Imported QtWebKit TP3 (git b57bc6801f1876c3220d5a4bfea33d620d477443)

Change-Id: I3b1d8a2808782c9f34d50240000e20cb38d3680f
Reviewed-by: Konstantin Tokarev <annulen@yandex.ru>

1 files changed, 1961 insertions, 500 deletions

diff --git a/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp b/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp
index 2062df3d9..06d114861 100644
--- a/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp
+++ b/Source/JavaScriptCore/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, 2012, 2013 Apple Inc. All rights reserved.
+*  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012, 2013, 2015 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>
@@ -28,21 +28,26 @@
 #include "Nodes.h"
 #include "NodeConstructors.h"
 
+#include "BuiltinNames.h"
 #include "BytecodeGenerator.h"
 #include "CallFrame.h"
 #include "Debugger.h"
 #include "JIT.h"
 #include "JSFunction.h"
+#include "JSGeneratorFunction.h"
 #include "JSGlobalObject.h"
-#include "JSNameScope.h"
+#include "JSONObject.h"
 #include "LabelScope.h"
 #include "Lexer.h"
-#include "Operations.h"
+#include "JSCInlines.h"
+#include "JSTemplateRegistryKey.h"
 #include "Parser.h"
 #include "PropertyNameArray.h"
 #include "RegExpCache.h"
 #include "RegExpObject.h"
 #include "SamplingTool.h"
+#include "StackAlignment.h"
+#include "TemplateRegistryKey.h"
 #include <wtf/Assertions.h>
 #include <wtf/RefCountedLeakCounter.h>
 #include <wtf/Threading.h>
@@ -119,6 +124,15 @@ JSValue StringNode::jsValue(BytecodeGenerator& generator) const
     return generator.addStringConstant(m_value);
 }
 
+// ------------------------------ NumberNode ----------------------------------
+
+RegisterID* NumberNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (dst == generator.ignoredResult())
+        return nullptr;
+    return generator.emitLoad(dst, jsValue(generator), isIntegerNode() ? SourceCodeRepresentation::Integer : SourceCodeRepresentation::Double);
+}
+
 // ------------------------------ RegExpNode -----------------------------------
 
 RegisterID* RegExpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
@@ -132,30 +146,197 @@ RegisterID* RegExpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* d
 
 RegisterID* ThisNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
+    if (generator.constructorKind() == ConstructorKind::Derived && generator.needsToUpdateArrowFunctionContext())
+        generator.emitLoadThisFromArrowFunctionLexicalEnvironment();
+
+    if (m_shouldAlwaysEmitTDZCheck || generator.constructorKind() == ConstructorKind::Derived || generator.isDerivedConstructorContext())
+        generator.emitTDZCheck(generator.thisRegister());
+
     if (dst == generator.ignoredResult())
         return 0;
-    return generator.moveToDestinationIfNeeded(dst, generator.thisRegister());
+
+    RegisterID* result = generator.moveToDestinationIfNeeded(dst, generator.thisRegister());
+    static const unsigned thisLength = 4;
+    generator.emitProfileType(generator.thisRegister(), position(), JSTextPosition(-1, position().offset + thisLength, -1));
+    return result;
+}
+
+// ------------------------------ SuperNode -------------------------------------
+
+RegisterID* SuperNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (dst == generator.ignoredResult())
+        return 0;
+
+    if (generator.isDerivedConstructorContext())
+        return generator.emitGetById(generator.finalDestination(dst), generator.emitLoadDerivedConstructorFromArrowFunctionLexicalEnvironment(), generator.propertyNames().underscoreProto);
+
+    RegisterID callee;
+    callee.setIndex(JSStack::Callee);
+    return generator.emitGetById(generator.finalDestination(dst), &callee, generator.propertyNames().underscoreProto);
+}
+
+static RegisterID* emitHomeObjectForCallee(BytecodeGenerator& generator)
+{
+    if (generator.isDerivedClassContext() || generator.isDerivedConstructorContext()) {
+        RegisterID* derivedConstructor = generator.emitLoadDerivedConstructorFromArrowFunctionLexicalEnvironment();
+        return generator.emitGetById(generator.newTemporary(), derivedConstructor, generator.propertyNames().homeObjectPrivateName);
+    }
+
+    RegisterID callee;
+    callee.setIndex(JSStack::Callee);
+    return generator.emitGetById(generator.newTemporary(), &callee, generator.propertyNames().homeObjectPrivateName);
+}
+
+static RegisterID* emitSuperBaseForCallee(BytecodeGenerator& generator)
+{
+    RefPtr<RegisterID> homeObject = emitHomeObjectForCallee(generator);
+    return generator.emitGetById(generator.newTemporary(), homeObject.get(), generator.propertyNames().underscoreProto);
+}
+
+// ------------------------------ NewTargetNode ----------------------------------
+
+RegisterID* NewTargetNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (dst == generator.ignoredResult())
+        return nullptr;
+
+    return generator.moveToDestinationIfNeeded(dst, generator.newTarget());
 }
 
