diff -r 000000000000 -r 4f2f89ce4247 JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,2061 @@
+/*
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
+ *
+ * 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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "BytecodeGenerator.h"
+
+#include "BatchedTransitionOptimizer.h"
+#include "PrototypeFunction.h"
+#include "JSFunction.h"
+#include "Interpreter.h"
+#include "UString.h"
+
+using namespace std;
+
+namespace JSC {
+
+/*
+    The layout of a register frame looks like this:
+
+    For
+
+    function f(x, y) {
+        var v1;
+        function g() { }
+        var v2;
+        return (x) * (y);
+    }
+
+    assuming (x) and (y) generated temporaries t1 and t2, you would have
+
+    ------------------------------------
+    |  x |  y |  g | v2 | v1 | t1 | t2 | <-- value held
+    ------------------------------------
+    | -5 | -4 | -3 | -2 | -1 | +0 | +1 | <-- register index
+    ------------------------------------
+    | params->|<-locals      | temps->
+
+    Because temporary registers are allocated in a stack-like fashion, we
+    can reclaim them with a simple popping algorithm. The same goes for labels.
+    (We never reclaim parameter or local registers, because parameters and
+    locals are DontDelete.)
+
+    The register layout before a function call looks like this:
+
+    For
+
+    function f(x, y)
+    {
+    }
+
+    f(1);
+
+    >                        <------------------------------
+    <                        >  reserved: call frame  |  1 | <-- value held
+    >         >snip<         <------------------------------
+    <                        > +0 | +1 | +2 | +3 | +4 | +5 | <-- register index
+    >                        <------------------------------
+    | params->|<-locals      | temps->
+
+    The call instruction fills in the "call frame" registers. It also pads
+    missing arguments at the end of the call:
+
+    >                        <-----------------------------------
+    <                        >  reserved: call frame  |  1 |  ? | <-- value held ("?" stands for "undefined")
+    >         >snip<         <-----------------------------------
+    <                        > +0 | +1 | +2 | +3 | +4 | +5 | +6 | <-- register index
+    >                        <-----------------------------------
+    | params->|<-locals      | temps->
+
+    After filling in missing arguments, the call instruction sets up the new
+    stack frame to overlap the end of the old stack frame:
+
+                             |---------------------------------->                        <
+                             |  reserved: call frame  |  1 |  ? <                        > <-- value held ("?" stands for "undefined")
+                             |---------------------------------->         >snip<         <
+                             | -7 | -6 | -5 | -4 | -3 | -2 | -1 <                        > <-- register index
+                             |---------------------------------->                        <
+                             |                        | params->|<-locals       | temps->
+
+    That way, arguments are "copied" into the callee's stack frame for free.
+
+    If the caller supplies too many arguments, this trick doesn't work. The
+    extra arguments protrude into space reserved for locals and temporaries.
+    In that case, the call instruction makes a real copy of the call frame header,
+    along with just the arguments expected by the callee, leaving the original
+    call frame header and arguments behind. (The call instruction can't just discard
+    extra arguments, because the "arguments" object may access them later.)
+    This copying strategy ensures that all named values will be at the indices
+    expected by the callee.
+*/
+
+#ifndef NDEBUG
+static bool s_dumpsGeneratedCode = false;
+#endif
+
+void BytecodeGenerator::setDumpsGeneratedCode(bool dumpsGeneratedCode)
+{
+#ifndef NDEBUG
+    s_dumpsGeneratedCode = dumpsGeneratedCode;
+#else
+    UNUSED_PARAM(dumpsGeneratedCode);
+#endif
+}
+
+bool BytecodeGenerator::dumpsGeneratedCode()
+{
+#ifndef NDEBUG
+    return s_dumpsGeneratedCode;
+#else
+    return false;
+#endif
+}
+
+void BytecodeGenerator::generate()
+{
+    m_codeBlock->setThisRegister(m_thisRegister.index());
+
+    m_scopeNode->emitBytecode(*this);
+
+#ifndef NDEBUG
+    m_codeBlock->setInstructionCount(m_codeBlock->instructions().size());
+
+    if (s_dumpsGeneratedCode)
+        m_codeBlock->dump(m_scopeChain->globalObject()->globalExec());
+#endif
+
+    if ((m_codeType == FunctionCode && !m_codeBlock->needsFullScopeChain() && !m_codeBlock->usesArguments()) || m_codeType == EvalCode)
+        symbolTable().clear();
+
+#if !ENABLE(OPCODE_SAMPLING)
+    if (!m_regeneratingForExceptionInfo && !m_usesExceptions && (m_codeType == FunctionCode || m_codeType == EvalCode))
+        m_codeBlock->clearExceptionInfo();
+#endif
+
+    m_codeBlock->shrinkToFit();
+}
+
+bool BytecodeGenerator::addVar(const Identifier& ident, bool isConstant, RegisterID*& r0)
+{
+    int index = m_calleeRegisters.size();
+    SymbolTableEntry newEntry(index, isConstant ? ReadOnly : 0);
+    pair<SymbolTable::iterator, bool> result = symbolTable().add(ident.ustring().rep(), newEntry);
+
+    if (!result.second) {
+        r0 = &registerFor(result.first->second.getIndex());
+        return false;
+    }
+
+    r0 = addVar();
+    return true;
+}
+
+bool BytecodeGenerator::addGlobalVar(const Identifier& ident, bool isConstant, RegisterID*& r0)
+{
+    int index = m_nextGlobalIndex;
+    SymbolTableEntry newEntry(index, isConstant ? ReadOnly : 0);
+    pair<SymbolTable::iterator, bool> result = symbolTable().add(ident.ustring().rep(), newEntry);
+
+    if (!result.second)
+        index = result.first->second.getIndex();
+    else {
+        --m_nextGlobalIndex;
+        m_globals.append(index + m_globalVarStorageOffset);
+    }
+
+    r0 = &registerFor(index);
+    return result.second;
+}
+
+void BytecodeGenerator::preserveLastVar()
+{
+    if ((m_firstConstantIndex = m_calleeRegisters.size()) != 0)
+        m_lastVar = &m_calleeRegisters.last();
+}
+
+BytecodeGenerator::BytecodeGenerator(ProgramNode* programNode, const Debugger* debugger, const ScopeChain& scopeChain, SymbolTable* symbolTable, ProgramCodeBlock* codeBlock)
+    : m_shouldEmitDebugHooks(!!debugger)
+    , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_scopeChain(&scopeChain)
+    , m_symbolTable(symbolTable)
+    , m_scopeNode(programNode)
+    , m_codeBlock(codeBlock)
+    , m_thisRegister(RegisterFile::ProgramCodeThisRegister)
+    , m_finallyDepth(0)
+    , m_dynamicScopeDepth(0)
+    , m_baseScopeDepth(0)
+    , m_codeType(GlobalCode)
+    , m_nextGlobalIndex(-1)
+    , m_nextConstantOffset(0)
+    , m_globalConstantIndex(0)
+    , m_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
+    , m_regeneratingForExceptionInfo(false)
+    , m_codeBlockBeingRegeneratedFrom(0)
+{
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->setNeedsFullScopeChain(true);
+
+    emitOpcode(op_enter);
+    codeBlock->setGlobalData(m_globalData);
+
+    // FIXME: Move code that modifies the global object to Interpreter::execute.
+    
+    m_codeBlock->m_numParameters = 1; // Allocate space for "this"
+
+    JSGlobalObject* globalObject = scopeChain.globalObject();
+    ExecState* exec = globalObject->globalExec();
+    RegisterFile* registerFile = &exec->globalData().interpreter->registerFile();
+    
+    // Shift register indexes in generated code to elide registers allocated by intermediate stack frames.
+    m_globalVarStorageOffset = -RegisterFile::CallFrameHeaderSize - m_codeBlock->m_numParameters - registerFile->size();
+
+    // Add previously defined symbols to bookkeeping.
