X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/b80e619319b1def83d1e8b4f84042b661be1be7f..6fe7ccc865dc7d7541b93c5bcaf6368d2c98a174:/bytecompiler/NodesCodegen.cpp

diff --git a/bytecompiler/NodesCodegen.cpp b/bytecompiler/NodesCodegen.cpp
index a7455e4..5ada260 100644
--- a/bytecompiler/NodesCodegen.cpp
+++ b/bytecompiler/NodesCodegen.cpp
@@ -1,7 +1,7 @@
 /*
 *  Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
 *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
-*  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+*  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
 *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
 *  Copyright (C) 2007 Maks Orlovich
 *  Copyright (C) 2007 Eric Seidel <eric@webkit.org>
@@ -42,6 +42,7 @@
 #include "RegExpCache.h"
 #include "RegExpObject.h"
 #include "SamplingTool.h"
+#include "UStringConcatenate.h"
 #include <wtf/Assertions.h>
 #include <wtf/RefCountedLeakCounter.h>
 #include <wtf/Threading.h>
@@ -75,34 +76,11 @@ namespace JSC {
 
 // ------------------------------ ThrowableExpressionData --------------------------------
 
-static void substitute(UString& string, const UString& substring)
+RegisterID* ThrowableExpressionData::emitThrowReferenceError(BytecodeGenerator& generator, const UString& message)
 {
-    unsigned position = string.find("%s");
-    ASSERT(position != UString::NotFound);
-    string = makeString(string.substr(0, position), substring, string.substr(position + 2));
-}
-
-RegisterID* ThrowableExpressionData::emitThrowError(BytecodeGenerator& generator, ErrorType type, const char* message)
-{
-    generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    RegisterID* exception = generator.emitNewError(generator.newTemporary(), type, jsString(generator.globalData(), message));
-    generator.emitThrow(exception);
-    return exception;
-}
-
-RegisterID* ThrowableExpressionData::emitThrowError(BytecodeGenerator& generator, ErrorType type, const char* messageTemplate, const UString& label)
-{
-    UString message = messageTemplate;
-    substitute(message, label);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    RegisterID* exception = generator.emitNewError(generator.newTemporary(), type, jsString(generator.globalData(), message));
-    generator.emitThrow(exception);
-    return exception;
-}
-
-inline RegisterID* ThrowableExpressionData::emitThrowError(BytecodeGenerator& generator, ErrorType type, const char* messageTemplate, const Identifier& label)
-{
-    return emitThrowError(generator, type, messageTemplate, label.ustring());
+    generator.emitThrowReferenceError(message);
+    return generator.newTemporary();
 }
 
 // ------------------------------ NullNode -------------------------------------
@@ -145,12 +123,9 @@ RegisterID* StringNode::emitBytecode(BytecodeGenerator& generator, RegisterID* d
 
 RegisterID* RegExpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RefPtr<RegExp> regExp = generator.globalData()->regExpCache()->lookupOrCreate(m_pattern.ustring(), m_flags.ustring());
-    if (!regExp->isValid())
-        return emitThrowError(generator, SyntaxError, "Invalid regular expression: %s", regExp->errorMessage());
     if (dst == generator.ignoredResult())
         return 0;
-    return generator.emitNewRegExp(generator.finalDestination(dst), regExp.get());
+    return generator.emitNewRegExp(generator.finalDestination(dst), RegExp::create(*generator.globalData(), m_pattern.ustring(), regExpFlags(m_flags.ustring())));
 }
 
 // ------------------------------ ThisNode -------------------------------------
@@ -177,7 +152,7 @@ RegisterID* ResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
         return generator.moveToDestinationIfNeeded(dst, local);
     }
     
-    generator.emitExpressionInfo(m_startOffset + m_ident.size(), m_ident.size(), 0);
+    generator.emitExpressionInfo(m_startOffset + m_ident.length(), m_ident.length(), 0);
     return generator.emitResolve(generator.finalDestination(dst), m_ident);
 }
 
@@ -196,9 +171,9 @@ RegisterID* ArrayNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
     }
 
     if (!firstPutElement && !m_elision)
-        return generator.emitNewArray(generator.finalDestination(dst), m_element);
+        return generator.emitNewArray(generator.finalDestination(dst), m_element, length);
 
-    RefPtr<RegisterID> array = generator.emitNewArray(generator.tempDestination(dst), m_element);
+    RefPtr<RegisterID> array = generator.emitNewArray(generator.tempDestination(dst), m_element, length);
 
     for (ElementNode* n = firstPutElement; n; n = n->next()) {
         RegisterID* value = generator.emitNode(n->value());
@@ -207,7 +182,7 @@ RegisterID* ArrayNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
     }
 
     if (m_elision) {
-        RegisterID* value = generator.emitLoad(0, jsNumber(generator.globalData(), m_elision + length));
+        RegisterID* value = generator.emitLoad(0, jsNumber(m_elision + length));
         generator.emitPutById(array.get(), generator.propertyNames().length, value);
     }
 
@@ -225,18 +200,18 @@ bool ArrayNode::isSimpleArray() const
     return true;
 }
 
-ArgumentListNode* ArrayNode::toArgumentList(JSGlobalData* globalData) const
+ArgumentListNode* ArrayNode::toArgumentList(JSGlobalData* globalData, int lineNumber) const
 {
     ASSERT(!m_elision && !m_optional);
     ElementNode* ptr = m_element;
     if (!ptr)
         return 0;
-    ArgumentListNode* head = new (globalData) ArgumentListNode(globalData, ptr->value());
+    ArgumentListNode* head = new (globalData) ArgumentListNode(lineNumber, ptr->value());
     ArgumentListNode* tail = head;
     ptr = ptr->next();
     for (; ptr; ptr = ptr->next()) {
         ASSERT(!ptr->elision());
-        tail = new (globalData) ArgumentListNode(globalData, tail, ptr->value());
+        tail = new (globalData) ArgumentListNode(lineNumber, tail, ptr->value());
     }
     return head;
 }
@@ -261,27 +236,79 @@ RegisterID* PropertyListNode::emitBytecode(BytecodeGenerator& generator, Registe
     
     generator.emitNewObject(newObj.get());
     