 // ------------------------------ ResolveNode ----------------------------------
 
 bool ResolveNode::isPure(BytecodeGenerator& generator) const
 {
-    return generator.resolve(m_ident).isStatic();
+    return generator.variable(m_ident).offset().isStack();
 }
 
 RegisterID* ResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ResolveResult resolveResult = generator.resolve(m_ident);
-    if (RegisterID* local = resolveResult.local()) {
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
         if (dst == generator.ignoredResult())
-            return 0;
+            return nullptr;
+
+        generator.emitProfileType(local, var, m_position, JSTextPosition(-1, m_position.offset + m_ident.length(), -1));
         return generator.moveToDestinationIfNeeded(dst, local);
     }
-
+    
     JSTextPosition divot = m_start + m_ident.length();
     generator.emitExpressionInfo(divot, m_start, divot);
-    return generator.emitResolve(generator.finalDestination(dst), resolveResult, m_ident);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(dst, var);
+    RegisterID* finalDest = generator.finalDestination(dst);
+    RegisterID* result = generator.emitGetFromScope(finalDest, scope.get(), var, ThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, finalDest, nullptr);
+    generator.emitProfileType(finalDest, var, m_position, JSTextPosition(-1, m_position.offset + m_ident.length(), -1));
+    return result;
+}
+
+// ------------------------------ TemplateStringNode -----------------------------------
+
+RegisterID* TemplateStringNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (dst == generator.ignoredResult())
+        return nullptr;
+    return generator.emitLoad(dst, JSValue(generator.addStringConstant(cooked())));
+}
+
+// ------------------------------ TemplateLiteralNode -----------------------------------
+
+RegisterID* TemplateLiteralNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (!m_templateExpressions) {
+        TemplateStringNode* templateString = m_templateStrings->value();
+        ASSERT_WITH_MESSAGE(!m_templateStrings->next(), "Only one template element exists because there's no expression in a given template literal.");
+        return generator.emitNode(dst, templateString);
+    }
+
+    Vector<RefPtr<RegisterID>, 16> temporaryRegisters;
+
+    TemplateStringListNode* templateString = m_templateStrings;
+    TemplateExpressionListNode* templateExpression = m_templateExpressions;
+    for (; templateExpression; templateExpression = templateExpression->next(), templateString = templateString->next()) {
+        // Evaluate TemplateString.
+        if (!templateString->value()->cooked().isEmpty()) {
+            temporaryRegisters.append(generator.newTemporary());
+            generator.emitNode(temporaryRegisters.last().get(), templateString->value());
+        }
+
+        // Evaluate Expression.
+        temporaryRegisters.append(generator.newTemporary());
+        generator.emitNode(temporaryRegisters.last().get(), templateExpression->value());
+        generator.emitToString(temporaryRegisters.last().get(), temporaryRegisters.last().get());
+    }
+
+    // Evaluate tail TemplateString.
+    if (!templateString->value()->cooked().isEmpty()) {
+        temporaryRegisters.append(generator.newTemporary());
+        generator.emitNode(temporaryRegisters.last().get(), templateString->value());
+    }
+
+    return generator.emitStrcat(generator.finalDestination(dst, temporaryRegisters[0].get()), temporaryRegisters[0].get(), temporaryRegisters.size());
+}
+
+// ------------------------------ TaggedTemplateNode -----------------------------------
+
+RegisterID* TaggedTemplateNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ExpectedFunction expectedFunction = NoExpectedFunction;
+    RefPtr<RegisterID> tag = nullptr;
+    RefPtr<RegisterID> base = nullptr;
+    if (!m_tag->isLocation()) {
+        tag = generator.newTemporary();
+        tag = generator.emitNode(tag.get(), m_tag);
+    } else if (m_tag->isResolveNode()) {
+        ResolveNode* resolve = static_cast<ResolveNode*>(m_tag);
+        const Identifier& identifier = resolve->identifier();
+        expectedFunction = generator.expectedFunctionForIdentifier(identifier);
+
+        Variable var = generator.variable(identifier);
+        if (RegisterID* local = var.local())
+            tag = generator.emitMove(generator.newTemporary(), local);
+        else {
+            tag = generator.newTemporary();
+            base = generator.newTemporary();
+
+            JSTextPosition newDivot = divotStart() + identifier.length();
+            generator.emitExpressionInfo(newDivot, divotStart(), newDivot);
+            generator.moveToDestinationIfNeeded(base.get(), generator.emitResolveScope(base.get(), var));
+            generator.emitGetFromScope(tag.get(), base.get(), var, ThrowIfNotFound);
+        }
+    } else if (m_tag->isBracketAccessorNode()) {
+        BracketAccessorNode* bracket = static_cast<BracketAccessorNode*>(m_tag);
+        base = generator.newTemporary();
+        base = generator.emitNode(base.get(), bracket->base());
+        RefPtr<RegisterID> property = generator.emitNode(bracket->subscript());
+        tag = generator.emitGetByVal(generator.newTemporary(), base.get(), property.get());
+    } else {
+        ASSERT(m_tag->isDotAccessorNode());
+        DotAccessorNode* dot = static_cast<DotAccessorNode*>(m_tag);
+        base = generator.newTemporary();
+        base = generator.emitNode(base.get(), dot->base());
+        tag = generator.emitGetById(generator.newTemporary(), base.get(), dot->identifier());
+    }
+
+    RefPtr<RegisterID> templateObject = generator.emitGetTemplateObject(generator.newTemporary(), this);
+
+    unsigned expressionsCount = 0;
+    for (TemplateExpressionListNode* templateExpression = m_templateLiteral->templateExpressions(); templateExpression; templateExpression = templateExpression->next())
+        ++expressionsCount;
+
+    CallArguments callArguments(generator, nullptr, 1 + expressionsCount);
+    if (base)
+        generator.emitMove(callArguments.thisRegister(), base.get());
+    else
+        generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+
+    unsigned argumentIndex = 0;
+    generator.emitMove(callArguments.argumentRegister(argumentIndex++), templateObject.get());
+    for (TemplateExpressionListNode* templateExpression = m_templateLiteral->templateExpressions(); templateExpression; templateExpression = templateExpression->next())
+        generator.emitNode(callArguments.argumentRegister(argumentIndex++), templateExpression->value());
+
+    return generator.emitCall(generator.finalDestination(dst, tag.get()), tag.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
 }
 
