auto import from //depot/cupcake/@136594

6 files changed, 2734 insertions, 0 deletions

diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
new file mode 100644
index 0000000..cd89c1e
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
@@ -0,0 +1,1792 @@
+/*
+ * 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 "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();
+        
+    m_codeBlock->setIsNumericCompareFunction(instructions() == m_globalData->numericCompareFunction(m_scopeChain->globalObject()->globalExec()));
+
+#if !ENABLE(OPCODE_SAMPLING)
+    if (!m_regeneratingForExceptionInfo && (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;
+    }
+
+    ++m_codeBlock->m_numVars;
+    r0 = newRegister();
+    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::allocateConstants(size_t count)
+{
+    m_codeBlock->m_numConstants = count;
+    if (!count)
+        return;
+    
+    m_nextConstantIndex = m_calleeRegisters.size();
+
+    for (size_t i = 0; i < count; ++i)
+        newRegister();
+    m_lastConstant = &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_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , 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) {
+            FuncDeclNode* funcDecl = functionStack[i].get();
+            globalObject->removeDirect(funcDecl->m_ident); // Make sure our new function is not shadowed by an old property.
+            emitNewFunction(addGlobalVar(funcDecl->m_ident, false), funcDecl);
+        }
+
+        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));
+
+        allocateConstants(programNode->neededConstants());
+
+        for (size_t i = 0; i < newVars.size(); ++i)
+            emitLoad(newVars[i], jsUndefined());
+    } else {
+        for (size_t i = 0; i < functionStack.size(); ++i) {
+            FuncDeclNode* funcDecl = functionStack[i].get();
+            globalObject->putWithAttributes(exec, funcDecl->m_ident, funcDecl->makeFunction(exec, 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);
+        }
+
+        allocateConstants(programNode->neededConstants());
+    }
+}
+
+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_finallyDepth(0)
+    , m_dynamicScopeDepth(0)
+    , m_baseScopeDepth(0)
+    , m_codeType(FunctionCode)
+    , m_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , m_regeneratingForExceptionInfo(false)
+    , m_codeBlockBeingRegeneratedFrom(0)
+{
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->setNeedsFullScopeChain(true);
+
+    codeBlock->setGlobalData(m_globalData);
+
+    bool usesArguments = functionBody->usesArguments();
+    codeBlock->setUsesArguments(usesArguments);
+    if (usesArguments) {
+        m_argumentsRegister.setIndex(RegisterFile::OptionalCalleeArguments);
+        addVar(propertyNames().arguments, false);
+    }
+
+    if (m_codeBlock->needsFullScopeChain()) {
+        ++m_codeBlock->m_numVars;
+        m_activationRegisterIndex = newRegister()->index();
+        emitOpcode(op_enter_with_activation);
+        instructions().append(m_activationRegisterIndex);
+    } else
+        emitOpcode(op_enter);
+
+    if (usesArguments)
+        emitOpcode(op_create_arguments);
+
+    const DeclarationStacks::FunctionStack& functionStack = functionBody->functionStack();
+    for (size_t i = 0; i < functionStack.size(); ++i) {
+        FuncDeclNode* funcDecl = functionStack[i].get();
+        const Identifier& ident = funcDecl->m_ident;
+        m_functions.add(ident.ustring().rep());
+        emitNewFunction(addVar(ident, false), funcDecl);
+    }
+
+    const DeclarationStacks::VarStack& varStack = functionBody->varStack();
+    for (size_t i = 0; i < varStack.size(); ++i)
+        addVar(varStack[i].first, varStack[i].second & DeclarationStacks::IsConstant);
+
+    const Identifier* parameters = functionBody->parameters();
+    size_t parameterCount = functionBody->parameterCount();
+    m_nextParameterIndex = -RegisterFile::CallFrameHeaderSize - parameterCount - 1;
+    m_parameters.grow(1 + parameterCount); // reserve space for "this"
+
+    // Add "this" as a parameter
+    m_thisRegister.setIndex(m_nextParameterIndex);
+    ++m_nextParameterIndex;
+    ++m_codeBlock->m_numParameters;
+
+    if (functionBody->usesThis() || m_shouldEmitDebugHooks) {
+        emitOpcode(op_convert_this);
+        instructions().append(m_thisRegister.index());
+    }
+    
+    for (size_t i = 0; i < parameterCount; ++i)
+        addParameter(parameters[i]);
+
+    allocateConstants(functionBody->neededConstants());
+}
+
+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_globalData(&scopeChain.globalObject()->globalExec()->globalData())
+    , m_lastOpcodeID(op_end)
+    , m_emitNodeDepth(0)
+    , 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"
+
+    allocateConstants(evalNode->neededConstants());
+}
+
+RegisterID* BytecodeGenerator::addParameter(const Identifier& ident)
+{
+    // Parameters overwrite var declarations, but not function declarations.