-    for (PropertyListNode* p = this; p; p = p->m_next) {
-        RegisterID* value = generator.emitNode(p->m_node->m_assign);
-        
-        switch (p->m_node->m_type) {
-            case PropertyNode::Constant: {
-                generator.emitDirectPutById(newObj.get(), p->m_node->name(), value);
-                break;
-            }
-            case PropertyNode::Getter: {
-                generator.emitPutGetter(newObj.get(), p->m_node->name(), value);
-                break;
+    // Fast case: this loop just handles regular value properties.
+    PropertyListNode* p = this;
+    for (; p && p->m_node->m_type == PropertyNode::Constant; p = p->m_next)
+        generator.emitDirectPutById(newObj.get(), p->m_node->name(), generator.emitNode(p->m_node->m_assign));
+
+    // Were there any get/set properties?
+    if (p) {
+        typedef std::pair<PropertyNode*, PropertyNode*> GetterSetterPair;
+        typedef HashMap<StringImpl*, GetterSetterPair> GetterSetterMap;
+        GetterSetterMap map;
+
+        // Build a map, pairing get/set values together.
+        for (PropertyListNode* q = p; q; q = q->m_next) {
+            PropertyNode* node = q->m_node;
+            if (node->m_type == PropertyNode::Constant)
+                continue;
+
+            GetterSetterPair pair(node, static_cast<PropertyNode*>(0));
+            GetterSetterMap::AddResult result = map.add(node->name().impl(), pair);
+            if (!result.isNewEntry)
+                result.iterator->second.second = node;
+        }
+
+        // Iterate over the remaining properties in the list.
+        for (; p; p = p->m_next) {
+            PropertyNode* node = p->m_node;
+            RegisterID* value = generator.emitNode(node->m_assign);
+
+            // Handle regular values.
+            if (node->m_type == PropertyNode::Constant) {
+                generator.emitDirectPutById(newObj.get(), node->name(), value);
+                continue;
             }
-            case PropertyNode::Setter: {
-                generator.emitPutSetter(newObj.get(), p->m_node->name(), value);
-                break;
+
+            // This is a get/set property, find its entry in the map.
+            ASSERT(node->m_type == PropertyNode::Getter || node->m_type == PropertyNode::Setter);
+            GetterSetterMap::iterator it = map.find(node->name().impl());
+            ASSERT(it != map.end());
+            GetterSetterPair& pair = it->second;
+
+            // Was this already generated as a part of its partner?
+            if (pair.second == node)
+                continue;
+    
+            // Generate the paired node now.
+            RefPtr<RegisterID> getterReg;
+            RefPtr<RegisterID> setterReg;
+
+            if (node->m_type == PropertyNode::Getter) {
+                getterReg = value;
+                if (pair.second) {
+                    ASSERT(pair.second->m_type == PropertyNode::Setter);
+                    setterReg = generator.emitNode(pair.second->m_assign);
+                } else {
+                    setterReg = generator.newTemporary();
+                    generator.emitLoad(setterReg.get(), jsUndefined());
+                }
+            } else {
+                ASSERT(node->m_type == PropertyNode::Setter);
+                setterReg = value;
+                if (pair.second) {
+                    ASSERT(pair.second->m_type == PropertyNode::Getter);
+                    getterReg = generator.emitNode(pair.second->m_assign);
+                } else {
+                    getterReg = generator.newTemporary();
+                    generator.emitLoad(getterReg.get(), jsUndefined());
+                }
             }
-            default:
-                ASSERT_NOT_REACHED();
+
+            generator.emitPutGetterSetter(newObj.get(), node->name(), getterReg.get(), setterReg.get());
         }
     }
-    
+
     return generator.moveToDestinationIfNeeded(dst, newObj.get());
 }
 
@@ -289,6 +316,12 @@ RegisterID* PropertyListNode::emitBytecode(BytecodeGenerator& generator, Registe
 
 RegisterID* BracketAccessorNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (m_base->isResolveNode() && generator.willResolveToArguments(static_cast<ResolveNode*>(m_base)->identifier())) {
+        RegisterID* property = generator.emitNode(m_subscript);
+        generator.emitExpressionInfo(divot(), startOffset(), endOffset());    
+        return generator.emitGetArgumentByVal(generator.finalDestination(dst), generator.uncheckedRegisterForArguments(), property);
+    }
+
     RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_subscriptHasAssignments, m_subscript->isPure(generator));
     RegisterID* property = generator.emitNode(m_subscript);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
@@ -299,6 +332,17 @@ RegisterID* BracketAccessorNode::emitBytecode(BytecodeGenerator& generator, Regi
 
 RegisterID* DotAccessorNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (m_ident == generator.propertyNames().length) {
+        if (!m_base->isResolveNode())
+            goto nonArgumentsPath;
+        ResolveNode* resolveNode = static_cast<ResolveNode*>(m_base);
+        if (!generator.willResolveToArguments(resolveNode->identifier()))
+            goto nonArgumentsPath;
+        generator.emitExpressionInfo(divot(), startOffset(), endOffset());    
+        return generator.emitGetArgumentsLength(generator.finalDestination(dst), generator.uncheckedRegisterForArguments());
+    }
+
+nonArgumentsPath:
     RegisterID* base = generator.emitNode(m_base);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
     return generator.emitGetById(generator.finalDestination(dst), base, m_ident);
@@ -317,7 +361,34 @@ RegisterID* ArgumentListNode::emitBytecode(BytecodeGenerator& generator, Registe
 RegisterID* NewExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> func = generator.emitNode(m_expr);
-    return generator.emitConstruct(generator.finalDestination(dst), func.get(), m_args, divot(), startOffset(), endOffset());
+    CallArguments callArguments(generator, m_args);
+    return generator.emitConstruct(generator.finalDestinationOrIgnored(dst), func.get(), callArguments, divot(), startOffset(), endOffset());
+}
+
+inline CallArguments::CallArguments(BytecodeGenerator& generator, ArgumentsNode* argumentsNode)
+    : m_argumentsNode(argumentsNode)
+{
+    if (generator.shouldEmitProfileHooks())
+        m_profileHookRegister = generator.newTemporary();
+
+    size_t argumentCountIncludingThis = 1; // 'this' register.
+    if (argumentsNode) {
+        for (ArgumentListNode* node = argumentsNode->m_listNode; node; node = node->m_next)
+            ++argumentCountIncludingThis;
+    }
+
+    m_argv.grow(argumentCountIncludingThis);
+    for (int i = argumentCountIncludingThis - 1; i >= 0; --i) {
+        m_argv[i] = generator.newTemporary();
+        ASSERT(static_cast<size_t>(i) == m_argv.size() - 1 || m_argv[i]->index() == m_argv[i + 1]->index() + 1);
+    }
+}
+
+inline void CallArguments::newArgument(BytecodeGenerator& generator)
+{
+    RefPtr<RegisterID> tmp = generator.newTemporary();
+    ASSERT(m_argv.isEmpty() || tmp->index() == m_argv.last()->index() + 1); // Calling convention assumes that all arguments are contiguous.
+    m_argv.append(tmp.release());
 }
 