+    m_globals.grow(symbolTable->size());
+    SymbolTable::iterator end = symbolTable->end();
+    for (SymbolTable::iterator it = symbolTable->begin(); it != end; ++it)
+        registerFor(it->second.getIndex()).setIndex(it->second.getIndex() + m_globalVarStorageOffset);
+        
+    BatchedTransitionOptimizer optimizer(globalObject);
+
+    const VarStack& varStack = programNode->varStack();
+    const FunctionStack& functionStack = programNode->functionStack();
+    bool canOptimizeNewGlobals = symbolTable->size() + functionStack.size() + varStack.size() < registerFile->maxGlobals();
+    if (canOptimizeNewGlobals) {
+        // Shift new symbols so they get stored prior to existing symbols.
+        m_nextGlobalIndex -= symbolTable->size();
+
+        for (size_t i = 0; i < functionStack.size(); ++i) {
+            FunctionBodyNode* function = functionStack[i];
+            globalObject->removeDirect(function->ident()); // Make sure our new function is not shadowed by an old property.
+            emitNewFunction(addGlobalVar(function->ident(), false), function);
+        }
+
+        Vector<RegisterID*, 32> newVars;
+        for (size_t i = 0; i < varStack.size(); ++i)
+            if (!globalObject->hasProperty(exec, *varStack[i].first))
+                newVars.append(addGlobalVar(*varStack[i].first, varStack[i].second & DeclarationStacks::IsConstant));
+
+        preserveLastVar();
+
+        for (size_t i = 0; i < newVars.size(); ++i)
+            emitLoad(newVars[i], jsUndefined());
+    } else {
+        for (size_t i = 0; i < functionStack.size(); ++i) {
+            FunctionBodyNode* function = functionStack[i];
+            globalObject->putWithAttributes(exec, function->ident(), new (exec) JSFunction(exec, makeFunction(exec, function), scopeChain.node()), DontDelete);
+        }
+        for (size_t i = 0; i < varStack.size(); ++i) {
+            if (globalObject->hasProperty(exec, *varStack[i].first))
+                continue;
+            int attributes = DontDelete;
+            if (varStack[i].second & DeclarationStacks::IsConstant)
+                attributes |= ReadOnly;
+            globalObject->putWithAttributes(exec, *varStack[i].first, jsUndefined(), attributes);
+        }
+
+        preserveLastVar();
+    }
+}
+
+BytecodeGenerator::BytecodeGenerator(FunctionBodyNode* functionBody, const Debugger* debugger, const ScopeChain& scopeChain, SymbolTable* symbolTable, CodeBlock* codeBlock)
+    : m_shouldEmitDebugHooks(!!debugger)
+    , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_scopeChain(&scopeChain)
+    , m_symbolTable(symbolTable)
+    , m_scopeNode(functionBody)
+    , m_codeBlock(codeBlock)
+    , m_activationRegister(0)
+    , m_finallyDepth(0)
+    , m_dynamicScopeDepth(0)
+    , m_baseScopeDepth(0)
+    , m_codeType(FunctionCode)
+    , m_nextConstantOffset(0)
+    , m_globalConstantIndex(0)
+    , m_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
+    , m_regeneratingForExceptionInfo(false)
+    , m_codeBlockBeingRegeneratedFrom(0)
+{
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->setNeedsFullScopeChain(true);
+
+    codeBlock->setGlobalData(m_globalData);
+
+    if (m_codeBlock->needsFullScopeChain()) {
+        m_activationRegister = addVar();
+        emitOpcode(op_enter_with_activation);
+        instructions().append(m_activationRegister->index());
+    } else
+        emitOpcode(op_enter);
+
+    // Both op_tear_off_activation and op_tear_off_arguments tear off the 'arguments'
+    // object, if created.
+    if (m_codeBlock->needsFullScopeChain() || functionBody->usesArguments()) {
+        RegisterID* unmodifiedArgumentsRegister = addVar(); // Anonymous, so it can't be modified by user code.
+        RegisterID* argumentsRegister = addVar(propertyNames().arguments, false); // Can be changed by assigning to 'arguments'.
+
+        // We can save a little space by hard-coding the knowledge that the two
+        // 'arguments' values are stored in consecutive registers, and storing
+        // only the index of the assignable one.
+        codeBlock->setArgumentsRegister(argumentsRegister->index());
+        ASSERT_UNUSED(unmodifiedArgumentsRegister, unmodifiedArgumentsRegister->index() == JSC::unmodifiedArgumentsRegister(codeBlock->argumentsRegister()));
+
+        emitOpcode(op_init_arguments);
+        instructions().append(argumentsRegister->index());
+
+        // The debugger currently retrieves the arguments object from an activation rather than pulling
+        // it from a call frame.  In the long-term it should stop doing that (<rdar://problem/6911886>),
+        // but for now we force eager creation of the arguments object when debugging.
+        if (m_shouldEmitDebugHooks) {
+            emitOpcode(op_create_arguments);
+            instructions().append(argumentsRegister->index());
+        }
+    }
+
+    const DeclarationStacks::FunctionStack& functionStack = functionBody->functionStack();
+    for (size_t i = 0; i < functionStack.size(); ++i) {
+        FunctionBodyNode* function = functionStack[i];
+        const Identifier& ident = function->ident();
+        m_functions.add(ident.ustring().rep());
+        emitNewFunction(addVar(ident, false), function);
+    }
+
+    const DeclarationStacks::VarStack& varStack = functionBody->varStack();
+    for (size_t i = 0; i < varStack.size(); ++i)
+        addVar(*varStack[i].first, varStack[i].second & DeclarationStacks::IsConstant);
+
+    FunctionParameters& parameters = *functionBody->parameters();
+    size_t parameterCount = parameters.size();
+    int nextParameterIndex = -RegisterFile::CallFrameHeaderSize - parameterCount - 1;
+    m_parameters.grow(1 + parameterCount); // reserve space for "this"
+
+    // Add "this" as a parameter
+    m_thisRegister.setIndex(nextParameterIndex);
+    ++m_codeBlock->m_numParameters;
+    
+    for (size_t i = 0; i < parameterCount; ++i)
+        addParameter(parameters[i], ++nextParameterIndex);
+
+    preserveLastVar();
+
+    if (isConstructor()) {
+        RefPtr<RegisterID> func = newTemporary();
+        RefPtr<RegisterID> funcProto = newTemporary();
+
+        emitOpcode(op_get_callee);
+        instructions().append(func->index());
+        // Load prototype.
+        emitGetByIdExceptionInfo(op_create_this);
+        emitGetById(funcProto.get(), func.get(), globalData()->propertyNames->prototype);
+
+        emitOpcode(op_create_this);
+        instructions().append(m_thisRegister.index());
+        instructions().append(funcProto->index());
+    } else if (functionBody->usesThis() || m_shouldEmitDebugHooks) {
+        emitOpcode(op_convert_this);
+        instructions().append(m_thisRegister.index());
+    }
+}
+
+BytecodeGenerator::BytecodeGenerator(EvalNode* evalNode, const Debugger* debugger, const ScopeChain& scopeChain, SymbolTable* symbolTable, EvalCodeBlock* codeBlock)
+    : m_shouldEmitDebugHooks(!!debugger)
+    , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_scopeChain(&scopeChain)
+    , m_symbolTable(symbolTable)
+    , m_scopeNode(evalNode)
+    , m_codeBlock(codeBlock)
+    , m_thisRegister(RegisterFile::ProgramCodeThisRegister)
+    , m_finallyDepth(0)
+    , m_dynamicScopeDepth(0)
+    , m_baseScopeDepth(codeBlock->baseScopeDepth())
+    , m_codeType(EvalCode)
+    , m_nextConstantOffset(0)
+    , m_globalConstantIndex(0)
+    , m_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
+    , m_regeneratingForExceptionInfo(false)
+    , m_codeBlockBeingRegeneratedFrom(0)
+{
+    if (m_shouldEmitDebugHooks || m_baseScopeDepth)
+        m_codeBlock->setNeedsFullScopeChain(true);
+
+    emitOpcode(op_enter);
+    codeBlock->setGlobalData(m_globalData);
+    m_codeBlock->m_numParameters = 1; // Allocate space for "this"
+
+    const DeclarationStacks::FunctionStack& functionStack = evalNode->functionStack();
+    for (size_t i = 0; i < functionStack.size(); ++i)
+        m_codeBlock->addFunctionDecl(makeFunction(m_globalData, functionStack[i]));
+
+    const DeclarationStacks::VarStack& varStack = evalNode->varStack();
+    unsigned numVariables = varStack.size();
+    Vector<Identifier> variables;
+    variables.reserveCapacity(numVariables);
+    for (size_t i = 0; i < numVariables; ++i)
+        variables.append(*varStack[i].first);
+    codeBlock->adoptVariables(variables);
+
+    preserveLastVar();
+}
+
+void BytecodeGenerator::addParameter(const Identifier& ident, int parameterIndex)
+{
+    // Parameters overwrite var declarations, but not function declarations.