+    RegisterID* result = 0;
+    UString::Rep* rep = ident.ustring().rep();
+    if (!m_functions.contains(rep)) {
+        symbolTable().set(rep, m_nextParameterIndex);
+        RegisterID& parameter = registerFor(m_nextParameterIndex);
+        parameter.setIndex(m_nextParameterIndex);
+        result = &parameter;
+    }
+
+    // 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_nextParameterIndex;
+    ++m_codeBlock->m_numParameters;
+    return result;
+}
+
+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;
+
+    return &registerFor(entry.getIndex());
+}
+
+RegisterID* BytecodeGenerator::constRegisterFor(const Identifier& ident)
+{
+    if (m_codeType == EvalCode)
+        return 0;
+
+    SymbolTableEntry entry = symbolTable().get(ident.ustring().rep());
+    ASSERT(!entry.isNull());
+
+    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() : 0); // 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)
+{
+    emitOpcode(target->isForward() ? op_jmp : op_loop);
+    instructions().append(target->offsetFrom(instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(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();
+            emitOpcode(op_loop_if_less);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->offsetFrom(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();
+            emitOpcode(op_loop_if_lesseq);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->offsetFrom(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();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(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();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    }
+
+    emitOpcode(target->isForward() ? op_jtrue : op_loop_if_true);
+    instructions().append(cond->index());
+    instructions().append(target->offsetFrom(instructions().size()));
+    return target;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* target)
+{
+    ASSERT(target->isForward());
+
+    if (m_lastOpcodeID == op_less) {
+        int dstIndex;
+        int src1Index;
+        int src2Index;
+
+        retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindBinaryOp();
+            emitOpcode(op_jnless);
+            instructions().append(src1Index);
+            instructions().append(src2Index);
+            instructions().append(target->offsetFrom(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();
+            emitOpcode(op_jtrue);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_eq_null) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jneq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    } else if (m_lastOpcodeID == op_neq_null) {
+        int dstIndex;
+        int srcIndex;
+
+        retrieveLastUnaryOp(dstIndex, srcIndex);
+
+        if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
+            rewindUnaryOp();
+            emitOpcode(op_jeq_null);
+            instructions().append(srcIndex);
+            instructions().append(target->offsetFrom(instructions().size()));
+            return target;
+        }
+    }
+
+    emitOpcode(op_jfalse);
+    instructions().append(cond->index());
+    instructions().append(target->offsetFrom(instructions().size()));
+    return target;
+}
+
+unsigned BytecodeGenerator::addConstant(FuncDeclNode* n)
+{
+    // No need to explicitly unique function body nodes -- they're unique already.
+    return m_codeBlock->addFunction(n);
+}
+
+unsigned BytecodeGenerator::addConstant(FuncExprNode* n)
+{
+    // No need to explicitly unique function expression nodes -- they're unique already.
+    return m_codeBlock->addFunctionExpression(n);
+}
+
+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::addConstant(JSValuePtr v)
+{
+    pair<JSValueMap::iterator, bool> result = m_jsValueMap.add(JSValuePtr::encode(v), m_nextConstantIndex);
+    if (result.second) {
+        RegisterID& constant = m_calleeRegisters[m_nextConstantIndex];
+        
+        ++m_nextConstantIndex;
+
+        m_codeBlock->addConstantRegister(JSValuePtr(v));
+        return &constant;
+    }
+
+    return &registerFor(result.first->second);
+}
+
+unsigned BytecodeGenerator::addUnexpectedConstant(JSValuePtr v)
+{
+    return m_codeBlock->addUnexpectedConstant(v);
+}
+
+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) {
+        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() - m_codeBlock->m_numVars).jsValue(m_scopeChain->globalObject()->globalExec()).isString()) {
+            const UString& value = asString(m_codeBlock->constantRegister(src2->index() - m_codeBlock->m_numVars).jsValue(m_scopeChain->globalObject()->globalExec()))->value();
+            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));
+    JSValuePtr& valueInMap = m_numberMap.add(number, noValue()).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, JSValuePtr(stringInMap));
+}
+
+RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, JSValuePtr v)
+{
+    RegisterID* constantID = addConstant(v);
+    if (dst)
+        return emitMove(dst, constantID);
+    return constantID;
+}
+
+RegisterID* BytecodeGenerator::emitUnexpectedLoad(RegisterID* dst, bool b)
+{
+    emitOpcode(op_unexpected_load);
+    instructions().append(dst->index());
+    instructions().append(addUnexpectedConstant(jsBoolean(b)));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitUnexpectedLoad(RegisterID* dst, double d)
+{
+    emitOpcode(op_unexpected_load);
+    instructions().append(dst->index());
+    instructions().append(addUnexpectedConstant(jsNumber(globalData(), d)));
+    return dst;
+}
+
+bool BytecodeGenerator::findScopedProperty(const Identifier& property, int& index, size_t& stackDepth, bool forWriting, 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;
+    
+    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;
+            index = entry.getIndex();
+            if (++iter == end)
+                globalObject = currentVariableObject;
+            return true;
+        }
+        if (currentVariableObject->isDynamicScope())
+            break;
+    }
+
+    // Can't locate the property but we're able to avoid a few lookups.
+    stackDepth = depth;
+    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;
+    if (!findScopedProperty(property, index, depth, false, 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) {
+            // 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(op_resolve_global);
+        instructions().append(dst->index());
+        instructions().append(globalObject);
+        instructions().append(addConstant(property));
+        instructions().append(0);
+        instructions().append(0);
+        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, JSValuePtr 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, JSValuePtr 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)
+{
+    emitOpcode(op_resolve_base);
+    instructions().append(dst->index());
+    instructions().append(addConstant(property));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property)
+{
+    emitOpcode(op_resolve_with_base);
+    instructions().append(baseDst->index());
+    instructions().append(propDst->index());
+    instructions().append(addConstant(property));
+    return baseDst;
+}
+
+RegisterID* BytecodeGenerator::emitResolveFunction(RegisterID* baseDst, RegisterID* funcDst, const Identifier& property)
+{
+    emitOpcode(op_resolve_func);
+    instructions().append(baseDst->index());
+    instructions().append(funcDst->index());
+    instructions().append(addConstant(property));
+    return baseDst;
+}
+
+RegisterID* BytecodeGenerator::emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property)
+{
+#if ENABLE(JIT)
+    m_codeBlock->addStructureStubInfo(StructureStubInfo(op_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(op_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);
+    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)
+{
+    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, FuncDeclNode* n)
+{
+    emitOpcode(op_new_func);
+    instructions().append(dst->index());
+    instructions().append(addConstant(n));
+    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)
+{
+    emitOpcode(op_new_func_exp);
+    instructions().append(r0->index());
+    instructions().append(addConstant(n));
+    return r0;
+}
+
+RegisterID* BytecodeGenerator::emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode* argumentsNode, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    return emitCall(op_call, dst, func, thisRegister, argumentsNode, divot, startOffset, endOffset);
+}
+
+RegisterID* BytecodeGenerator::emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode* argumentsNode, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    return emitCall(op_call_eval, dst, func, thisRegister, argumentsNode, divot, startOffset, endOffset);
+}
+
+RegisterID* BytecodeGenerator::emitCall(OpcodeID opcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode* argumentsNode, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    ASSERT(opcodeID == op_call || opcodeID == op_call_eval);
+    ASSERT(func->refCount());
+    ASSERT(thisRegister->refCount());
+
+    RegisterID* originalFunc = func;
+    if (m_shouldEmitProfileHooks) {
+        // If codegen decided to recycle func as this call's destination register,
+        // we need to undo that optimization here so that func will still be around
+        // for the sake of op_profile_did_call.