 // ------------------------------ ArrayNode ------------------------------------
@@ -167,7 +348,7 @@ RegisterID* ArrayNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
     unsigned length = 0;
     ElementNode* firstPutElement;
     for (firstPutElement = m_element; firstPutElement; firstPutElement = firstPutElement->next()) {
-        if (firstPutElement->elision())
+        if (firstPutElement->elision() || firstPutElement->value()->isSpreadExpression())
             break;
         ++length;
     }
@@ -176,8 +357,10 @@ RegisterID* ArrayNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
         return generator.emitNewArray(generator.finalDestination(dst), m_element, length);
 
     RefPtr<RegisterID> array = generator.emitNewArray(generator.tempDestination(dst), m_element, length);
-
-    for (ElementNode* n = firstPutElement; n; n = n->next()) {
+    ElementNode* n = firstPutElement;
+    for (; n; n = n->next()) {
+        if (n->value()->isSpreadExpression())
+            goto handleSpread;
         RegisterID* value = generator.emitNode(n->value());
         length += n->elision();
         generator.emitPutByIndex(array.get(), length++, value);
@@ -189,6 +372,31 @@ RegisterID* ArrayNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
     }
 
     return generator.moveToDestinationIfNeeded(dst, array.get());
+    
+handleSpread:
+    RefPtr<RegisterID> index = generator.emitLoad(generator.newTemporary(), jsNumber(length));
+    auto spreader = [this, array, index](BytecodeGenerator& generator, RegisterID* value)
+    {
+        generator.emitDirectPutByVal(array.get(), index.get(), value);
+        generator.emitInc(index.get());
+    };
+    for (; n; n = n->next()) {
+        if (n->elision())
+            generator.emitBinaryOp(op_add, index.get(), index.get(), generator.emitLoad(0, jsNumber(n->elision())), OperandTypes(ResultType::numberTypeIsInt32(), ResultType::numberTypeIsInt32()));
+        if (n->value()->isSpreadExpression()) {
+            SpreadExpressionNode* spread = static_cast<SpreadExpressionNode*>(n->value());
+            generator.emitEnumeration(spread, spread->expression(), spreader);
+        } else {
+            generator.emitDirectPutByVal(array.get(), index.get(), generator.emitNode(n->value()));
+            generator.emitInc(index.get());
+        }
+    }
+    
+    if (m_elision) {
+        generator.emitBinaryOp(op_add, index.get(), index.get(), generator.emitLoad(0, jsNumber(m_elision)), OperandTypes(ResultType::numberTypeIsInt32(), ResultType::numberTypeIsInt32()));
+        generator.emitPutById(array.get(), generator.propertyNames().length, index.get());
+    }
+    return generator.moveToDestinationIfNeeded(dst, array.get());
 }
 