+    UString::Rep* rep = ident.ustring().rep();
+    if (!m_functions.contains(rep)) {
+        symbolTable().set(rep, parameterIndex);
+        RegisterID& parameter = registerFor(parameterIndex);
+        parameter.setIndex(parameterIndex);
+    }
+
+    // To maintain the calling convention, we have to allocate unique space for
+    // each parameter, even if the parameter doesn't make it into the symbol table.
+    ++m_codeBlock->m_numParameters;
+}
+
+RegisterID* BytecodeGenerator::registerFor(const Identifier& ident)
+{
+    if (ident == propertyNames().thisIdentifier)
+        return &m_thisRegister;
+
+    if (!shouldOptimizeLocals())
+        return 0;
+
+    SymbolTableEntry entry = symbolTable().get(ident.ustring().rep());
+    if (entry.isNull())
+        return 0;
+
+    if (ident == propertyNames().arguments)
+        createArgumentsIfNecessary();
+
+    return &registerFor(entry.getIndex());
+}
+
+bool BytecodeGenerator::willResolveToArguments(const Identifier& ident)
+{
+    if (ident != propertyNames().arguments)
+        return false;
+    
+    if (!shouldOptimizeLocals())
+        return false;
+    
+    SymbolTableEntry entry = symbolTable().get(ident.ustring().rep());
+    if (entry.isNull())
+        return false;
+    
+    if (m_codeBlock->usesArguments() && m_codeType == FunctionCode)
+        return true;
+    
+    return false;
+}
+
+RegisterID* BytecodeGenerator::uncheckedRegisterForArguments()
+{
+    ASSERT(willResolveToArguments(propertyNames().arguments));
+
+    SymbolTableEntry entry = symbolTable().get(propertyNames().arguments.ustring().rep());
+    ASSERT(!entry.isNull());
+    return &registerFor(entry.getIndex());
+}
+
+RegisterID* BytecodeGenerator::constRegisterFor(const Identifier& ident)
+{
+    if (m_codeType == EvalCode)
+        return 0;
+
+    SymbolTableEntry entry = symbolTable().get(ident.ustring().rep());
+    if (entry.isNull())
+        return 0;
+
+    return &registerFor(entry.getIndex());
+}
+
+bool BytecodeGenerator::isLocal(const Identifier& ident)
+{
+    if (ident == propertyNames().thisIdentifier)
+        return true;
+    
+    return shouldOptimizeLocals() && symbolTable().contains(ident.ustring().rep());
+}
+
+bool BytecodeGenerator::isLocalConstant(const Identifier& ident)
+{
+    return symbolTable().get(ident.ustring().rep()).isReadOnly();
+}
+
+RegisterID* BytecodeGenerator::newRegister()
+{
+    m_calleeRegisters.append(m_calleeRegisters.size());
+    m_codeBlock->m_numCalleeRegisters = max<int>(m_codeBlock->m_numCalleeRegisters, m_calleeRegisters.size());
+    return &m_calleeRegisters.last();
+}
+
+RegisterID* BytecodeGenerator::newTemporary()
+{
+    // Reclaim free register IDs.
+    while (m_calleeRegisters.size() && !m_calleeRegisters.last().refCount())
+        m_calleeRegisters.removeLast();
+        
+    RegisterID* result = newRegister();
+    result->setTemporary();
+    return result;
+}
+
+RegisterID* BytecodeGenerator::highestUsedRegister()
+{
+    size_t count = m_codeBlock->m_numCalleeRegisters;
+    while (m_calleeRegisters.size() < count)
+        newRegister();
+    return &m_calleeRegisters.last();
+}
+
+PassRefPtr<LabelScope> BytecodeGenerator::newLabelScope(LabelScope::Type type, const Identifier* name)
+{
+    // Reclaim free label scopes.
+    while (m_labelScopes.size() && !m_labelScopes.last().refCount())
+        m_labelScopes.removeLast();
+
+    // Allocate new label scope.
+    LabelScope scope(type, name, scopeDepth(), newLabel(), type == LabelScope::Loop ? newLabel() : PassRefPtr<Label>()); // Only loops have continue targets.
+    m_labelScopes.append(scope);
+    return &m_labelScopes.last();
+}
+
+PassRefPtr<Label> BytecodeGenerator::newLabel()
+{
+    // Reclaim free label IDs.
+    while (m_labels.size() && !m_labels.last().refCount())
+        m_labels.removeLast();
+
+    // Allocate new label ID.
+    m_labels.append(m_codeBlock);
+    return &m_labels.last();
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitLabel(Label* l0)
+{
+    unsigned newLabelIndex = instructions().size();
+    l0->setLocation(newLabelIndex);
+
+    if (m_codeBlock->numberOfJumpTargets()) {
+        unsigned lastLabelIndex = m_codeBlock->lastJumpTarget();
+        ASSERT(lastLabelIndex <= newLabelIndex);
+        if (newLabelIndex == lastLabelIndex) {
+            // Peephole optimizations have already been disabled by emitting the last label
+            return l0;
+        }
+    }
+
+    m_codeBlock->addJumpTarget(newLabelIndex);
+
+    // This disables peephole optimizations when an instruction is a jump target
+    m_lastOpcodeID = op_end;
+    return l0;
+}
+
+void BytecodeGenerator::emitOpcode(OpcodeID opcodeID)
+{
+    instructions().append(globalData()->interpreter->getOpcode(opcodeID));
+    m_lastOpcodeID = opcodeID;
+}
+
+void BytecodeGenerator::retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index)
+{
+    ASSERT(instructions().size() >= 4);
+    size_t size = instructions().size();
+    dstIndex = instructions().at(size - 3).u.operand;
+    src1Index = instructions().at(size - 2).u.operand;
+    src2Index = instructions().at(size - 1).u.operand;
+}
+
+void BytecodeGenerator::retrieveLastUnaryOp(int& dstIndex, int& srcIndex)
+{
+    ASSERT(instructions().size() >= 3);
+    size_t size = instructions().size();
+    dstIndex = instructions().at(size - 2).u.operand;
+    srcIndex = instructions().at(size - 1).u.operand;
+}
+
+void ALWAYS_INLINE BytecodeGenerator::rewindBinaryOp()
+{
+    ASSERT(instructions().size() >= 4);
+    instructions().shrink(instructions().size() - 4);
+}
+
+void ALWAYS_INLINE BytecodeGenerator::rewindUnaryOp()
+{
+    ASSERT(instructions().size() >= 3);
+    instructions().shrink(instructions().size() - 3);
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJump(Label* target)
+{
+    size_t begin = instructions().size();
+    emitOpcode(target->isForward() ? op_jmp : op_loop);
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* target)
+{
+    if (m_lastOpcodeID == op_less) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindBinaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(target->isForward() ? op_jless : op_loop_if_less);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_lesseq) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindBinaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(target->isForward() ? op_jlesseq : op_loop_if_lesseq);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_eq_null && target->isForward()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_neq_null && target->isForward()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    }
+
+    size_t begin = instructions().size();
+
+    emitOpcode(target->isForward() ? op_jtrue : op_loop_if_true);
+    instructions().append(cond->index());
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* target)
+{
+    if (m_lastOpcodeID == op_less && target->isForward()) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindBinaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jnless);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_lesseq && target->isForward()) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindBinaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jnlesseq);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_not) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(target->isForward() ? op_jtrue : op_loop_if_true);
+            instructions().append(srcIndex);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_eq_null && target->isForward()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_neq_null && target->isForward()) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+
+            size_t begin = instructions().size();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->bind(begin, instructions().size()));
+            return target;
+        }
+    }
+
+    size_t begin = instructions().size();
+    emitOpcode(target->isForward() ? op_jfalse : op_loop_if_false);
+    instructions().append(cond->index());
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionCall(RegisterID* cond, Label* target)
+{
+    size_t begin = instructions().size();
+
+    emitOpcode(op_jneq_ptr);