+        if (dst == func) {
+            RefPtr<RegisterID> movedThisRegister = emitMove(newTemporary(), thisRegister);
+            RefPtr<RegisterID> movedFunc = emitMove(thisRegister, func);
+            
+            thisRegister = movedThisRegister.release().releaseRef();
+            func = movedFunc.release().releaseRef();
+        }
+    }
+
+    // Generate code for arguments.
+    Vector<RefPtr<RegisterID>, 16> argv;
+    argv.append(thisRegister);
+    for (ArgumentListNode* n = argumentsNode->m_listNode.get(); n; n = n->m_next.get()) {
+        argv.append(newTemporary());
+        // op_call requires the arguments to be a sequential range of registers
+        ASSERT(argv[argv.size() - 1]->index() == argv[argv.size() - 2]->index() + 1);
+        emitNode(argv.last().get(), 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(func->index());
+
+#if ENABLE(JIT)
+        m_codeBlock->addFunctionRegisterInfo(instructions().size(), func->index());
+#endif
+    }
+
+    emitExpressionInfo(divot, startOffset, endOffset);
+
+#if ENABLE(JIT)
+    m_codeBlock->addCallLinkInfo();
+#endif
+
+    // Emit call.
+    emitOpcode(opcodeID);
+    instructions().append(dst->index()); // dst
+    instructions().append(func->index()); // func
+    instructions().append(argv.size()); // argCount
+    instructions().append(argv[0]->index() + argv.size() + RegisterFile::CallFrameHeaderSize); // registerOffset
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_did_call);
+        instructions().append(func->index());
+
+        if (dst == originalFunc) {
+            thisRegister->deref();
+            func->deref();
+        }
+    }
+
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitReturn(RegisterID* src)
+{
+    if (m_codeBlock->needsFullScopeChain()) {
+        emitOpcode(op_tear_off_activation);
+        instructions().append(m_activationRegisterIndex);
+    } else if (m_codeBlock->usesArguments() && m_codeBlock->m_numParameters > 1)
+        emitOpcode(op_tear_off_arguments);
+
+    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, ArgumentsNode* argumentsNode, unsigned divot, unsigned startOffset, unsigned endOffset)
+{
+    ASSERT(func->refCount());
+
+    RegisterID* originalFunc = func;
+    if (m_shouldEmitProfileHooks) {
+        // If codegen decided to recycle func as this call's destination register,
+        // we need to undo that optimization here so that func will still be around
+        // for the sake of op_profile_did_call.
+        if (dst == func) {
+            RefPtr<RegisterID> movedFunc = emitMove(newTemporary(), func);
+            func = movedFunc.release().releaseRef();
+        }
+    }
+
+    RefPtr<RegisterID> funcProto = newTemporary();
+
+    // Generate code for arguments.
+    Vector<RefPtr<RegisterID>, 16> argv;
+    argv.append(newTemporary()); // reserve space for "this"
+    for (ArgumentListNode* n = argumentsNode ? argumentsNode->m_listNode.get() : 0; n; n = n->m_next.get()) {
+        argv.append(newTemporary());
+        // op_construct requires the arguments to be a sequential range of registers
+        ASSERT(argv[argv.size() - 1]->index() == argv[argv.size() - 2]->index() + 1);
+        emitNode(argv.last().get(), n);
+    }
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_will_call);
+        instructions().append(func->index());
+    }
+
+    // Load prototype.
+    emitExpressionInfo(divot, startOffset, endOffset);
+    emitGetByIdExceptionInfo(op_construct);
+    emitGetById(funcProto.get(), func, globalData()->propertyNames->prototype);
+
+    // 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(dst->index()); // dst
+    instructions().append(func->index()); // func
+    instructions().append(argv.size()); // argCount
+    instructions().append(argv[0]->index() + argv.size() + RegisterFile::CallFrameHeaderSize); // registerOffset
+    instructions().append(funcProto->index()); // proto
+    instructions().append(argv[0]->index()); // thisRegister
+
+    emitOpcode(op_construct_verify);
+    instructions().append(dst->index());
+    instructions().append(argv[0]->index());
+
+    if (m_shouldEmitProfileHooks) {
+        emitOpcode(op_profile_did_call);
+        instructions().append(func->index());
+        
+        if (dst == originalFunc)
+            func->deref();
+    }
+
+    return dst;
+}
+
+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 (!m_shouldEmitDebugHooks)
+        return;
+    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.