 bool ArrayNode::isSimpleArray() const
@@ -202,7 +410,7 @@ bool ArrayNode::isSimpleArray() const
     return true;
 }
 
-ArgumentListNode* ArrayNode::toArgumentList(VM* vm, int lineNumber, int startPosition) const
+ArgumentListNode* ArrayNode::toArgumentList(ParserArena& parserArena, int lineNumber, int startPosition) const
 {
     ASSERT(!m_elision && !m_optional);
     ElementNode* ptr = m_element;
@@ -211,12 +419,12 @@ ArgumentListNode* ArrayNode::toArgumentList(VM* vm, int lineNumber, int startPos
     JSTokenLocation location;
     location.line = lineNumber;
     location.startOffset = startPosition;
-    ArgumentListNode* head = new (vm) ArgumentListNode(location, ptr->value());
+    ArgumentListNode* head = new (parserArena) ArgumentListNode(location, ptr->value());
     ArgumentListNode* tail = head;
     ptr = ptr->next();
     for (; ptr; ptr = ptr->next()) {
         ASSERT(!ptr->elision());
-        tail = new (vm) ArgumentListNode(location, tail, ptr->value());
+        tail = new (parserArena) ArgumentListNode(location, tail, ptr->value());
     }
     return head;
 }
@@ -225,134 +433,223 @@ ArgumentListNode* ArrayNode::toArgumentList(VM* vm, int lineNumber, int startPos
 
 RegisterID* ObjectLiteralNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-     if (!m_list) {
-         if (dst == generator.ignoredResult())
-             return 0;
-         return generator.emitNewObject(generator.finalDestination(dst));
-     }
-     return generator.emitNode(dst, m_list);
+    if (!m_list) {
+        if (dst == generator.ignoredResult())
+            return 0;
+        return generator.emitNewObject(generator.finalDestination(dst));
+    }
+    RefPtr<RegisterID> newObj = generator.emitNewObject(generator.tempDestination(dst));
+    generator.emitNode(newObj.get(), m_list);
+    return generator.moveToDestinationIfNeeded(dst, newObj.get());
 }
 
 // ------------------------------ PropertyListNode -----------------------------
 
+static inline void emitPutHomeObject(BytecodeGenerator& generator, RegisterID* function, RegisterID* homeObject)
+{
+    generator.emitPutById(function, generator.propertyNames().homeObjectPrivateName, homeObject);
+}
+
 RegisterID* PropertyListNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RefPtr<RegisterID> newObj = generator.tempDestination(dst);
-    
-    generator.emitNewObject(newObj.get());
-    
     // 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));
+    for (; p && (p->m_node->m_type & PropertyNode::Constant); p = p->m_next)
+        emitPutConstantProperty(generator, dst, *p->m_node);
 