+    instructions().append(cond->index());
+    instructions().append(m_scopeChain->globalObject()->d()->callFunction);
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionApply(RegisterID* cond, Label* target)
+{
+    size_t begin = instructions().size();
+
+    emitOpcode(op_jneq_ptr);
+    instructions().append(cond->index());
+    instructions().append(m_scopeChain->globalObject()->d()->applyFunction);
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+unsigned BytecodeGenerator::addConstant(const Identifier& ident)
+{
+    UString::Rep* rep = ident.ustring().rep();
+    pair<IdentifierMap::iterator, bool> result = m_identifierMap.add(rep, m_codeBlock->numberOfIdentifiers());
+    if (result.second) // new entry
+        m_codeBlock->addIdentifier(Identifier(m_globalData, rep));
+
+    return result.first->second;
+}
+
+RegisterID* BytecodeGenerator::addConstantValue(JSValue v)
+{
+    int index = m_nextConstantOffset;
+
+    pair<JSValueMap::iterator, bool> result = m_jsValueMap.add(JSValue::encode(v), m_nextConstantOffset);
+    if (result.second) {
+        m_constantPoolRegisters.append(FirstConstantRegisterIndex + m_nextConstantOffset);
+        ++m_nextConstantOffset;
+        m_codeBlock->addConstantRegister(JSValue(v));
+    } else
+        index = result.first->second;
+
+    return &m_constantPoolRegisters[index];
+}
+
+unsigned BytecodeGenerator::addRegExp(RegExp* r)
+{
+    return m_codeBlock->addRegExp(r);
+}
+
+RegisterID* BytecodeGenerator::emitMove(RegisterID* dst, RegisterID* src)
+{
+    emitOpcode(op_mov);
+    instructions().append(dst->index());
+    instructions().append(src->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitUnaryOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src)
+{
+    emitOpcode(opcodeID);
+    instructions().append(dst->index());
+    instructions().append(src->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPreInc(RegisterID* srcDst)
+{
+    emitOpcode(op_pre_inc);
+    instructions().append(srcDst->index());
+    return srcDst;
+}
+
+RegisterID* BytecodeGenerator::emitPreDec(RegisterID* srcDst)
+{
+    emitOpcode(op_pre_dec);
+    instructions().append(srcDst->index());
+    return srcDst;
+}
+
+RegisterID* BytecodeGenerator::emitPostInc(RegisterID* dst, RegisterID* srcDst)
+{
+    emitOpcode(op_post_inc);
+    instructions().append(dst->index());
+    instructions().append(srcDst->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPostDec(RegisterID* dst, RegisterID* srcDst)
+{
+    emitOpcode(op_post_dec);
+    instructions().append(dst->index());
+    instructions().append(srcDst->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitBinaryOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes types)
+{
+    emitOpcode(opcodeID);
+    instructions().append(dst->index());
+    instructions().append(src1->index());
+    instructions().append(src2->index());
+
+    if (opcodeID == op_bitor || opcodeID == op_bitand || opcodeID == op_bitxor ||
+        opcodeID == op_add || opcodeID == op_mul || opcodeID == op_sub || opcodeID == op_div)
+        instructions().append(types.toInt());
+
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitEqualityOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2)
+{
+    if (m_lastOpcodeID == op_typeof) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (src1->index() == dstIndex
+            && src1->isTemporary()
+            && m_codeBlock->isConstantRegisterIndex(src2->index())
+            && m_codeBlock->constantRegister(src2->index()).jsValue().isString()) {
+            const UString& value = asString(m_codeBlock->constantRegister(src2->index()).jsValue())->tryGetValue();
+            if (value == "undefined") {
+                rewindUnaryOp();
+                emitOpcode(op_is_undefined);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+            if (value == "boolean") {
+                rewindUnaryOp();
+                emitOpcode(op_is_boolean);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+            if (value == "number") {
+                rewindUnaryOp();
+                emitOpcode(op_is_number);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+            if (value == "string") {
+                rewindUnaryOp();
+                emitOpcode(op_is_string);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+            if (value == "object") {
+                rewindUnaryOp();
+                emitOpcode(op_is_object);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+            if (value == "function") {
+                rewindUnaryOp();
+                emitOpcode(op_is_function);
+                instructions().append(dst->index());
+                instructions().append(srcIndex);
+                return dst;
+            }
+        }
+    }
+
+    emitOpcode(opcodeID);
+    instructions().append(dst->index());
+    instructions().append(src1->index());
+    instructions().append(src2->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, bool b)
+{
+    return emitLoad(dst, jsBoolean(b));
+}
+
+RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, double number)
+{
+    // FIXME: Our hash tables won't hold infinity, so we make a new JSNumberCell each time.
+    // Later we can do the extra work to handle that like the other cases.
+    if (number == HashTraits<double>::emptyValue() || HashTraits<double>::isDeletedValue(number))
+        return emitLoad(dst, jsNumber(globalData(), number));
+    JSValue& valueInMap = m_numberMap.add(number, JSValue()).first->second;
+    if (!valueInMap)
+        valueInMap = jsNumber(globalData(), number);
+    return emitLoad(dst, valueInMap);
+}
+
+RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, const Identifier& identifier)
+{
+    JSString*& stringInMap = m_stringMap.add(identifier.ustring().rep(), 0).first->second;
+    if (!stringInMap)
+        stringInMap = jsOwnedString(globalData(), identifier.ustring());
+    return emitLoad(dst, JSValue(stringInMap));
+}
+
+RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, JSValue v)
+{
+    RegisterID* constantID = addConstantValue(v);
+    if (dst)
+        return emitMove(dst, constantID);
+    return constantID;
+}
+
+bool BytecodeGenerator::findScopedProperty(const Identifier& property, int& index, size_t& stackDepth, bool forWriting, bool& requiresDynamicChecks, JSObject*& globalObject)
+{
+    // Cases where we cannot statically optimize the lookup.
+    if (property == propertyNames().arguments || !canOptimizeNonLocals()) {
+        stackDepth = 0;
+        index = missingSymbolMarker();
+
+        if (shouldOptimizeLocals() && m_codeType == GlobalCode) {
+            ScopeChainIterator iter = m_scopeChain->begin();
+            globalObject = *iter;
+            ASSERT((++iter) == m_scopeChain->end());
+        }
+        return false;
+    }
+
+    size_t depth = 0;
+    requiresDynamicChecks = false;
+    ScopeChainIterator iter = m_scopeChain->begin();
+    ScopeChainIterator end = m_scopeChain->end();
+    for (; iter != end; ++iter, ++depth) {
+        JSObject* currentScope = *iter;
+        if (!currentScope->isVariableObject())
+            break;
+        JSVariableObject* currentVariableObject = static_cast<JSVariableObject*>(currentScope);
+        SymbolTableEntry entry = currentVariableObject->symbolTable().get(property.ustring().rep());
+
+        // Found the property
+        if (!entry.isNull()) {
+            if (entry.isReadOnly() && forWriting) {
+                stackDepth = 0;
+                index = missingSymbolMarker();
+                if (++iter == end)
+                    globalObject = currentVariableObject;
+                return false;
+            }
+            stackDepth = depth + m_codeBlock->needsFullScopeChain();
+            index = entry.getIndex();
+            if (++iter == end)
+                globalObject = currentVariableObject;
+            return true;
+        }
+        bool scopeRequiresDynamicChecks = false;
+        if (currentVariableObject->isDynamicScope(scopeRequiresDynamicChecks))
+            break;
+        requiresDynamicChecks |= scopeRequiresDynamicChecks;
+    }
+    // Can't locate the property but we're able to avoid a few lookups.