+    while (m_labelScopes.size() && !m_labelScopes.last().refCount())
+        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) {
+            // 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->offsetFrom(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->offsetFrom(instructions().size()));
+            emitLabel(nextInsn.get());
+        }
+
+        // To get here there must be at least one finally block present
+        do {
+            ASSERT(topScope->isFinallyBlock);
+            emitJumpSubroutine(topScope->finallyContext.retAddrDst, topScope->finallyContext.finallyAddr);
+            --topScope;
+            if (!topScope->isFinallyBlock)
+                break;
+        } while (topScope > bottomScope);
+    }
+    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);
+
+    emitOpcode(op_jmp_scopes);
+    instructions().append(scopeDelta);
+    instructions().append(target->offsetFrom(instructions().size()));
+    return target;
+}
+
+RegisterID* BytecodeGenerator::emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target)
+{
+    emitOpcode(op_next_pname);
+    instructions().append(dst->index());
+    instructions().append(iter->index());
+    instructions().append(target->offsetFrom(instructions().size()));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitCatch(RegisterID* targetRegister, Label* start, Label* end)
+{
+#if ENABLE(JIT)
+    HandlerInfo info = { start->offsetFrom(0), end->offsetFrom(0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth, 0 };
+#else
+    HandlerInfo info = { start->offsetFrom(0), end->offsetFrom(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, ErrorType type, JSValuePtr message)
+{
+    emitOpcode(op_new_error);
+    instructions().append(dst->index());
+    instructions().append(static_cast<int>(type));
+    instructions().append(addUnexpectedConstant(message));
+    return dst;
+}
+
+PassRefPtr<Label> BytecodeGenerator::emitJumpSubroutine(RegisterID* retAddrDst, Label* finally)
+{
+    emitOpcode(op_jsr);
+    instructions().append(retAddrDst->index());
+    instructions().append(finally->offsetFrom(instructions().size()));
+    return finally;
+}
+
+void BytecodeGenerator::emitSubroutineReturn(RegisterID* retAddrSrc)
+{
+    emitOpcode(op_sret);
+    instructions().append(retAddrSrc->index());
+}
+
+void BytecodeGenerator::emitPushNewScope(RegisterID* dst, 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(JSValuePtr::makeInt32Fast(key) && (JSValuePtr::makeInt32Fast(key).getInt32Fast() == 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]->offsetFrom(switchAddress)); 
+    }
+}
+
+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->size() == 1);
+    
+    int32_t key = clause->data()[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]->offsetFrom(switchAddress)); 
+    }
+}
+
+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]->offsetFrom(switchAddress);
+#if ENABLE(JIT)
+        location.ctiOffset = 0;
+#endif
+        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->offsetFrom(switchInfo.bytecodeOffset + 3);
+
+        SimpleJumpTable& jumpTable = m_codeBlock->addImmediateSwitchJumpTable();
+        prepareJumpTableForImmediateSwitch(jumpTable, switchInfo.bytecodeOffset + 3, clauseCount, labels, nodes, min, max);
+    } else if (switchInfo.switchType == SwitchInfo::SwitchCharacter) {
+        instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfCharacterSwitchJumpTables();
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->offsetFrom(switchInfo.bytecodeOffset + 3);
+        
+        SimpleJumpTable& jumpTable = m_codeBlock->addCharacterSwitchJumpTable();
+        prepareJumpTableForCharacterSwitch(jumpTable, switchInfo.bytecodeOffset + 3, clauseCount, labels, nodes, min, max);
+    } else {
+        ASSERT(switchInfo.switchType == SwitchInfo::SwitchString);
+        instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfStringSwitchJumpTables();
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->offsetFrom(switchInfo.bytecodeOffset + 3);
+
+        StringJumpTable& jumpTable = m_codeBlock->addStringSwitchJumpTable();
+        prepareJumpTableForStringSwitch(jumpTable, switchInfo.bytecodeOffset + 3, 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(), SyntaxError, jsString(globalData(), "Expression too deep"));
+    emitThrow(exception);
+    return exception;
+}
+
+} // namespace JSC
diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
new file mode 100644
index 0000000..ceb5881
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -0,0 +1,480 @@
+/*
+ * 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.
+ */
+
+#ifndef BytecodeGenerator_h
+#define BytecodeGenerator_h
+
+#include "CodeBlock.h"
+#include "HashTraits.h"
+#include "Instruction.h"
+#include "Label.h"
+#include "LabelScope.h"
+#include "Interpreter.h"
+#include "RegisterID.h"
+#include "SegmentedVector.h"
+#include "SymbolTable.h"
+#include "Debugger.h"
+#include "Nodes.h"
+#include <wtf/PassRefPtr.h>
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+    class Identifier;
+    class ScopeChain;
+    class ScopeNode;
+
+    struct FinallyContext {
+        Label* finallyAddr;
+        RegisterID* retAddrDst;
+    };
+
+    struct ControlFlowContext {
+        bool isFinallyBlock;
+        FinallyContext finallyContext;
+    };
+
+    class BytecodeGenerator {
+    public:
+        typedef DeclarationStacks::VarStack VarStack;
+        typedef DeclarationStacks::FunctionStack FunctionStack;
+
+        static void setDumpsGeneratedCode(bool dumpsGeneratedCode);
+        static bool dumpsGeneratedCode();
+
+        BytecodeGenerator(ProgramNode*, const Debugger*, const ScopeChain&, SymbolTable*, ProgramCodeBlock*);
+        BytecodeGenerator(FunctionBodyNode*, const Debugger*, const ScopeChain&, SymbolTable*, CodeBlock*);
+        BytecodeGenerator(EvalNode*, const Debugger*, const ScopeChain&, SymbolTable*, EvalCodeBlock*);
+
+        JSGlobalData* globalData() const { return m_globalData; }
+        const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
+
+        void generate();
+
+        // Returns the register corresponding to a local variable, or 0 if no
+        // such register exists. Registers returned by registerFor do not
+        // require explicit reference counting.
+        RegisterID* registerFor(const Identifier&);
+
+        // Behaves as registerFor does, but ignores dynamic scope as
+        // dynamic scope should not interfere with const initialisation
+        RegisterID* constRegisterFor(const Identifier&);
+
+        // Searches the scope chain in an attempt to  statically locate the requested
+        // property.  Returns false if for any reason the property cannot be safely
+        // optimised at all.  Otherwise it will return the index and depth of the
+        // VariableObject that defines the property.  If the property cannot be found
+        // statically, depth will contain the depth of the scope chain where dynamic
+        // lookup must begin.
+        //
+        // NB: depth does _not_ include the local scope.  eg. a depth of 0 refers
+        // to the scope containing this codeblock.