 // ------------------------------ EvalFunctionCallNode ----------------------------------
@@ -325,10 +396,10 @@ RegisterID* NewExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
 RegisterID* EvalFunctionCallNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> func = generator.tempDestination(dst);
-    RefPtr<RegisterID> thisRegister = generator.newTemporary();
+    CallArguments callArguments(generator, m_args);
     generator.emitExpressionInfo(divot() - startOffset() + 4, 4, 0);
-    generator.emitResolveWithBase(thisRegister.get(), func.get(), generator.propertyNames().eval);
-    return generator.emitCallEval(generator.finalDestination(dst, func.get()), func.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+    generator.emitResolveWithThis(callArguments.thisRegister(), func.get(), generator.propertyNames().eval);
+    return generator.emitCallEval(generator.finalDestination(dst, func.get()), func.get(), callArguments, divot(), startOffset(), endOffset());
 }
 
 // ------------------------------ FunctionCallValueNode ----------------------------------
@@ -336,8 +407,9 @@ RegisterID* EvalFunctionCallNode::emitBytecode(BytecodeGenerator& generator, Reg
 RegisterID* FunctionCallValueNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> func = generator.emitNode(m_expr);
-    RefPtr<RegisterID> thisRegister = generator.emitLoad(generator.newTemporary(), jsNull());
-    return generator.emitCall(generator.finalDestination(dst, func.get()), func.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+    CallArguments callArguments(generator, m_args);
+    generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+    return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), callArguments, divot(), startOffset(), endOffset());
 }
 
 // ------------------------------ FunctionCallResolveNode ----------------------------------
@@ -345,8 +417,10 @@ RegisterID* FunctionCallValueNode::emitBytecode(BytecodeGenerator& generator, Re
 RegisterID* FunctionCallResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     if (RefPtr<RegisterID> local = generator.registerFor(m_ident)) {
-        RefPtr<RegisterID> thisRegister = generator.emitLoad(generator.newTemporary(), jsNull());
-        return generator.emitCall(generator.finalDestination(dst, thisRegister.get()), local.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+        RefPtr<RegisterID> function = generator.emitMove(generator.tempDestination(dst), local.get());
+        CallArguments callArguments(generator, m_args);
+        generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+        return generator.emitCall(generator.finalDestinationOrIgnored(dst, callArguments.thisRegister()), function.get(), callArguments, divot(), startOffset(), endOffset());
     }
 
     int index = 0;
@@ -355,16 +429,17 @@ RegisterID* FunctionCallResolveNode::emitBytecode(BytecodeGenerator& generator,
     bool requiresDynamicChecks = false;
     if (generator.findScopedProperty(m_ident, index, depth, false, requiresDynamicChecks, globalObject) && index != missingSymbolMarker() && !requiresDynamicChecks) {
         RefPtr<RegisterID> func = generator.emitGetScopedVar(generator.newTemporary(), depth, index, globalObject);
-        RefPtr<RegisterID> thisRegister = generator.emitLoad(generator.newTemporary(), jsNull());
-        return generator.emitCall(generator.finalDestination(dst, func.get()), func.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+        CallArguments callArguments(generator, m_args);
+        generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+        return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), callArguments, divot(), startOffset(), endOffset());
     }
 
     RefPtr<RegisterID> func = generator.newTemporary();
-    RefPtr<RegisterID> thisRegister = generator.newTemporary();
+    CallArguments callArguments(generator, m_args);
     int identifierStart = divot() - startOffset();
-    generator.emitExpressionInfo(identifierStart + m_ident.size(), m_ident.size(), 0);
-    generator.emitResolveWithBase(thisRegister.get(), func.get(), m_ident);
-    return generator.emitCall(generator.finalDestination(dst, func.get()), func.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+    generator.emitExpressionInfo(identifierStart + m_ident.length(), m_ident.length(), 0);
+    generator.emitResolveWithThis(callArguments.thisRegister(), func.get(), m_ident);
+    return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), callArguments, divot(), startOffset(), endOffset());
 }
 
 // ------------------------------ FunctionCallBracketNode ----------------------------------
@@ -375,8 +450,9 @@ RegisterID* FunctionCallBracketNode::emitBytecode(BytecodeGenerator& generator,
     RegisterID* property = generator.emitNode(m_subscript);
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     RefPtr<RegisterID> function = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property);
-    RefPtr<RegisterID> thisRegister = generator.emitMove(generator.newTemporary(), base.get());
-    return generator.emitCall(generator.finalDestination(dst, function.get()), function.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+    CallArguments callArguments(generator, m_args);
+    generator.emitMove(callArguments.thisRegister(), base.get());
+    return generator.emitCall(generator.finalDestinationOrIgnored(dst, function.get()), function.get(), callArguments, divot(), startOffset(), endOffset());
 }
 
 // ------------------------------ FunctionCallDotNode ----------------------------------
@@ -384,12 +460,12 @@ RegisterID* FunctionCallBracketNode::emitBytecode(BytecodeGenerator& generator,
 RegisterID* FunctionCallDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> function = generator.tempDestination(dst);
-    RefPtr<RegisterID> thisRegister = generator.newTemporary();
-    generator.emitNode(thisRegister.get(), m_base);
+    CallArguments callArguments(generator, m_args);
+    generator.emitNode(callArguments.thisRegister(), m_base);
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     generator.emitMethodCheck();
-    generator.emitGetById(function.get(), thisRegister.get(), m_ident);
-    return generator.emitCall(generator.finalDestination(dst, function.get()), function.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+    generator.emitGetById(function.get(), callArguments.thisRegister(), m_ident);
+    return generator.emitCall(generator.finalDestinationOrIgnored(dst, function.get()), function.get(), callArguments, divot(), startOffset(), endOffset());
 }
 