     // Were there any get/set properties?
     if (p) {
+        // Build a list of getter/setter pairs to try to put them at the same time. If we encounter
+        // a computed property, just emit everything as that may override previous values.
+        bool hasComputedProperty = false;
+
         typedef std::pair<PropertyNode*, PropertyNode*> GetterSetterPair;
-        typedef HashMap<StringImpl*, GetterSetterPair> GetterSetterMap;
+        typedef HashMap<UniquedStringImpl*, GetterSetterPair, IdentifierRepHash> 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)
+            if (node->m_type & PropertyNode::Computed) {
+                hasComputedProperty = true;
+                break;
+            }
+            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->value.second = node;
+            // Duplicates are possible.
+            GetterSetterPair pair(node, static_cast<PropertyNode*>(nullptr));
+            GetterSetterMap::AddResult result = map.add(node->name()->impl(), pair);
+            if (!result.isNewEntry) {
+                if (result.iterator->value.first->m_type == node->m_type)
+                    result.iterator->value.first = node;
+                else
+                    result.iterator->value.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);
+            if (node->m_type & PropertyNode::Constant) {
+                emitPutConstantProperty(generator, dst, *node);
+                continue;
+            }
+
+            RefPtr<RegisterID> value = generator.emitNode(node->m_assign);
+            bool isClassProperty = node->needsSuperBinding();
+            if (isClassProperty)
+                emitPutHomeObject(generator, value.get(), dst);
+            unsigned attribute = isClassProperty ? (Accessor | DontEnum) : Accessor;
+
+            ASSERT(node->m_type & (PropertyNode::Getter | PropertyNode::Setter));
+
+            // This is a get/set property which may be overridden by a computed property later.
+            if (hasComputedProperty) {
+                // Computed accessors.
+                if (node->m_type & PropertyNode::Computed) {
+                    RefPtr<RegisterID> propertyName = generator.emitNode(node->m_expression);
+                    if (node->m_type & PropertyNode::Getter)
+                        generator.emitPutGetterByVal(dst, propertyName.get(), attribute, value.get());
+                    else
+                        generator.emitPutSetterByVal(dst, propertyName.get(), attribute, value.get());
+                    continue;
+                }
+
+                if (node->m_type & PropertyNode::Getter)
+                    generator.emitPutGetterById(dst, *node->name(), attribute, value.get());
+                else
+                    generator.emitPutSetterById(dst, *node->name(), attribute, value.get());
                 continue;
             }
 
-            // 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());
+            // This is a get/set property pair.
+            GetterSetterMap::iterator it = map.find(node->name()->impl());
             ASSERT(it != map.end());
             GetterSetterPair& pair = it->value;
 
             // 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;
+            RegisterID* secondReg = nullptr;
 
-            if (node->m_type == PropertyNode::Getter) {
+            if (node->m_type & PropertyNode::Getter) {
                 getterReg = value;
                 if (pair.second) {
-                    ASSERT(pair.second->m_type == PropertyNode::Setter);
+                    ASSERT(pair.second->m_type & PropertyNode::Setter);
                     setterReg = generator.emitNode(pair.second->m_assign);
+                    secondReg = setterReg.get();
                 } else {
                     setterReg = generator.newTemporary();
                     generator.emitLoad(setterReg.get(), jsUndefined());
                 }
             } else {
-                ASSERT(node->m_type == PropertyNode::Setter);
+                ASSERT(node->m_type & PropertyNode::Setter);
                 setterReg = value;
                 if (pair.second) {
-                    ASSERT(pair.second->m_type == PropertyNode::Getter);
+                    ASSERT(pair.second->m_type & PropertyNode::Getter);
                     getterReg = generator.emitNode(pair.second->m_assign);
+                    secondReg = getterReg.get();
                 } else {
                     getterReg = generator.newTemporary();
                     generator.emitLoad(getterReg.get(), jsUndefined());
                 }
             }
 
-            generator.emitPutGetterSetter(newObj.get(), node->name(), getterReg.get(), setterReg.get());
+            ASSERT(!pair.second || isClassProperty == pair.second->needsSuperBinding());
+            if (isClassProperty && pair.second)
+                emitPutHomeObject(generator, secondReg, dst);
+
+            generator.emitPutGetterSetter(dst, *node->name(), attribute, getterReg.get(), setterReg.get());
         }
     }
 
-    return generator.moveToDestinationIfNeeded(dst, newObj.get());
+    return dst;
+}
+
+void PropertyListNode::emitPutConstantProperty(BytecodeGenerator& generator, RegisterID* newObj, PropertyNode& node)
+{
+    RefPtr<RegisterID> value = generator.emitNode(node.m_assign);
+    if (node.needsSuperBinding()) {
+        emitPutHomeObject(generator, value.get(), newObj);
+
+        RefPtr<RegisterID> propertyNameRegister;
+        if (node.name())
+            propertyNameRegister = generator.emitLoad(generator.newTemporary(), *node.name());
+        else
+            propertyNameRegister = generator.emitNode(node.m_expression);
+
+        generator.emitCallDefineProperty(newObj, propertyNameRegister.get(),
+            value.get(), nullptr, nullptr, BytecodeGenerator::PropertyConfigurable | BytecodeGenerator::PropertyWritable, m_position);
+        return;
+    }
+    if (const auto* identifier = node.name()) {
+        Optional<uint32_t> optionalIndex = parseIndex(*identifier);
+        if (!optionalIndex) {
+            generator.emitDirectPutById(newObj, *identifier, value.get(), node.putType());
+            return;
+        }
+
+        RefPtr<RegisterID> index = generator.emitLoad(generator.newTemporary(), jsNumber(optionalIndex.value()));
+        generator.emitDirectPutByVal(newObj, index.get(), value.get());
+        return;
+    }
+    RefPtr<RegisterID> propertyName = generator.emitNode(node.m_expression);
+    generator.emitDirectPutByVal(newObj, propertyName.get(), value.get());
 }
 