+        bool findScopedProperty(const Identifier&, int& index, size_t& depth, bool forWriting, JSObject*& globalObject);
+
+        // Returns the register storing "this"
+        RegisterID* thisRegister() { return &m_thisRegister; }
+
+        bool isLocal(const Identifier&);
+        bool isLocalConstant(const Identifier&);
+
+        // Returns the next available temporary register. Registers returned by
+        // newTemporary require a modified form of reference counting: any
+        // register with a refcount of 0 is considered "available", meaning that
+        // the next instruction may overwrite it.
+        RegisterID* newTemporary();
+
+        RegisterID* highestUsedRegister();
+
+        // The same as newTemporary(), but this function returns "suggestion" if
+        // "suggestion" is a temporary. This function is helpful in situations
+        // where you've put "suggestion" in a RefPtr, but you'd like to allow
+        // the next instruction to overwrite it anyway.
+        RegisterID* newTemporaryOr(RegisterID* suggestion) { return suggestion->isTemporary() ? suggestion : newTemporary(); }
+
+        // Functions for handling of dst register
+
+        RegisterID* ignoredResult() { return &m_ignoredResultRegister; }
+
+        // Returns a place to write intermediate values of an operation
+        // which reuses dst if it is safe to do so.
+        RegisterID* tempDestination(RegisterID* dst)
+        {
+            return (dst && dst != ignoredResult() && dst->isTemporary()) ? dst : newTemporary();
+        }
+
+        // Returns the place to write the final output of an operation.
+        RegisterID* finalDestination(RegisterID* originalDst, RegisterID* tempDst = 0)
+        {
+            if (originalDst && originalDst != ignoredResult())
+                return originalDst;
+            ASSERT(tempDst != ignoredResult());
+            if (tempDst && tempDst->isTemporary())
+                return tempDst;
+            return newTemporary();
+        }
+
+        RegisterID* destinationForAssignResult(RegisterID* dst)
+        {
+            if (dst && dst != ignoredResult() && m_codeBlock->needsFullScopeChain())
+                return dst->isTemporary() ? dst : newTemporary();
+            return 0;
+        }
+
+        // Moves src to dst if dst is not null and is different from src, otherwise just returns src.
+        RegisterID* moveToDestinationIfNeeded(RegisterID* dst, RegisterID* src)
+        {
+            return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
+        }
+
+        PassRefPtr<LabelScope> newLabelScope(LabelScope::Type, const Identifier* = 0);
+        PassRefPtr<Label> newLabel();
+
+        // The emitNode functions are just syntactic sugar for calling
+        // Node::emitCode. These functions accept a 0 for the register,
+        // meaning that the node should allocate a register, or ignoredResult(),
+        // meaning that the node need not put the result in a register.
+        // Other emit functions do not accept 0 or ignoredResult().
+        RegisterID* emitNode(RegisterID* dst, Node* n)
+        {
+            // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
+            ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
+            if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
+                LineInfo info = { instructions().size(), n->lineNo() };
+                m_codeBlock->addLineInfo(info);
+            }
+            if (m_emitNodeDepth >= s_maxEmitNodeDepth)
+                return emitThrowExpressionTooDeepException();
+            ++m_emitNodeDepth;
+            RegisterID* r = n->emitBytecode(*this, dst);
+            --m_emitNodeDepth;
+            return r;
+        }
+
+        RegisterID* emitNode(Node* n)
+        {
+            return emitNode(0, n);
+        }
+
+        void emitExpressionInfo(unsigned divot, unsigned startOffset, unsigned endOffset)
+        { 
+            divot -= m_codeBlock->sourceOffset();
+            if (divot > ExpressionRangeInfo::MaxDivot) {
+                // Overflow has occurred, we can only give line number info for errors for this region
+                divot = 0;
+                startOffset = 0;
+                endOffset = 0;
+            } else if (startOffset > ExpressionRangeInfo::MaxOffset) {
+                // If the start offset is out of bounds we clear both offsets
+                // so we only get the divot marker.  Error message will have to be reduced
+                // to line and column number.
+                startOffset = 0;
+                endOffset = 0;
+            } else if (endOffset > ExpressionRangeInfo::MaxOffset) {
+                // The end offset is only used for additional context, and is much more likely
+                // to overflow (eg. function call arguments) so we are willing to drop it without
+                // dropping the rest of the range.
+                endOffset = 0;
+            }
+            
+            ExpressionRangeInfo info;
+            info.instructionOffset = instructions().size();
+            info.divotPoint = divot;
+            info.startOffset = startOffset;
+            info.endOffset = endOffset;
+            m_codeBlock->addExpressionInfo(info);
+        }
+
+        void emitGetByIdExceptionInfo(OpcodeID opcodeID)
+        {
+            // Only op_construct and op_instanceof need exception info for
+            // a preceding op_get_by_id.