+    stackDepth = depth + m_codeBlock->needsFullScopeChain();
+    index = missingSymbolMarker();
+    JSObject* scope = *iter;
+    if (++iter == end)
+        globalObject = scope;
+    return true;
+}
+
+RegisterID* BytecodeGenerator::emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype)
+{ 
+    emitOpcode(op_instanceof);
+    instructions().append(dst->index());
+    instructions().append(value->index());
+    instructions().append(base->index());
+    instructions().append(basePrototype->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitResolve(RegisterID* dst, const Identifier& property)
+{
+    size_t depth = 0;
+    int index = 0;
+    JSObject* globalObject = 0;
+    bool requiresDynamicChecks = false;
+    if (!findScopedProperty(property, index, depth, false, requiresDynamicChecks, globalObject) && !globalObject) {
+        // We can't optimise at all :-(
+        emitOpcode(op_resolve);
+        instructions().append(dst->index());
+        instructions().append(addConstant(property));
+        return dst;
+    }
+
+    if (globalObject) {
+        bool forceGlobalResolve = false;
+        if (m_regeneratingForExceptionInfo) {
+#if ENABLE(JIT)
+            forceGlobalResolve = m_codeBlockBeingRegeneratedFrom->hasGlobalResolveInfoAtBytecodeOffset(instructions().size());
+#else
+            forceGlobalResolve = m_codeBlockBeingRegeneratedFrom->hasGlobalResolveInstructionAtBytecodeOffset(instructions().size());
+#endif
+        }
+
+        if (index != missingSymbolMarker() && !forceGlobalResolve && !requiresDynamicChecks) {
+            // Directly index the property lookup across multiple scopes.
+            return emitGetScopedVar(dst, depth, index, globalObject);
+        }
+
+#if ENABLE(JIT)
+        m_codeBlock->addGlobalResolveInfo(instructions().size());
+#else
+        m_codeBlock->addGlobalResolveInstruction(instructions().size());
+#endif
+        emitOpcode(requiresDynamicChecks ? op_resolve_global_dynamic : op_resolve_global);
+        instructions().append(dst->index());
+        instructions().append(globalObject);
+        instructions().append(addConstant(property));
+        instructions().append(0);
+        instructions().append(0);
+        if (requiresDynamicChecks)
+            instructions().append(depth);
+        return dst;
+    }
+
+    if (requiresDynamicChecks) {
+        // If we get here we have eval nested inside a |with| just give up
+        emitOpcode(op_resolve);
+        instructions().append(dst->index());
+        instructions().append(addConstant(property));
+        return dst;
+    }
+
+    if (index != missingSymbolMarker()) {
+        // Directly index the property lookup across multiple scopes.
+        return emitGetScopedVar(dst, depth, index, globalObject);
+    }
+
+    // In this case we are at least able to drop a few scope chains from the
+    // lookup chain, although we still need to hash from then on.
+    emitOpcode(op_resolve_skip);
+    instructions().append(dst->index());
+    instructions().append(addConstant(property));
+    instructions().append(depth);
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitGetScopedVar(RegisterID* dst, size_t depth, int index, JSValue globalObject)
+{
+    if (globalObject) {
+        emitOpcode(op_get_global_var);
+        instructions().append(dst->index());
+        instructions().append(asCell(globalObject));
+        instructions().append(index);
+        return dst;
+    }
+
+    emitOpcode(op_get_scoped_var);
+    instructions().append(dst->index());
+    instructions().append(index);
+    instructions().append(depth);
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPutScopedVar(size_t depth, int index, RegisterID* value, JSValue globalObject)
+{
+    if (globalObject) {
+        emitOpcode(op_put_global_var);
+        instructions().append(asCell(globalObject));
+        instructions().append(index);
+        instructions().append(value->index());
+        return value;
+    }
+    emitOpcode(op_put_scoped_var);
+    instructions().append(index);
+    instructions().append(depth);
+    instructions().append(value->index());
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitResolveBase(RegisterID* dst, const Identifier& property)
+{
+    size_t depth = 0;
+    int index = 0;
+    JSObject* globalObject = 0;
+    bool requiresDynamicChecks = false;
+    findScopedProperty(property, index, depth, false, requiresDynamicChecks, globalObject);
+    if (!globalObject || requiresDynamicChecks) {
+        // We can't optimise at all :-(
+        emitOpcode(op_resolve_base);
+        instructions().append(dst->index());
+        instructions().append(addConstant(property));
+        return dst;
+    }
+
+    // Global object is the base
+    return emitLoad(dst, JSValue(globalObject));
+}
+
+RegisterID* BytecodeGenerator::emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property)
+{
+    size_t depth = 0;
+    int index = 0;
+    JSObject* globalObject = 0;
+    bool requiresDynamicChecks = false;
+    if (!findScopedProperty(property, index, depth, false, requiresDynamicChecks, globalObject) || !globalObject || requiresDynamicChecks) {
+        // We can't optimise at all :-(
+        emitOpcode(op_resolve_with_base);
+        instructions().append(baseDst->index());
+        instructions().append(propDst->index());
+        instructions().append(addConstant(property));
+        return baseDst;
+    }
+
+    bool forceGlobalResolve = false;
+    if (m_regeneratingForExceptionInfo) {
+#if ENABLE(JIT)
+        forceGlobalResolve = m_codeBlockBeingRegeneratedFrom->hasGlobalResolveInfoAtBytecodeOffset(instructions().size());
+#else
+        forceGlobalResolve = m_codeBlockBeingRegeneratedFrom->hasGlobalResolveInstructionAtBytecodeOffset(instructions().size());
+#endif
+    }
+
+    // Global object is the base
+    emitLoad(baseDst, JSValue(globalObject));
+
+    if (index != missingSymbolMarker() && !forceGlobalResolve) {
+        // Directly index the property lookup across multiple scopes.
+        emitGetScopedVar(propDst, depth, index, globalObject);
+        return baseDst;
+    }
+
+#if ENABLE(JIT)
+    m_codeBlock->addGlobalResolveInfo(instructions().size());
+#else
+    m_codeBlock->addGlobalResolveInstruction(instructions().size());
+#endif
+    emitOpcode(requiresDynamicChecks ? op_resolve_global_dynamic : op_resolve_global);
+    instructions().append(propDst->index());
+    instructions().append(globalObject);
+    instructions().append(addConstant(property));
+    instructions().append(0);
+    instructions().append(0);
+    if (requiresDynamicChecks)
+        instructions().append(depth);
+    return baseDst;
+}
+
+void BytecodeGenerator::emitMethodCheck()
+{
+    emitOpcode(op_method_check);
+}
+
+RegisterID* BytecodeGenerator::emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property)
+{
+#if ENABLE(JIT)
+    m_codeBlock->addStructureStubInfo(StructureStubInfo(access_get_by_id));
+#else
+    m_codeBlock->addPropertyAccessInstruction(instructions().size());
+#endif
+
+    emitOpcode(op_get_by_id);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPutById(RegisterID* base, const Identifier& property, RegisterID* value)
+{
+#if ENABLE(JIT)
+    m_codeBlock->addStructureStubInfo(StructureStubInfo(access_put_by_id));
+#else
+    m_codeBlock->addPropertyAccessInstruction(instructions().size());
+#endif
+
+    emitOpcode(op_put_by_id);
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    instructions().append(value->index());
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitDirectPutById(RegisterID* base, const Identifier& property, RegisterID* value)
+{
+#if ENABLE(JIT)
+    m_codeBlock->addStructureStubInfo(StructureStubInfo(access_put_by_id));
+#else
+    m_codeBlock->addPropertyAccessInstruction(instructions().size());
+#endif
+    
+    emitOpcode(op_put_by_id);
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    instructions().append(value->index());
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(0);
+    instructions().append(property != m_globalData->propertyNames->underscoreProto);
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value)
+{
+    emitOpcode(op_put_getter);
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    instructions().append(value->index());
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value)
+{
+    emitOpcode(op_put_setter);
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    instructions().append(value->index());
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier& property)
+{
+    emitOpcode(op_del_by_id);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(addConstant(property));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
+{
+    for (size_t i = m_forInContextStack.size(); i > 0; i--) {
+        ForInContext& context = m_forInContextStack[i - 1];
+        if (context.propertyRegister == property) {
+            emitOpcode(op_get_by_pname);
+            instructions().append(dst->index());