 // ------------------------------ BracketAccessorNode --------------------------------
 
+static bool isNonIndexStringElement(ExpressionNode& element)
+{
+    return element.isString() && !parseIndex(static_cast<StringNode&>(element).value());
+}
+
 RegisterID* BracketAccessorNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    if (m_base->isResolveNode() 
-        && generator.willResolveToArguments(static_cast<ResolveNode*>(m_base)->identifier())
-        && !generator.symbolTable().slowArguments()) {
+    if (m_base->isSuperNode()) {
+        // FIXME: Should we generate the profiler info?
+        if (isNonIndexStringElement(*m_subscript)) {
+            const Identifier& id = static_cast<StringNode*>(m_subscript)->value();
+            return generator.emitGetById(generator.finalDestination(dst), emitSuperBaseForCallee(generator), id);
+        }
+        return generator.emitGetByVal(generator.finalDestination(dst), emitSuperBaseForCallee(generator), generator.emitNode(m_subscript));
+    }
+
+    RegisterID* ret;
+    RegisterID* finalDest = generator.finalDestination(dst);
+
+    if (isNonIndexStringElement(*m_subscript)) {
+        RefPtr<RegisterID> base = generator.emitNode(m_base);
+        ret = generator.emitGetById(finalDest, base.get(), static_cast<StringNode*>(m_subscript)->value());
+    } else {
+        RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_subscriptHasAssignments, m_subscript->isPure(generator));
         RegisterID* property = generator.emitNode(m_subscript);
-        generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-        return generator.emitGetArgumentByVal(generator.finalDestination(dst), generator.uncheckedRegisterForArguments(), property);
+        ret = generator.emitGetByVal(finalDest, base.get(), property);
     }
 
-    RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_subscriptHasAssignments, m_subscript->isPure(generator));
-    RegisterID* property = generator.emitNode(m_subscript);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitGetByVal(generator.finalDestination(dst), base.get(), property);
+
+    generator.emitProfileType(finalDest, divotStart(), divotEnd());
+    return ret;
 }
 
 // ------------------------------ DotAccessorNode --------------------------------
 
 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(), divotStart(), divotEnd());
-        return generator.emitGetArgumentsLength(generator.finalDestination(dst), generator.uncheckedRegisterForArguments());
-    }
-
-nonArgumentsPath:
-    RegisterID* base = generator.emitNode(m_base);
+    RefPtr<RegisterID> base = m_base->isSuperNode() ? emitSuperBaseForCallee(generator) : generator.emitNode(m_base);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitGetById(generator.finalDestination(dst), base, m_ident);
+    RegisterID* finalDest = generator.finalDestination(dst);
+    RegisterID* ret = generator.emitGetById(finalDest, base.get(), m_ident);
+    generator.emitProfileType(finalDest, divotStart(), divotEnd());
+    return ret;
 }
 
 // ------------------------------ ArgumentListNode -----------------------------
@@ -373,17 +670,20 @@ RegisterID* NewExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
     else
         expectedFunction = NoExpectedFunction;
     RefPtr<RegisterID> func = generator.emitNode(m_expr);
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, func.get());
     CallArguments callArguments(generator, m_args);
-    return generator.emitConstruct(generator.finalDestinationOrIgnored(dst), func.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitMove(callArguments.thisRegister(), func.get());
+    return generator.emitConstruct(returnValue.get(), func.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
 }
 
-inline CallArguments::CallArguments(BytecodeGenerator& generator, ArgumentsNode* argumentsNode)
+CallArguments::CallArguments(BytecodeGenerator& generator, ArgumentsNode* argumentsNode, unsigned additionalArguments)
     : m_argumentsNode(argumentsNode)
+    , m_padding(0)
 {
     if (generator.shouldEmitProfileHooks())
         m_profileHookRegister = generator.newTemporary();
 