+            ASSERT(opcodeID == op_construct || opcodeID == op_instanceof);
+            GetByIdExceptionInfo info;
+            info.bytecodeOffset = instructions().size();
+            info.isOpConstruct = (opcodeID == op_construct);
+            m_codeBlock->addGetByIdExceptionInfo(info);
+        }
+        
+        ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
+        {
+            return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;
+        }
+
+        ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsPure)
+        {
+            if (leftHandSideNeedsCopy(rightHasAssignments, rightIsPure)) {
+                PassRefPtr<RegisterID> dst = newTemporary();
+                emitNode(dst.get(), n);
+                return dst;
+            }
+
+            return PassRefPtr<RegisterID>(emitNode(n));
+        }
+
+        RegisterID* emitLoad(RegisterID* dst, bool);
+        RegisterID* emitLoad(RegisterID* dst, double);
+        RegisterID* emitLoad(RegisterID* dst, const Identifier&);
+        RegisterID* emitLoad(RegisterID* dst, JSValuePtr);
+        RegisterID* emitUnexpectedLoad(RegisterID* dst, bool);
+        RegisterID* emitUnexpectedLoad(RegisterID* dst, double);
+
+        RegisterID* emitUnaryOp(OpcodeID, RegisterID* dst, RegisterID* src);
+        RegisterID* emitBinaryOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes);
+        RegisterID* emitEqualityOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2);
+        RegisterID* emitUnaryNoDstOp(OpcodeID, RegisterID* src);
+
+        RegisterID* emitNewObject(RegisterID* dst);
+        RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision
+
+        RegisterID* emitNewFunction(RegisterID* dst, FuncDeclNode* func);
+        RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
+        RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
+
+        RegisterID* emitMove(RegisterID* dst, RegisterID* src);
+
+        RegisterID* emitToJSNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_jsnumber, dst, src); }
+        RegisterID* emitPreInc(RegisterID* srcDst);
+        RegisterID* emitPreDec(RegisterID* srcDst);
+        RegisterID* emitPostInc(RegisterID* dst, RegisterID* srcDst);
+        RegisterID* emitPostDec(RegisterID* dst, RegisterID* srcDst);
+
+        RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
+        RegisterID* emitTypeOf(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_typeof, dst, src); }
+        RegisterID* emitIn(RegisterID* dst, RegisterID* property, RegisterID* base) { return emitBinaryOp(op_in, dst, property, base, OperandTypes()); }
+
+        RegisterID* emitResolve(RegisterID* dst, const Identifier& property);
+        RegisterID* emitGetScopedVar(RegisterID* dst, size_t skip, int index, JSValuePtr globalObject);
+        RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValuePtr globalObject);
+
+        RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
+        RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
+        RegisterID* emitResolveFunction(RegisterID* baseDst, RegisterID* funcDst, const Identifier& property);
+
+        RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
+        RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
+        RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
+        RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
+        RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
+        RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
+        RegisterID* emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value);
+
+        RegisterID* emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+        RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+
+        RegisterID* emitReturn(RegisterID* src);
+        RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }
+
+        RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+
+        PassRefPtr<Label> emitLabel(Label*);
+        PassRefPtr<Label> emitJump(Label* target);
+        PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
+        PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
+        PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);
+
+        PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
+        void emitSubroutineReturn(RegisterID* retAddrSrc);
+
+        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
+        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);
+
+        RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
+        void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
+        RegisterID* emitNewError(RegisterID* dst, ErrorType type, JSValuePtr message);
+        void emitPushNewScope(RegisterID* dst, Identifier& property, RegisterID* value);
+
+        RegisterID* emitPushScope(RegisterID* scope);
+        void emitPopScope();
+
+        void emitDebugHook(DebugHookID, int firstLine, int lastLine);
+
+        int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
+
+        void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
+        void popFinallyContext();
+
+        LabelScope* breakTarget(const Identifier&);
+        LabelScope* continueTarget(const Identifier&);
+
+        void beginSwitch(RegisterID*, SwitchInfo::SwitchType);
+        void endSwitch(uint32_t clauseCount, RefPtr<Label>*, ExpressionNode**, Label* defaultLabel, int32_t min, int32_t range);
+
+        CodeType codeType() const { return m_codeType; }
+
+        void setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
+        {
+            m_regeneratingForExceptionInfo = true;
+            m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
+        }
+
+    private:
+        void emitOpcode(OpcodeID);
+        void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
+        void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
+        void rewindBinaryOp();
+        void rewindUnaryOp();
+
+        PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
+
+        struct JSValueHashTraits : HashTraits<JSValueEncodedAsPointer*> {
+            static void constructDeletedValue(JSValueEncodedAsPointer*& slot) { slot = JSValuePtr::encode(jsImpossibleValue()); }
+            static bool isDeletedValue(JSValueEncodedAsPointer* value) { return value == JSValuePtr::encode(jsImpossibleValue()); }
+        };
+
+        typedef HashMap<JSValueEncodedAsPointer*, unsigned, PtrHash<JSValueEncodedAsPointer*>, JSValueHashTraits> JSValueMap;
+
+        struct IdentifierMapIndexHashTraits {
+            typedef int TraitType;
+            typedef IdentifierMapIndexHashTraits StorageTraits;
+            static int emptyValue() { return std::numeric_limits<int>::max(); }
+            static const bool emptyValueIsZero = false;
+            static const bool needsDestruction = false;
+            static const bool needsRef = false;
+        };
+
+        typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
+        typedef HashMap<double, JSValuePtr> NumberMap;
+        typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
+
+        RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+        
+        RegisterID* newRegister();
+
+        // Returns the RegisterID corresponding to ident.
+        RegisterID* addVar(const Identifier& ident, bool isConstant)
+        {
+            RegisterID* local;
+            addVar(ident, isConstant, local);
+            return local;
+        }
+        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
+        bool addVar(const Identifier&, bool isConstant, RegisterID*&);
+
+        // Returns the RegisterID corresponding to ident.