 RegisterID* CallFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
@@ -399,31 +475,38 @@ RegisterID* CallFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator,
     RefPtr<RegisterID> base = generator.emitNode(m_base);
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     RefPtr<RegisterID> function = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RefPtr<RegisterID> finalDestination = generator.finalDestination(dst, function.get());
+    RefPtr<RegisterID> finalDestinationOrIgnored = generator.finalDestinationOrIgnored(dst, function.get());
     generator.emitJumpIfNotFunctionCall(function.get(), realCall.get());
     {
-        RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
-        RefPtr<RegisterID> thisRegister = generator.newTemporary();
-        ArgumentListNode* oldList = m_args->m_listNode;
         if (m_args->m_listNode && m_args->m_listNode->m_expr) {
-            generator.emitNode(thisRegister.get(), m_args->m_listNode->m_expr);
+            ArgumentListNode* oldList = m_args->m_listNode;
             m_args->m_listNode = m_args->m_listNode->m_next;
-        } else
-            generator.emitLoad(thisRegister.get(), jsNull());
 
-        generator.emitCall(finalDestination.get(), realFunction.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
-        generator.emitJump(end.get());
-        m_args->m_listNode = oldList;
+            RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+            CallArguments callArguments(generator, m_args);
+            generator.emitNode(callArguments.thisRegister(), oldList->m_expr);
+            generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), callArguments, divot(), startOffset(), endOffset());
+            generator.emitJump(end.get());
+
+            m_args->m_listNode = oldList;
+        } else {
+            RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+            CallArguments callArguments(generator, m_args);
+            generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+            generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), callArguments, divot(), startOffset(), endOffset());
+            generator.emitJump(end.get());
+        }
     }
     generator.emitLabel(realCall.get());
     {
-        RefPtr<RegisterID> thisRegister = generator.emitMove(generator.newTemporary(), base.get());
-        generator.emitCall(finalDestination.get(), function.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+        CallArguments callArguments(generator, m_args);
+        generator.emitMove(callArguments.thisRegister(), base.get());
+        generator.emitCall(finalDestinationOrIgnored.get(), function.get(), callArguments, divot(), startOffset(), endOffset());
     }
     generator.emitLabel(end.get());
-    return finalDestination.get();
+    return finalDestinationOrIgnored.get();
 }
-    
+
 static bool areTrivialApplyArguments(ArgumentsNode* args)
 {
     return !args->m_listNode || !args->m_listNode->m_expr || !args->m_listNode->m_next
@@ -442,57 +525,65 @@ RegisterID* ApplyFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator,
     RefPtr<RegisterID> base = generator.emitNode(m_base);
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     RefPtr<RegisterID> function = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RefPtr<RegisterID> finalDestination = generator.finalDestination(dst, function.get());
+    RefPtr<RegisterID> finalDestinationOrIgnored = generator.finalDestinationOrIgnored(dst, function.get());
     generator.emitJumpIfNotFunctionApply(function.get(), realCall.get());
     {
         if (mayBeCall) {
-            RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
-            RefPtr<RegisterID> thisRegister = generator.newTemporary();
-            ArgumentListNode* oldList = m_args->m_listNode;
             if (m_args->m_listNode && m_args->m_listNode->m_expr) {
-                generator.emitNode(thisRegister.get(), m_args->m_listNode->m_expr);
-                m_args->m_listNode = m_args->m_listNode->m_next;
-                if (m_args->m_listNode) {
-                    ASSERT(m_args->m_listNode->m_expr->isSimpleArray());
-                    ASSERT(!m_args->m_listNode->m_next);
-                    m_args->m_listNode = static_cast<ArrayNode*>(m_args->m_listNode->m_expr)->toArgumentList(generator.globalData());
+                ArgumentListNode* oldList = m_args->m_listNode;
+                if (m_args->m_listNode->m_next) {
+                    ASSERT(m_args->m_listNode->m_next->m_expr->isSimpleArray());
+                    ASSERT(!m_args->m_listNode->m_next->m_next);
+                    m_args->m_listNode = static_cast<ArrayNode*>(m_args->m_listNode->m_next->m_expr)->toArgumentList(generator.globalData(), 0);
+                    RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+                    CallArguments callArguments(generator, m_args);
+                    generator.emitNode(callArguments.thisRegister(), oldList->m_expr);
+                    generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), callArguments, divot(), startOffset(), endOffset());
+                } else {
+                    m_args->m_listNode = m_args->m_listNode->m_next;
+                    RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+                    CallArguments callArguments(generator, m_args);
+                    generator.emitNode(callArguments.thisRegister(), oldList->m_expr);
+                    generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), callArguments, divot(), startOffset(), endOffset());
                 }
-            } else
-                generator.emitLoad(thisRegister.get(), jsNull());
-            generator.emitCall(finalDestination.get(), realFunction.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
-            m_args->m_listNode = oldList;
+                m_args->m_listNode = oldList;
+            } else {
+                RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+                CallArguments callArguments(generator, m_args);
+                generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+                generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), callArguments, divot(), startOffset(), endOffset());
+            }
         } else {
             ASSERT(m_args->m_listNode && m_args->m_listNode->m_next);
-            RefPtr<RegisterID> realFunction = generator.emitMove(generator.newTemporary(), base.get());
-            RefPtr<RegisterID> argsCountRegister = generator.newTemporary();
-            RefPtr<RegisterID> thisRegister = generator.newTemporary();
-            RefPtr<RegisterID> argsRegister = generator.newTemporary();
-            generator.emitNode(thisRegister.get(), m_args->m_listNode->m_expr);
+            RefPtr<RegisterID> profileHookRegister;
+            if (generator.shouldEmitProfileHooks())
+                profileHookRegister = generator.newTemporary();
+            RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+            RefPtr<RegisterID> thisRegister = generator.emitNode(m_args->m_listNode->m_expr);
+            RefPtr<RegisterID> argsRegister;
             ArgumentListNode* args = m_args->m_listNode->m_next;
-            bool isArgumentsApply = false;
-            if (args->m_expr->isResolveNode()) {
-                ResolveNode* resolveNode = static_cast<ResolveNode*>(args->m_expr);
-                isArgumentsApply = generator.willResolveToArguments(resolveNode->identifier());
-                if (isArgumentsApply)
-                    generator.emitMove(argsRegister.get(), generator.uncheckedRegisterForArguments());
-            }
-            if (!isArgumentsApply)
-                generator.emitNode(argsRegister.get(), args->m_expr);
+            if (args->m_expr->isResolveNode() && generator.willResolveToArguments(static_cast<ResolveNode*>(args->m_expr)->identifier()))
+                argsRegister = generator.uncheckedRegisterForArguments();
+            else
+                argsRegister = generator.emitNode(args->m_expr);
+
+            // Function.prototype.apply ignores extra arguments, but we still
+            // need to evaluate them for side effects.
             while ((args = args->m_next))
                 generator.emitNode(args->m_expr);
 