-    size_t argumentCountIncludingThis = 1; // 'this' register.
+    size_t argumentCountIncludingThis = 1 + additionalArguments; // 'this' register.
     if (argumentsNode) {
         for (ArgumentListNode* node = argumentsNode->m_listNode; node; node = node->m_next)
             ++argumentCountIncludingThis;
@@ -392,26 +692,56 @@ inline CallArguments::CallArguments(BytecodeGenerator& generator, ArgumentsNode*
     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);
+        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());
+    // We need to ensure that the frame size is stack-aligned
+    while ((JSStack::CallFrameHeaderSize + m_argv.size()) % stackAlignmentRegisters()) {
+        m_argv.insert(0, generator.newTemporary());
+        m_padding++;
+    }
+    
+    while (stackOffset() % stackAlignmentRegisters()) {
+        m_argv.insert(0, generator.newTemporary());
+        m_padding++;
+    }
 }
 
 // ------------------------------ EvalFunctionCallNode ----------------------------------
 
 RegisterID* EvalFunctionCallNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RefPtr<RegisterID> func = generator.tempDestination(dst);
+    // We need try to load 'this' before call eval in constructor, because 'this' can created by 'super' in some of the arrow function
+    // var A = class A {
+    //   constructor () { this.id = 'A'; }
+    // }
+    //
+    // var B = class B extend A {
+    //    constructor () {
+    //       var arrow = () => super();
+    //       arrow();
+    //       eval("this.id = 'B'");
+    //    }
+    // }
+    if (generator.constructorKind() == ConstructorKind::Derived && generator.needsToUpdateArrowFunctionContext())
+        generator.emitLoadThisFromArrowFunctionLexicalEnvironment();
+
+    Variable var = generator.variable(generator.propertyNames().eval);
+    if (RegisterID* local = var.local()) {
+        RefPtr<RegisterID> func = generator.emitMove(generator.tempDestination(dst), local);
+        CallArguments callArguments(generator, m_args);
+        generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+        return generator.emitCallEval(generator.finalDestination(dst, func.get()), func.get(), callArguments, divot(), divotStart(), divotEnd());
+    }
+
+    RefPtr<RegisterID> func = generator.newTemporary();
     CallArguments callArguments(generator, m_args);
     JSTextPosition newDivot = divotStart() + 4;
     generator.emitExpressionInfo(newDivot, divotStart(), newDivot);
-    generator.emitResolveWithThis(callArguments.thisRegister(), func.get(), generator.resolve(generator.propertyNames().eval), generator.propertyNames().eval);
+    generator.moveToDestinationIfNeeded(
+        callArguments.thisRegister(),
+        generator.emitResolveScope(callArguments.thisRegister(), var));
+    generator.emitGetFromScope(func.get(), callArguments.thisRegister(), var, ThrowIfNotFound);
     return generator.emitCallEval(generator.finalDestination(dst, func.get()), func.get(), callArguments, divot(), divotStart(), divotEnd());
 }
 
@@ -420,9 +750,25 @@ RegisterID* EvalFunctionCallNode::emitBytecode(BytecodeGenerator& generator, Reg
 RegisterID* FunctionCallValueNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> func = generator.emitNode(m_expr);
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, func.get());
     CallArguments callArguments(generator, m_args);
+    if (m_expr->isSuperNode()) {
+        ASSERT(generator.isConstructor() || generator.derivedContextType() == DerivedContextType::DerivedConstructorContext);
+        ASSERT(generator.constructorKind() == ConstructorKind::Derived || generator.derivedContextType() == DerivedContextType::DerivedConstructorContext);
+        generator.emitMove(callArguments.thisRegister(), generator.newTarget());
+        RegisterID* ret = generator.emitConstruct(returnValue.get(), func.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        generator.emitMove(generator.thisRegister(), ret);
+        
+        bool isConstructorKindDerived = generator.constructorKind() == ConstructorKind::Derived;
+        if (generator.isDerivedConstructorContext() || (isConstructorKindDerived && generator.needsToUpdateArrowFunctionContext()))
+            generator.emitPutThisToArrowFunctionContextScope();
+        
+        return ret;
+    }
     generator.emitLoad(callArguments.thisRegister(), jsUndefined());
-    return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    RegisterID* ret = generator.emitCallInTailPosition(returnValue.get(), func.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return ret;
 }
 
 // ------------------------------ FunctionCallResolveNode ----------------------------------
@@ -430,45 +776,138 @@ RegisterID* FunctionCallValueNode::emitBytecode(BytecodeGenerator& generator, Re
 RegisterID* FunctionCallResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     ExpectedFunction expectedFunction = generator.expectedFunctionForIdentifier(m_ident);
-    ResolveResult resolveResult = generator.resolve(m_ident);
 