+        RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
+        {
+            RegisterID* local;
+            addGlobalVar(ident, isConstant, local);
+            return local;
+        }
+        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
+        bool addGlobalVar(const Identifier&, bool isConstant, RegisterID*&);
+
+        RegisterID* addParameter(const Identifier&);
+        
+        void allocateConstants(size_t);
+
+        RegisterID& registerFor(int index)
+        {
+            if (index >= 0)
+                return m_calleeRegisters[index];
+
+            if (index == RegisterFile::OptionalCalleeArguments)
+                return m_argumentsRegister;
+
+            if (m_parameters.size()) {
+                ASSERT(!m_globals.size());
+                return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
+            }
+
+            return m_globals[-index - 1];
+        }
+
+        unsigned addConstant(FuncDeclNode*);
+        unsigned addConstant(FuncExprNode*);
+        unsigned addConstant(const Identifier&);
+        RegisterID* addConstant(JSValuePtr);
+        unsigned addUnexpectedConstant(JSValuePtr);
+        unsigned addRegExp(RegExp*);
+
+        Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
+        SymbolTable& symbolTable() { return *m_symbolTable; }
+
+        bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
+        bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }
+
+        RegisterID* emitThrowExpressionTooDeepException();
+
+        bool m_shouldEmitDebugHooks;
+        bool m_shouldEmitProfileHooks;
+
+        const ScopeChain* m_scopeChain;
+        SymbolTable* m_symbolTable;
+
+        ScopeNode* m_scopeNode;
+        CodeBlock* m_codeBlock;
+
+        HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
+        RegisterID m_ignoredResultRegister;
+        RegisterID m_thisRegister;
+        RegisterID m_argumentsRegister;
+        int m_activationRegisterIndex;
+        SegmentedVector<RegisterID, 512> m_calleeRegisters;
+        SegmentedVector<RegisterID, 512> m_parameters;
+        SegmentedVector<RegisterID, 512> m_globals;
+        SegmentedVector<LabelScope, 256> m_labelScopes;
+        SegmentedVector<Label, 256> m_labels;
+        RefPtr<RegisterID> m_lastConstant;
+        int m_finallyDepth;
+        int m_dynamicScopeDepth;
+        int m_baseScopeDepth;
+        CodeType m_codeType;
+
+        Vector<ControlFlowContext> m_scopeContextStack;
+        Vector<SwitchInfo> m_switchContextStack;
+
+        int m_nextGlobalIndex;
+        int m_nextParameterIndex;
+        int m_nextConstantIndex;
+
+        int m_globalVarStorageOffset;
+
+        // Constant pool
+        IdentifierMap m_identifierMap;
+        JSValueMap m_jsValueMap;
+        NumberMap m_numberMap;
+        IdentifierStringMap m_stringMap;
+
+        JSGlobalData* m_globalData;
+
+        OpcodeID m_lastOpcodeID;
+
+        unsigned m_emitNodeDepth;
+
+        bool m_regeneratingForExceptionInfo;
+        CodeBlock* m_codeBlockBeingRegeneratedFrom;
+
+        static const unsigned s_maxEmitNodeDepth = 10000;
+    };
+
+}
+
+#endif // BytecodeGenerator_h
diff --git a/JavaScriptCore/bytecompiler/Label.h b/JavaScriptCore/bytecompiler/Label.h
new file mode 100644
index 0000000..0b3d038
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/Label.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2008 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.
+ * 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.
+ */
+
+#ifndef Label_h
+#define Label_h
+
+#include "CodeBlock.h"
+#include "Instruction.h"
+#include <wtf/Assertions.h>
+#include <wtf/Vector.h>
+#include <limits.h>
+
+namespace JSC {
+
+    class Label {
+    public:
+        explicit Label(CodeBlock* codeBlock)
+            : m_refCount(0)
+            , m_location(invalidLocation)
+            , m_codeBlock(codeBlock)
+        {
+        }
+
+        void setLocation(unsigned location)
+        {
+            m_location = location;
+
+            unsigned size = m_unresolvedJumps.size();
+            for (unsigned i = 0; i < size; ++i) {
+                unsigned j = m_unresolvedJumps[i];
+                m_codeBlock->instructions()[j].u.operand = m_location - j;
+            }
+        }
+
+        int offsetFrom(int location) const
+        {
+            if (m_location == invalidLocation) {
+                m_unresolvedJumps.append(location);
+                return 0;
+            }
+            return m_location - location;
+        }
+
+        void ref() { ++m_refCount; }
+        void deref()
+        {
+            --m_refCount;
+            ASSERT(m_refCount >= 0);
+        }
+        int refCount() const { return m_refCount; }
+
+        bool isForward() const { return m_location == invalidLocation; }
+
+    private:
+        typedef Vector<int, 8> JumpVector;
+
+        static const unsigned invalidLocation = UINT_MAX;
+
+        int m_refCount;
+        unsigned m_location;
+        CodeBlock* m_codeBlock;
+        mutable JumpVector m_unresolvedJumps;
+    };
+
+} // namespace JSC
+
+#endif // Label_h
diff --git a/JavaScriptCore/bytecompiler/LabelScope.h b/JavaScriptCore/bytecompiler/LabelScope.h
new file mode 100644
index 0000000..cc21fff
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/LabelScope.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2008 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.
+ * 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.
+ */
+
+#ifndef LabelScope_h
+#define LabelScope_h
+
+#include <wtf/PassRefPtr.h>
+#include "Label.h"
+
+namespace JSC {
+
+    class Identifier;
+
+    class LabelScope {
+    public:
+        enum Type { Loop, Switch, NamedLabel };
+
+        LabelScope(Type type, const Identifier* name, int scopeDepth, PassRefPtr<Label> breakTarget, PassRefPtr<Label> continueTarget)
+            : m_refCount(0)
+            , m_type(type)
+            , m_name(name)
+            , m_scopeDepth(scopeDepth)
+            , m_breakTarget(breakTarget)
+            , m_continueTarget(continueTarget)
+        {
+        }
+
+        void ref() { ++m_refCount; }
+        void deref()
+        {
+            --m_refCount;
+            ASSERT(m_refCount >= 0);
+        }
+        int refCount() const { return m_refCount; }
+
+        Label* breakTarget() const { return m_breakTarget.get(); }
+        Label* continueTarget() const { return m_continueTarget.get(); }
+
+        Type type() const { return m_type; }
+        const Identifier* name() const { return m_name; }
+        int scopeDepth() const { return m_scopeDepth; }
+
+    private:
+        int m_refCount;
+        Type m_type;
+        const Identifier* m_name;
+        int m_scopeDepth;
+        RefPtr<Label> m_breakTarget;
+        RefPtr<Label> m_continueTarget;
+    };
+
+} // namespace JSC
+
+#endif // LabelScope_h
diff --git a/JavaScriptCore/bytecompiler/RegisterID.h b/JavaScriptCore/bytecompiler/RegisterID.h
new file mode 100644
index 0000000..0223c2a
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/RegisterID.h
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2008 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.
+ * 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.