-            generator.emitLoadVarargs(argsCountRegister.get(), argsRegister.get());
-            generator.emitCallVarargs(finalDestination.get(), realFunction.get(), thisRegister.get(), argsCountRegister.get(), divot(), startOffset(), endOffset());
+            generator.emitCallVarargs(finalDestinationOrIgnored.get(), realFunction.get(), thisRegister.get(), argsRegister.get(), generator.newTemporary(), profileHookRegister.get(), divot(), startOffset(), endOffset());
         }
         generator.emitJump(end.get());
     }
     generator.emitLabel(realCall.get());
     {
-        RefPtr<RegisterID> thisRegister = generator.emitMove(generator.newTemporary(), base.get());
-        generator.emitCall(finalDestination.get(), function.get(), thisRegister.get(), m_args, divot(), startOffset(), endOffset());
+        CallArguments callArguments(generator, m_args);
+        generator.emitMove(callArguments.thisRegister(), base.get());
+        generator.emitCall(finalDestinationOrIgnored.get(), function.get(), callArguments, divot(), startOffset(), endOffset());
     }
     generator.emitLabel(end.get());
-    return finalDestination.get();
+    return finalDestinationOrIgnored.get();
 }
 
 // ------------------------------ PostfixResolveNode ----------------------------------
@@ -605,7 +696,7 @@ RegisterID* PostfixDotNode::emitBytecode(BytecodeGenerator& generator, RegisterI
 
 RegisterID* PostfixErrorNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    return emitThrowError(generator, ReferenceError, m_operator == OpPlusPlus
+    return emitThrowReferenceError(generator, m_operator == OpPlusPlus
         ? "Postfix ++ operator applied to value that is not a reference."
         : "Postfix -- operator applied to value that is not a reference.");
 }
@@ -714,7 +805,7 @@ RegisterID* PrefixResolveNode::emitBytecode(BytecodeGenerator& generator, Regist
     size_t depth = 0;
     JSObject* globalObject = 0;
     bool requiresDynamicChecks = false;
-    if (generator.findScopedProperty(m_ident, index, depth, false, requiresDynamicChecks, globalObject) && index != missingSymbolMarker() && !requiresDynamicChecks) {
+    if (generator.findScopedProperty(m_ident, index, depth, true, requiresDynamicChecks, globalObject) && index != missingSymbolMarker() && !requiresDynamicChecks) {
         RefPtr<RegisterID> propDst = generator.emitGetScopedVar(generator.tempDestination(dst), depth, index, globalObject);
         emitPreIncOrDec(generator, propDst.get(), m_operator);
         generator.emitPutScopedVar(depth, index, propDst.get(), globalObject);
@@ -770,7 +861,7 @@ RegisterID* PrefixDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID
 
 RegisterID* PrefixErrorNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    return emitThrowError(generator, ReferenceError, m_operator == OpPlusPlus
+    return emitThrowReferenceError(generator, m_operator == OpPlusPlus
         ? "Prefix ++ operator applied to value that is not a reference."
         : "Prefix -- operator applied to value that is not a reference.");
 }
@@ -783,7 +874,15 @@ RegisterID* UnaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
     return generator.emitUnaryOp(opcodeID(), generator.finalDestination(dst), src);
 }
 
-
+// ------------------------------ BitwiseNotNode -----------------------------------
+ 
+RegisterID* BitwiseNotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    RefPtr<RegisterID> src2 = generator.emitLoad(generator.newTemporary(), jsNumber(-1));
+    RegisterID* src1 = generator.emitNode(m_expr);
+    return generator.emitBinaryOp(op_bitxor, generator.finalDestination(dst, src1), src1, src2.get(), OperandTypes(m_expr->resultDescriptor(), ResultType::numberTypeIsInt32()));
+}
+ 
 // ------------------------------ LogicalNotNode -----------------------------------
 
 void LogicalNotNode::emitBytecodeInConditionContext(BytecodeGenerator& generator, Label* trueTarget, Label* falseTarget, bool fallThroughMeansTrue)
@@ -830,8 +929,6 @@ RegisterID* BinaryOpNode::emitStrcat(BytecodeGenerator& generator, RegisterID* d
     ASSERT(isAdd());
     ASSERT(resultDescriptor().definitelyIsString());
 
-    IncreaseEmitNodeDepth stackGuard(generator, 3);
-
     // Create a list of expressions for all the adds in the tree of nodes we can convert into
     // a string concatenation.  The rightmost node (c) is added first.  The rightmost node is
     // added first, and the leftmost child is never added, so the vector produced for the
@@ -957,13 +1054,6 @@ RegisterID* StrictEqualNode::emitBytecode(BytecodeGenerator& generator, Register
     return generator.emitEqualityOp(op_stricteq, generator.finalDestination(dst, src1.get()), src1.get(), src2);
 }
 