+            instructions().append(base->index());
+            instructions().append(property->index());
+            instructions().append(context.expectedSubscriptRegister->index());
+            instructions().append(context.iterRegister->index());
+            instructions().append(context.indexRegister->index());
+            return dst;
+        }
+    }
+    emitOpcode(op_get_by_val);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(property->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value)
+{
+    emitOpcode(op_put_by_val);
+    instructions().append(base->index());
+    instructions().append(property->index());
+    instructions().append(value->index());
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
+{
+    emitOpcode(op_del_by_val);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(property->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value)
+{
+    emitOpcode(op_put_by_index);
+    instructions().append(base->index());
+    instructions().append(index);
+    instructions().append(value->index());
+    return value;
+}
+
+RegisterID* BytecodeGenerator::emitNewObject(RegisterID* dst)
+{
+    emitOpcode(op_new_object);
+    instructions().append(dst->index());
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNewArray(RegisterID* dst, ElementNode* elements)
+{
+    Vector<RefPtr<RegisterID>, 16> argv;
+    for (ElementNode* n = elements; n; n = n->next()) {
+        if (n->elision())
+            break;
+        argv.append(newTemporary());
+        // op_new_array requires the initial values to be a sequential range of registers
+        ASSERT(argv.size() == 1 || argv[argv.size() - 1]->index() == argv[argv.size() - 2]->index() + 1);
+        emitNode(argv.last().get(), n->value());
+    }
+    emitOpcode(op_new_array);
+    instructions().append(dst->index());
+    instructions().append(argv.size() ? argv[0]->index() : 0); // argv
+    instructions().append(argv.size()); // argc
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNewFunction(RegisterID* dst, FunctionBodyNode* function)
+{
+    unsigned index = m_codeBlock->addFunctionDecl(makeFunction(m_globalData, function));
+
+    emitOpcode(op_new_func);
+    instructions().append(dst->index());
+    instructions().append(index);
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNewRegExp(RegisterID* dst, RegExp* regExp)
+{
+    emitOpcode(op_new_regexp);
+    instructions().append(dst->index());
+    instructions().append(addRegExp(regExp));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNewFunctionExpression(RegisterID* r0, FuncExprNode* n)
+{
+    FunctionBodyNode* function = n->body();
+    unsigned index = m_codeBlock->addFunctionExpr(makeFunction(m_globalData, function));
+
+    emitOpcode(op_new_func_exp);
+    instructions().append(r0->index());
+    instructions().append(index);
+    return r0;
+}
+
+RegisterID* BytecodeGenerator::emitCall(RegisterID* dst, RegisterID* func, CallArguments& callArguments, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    return emitCall(op_call, dst, func, callArguments, divot, startOffset, endOffset);
+}
+
+void BytecodeGenerator::createArgumentsIfNecessary()
+{
+    if (m_codeType != FunctionCode)
+        return;
+    ASSERT(m_codeBlock->usesArguments());
+
+    emitOpcode(op_create_arguments);
+    instructions().append(m_codeBlock->argumentsRegister());
+}
+
+RegisterID* BytecodeGenerator::emitCallEval(RegisterID* dst, RegisterID* func, CallArguments& callArguments, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    return emitCall(op_call_eval, dst, func, callArguments, divot, startOffset, endOffset);
+}
+
+RegisterID* BytecodeGenerator::emitCall(OpcodeID opcodeID, RegisterID* dst, RegisterID* func, CallArguments& callArguments, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    ASSERT(opcodeID == op_call || opcodeID == op_call_eval);
+    ASSERT(func->refCount());
+
+    if (m_shouldEmitProfileHooks)
+        emitMove(callArguments.profileHookRegister(), func);
+
+    // Generate code for arguments.
+    unsigned argumentIndex = 0;
+    for (ArgumentListNode* n = callArguments.argumentsNode()->m_listNode; n; n = n->m_next)
+        emitNode(callArguments.argumentRegister(argumentIndex++), n);
+
+    // Reserve space for call frame.
+    Vector<RefPtr<RegisterID>, RegisterFile::CallFrameHeaderSize> callFrame;
+    for (int i = 0; i < RegisterFile::CallFrameHeaderSize; ++i)
+        callFrame.append(newTemporary());
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_will_call);
+        instructions().append(callArguments.profileHookRegister()->index());
+
+#if ENABLE(JIT)
+        m_codeBlock->addFunctionRegisterInfo(instructions().size(), callArguments.profileHookRegister()->index());
+#endif
+    }
+
+    emitExpressionInfo(divot, startOffset, endOffset);
+
+#if ENABLE(JIT)
+    m_codeBlock->addCallLinkInfo();
+#endif
+
+    // Emit call.
+    emitOpcode(opcodeID);
+    instructions().append(func->index()); // func
+    instructions().append(callArguments.count()); // argCount
+    instructions().append(callArguments.callFrame()); // registerOffset
+    if (dst != ignoredResult()) {
+        emitOpcode(op_call_put_result);
+        instructions().append(dst->index()); // dst
+    }
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_did_call);
+        instructions().append(callArguments.profileHookRegister()->index());
+    }
+
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitLoadVarargs(RegisterID* argCountDst, RegisterID* arguments)
+{
+    ASSERT(argCountDst->index() < arguments->index());
+    emitOpcode(op_load_varargs);
+    instructions().append(argCountDst->index());
+    instructions().append(arguments->index());
+    return argCountDst;
+}
+
+RegisterID* BytecodeGenerator::emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* argCountRegister, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    ASSERT(func->refCount());
+    ASSERT(thisRegister->refCount());
+    ASSERT(dst != func);
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_will_call);
+        instructions().append(func->index());
+        
+#if ENABLE(JIT)
+        m_codeBlock->addFunctionRegisterInfo(instructions().size(), func->index());
+#endif
+    }
+    
+    emitExpressionInfo(divot, startOffset, endOffset);
+    
+    // Emit call.
+    emitOpcode(op_call_varargs);
+    instructions().append(func->index()); // func
+    instructions().append(argCountRegister->index()); // arg count
+    instructions().append(thisRegister->index() + RegisterFile::CallFrameHeaderSize); // initial registerOffset
+    if (dst != ignoredResult()) {
+        emitOpcode(op_call_put_result);
+        instructions().append(dst->index()); // dst
+    }
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_did_call);
+        instructions().append(func->index());
+    }
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitReturn(RegisterID* src)
+{
+    if (m_codeBlock->needsFullScopeChain()) {
+        emitOpcode(op_tear_off_activation);
+        instructions().append(m_activationRegister->index());
+        instructions().append(m_codeBlock->argumentsRegister());
+    } else if (m_codeBlock->usesArguments() && m_codeBlock->m_numParameters > 1) { // If there are no named parameters, there's nothing to tear off, since extra / unnamed parameters get copied to the arguments object at construct time.
+        emitOpcode(op_tear_off_arguments);
+        instructions().append(m_codeBlock->argumentsRegister());
+    }
+
+    // Constructors use op_ret_object_or_this to check the result is an
+    // object, unless we can trivially determine the check is not
+    // necessary (currently, if the return value is 'this').
+    if (isConstructor() && (src->index() != m_thisRegister.index())) {
+        emitOpcode(op_ret_object_or_this);
+        instructions().append(src->index());
+        instructions().append(m_thisRegister.index());
+        return src;
+    }
+    return emitUnaryNoDstOp(op_ret, src);
+}
+
+RegisterID* BytecodeGenerator::emitUnaryNoDstOp(OpcodeID opcodeID, RegisterID* src)
+{
+    emitOpcode(opcodeID);
+    instructions().append(src->index());
+    return src;
+}
+
+RegisterID* BytecodeGenerator::emitConstruct(RegisterID* dst, RegisterID* func, CallArguments& callArguments, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    ASSERT(func->refCount());
+
+    if (m_shouldEmitProfileHooks)
+        emitMove(callArguments.profileHookRegister(), func);
+
+    // Generate code for arguments.
+    unsigned argumentIndex = 0;
+    if (ArgumentsNode* argumentsNode = callArguments.argumentsNode()) {
+        for (ArgumentListNode* n = argumentsNode->m_listNode; n; n = n->m_next)
+            emitNode(callArguments.argumentRegister(argumentIndex++), n);
+    }
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_will_call);
+        instructions().append(callArguments.profileHookRegister()->index());
+    }
+
+    // Reserve space for call frame.