+ */
+
+#ifndef RegisterID_h
+#define RegisterID_h
+
+#include <wtf/Assertions.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/VectorTraits.h>
+
+namespace JSC {
+
+    class RegisterID : Noncopyable {
+    public:
+        RegisterID()
+            : m_refCount(0)
+            , m_isTemporary(false)
+#ifndef NDEBUG
+            , m_didSetIndex(false)
+#endif
+        {
+        }
+
+        explicit RegisterID(int index)
+            : m_refCount(0)
+            , m_index(index)
+            , m_isTemporary(false)
+#ifndef NDEBUG
+            , m_didSetIndex(true)
+#endif
+        {
+        }
+
+        void setIndex(int index)
+        {
+            ASSERT(!m_refCount);
+#ifndef NDEBUG
+            m_didSetIndex = true;
+#endif
+            m_index = index;
+        }
+
+        void setTemporary()
+        {
+            m_isTemporary = true;
+        }
+
+        int index() const
+        {
+            ASSERT(m_didSetIndex);
+            return m_index;
+        }
+
+        bool isTemporary()
+        {
+            return m_isTemporary;
+        }
+
+        void ref()
+        {
+            ++m_refCount;
+        }
+
+        void deref()
+        {
+            --m_refCount;
+            ASSERT(m_refCount >= 0);
+        }
+
+        int refCount() const
+        {
+            return m_refCount;
+        }
+
+    private:
+
+        int m_refCount;
+        int m_index;
+        bool m_isTemporary;
+#ifndef NDEBUG
+        bool m_didSetIndex;
+#endif
+    };
+
+} // namespace JSC
+
+namespace WTF {
+
+    template<> struct VectorTraits<JSC::RegisterID> : VectorTraitsBase<true, JSC::RegisterID> {
+        static const bool needsInitialization = true;
+        static const bool canInitializeWithMemset = true; // Default initialization just sets everything to 0 or false, so this is safe.
+    };
+
+} // namespace WTF
+
+#endif // RegisterID_h
diff --git a/JavaScriptCore/bytecompiler/SegmentedVector.h b/JavaScriptCore/bytecompiler/SegmentedVector.h
new file mode 100644
index 0000000..bbab04f
--- /dev/null
+++ b/JavaScriptCore/bytecompiler/SegmentedVector.h
@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2008 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.
+ * 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.
+ */
+
+#ifndef SegmentedVector_h
+#define SegmentedVector_h
+
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+    // SegmentedVector is just like Vector, but it doesn't move the values
+    // stored in its buffer when it grows. Therefore, it is safe to keep
+    // pointers into a SegmentedVector.
+    template <typename T, size_t SegmentSize> class SegmentedVector {
+    public:
+        SegmentedVector()
+            : m_size(0)
+        {
+            m_segments.append(&m_inlineSegment);
+        }
+
+        ~SegmentedVector()
+        {
+            deleteAllSegments();
+        }
+
+        size_t size() const { return m_size; }
+
+        T& at(size_t index)
+        {
+            if (index < SegmentSize)
+                return m_inlineSegment[index];
+            return segmentFor(index)->at(subscriptFor(index));
+        }
+
+        T& operator[](size_t index)
+        {
+            return at(index);
+        }
+
+        T& last()
+        {
+            return at(size() - 1);
+        }
+
+        template <typename U> void append(const U& value)
+        {
+            ++m_size;
+
+            if (m_size <= SegmentSize) {
+                m_inlineSegment.uncheckedAppend(value);
+                return;
+            }
+
+            if (!segmentExistsFor(m_size - 1))
+                m_segments.append(new Segment);
+            segmentFor(m_size - 1)->uncheckedAppend(value);
+        }
+
+        void removeLast()
+        {
+            if (m_size <= SegmentSize)
+                m_inlineSegment.removeLast();
+            else
+                segmentFor(m_size - 1)->removeLast();
+            --m_size;
+        }
+
+        void grow(size_t size)
+        {
+            ASSERT(size > m_size);
+            ensureSegmentsFor(size);
+            m_size = size;
+        }
+
+        void clear()
+        {
+            deleteAllSegments();
+            m_segments.resize(1);
+            m_inlineSegment.clear();
+            m_size = 0;
+        }
+
+    private:
+        typedef Vector<T, SegmentSize> Segment;
+        
+        void deleteAllSegments()
+        {
+            // Skip the first segment, because it's our inline segment, which was
+            // not created by new.
+            for (size_t i = 1; i < m_segments.size(); i++)
+                delete m_segments[i];
+        }
+        
+        bool segmentExistsFor(size_t index)
+        {
+            return index / SegmentSize < m_segments.size();
+        }
+        
+        Segment* segmentFor(size_t index)
+        {
+            return m_segments[index / SegmentSize];
+        }
+        
+        size_t subscriptFor(size_t index)
+        {
+            return index % SegmentSize;
+        }
+        
+        void ensureSegmentsFor(size_t size)
+        {
+            size_t segmentCount = m_size / SegmentSize;
+            if (m_size % SegmentSize)
+                ++segmentCount;
+            segmentCount = std::max<size_t>(segmentCount, 1); // We always have at least our inline segment.
+
+            size_t neededSegmentCount = size / SegmentSize;
+            if (size % SegmentSize)
+                ++neededSegmentCount;
+
+            // Fill up to N - 1 segments.
+            size_t end = neededSegmentCount - 1;
+            for (size_t i = segmentCount - 1; i < end; ++i)
+                ensureSegment(i, SegmentSize);
+            
+            // Grow segment N to accomodate the remainder.
+            ensureSegment(end, subscriptFor(size - 1) + 1);
+        }
+
+        void ensureSegment(size_t segmentIndex, size_t size)
+        {
+            ASSERT(segmentIndex <= m_segments.size());
+            if (segmentIndex == m_segments.size())
+                m_segments.append(new Segment);
+            m_segments[segmentIndex]->grow(size);
+        }
+
+        size_t m_size;
+        Segment m_inlineSegment;
+        Vector<Segment*, 32> m_segments;
+    };
+
+} // namespace JSC
+
+#endif // SegmentedVector_h