-RegisterID* ReverseBinaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
-{
-    RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1, m_rightHasAssignments, m_expr2->isPure(generator));
-    RegisterID* src2 = generator.emitNode(m_expr2);
-    return generator.emitBinaryOp(opcodeID(), generator.finalDestination(dst, src1.get()), src2, src1.get(), OperandTypes(m_expr2->resultDescriptor(), m_expr1->resultDescriptor()));
-}
-
 RegisterID* ThrowableBinaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1, m_rightHasAssignments, m_expr2->isPure(generator));
@@ -978,7 +1068,9 @@ RegisterID* InstanceOfNode::emitBytecode(BytecodeGenerator& generator, RegisterI
     RefPtr<RegisterID> src2 = generator.emitNode(m_expr2);
 
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    generator.emitGetByIdExceptionInfo(op_instanceof);
+    generator.emitCheckHasInstance(src2.get());
+
+    generator.emitExpressionInfo(divot(), startOffset(), endOffset());
     RegisterID* src2Prototype = generator.emitGetById(generator.newTemporary(), src2.get(), generator.globalData()->propertyNames->prototype);
 
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
@@ -1119,10 +1211,9 @@ static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(BytecodeGenerator& gen
 RegisterID* ReadModifyResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     if (RegisterID* local = generator.registerFor(m_ident)) {
-        if (generator.isLocalConstant(m_ident)) {
+        if (generator.isLocalConstant(m_ident))
             return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
-        }
-        
+
         if (generator.leftHandSideNeedsCopy(m_rightHasAssignments, m_right->isPure(generator))) {
             RefPtr<RegisterID> result = generator.newTemporary();
             generator.emitMove(result.get(), local);
@@ -1147,7 +1238,7 @@ RegisterID* ReadModifyResolveNode::emitBytecode(BytecodeGenerator& generator, Re
     }
 
     RefPtr<RegisterID> src1 = generator.tempDestination(dst);
-    generator.emitExpressionInfo(divot() - startOffset() + m_ident.size(), m_ident.size(), 0);
+    generator.emitExpressionInfo(divot() - startOffset() + m_ident.length(), m_ident.length(), 0);
     RefPtr<RegisterID> base = generator.emitResolveWithBase(generator.newTemporary(), src1.get(), m_ident);
     RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()), this);
     return generator.emitPutById(base.get(), m_ident, result);
@@ -1177,7 +1268,7 @@ RegisterID* AssignResolveNode::emitBytecode(BytecodeGenerator& generator, Regist
         return value;
     }
 
-    RefPtr<RegisterID> base = generator.emitResolveBase(generator.newTemporary(), m_ident);
+    RefPtr<RegisterID> base = generator.emitResolveBaseForPut(generator.newTemporary(), m_ident);
     if (dst == generator.ignoredResult())
         dst = 0;
     RegisterID* value = generator.emitNode(dst, m_right);
@@ -1193,8 +1284,9 @@ RegisterID* AssignDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID
     RefPtr<RegisterID> value = generator.destinationForAssignResult(dst);
     RegisterID* result = generator.emitNode(value.get(), m_right);
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    generator.emitPutById(base.get(), m_ident, result);
-    return generator.moveToDestinationIfNeeded(dst, result);
+    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result : generator.moveToDestinationIfNeeded(generator.tempDestination(result), result);
+    generator.emitPutById(base.get(), m_ident, forwardResult);
+    return generator.moveToDestinationIfNeeded(dst, forwardResult);
 }
 
 // ------------------------------ ReadModifyDotNode -----------------------------------
@@ -1215,7 +1307,7 @@ RegisterID* ReadModifyDotNode::emitBytecode(BytecodeGenerator& generator, Regist
 
 RegisterID* AssignErrorNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    return emitThrowError(generator, ReferenceError, "Left side of assignment is not a reference.");
+    return emitThrowReferenceError(generator, "Left side of assignment is not a reference.");
 }
 
 // ------------------------------ AssignBracketNode -----------------------------------
@@ -1228,8 +1320,9 @@ RegisterID* AssignBracketNode::emitBytecode(BytecodeGenerator& generator, Regist
     RegisterID* result = generator.emitNode(value.get(), m_right);
 
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    generator.emitPutByVal(base.get(), property.get(), result);
-    return generator.moveToDestinationIfNeeded(dst, result);
+    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result : generator.moveToDestinationIfNeeded(generator.tempDestination(result), result);
+    generator.emitPutByVal(base.get(), property.get(), forwardResult);
+    return generator.moveToDestinationIfNeeded(dst, forwardResult);
 }
 
 // ------------------------------ ReadModifyBracketNode -----------------------------------
@@ -1263,6 +1356,7 @@ RegisterID* CommaNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
 
 RegisterID* ConstDeclNode::emitCodeSingle(BytecodeGenerator& generator)
 {
+    // FIXME: This code does not match the behavior of const in Firefox.
     if (RegisterID* local = generator.constRegisterFor(m_ident)) {
         if (!m_init)
             return local;
@@ -1270,17 +1364,30 @@ RegisterID* ConstDeclNode::emitCodeSingle(BytecodeGenerator& generator)
         return generator.emitNode(local, m_init);
     }
 
-    if (generator.codeType() != EvalCode) {
-        if (m_init)
-            return generator.emitNode(m_init);
-        else
-            return generator.emitResolve(generator.newTemporary(), m_ident);
+    RefPtr<RegisterID> value = m_init ? generator.emitNode(m_init) : generator.emitLoad(0, jsUndefined());
+
+    ScopeChainIterator iter = generator.scopeChain()->begin();
+    ScopeChainIterator end = generator.scopeChain()->end();
+    size_t depth = 0;
+    for (; iter != end; ++iter, ++depth) {
+        JSObject* currentScope = iter->get();
+        if (!currentScope->isVariableObject())
+            continue;
+        JSVariableObject* currentVariableObject = static_cast<JSVariableObject*>(currentScope);
+        SymbolTableEntry entry = currentVariableObject->symbolTable().get(m_ident.impl());
+        if (entry.isNull())
+            continue;
+
+        return generator.emitPutScopedVar(generator.scopeDepth() + depth, entry.getIndex(), value.get(), currentVariableObject->isGlobalObject() ? currentVariableObject : 0);
     }
-    // FIXME: While this code should only be hit in eval code, it will potentially
-    // assign to the wrong base if m_ident exists in an intervening dynamic scope.
+
+    if (generator.codeType() != EvalCode)
+        return value.get();
+
+    // FIXME: While this code should only be hit in an eval block, it will assign
+    // to the wrong base if m_ident exists in an intervening with scope.
     RefPtr<RegisterID> base = generator.emitResolveBase(generator.newTemporary(), m_ident);
-    RegisterID* value = m_init ? generator.emitNode(m_init) : generator.emitLoad(0, jsUndefined());
-    return generator.emitPutById(base.get(), m_ident, value);
+    return generator.emitPutById(base.get(), m_ident, value.get());
 }
 