+    Vector<RefPtr<RegisterID>, RegisterFile::CallFrameHeaderSize> callFrame;
+    for (int i = 0; i < RegisterFile::CallFrameHeaderSize; ++i)
+        callFrame.append(newTemporary());
+
+    emitExpressionInfo(divot, startOffset, endOffset);
+
+#if ENABLE(JIT)
+    m_codeBlock->addCallLinkInfo();
+#endif
+
+    emitOpcode(op_construct);
+    instructions().append(func->index()); // func
+    instructions().append(callArguments.count()); // argCount
+    instructions().append(callArguments.callFrame()); // registerOffset
+    if (dst != ignoredResult()) {
+        emitOpcode(op_call_put_result);
+        instructions().append(dst->index()); // dst
+    }
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_did_call);
+        instructions().append(callArguments.profileHookRegister()->index());
+    }
+
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitStrcat(RegisterID* dst, RegisterID* src, int count)
+{
+    emitOpcode(op_strcat);
+    instructions().append(dst->index());
+    instructions().append(src->index());
+    instructions().append(count);
+
+    return dst;
+}
+
+void BytecodeGenerator::emitToPrimitive(RegisterID* dst, RegisterID* src)
+{
+    emitOpcode(op_to_primitive);
+    instructions().append(dst->index());
+    instructions().append(src->index());
+}
+
+RegisterID* BytecodeGenerator::emitPushScope(RegisterID* scope)
+{
+    ASSERT(scope->isTemporary());
+    ControlFlowContext context;
+    context.isFinallyBlock = false;
+    m_scopeContextStack.append(context);
+    m_dynamicScopeDepth++;
+
+    return emitUnaryNoDstOp(op_push_scope, scope);
+}
+
+void BytecodeGenerator::emitPopScope()
+{
+    ASSERT(m_scopeContextStack.size());
+    ASSERT(!m_scopeContextStack.last().isFinallyBlock);
+
+    emitOpcode(op_pop_scope);
+
+    m_scopeContextStack.removeLast();
+    m_dynamicScopeDepth--;
+}
+
+void BytecodeGenerator::emitDebugHook(DebugHookID debugHookID, int firstLine, int lastLine)
+{
+#if ENABLE(DEBUG_WITH_BREAKPOINT)
+    if (debugHookID != DidReachBreakpoint)
+        return;
+#else
+    if (!m_shouldEmitDebugHooks)
+        return;
+#endif
+    emitOpcode(op_debug);
+    instructions().append(debugHookID);
+    instructions().append(firstLine);
+    instructions().append(lastLine);
+}
+
+void BytecodeGenerator::pushFinallyContext(Label* target, RegisterID* retAddrDst)
+{
+    ControlFlowContext scope;
+    scope.isFinallyBlock = true;
+    FinallyContext context = { target, retAddrDst };
+    scope.finallyContext = context;
+    m_scopeContextStack.append(scope);
+    m_finallyDepth++;
+}
+
+void BytecodeGenerator::popFinallyContext()
+{
+    ASSERT(m_scopeContextStack.size());
+    ASSERT(m_scopeContextStack.last().isFinallyBlock);
+    ASSERT(m_finallyDepth > 0);
+    m_scopeContextStack.removeLast();
+    m_finallyDepth--;
+}
+
+LabelScope* BytecodeGenerator::breakTarget(const Identifier& name)
+{
+    // Reclaim free label scopes.
+    //
+    // The condition was previously coded as 'm_labelScopes.size() && !m_labelScopes.last().refCount()',
+    // however sometimes this appears to lead to GCC going a little haywire and entering the loop with
+    // size 0, leading to segfaulty badness.  We are yet to identify a valid cause within our code to
+    // cause the GCC codegen to misbehave in this fashion, and as such the following refactoring of the
+    // loop condition is a workaround.
+    while (m_labelScopes.size()) {
+        if  (m_labelScopes.last().refCount())
+            break;
+        m_labelScopes.removeLast();
+    }
+
+    if (!m_labelScopes.size())
+        return 0;
+
+    // We special-case the following, which is a syntax error in Firefox:
+    // label:
+    //     break;
+    if (name.isEmpty()) {
+        for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
+            LabelScope* scope = &m_labelScopes[i];
+            if (scope->type() != LabelScope::NamedLabel) {
+                ASSERT(scope->breakTarget());
+                return scope;
+            }
+        }
+        return 0;
+    }
+
+    for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
+        LabelScope* scope = &m_labelScopes[i];
+        if (scope->name() && *scope->name() == name) {
+            ASSERT(scope->breakTarget());
+            return scope;
+        }
+    }
+    return 0;
+}
+
+LabelScope* BytecodeGenerator::continueTarget(const Identifier& name)
+{
+    // Reclaim free label scopes.
+    while (m_labelScopes.size() && !m_labelScopes.last().refCount())
+        m_labelScopes.removeLast();
+
+    if (!m_labelScopes.size())
+        return 0;
+
+    if (name.isEmpty()) {
+        for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
+            LabelScope* scope = &m_labelScopes[i];
+            if (scope->type() == LabelScope::Loop) {
+                ASSERT(scope->continueTarget());
+                return scope;
+            }
+        }
+        return 0;
+    }
+
+    // Continue to the loop nested nearest to the label scope that matches
+    // 'name'.
+    LabelScope* result = 0;
+    for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
+        LabelScope* scope = &m_labelScopes[i];
+        if (scope->type() == LabelScope::Loop) {
+            ASSERT(scope->continueTarget());
+            result = scope;
+        }
+        if (scope->name() && *scope->name() == name)
+            return result; // may be 0
+    }
+    return 0;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope)
+{
+    while (topScope > bottomScope) {
+        // First we count the number of dynamic scopes we need to remove to get
+        // to a finally block.
+        int nNormalScopes = 0;
+        while (topScope > bottomScope) {
+            if (topScope->isFinallyBlock)
+                break;
+            ++nNormalScopes;
+            --topScope;
+        }
+
+        if (nNormalScopes) {
+            size_t begin = instructions().size();
+
+            // We need to remove a number of dynamic scopes to get to the next
+            // finally block
+            emitOpcode(op_jmp_scopes);
+            instructions().append(nNormalScopes);
+
+            // If topScope == bottomScope then there isn't actually a finally block
+            // left to emit, so make the jmp_scopes jump directly to the target label
+            if (topScope == bottomScope) {
+                instructions().append(target->bind(begin, instructions().size()));
+                return target;
+            }
+
+            // Otherwise we just use jmp_scopes to pop a group of scopes and go
+            // to the next instruction
+            RefPtr<Label> nextInsn = newLabel();
+            instructions().append(nextInsn->bind(begin, instructions().size()));
+            emitLabel(nextInsn.get());
+        }
+
+        while (topScope > bottomScope && topScope->isFinallyBlock) {
+            emitJumpSubroutine(topScope->finallyContext.retAddrDst, topScope->finallyContext.finallyAddr);
+            --topScope;
+        }
+    }
+    return emitJump(target);
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpScopes(Label* target, int targetScopeDepth)
+{
+    ASSERT(scopeDepth() - targetScopeDepth >= 0);
+    ASSERT(target->isForward());
+
+    size_t scopeDelta = scopeDepth() - targetScopeDepth;
+    ASSERT(scopeDelta <= m_scopeContextStack.size());
+    if (!scopeDelta)
+        return emitJump(target);
+
+    if (m_finallyDepth)
+        return emitComplexJumpScopes(target, &m_scopeContextStack.last(), &m_scopeContextStack.last() - scopeDelta);
+
+    size_t begin = instructions().size();
+
+    emitOpcode(op_jmp_scopes);
+    instructions().append(scopeDelta);
+    instructions().append(target->bind(begin, instructions().size()));
+    return target;
+}
+
+RegisterID* BytecodeGenerator::emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget)
+{
+    size_t begin = instructions().size();
+
+    emitOpcode(op_get_pnames);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(i->index());
+    instructions().append(size->index());
+    instructions().append(breakTarget->bind(begin, instructions().size()));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target)
+{
+    size_t begin = instructions().size();
+
+    emitOpcode(op_next_pname);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(i->index());
+    instructions().append(size->index());
+    instructions().append(iter->index());
+    instructions().append(target->bind(begin, instructions().size()));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitCatch(RegisterID* targetRegister, Label* start, Label* end)
+{
+    m_usesExceptions = true;
+#if ENABLE(JIT)
+    HandlerInfo info = { start->bind(0, 0), end->bind(0, 0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth, CodeLocationLabel() };
+#else
+    HandlerInfo info = { start->bind(0, 0), end->bind(0, 0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth };
+#endif
+
+    m_codeBlock->addExceptionHandler(info);
+    emitOpcode(op_catch);
+    instructions().append(targetRegister->index());
+    return targetRegister;
+}
+
+RegisterID* BytecodeGenerator::emitNewError(RegisterID* dst, bool isReferenceError, JSValue message)
+{
+    emitOpcode(op_new_error);
+    instructions().append(dst->index());
+    instructions().append(isReferenceError);
+    instructions().append(addConstantValue(message)->index());
+    return dst;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpSubroutine(RegisterID* retAddrDst, Label* finally)
+{
+    size_t begin = instructions().size();
+
+    emitOpcode(op_jsr);
+    instructions().append(retAddrDst->index());
+    instructions().append(finally->bind(begin, instructions().size()));
+    emitLabel(newLabel().get()); // Record the fact that the next instruction is implicitly labeled, because op_sret will return to it.
