u.operand;

    // create jump table for switch destinations, track this switch statement.
    StringJumpTable* jumpTable = &m_codeBlock->stringSwitchJumpTable(tableIndex);
    m_switches.append(SwitchRecord(jumpTable, m_bytecodeIndex, defaultOffset));

    JITStubCall stubCall(this, cti_op_switch_string);
    stubCall.addArgument(scrutinee);
    stubCall.addArgument(Imm32(tableIndex));
    stubCall.call();
    jump(regT0);
}

void JIT::emit_op_new_error(Instruction* currentInstruction)
{
    unsigned dst = currentInstruction[1].u.operand;
    unsigned type = currentInstruction[2].u.operand;
    unsigned message = currentInstruction[3].u.operand;

    JITStubCall stubCall(this, cti_op_new_error);
    stubCall.addArgument(Imm32(type));
    stubCall.addArgument(m_codeBlock->getConstant(message));
    stubCall.addArgument(Imm32(m_bytecodeIndex));
    stubCall.call(dst);
}

void JIT::emit_op_debug(Instruction* currentInstruction)
{
    JITStubCall stubCall(this, cti_op_debug);
    stubCall.addArgument(Imm32(currentInstruction[1].u.operand));
    stubCall.addArgument(Imm32(currentInstruction[2].u.operand));
    stubCall.addArgument(Imm32(currentInstruction[3].u.operand));
    stubCall.call();
}


void JIT::emit_op_enter(Instruction*)
{
    // Even though JIT code doesn't use them, we initialize our constant
    // registers to zap stale pointers, to avoid unnecessarily prolonging
    // object lifetime and increasing GC pressure.
    for (int i = 0; i < m_codeBlock->m_numVars; ++i)
        emitStore(i, jsUndefined());
}

void JIT::emit_op_enter_with_activation(Instruction* currentInstruction)
{
    emit_op_enter(currentInstruction);

    JITStubCall(this, cti_op_push_activation).call(currentInstruction[1].u.operand);
}

void JIT::emit_op_create_arguments(Instruction*)
{
    Jump argsNotCell = branch32(NotEqual, tagFor(RegisterFile::ArgumentsRegister, callFrameRegister), Imm32(JSValue::CellTag));
    Jump argsNotNull = branchTestPtr(NonZero, payloadFor(RegisterFile::ArgumentsRegister, callFrameRegister));

    // If we get here the arguments pointer is a null cell - i.e. arguments need lazy creation.
    if (m_codeBlock->m_numParameters == 1)
        JITStubCall(this, cti_op_create_arguments_no_params).call();
    else
        JITStubCall(this, cti_op_create_arguments).call();

    argsNotCell.link(this);
    argsNotNull.link(this);
}
    
void JIT::emit_op_init_arguments(Instruction*)
{
    emitStore(RegisterFile::ArgumentsRegister, JSValue(), callFrameRegister);
}

void JIT::emit_op_convert_this(Instruction* currentInstruction)
{
    unsigned thisRegister = currentInstruction[1].u.operand;
    
    emitLoad(thisRegister, regT1, regT0);

    addSlowCase(branch32(NotEqual, regT1, Imm32(JSValue::CellTag)));

    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSCell, m_structure)), regT2);
    addSlowCase(branchTest32(NonZero, Address(regT2, OBJECT_OFFSETOF(Structure, m_typeInfo.m_flags)), Imm32(NeedsThisConversion)));

    map(m_bytecodeIndex + OPCODE_LENGTH(op_convert_this), thisRegister, regT1, regT0);
}

void JIT::emitSlow_op_convert_this(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
{
    unsigned thisRegister = currentInstruction[1].u.operand;

    linkSlowCase(iter);
    linkSlowCase(iter);

    JITStubCall stubCall(this, cti_op_convert_this);
    stubCall.addArgument(regT1, regT0);
    stubCall.call(thisRegister);
}

void JIT::emit_op_profile_will_call(Instruction* currentInstruction)
{
    peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof (void*));
    Jump noProfiler = branchTestPtr(Zero, Address(regT2));

    JITStubCall stubCall(this, cti_op_profile_will_call);
    stubCall.addArgument(currentInstruction[1].u.operand);
    stubCall.call();
    noProfiler.link(this);
}

void JIT::emit_op_profile_did_call(Instruction* currentInstruction)
{
    peek(regT2, OBJECT_OFFSETOF(JITStackFrame, enabledProfilerReference) / sizeof (void*));
    Jump noProfiler = branchTestPtr(Zero, Address(regT2));

    JITStubCall stubCall(this, cti_op_profile_did_call);
    stubCall.addArgument(currentInstruction[1].u.operand);
    stubCall.call();
    noProfiler.link(this);
}

} // namespace JSC

#endif // ENABLE(JIT)