 RegisterID* ConstDeclNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
@@ -1323,6 +1430,11 @@ inline StatementNode* BlockNode::lastStatement() const
     return m_statements ? m_statements->lastStatement() : 0;
 }
 
+inline StatementNode* BlockNode::singleStatement() const
+{
+    return m_statements ? m_statements->singleStatement() : 0;
+}
+
 RegisterID* BlockNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     if (m_statements)
@@ -1427,7 +1539,7 @@ RegisterID* DoWhileNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
 
     RefPtr<Label> topOfLoop = generator.newLabel();
     generator.emitLabel(topOfLoop.get());
-
+    generator.emitLoopHint();
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
    
     RefPtr<RegisterID> result = generator.emitNode(dst, m_statement);
@@ -1455,6 +1567,7 @@ RegisterID* WhileNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
 
     RefPtr<Label> topOfLoop = generator.newLabel();
     generator.emitLabel(topOfLoop.get());
+    generator.emitLoopHint();
     
     generator.emitNode(dst, m_statement);
 
@@ -1490,6 +1603,7 @@ RegisterID* ForNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
     RefPtr<Label> topOfLoop = generator.newLabel();
     generator.emitLabel(topOfLoop.get());
+    generator.emitLoopHint();
 
     RefPtr<RegisterID> result = generator.emitNode(dst, m_statement);
 
@@ -1517,12 +1631,10 @@ RegisterID* ForNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
 RegisterID* ForInNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    IncreaseEmitNodeDepth stackGuard(generator);
-
     RefPtr<LabelScope> scope = generator.newLabelScope(LabelScope::Loop);
 
     if (!m_lexpr->isLocation())
-        return emitThrowError(generator, ReferenceError, "Left side of for-in statement is not a reference.");
+        return emitThrowReferenceError(generator, "Left side of for-in statement is not a reference.");
 
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
 
@@ -1539,6 +1651,7 @@ RegisterID* ForInNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
 
     RefPtr<Label> loopStart = generator.newLabel();
     generator.emitLabel(loopStart.get());
+    generator.emitLoopHint();
 
     RegisterID* propertyName;
     bool optimizedForinAccess = false;
@@ -1548,7 +1661,7 @@ RegisterID* ForInNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
         if (!propertyName) {
             propertyName = generator.newTemporary();
             RefPtr<RegisterID> protect = propertyName;
-            RegisterID* base = generator.emitResolveBase(generator.newTemporary(), ident);
+            RegisterID* base = generator.emitResolveBaseForPut(generator.newTemporary(), ident);
 
             generator.emitExpressionInfo(divot(), startOffset(), endOffset());
             generator.emitPutById(base, ident, propertyName);
@@ -1598,11 +1711,7 @@ RegisterID* ContinueNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
     
     LabelScope* scope = generator.continueTarget(m_ident);
-
-    if (!scope)
-        return m_ident.isEmpty()
-            ? emitThrowError(generator, SyntaxError, "Invalid continue statement.")
-            : emitThrowError(generator, SyntaxError, "Undefined label: '%s'.", m_ident);
+    ASSERT(scope);
 
     generator.emitJumpScopes(scope->continueTarget(), scope->scopeDepth());
     return dst;
@@ -1616,11 +1725,7 @@ RegisterID* BreakNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
     
     LabelScope* scope = generator.breakTarget(m_ident);
-    
-    if (!scope)
-        return m_ident.isEmpty()
-            ? emitThrowError(generator, SyntaxError, "Invalid break statement.")
-            : emitThrowError(generator, SyntaxError, "Undefined label: '%s'.", m_ident);
+    ASSERT(scope);
 
     generator.emitJumpScopes(scope->breakTarget(), scope->scopeDepth());
     return dst;
@@ -1631,8 +1736,7 @@ RegisterID* BreakNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
 RegisterID* ReturnNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
-    if (generator.codeType() != FunctionCode)
-        return emitThrowError(generator, SyntaxError, "Invalid return statement.");
+    ASSERT(generator.codeType() == FunctionCode);
 
     if (dst == generator.ignoredResult())
         dst = 0;
@@ -1640,7 +1744,7 @@ RegisterID* ReturnNode::emitBytecode(BytecodeGenerator& generator, RegisterID* d
     RefPtr<RegisterID> returnRegister;
     if (generator.scopeDepth()) {
         RefPtr<Label> l0 = generator.newLabel();
-        if (generator.hasFinaliser() && !r0->isTemporary()) {
+        if (generator.hasFinaliser()) {
             returnRegister = generator.emitMove(generator.newTemporary(), r0);
             r0 = returnRegister.get();
         }
@@ -1708,8 +1812,8 @@ static void processClauseList(ClauseListNode* list, Vector<ExpressionNode*, 8>&
                 break;
             }
             const UString& value = static_cast<StringNode*>(clauseExpression)->value().ustring();
-            if (singleCharacterSwitch &= value.size() == 1) {
-                int32_t intVal = value.rep()->characters()[0];
+            if (singleCharacterSwitch &= value.length() == 1) {
+                int32_t intVal = value[0];
                 if (intVal < min_num)
                     min_num = intVal;
                 if (intVal > max_num)
@@ -1837,8 +1941,7 @@ RegisterID* LabelNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
 {
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
 
-    if (generator.breakTarget(m_name))
-        return emitThrowError(generator, SyntaxError, "Duplicate label: %s.", m_name);
+    ASSERT(!generator.breakTarget(m_name));
 
     RefPtr<LabelScope> scope = generator.newLabelScope(LabelScope::NamedLabel, &m_name);
     RegisterID* r0 = generator.emitNode(dst, m_statement);
@@ -1868,18 +1971,11 @@ RegisterID* TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
     // NOTE: The catch and finally blocks must be labeled explicitly, so the
     // optimizer knows they may be jumped to from anywhere.
 