+    return finally;
+}
+
+void BytecodeGenerator::emitSubroutineReturn(RegisterID* retAddrSrc)
+{
+    emitOpcode(op_sret);
+    instructions().append(retAddrSrc->index());
+}
+
+void BytecodeGenerator::emitPushNewScope(RegisterID* dst, const Identifier& property, RegisterID* value)
+{
+    ControlFlowContext context;
+    context.isFinallyBlock = false;
+    m_scopeContextStack.append(context);
+    m_dynamicScopeDepth++;
+
+    emitOpcode(op_push_new_scope);
+    instructions().append(dst->index());
+    instructions().append(addConstant(property));
+    instructions().append(value->index());
+}
+
+void BytecodeGenerator::beginSwitch(RegisterID* scrutineeRegister, SwitchInfo::SwitchType type)
+{
+    SwitchInfo info = { instructions().size(), type };
+    switch (type) {
+        case SwitchInfo::SwitchImmediate:
+            emitOpcode(op_switch_imm);
+            break;
+        case SwitchInfo::SwitchCharacter:
+            emitOpcode(op_switch_char);
+            break;
+        case SwitchInfo::SwitchString:
+            emitOpcode(op_switch_string);
+            break;
+        default:
+            ASSERT_NOT_REACHED();
+    }
+
+    instructions().append(0); // place holder for table index
+    instructions().append(0); // place holder for default target    
+    instructions().append(scrutineeRegister->index());
+    m_switchContextStack.append(info);
+}
+
+static int32_t keyForImmediateSwitch(ExpressionNode* node, int32_t min, int32_t max)
+{
+    UNUSED_PARAM(max);
+    ASSERT(node->isNumber());
+    double value = static_cast<NumberNode*>(node)->value();
+    int32_t key = static_cast<int32_t>(value);
+    ASSERT(key == value);
+    ASSERT(key >= min);
+    ASSERT(key <= max);
+    return key - min;
+}
+
+static void prepareJumpTableForImmediateSwitch(SimpleJumpTable& jumpTable, int32_t switchAddress, uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes, int32_t min, int32_t max)
+{
+    jumpTable.min = min;
+    jumpTable.branchOffsets.resize(max - min + 1);
+    jumpTable.branchOffsets.fill(0);
+    for (uint32_t i = 0; i < clauseCount; ++i) {
+        // We're emitting this after the clause labels should have been fixed, so 
+        // the labels should not be "forward" references
+        ASSERT(!labels[i]->isForward());
+        jumpTable.add(keyForImmediateSwitch(nodes[i], min, max), labels[i]->bind(switchAddress, switchAddress + 3)); 
+    }
+}
+
+static int32_t keyForCharacterSwitch(ExpressionNode* node, int32_t min, int32_t max)
+{
+    UNUSED_PARAM(max);
+    ASSERT(node->isString());
+    UString::Rep* clause = static_cast<StringNode*>(node)->value().ustring().rep();
+    ASSERT(clause->length() == 1);
+    
+    int32_t key = clause->characters()[0];
+    ASSERT(key >= min);
+    ASSERT(key <= max);
+    return key - min;
+}
+
+static void prepareJumpTableForCharacterSwitch(SimpleJumpTable& jumpTable, int32_t switchAddress, uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes, int32_t min, int32_t max)
+{
+    jumpTable.min = min;
+    jumpTable.branchOffsets.resize(max - min + 1);
+    jumpTable.branchOffsets.fill(0);
+    for (uint32_t i = 0; i < clauseCount; ++i) {
+        // We're emitting this after the clause labels should have been fixed, so 
+        // the labels should not be "forward" references
+        ASSERT(!labels[i]->isForward());
+        jumpTable.add(keyForCharacterSwitch(nodes[i], min, max), labels[i]->bind(switchAddress, switchAddress + 3)); 
+    }
+}
+
+static void prepareJumpTableForStringSwitch(StringJumpTable& jumpTable, int32_t switchAddress, uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes)
+{
+    for (uint32_t i = 0; i < clauseCount; ++i) {
+        // We're emitting this after the clause labels should have been fixed, so 
+        // the labels should not be "forward" references
+        ASSERT(!labels[i]->isForward());
+        
+        ASSERT(nodes[i]->isString());
+        UString::Rep* clause = static_cast<StringNode*>(nodes[i])->value().ustring().rep();
+        OffsetLocation location;
+        location.branchOffset = labels[i]->bind(switchAddress, switchAddress + 3);
+        jumpTable.offsetTable.add(clause, location);
+    }
+}
+
+void BytecodeGenerator::endSwitch(uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes, Label* defaultLabel, int32_t min, int32_t max)
+{
+    SwitchInfo switchInfo = m_switchContextStack.last();
+    m_switchContextStack.removeLast();
+    if (switchInfo.switchType == SwitchInfo::SwitchImmediate) {
+        instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfImmediateSwitchJumpTables();
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
+
+        SimpleJumpTable& jumpTable = m_codeBlock->addImmediateSwitchJumpTable();
+        prepareJumpTableForImmediateSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes, min, max);
+    } else if (switchInfo.switchType == SwitchInfo::SwitchCharacter) {
+        instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfCharacterSwitchJumpTables();
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
+        
+        SimpleJumpTable& jumpTable = m_codeBlock->addCharacterSwitchJumpTable();
+        prepareJumpTableForCharacterSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes, min, max);
+    } else {
+        ASSERT(switchInfo.switchType == SwitchInfo::SwitchString);
+        instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfStringSwitchJumpTables();
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
+
+        StringJumpTable& jumpTable = m_codeBlock->addStringSwitchJumpTable();
+        prepareJumpTableForStringSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes);
+    }
+}
+
+RegisterID* BytecodeGenerator::emitThrowExpressionTooDeepException()
+{
+    // It would be nice to do an even better job of identifying exactly where the expression is.
+    // And we could make the caller pass the node pointer in, if there was some way of getting
+    // that from an arbitrary node. However, calling emitExpressionInfo without any useful data
+    // is still good enough to get us an accurate line number.
+    emitExpressionInfo(0, 0, 0);
+    RegisterID* exception = emitNewError(newTemporary(), false, jsString(globalData(), "Expression too deep"));
+    emitThrow(exception);
+    return exception;
+}
+
+void BytecodeGenerator::setIsNumericCompareFunction(bool isNumericCompareFunction)
+{
+    m_codeBlock->setIsNumericCompareFunction(isNumericCompareFunction);
+}
+
+int BytecodeGenerator::argumentNumberFor(const Identifier& ident)
+{
+    int parameterCount = m_parameters.size(); // includes 'this'
+    RegisterID* registerID = registerFor(ident);
+    if (!registerID)
+        return 0;
+    int index = registerID->index() + RegisterFile::CallFrameHeaderSize + parameterCount;
+    return (index > 0 && index < parameterCount) ? index : 0;
+}
+
+} // namespace JSC