-    IncreaseEmitNodeDepth stackGuard(generator);
-
     generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine());
 
     RefPtr<Label> tryStartLabel = generator.newLabel();
-    RefPtr<Label> finallyStart;
-    RefPtr<RegisterID> finallyReturnAddr;
-    if (m_finallyBlock) {
-        finallyStart = generator.newLabel();
-        finallyReturnAddr = generator.newTemporary();
-        generator.pushFinallyContext(finallyStart.get(), finallyReturnAddr.get());
-    }
+    if (m_finallyBlock)
+        generator.pushFinallyContext(m_finallyBlock);
 
     generator.emitLabel(tryStartLabel.get());
     generator.emitNode(dst, m_tryBlock);
@@ -1893,13 +1989,7 @@ RegisterID* TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
         // Uncaught exception path: the catch block.
         RefPtr<Label> here = generator.emitLabel(generator.newLabel().get());
         RefPtr<RegisterID> exceptionRegister = generator.emitCatch(generator.newTemporary(), tryStartLabel.get(), here.get());
-        if (m_catchHasEval) {
-            RefPtr<RegisterID> dynamicScopeObject = generator.emitNewObject(generator.newTemporary());
-            generator.emitPutById(dynamicScopeObject.get(), m_exceptionIdent, exceptionRegister.get());
-            generator.emitMove(exceptionRegister.get(), dynamicScopeObject.get());
-            generator.emitPushScope(exceptionRegister.get());
-        } else
-            generator.emitPushNewScope(exceptionRegister.get(), m_exceptionIdent, exceptionRegister.get());
+        generator.emitPushNewScope(exceptionRegister.get(), m_exceptionIdent, exceptionRegister.get());
         generator.emitNode(dst, m_catchBlock);
         generator.emitPopScope();
         generator.emitLabel(catchEndLabel.get());
@@ -1907,27 +1997,18 @@ RegisterID* TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
     if (m_finallyBlock) {
         generator.popFinallyContext();
-        // there may be important registers live at the time we jump
-        // to a finally block (such as for a return or throw) so we
-        // ref the highest register ever used as a conservative
-        // approach to not clobbering anything important
-        RefPtr<RegisterID> highestUsedRegister = generator.highestUsedRegister();
+
         RefPtr<Label> finallyEndLabel = generator.newLabel();
 
-        // Normal path: invoke the finally block, then jump over it.
-        generator.emitJumpSubroutine(finallyReturnAddr.get(), finallyStart.get());
+        // Normal path: run the finally code, and jump to the end.
+        generator.emitNode(dst, m_finallyBlock);
         generator.emitJump(finallyEndLabel.get());
 
         // Uncaught exception path: invoke the finally block, then re-throw the exception.
         RefPtr<Label> here = generator.emitLabel(generator.newLabel().get());
         RefPtr<RegisterID> tempExceptionRegister = generator.emitCatch(generator.newTemporary(), tryStartLabel.get(), here.get());
-        generator.emitJumpSubroutine(finallyReturnAddr.get(), finallyStart.get());
-        generator.emitThrow(tempExceptionRegister.get());
-
-        // The finally block.
-        generator.emitLabel(finallyStart.get());
         generator.emitNode(dst, m_finallyBlock);
-        generator.emitSubroutineReturn(finallyReturnAddr.get());
+        generator.emitThrow(tempExceptionRegister.get());
 
         generator.emitLabel(finallyEndLabel.get());
     }
@@ -1939,8 +2020,8 @@ RegisterID* TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
 inline void ScopeNode::emitStatementsBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    if (m_data->m_statements)
-        m_data->m_statements->emitBytecode(generator, dst);
+    if (m_statements)
+        m_statements->emitBytecode(generator, dst);
 }
 
 // ------------------------------ ProgramNode -----------------------------
@@ -1979,16 +2060,41 @@ RegisterID* FunctionBodyNode::emitBytecode(BytecodeGenerator& generator, Registe
 {
     generator.emitDebugHook(DidEnterCallFrame, firstLine(), lastLine());
     emitStatementsBytecode(generator, generator.ignoredResult());
+
     StatementNode* singleStatement = this->singleStatement();
+    ReturnNode* returnNode = 0;
+
+    // Check for a return statement at the end of a function composed of a single block.
     if (singleStatement && singleStatement->isBlock()) {
         StatementNode* lastStatementInBlock = static_cast<BlockNode*>(singleStatement)->lastStatement();
         if (lastStatementInBlock && lastStatementInBlock->isReturnNode())
-            return 0;
+            returnNode = static_cast<ReturnNode*>(lastStatementInBlock);
+    }
+
+    // If there is no return we must automatically insert one.
+    if (!returnNode) {
+        RegisterID* r0 = generator.isConstructor() ? generator.thisRegister() : generator.emitLoad(0, jsUndefined());
+        generator.emitDebugHook(WillLeaveCallFrame, firstLine(), lastLine());
+        generator.emitReturn(r0);
+        return 0;
+    }
+
+    // If there is a return statment, and it is the only statement in the function, check if this is a numeric compare.
+    if (static_cast<BlockNode*>(singleStatement)->singleStatement()) {
+        ExpressionNode* returnValueExpression = returnNode->value();
+        if (returnValueExpression && returnValueExpression->isSubtract()) {
+            ExpressionNode* lhsExpression = static_cast<SubNode*>(returnValueExpression)->lhs();
+            ExpressionNode* rhsExpression = static_cast<SubNode*>(returnValueExpression)->rhs();
+            if (lhsExpression->isResolveNode()
+                && rhsExpression->isResolveNode()
+                && generator.isArgumentNumber(static_cast<ResolveNode*>(lhsExpression)->identifier(), 0)
+                && generator.isArgumentNumber(static_cast<ResolveNode*>(rhsExpression)->identifier(), 1)) {
+                
+                generator.setIsNumericCompareFunction(true);
+            }
+        }
     }
 
-    RegisterID* r0 = generator.emitLoad(0, jsUndefined());
-    generator.emitDebugHook(WillLeaveCallFrame, firstLine(), lastLine());
-    generator.emitReturn(r0);
     return 0;
 }