-    if (RegisterID* local = resolveResult.local()) {
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
         RefPtr<RegisterID> func = generator.emitMove(generator.tempDestination(dst), local);
+        RefPtr<RegisterID> returnValue = generator.finalDestination(dst, func.get());
         CallArguments callArguments(generator, m_args);
         generator.emitLoad(callArguments.thisRegister(), jsUndefined());
         // This passes NoExpectedFunction because we expect that if the function is in a
         // local variable, then it's not one of our built-in constructors.
-        return generator.emitCall(generator.finalDestinationOrIgnored(dst, callArguments.thisRegister()), func.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
-    }
-
-    if (resolveResult.isStatic()) {
-        RefPtr<RegisterID> func = generator.newTemporary();
-        CallArguments callArguments(generator, m_args);
-        generator.emitGetStaticVar(func.get(), resolveResult, m_ident);
-        generator.emitLoad(callArguments.thisRegister(), jsUndefined());
-        return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        RegisterID* ret = generator.emitCallInTailPosition(returnValue.get(), func.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+        return ret;
     }
 
     RefPtr<RegisterID> func = generator.newTemporary();
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, func.get());
     CallArguments callArguments(generator, m_args);
 
     JSTextPosition newDivot = divotStart() + m_ident.length();
     generator.emitExpressionInfo(newDivot, divotStart(), newDivot);
-    generator.emitResolveWithThis(callArguments.thisRegister(), func.get(), resolveResult, m_ident);
-    return generator.emitCall(generator.finalDestinationOrIgnored(dst, func.get()), func.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.moveToDestinationIfNeeded(
+        callArguments.thisRegister(),
+        generator.emitResolveScope(callArguments.thisRegister(), var));
+    generator.emitGetFromScope(func.get(), callArguments.thisRegister(), var, ThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, func.get(), nullptr);
+    RegisterID* ret = generator.emitCallInTailPosition(returnValue.get(), func.get(), expectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return ret;
+}
+
+// ------------------------------ BytecodeIntrinsicNode ----------------------------------
+
+RegisterID* BytecodeIntrinsicNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    return (this->*m_emitter)(generator, dst);
+}
+
+RegisterID* BytecodeIntrinsicNode::emit_intrinsic_assert(BytecodeGenerator& generator, RegisterID* dst)
+{
+#ifndef NDEBUG
+    ArgumentListNode* node = m_args->m_listNode;
+    RefPtr<RegisterID> condition = generator.emitNode(node);
+    generator.emitAssert(condition.get(), node->firstLine());
+    return dst;
+#else
+    UNUSED_PARAM(generator);
+    return dst;
+#endif
+}
+
+RegisterID* BytecodeIntrinsicNode::emit_intrinsic_putByValDirect(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ArgumentListNode* node = m_args->m_listNode;
+    RefPtr<RegisterID> base = generator.emitNode(node);
+    node = node->m_next;
+    RefPtr<RegisterID> index = generator.emitNode(node);
+    node = node->m_next;
+    RefPtr<RegisterID> value = generator.emitNode(node);
+
+    ASSERT(!node->m_next);
+
+    return generator.moveToDestinationIfNeeded(dst, generator.emitDirectPutByVal(base.get(), index.get(), value.get()));
+}
+
+RegisterID* BytecodeIntrinsicNode::emit_intrinsic_toString(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ArgumentListNode* node = m_args->m_listNode;
+    RefPtr<RegisterID> src = generator.emitNode(node);
+    ASSERT(!node->m_next);
+
+    return generator.moveToDestinationIfNeeded(dst, generator.emitToString(generator.tempDestination(dst), src.get()));
+}
+
+RegisterID* BytecodeIntrinsicNode::emit_intrinsic_isObject(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ArgumentListNode* node = m_args->m_listNode;
+    RefPtr<RegisterID> src = generator.emitNode(node);
+    ASSERT(!node->m_next);
+
+    return generator.moveToDestinationIfNeeded(dst, generator.emitIsObject(generator.tempDestination(dst), src.get()));
 }
 
+
+#define JSC_DECLARE_BYTECODE_INTRINSIC_CONSTANT_GENERATORS(name) \
+    RegisterID* BytecodeIntrinsicNode::emit_intrinsic_##name(BytecodeGenerator& generator, RegisterID* dst) \
+    { \
+        ASSERT(!m_args); \
+        ASSERT(type() == Type::Constant); \
+        if (dst == generator.ignoredResult()) \
+            return nullptr; \
+        return generator.emitLoad(dst, generator.vm()->bytecodeIntrinsicRegistry().name##Value(generator)); \
+    }
+    JSC_COMMON_BYTECODE_INTRINSIC_CONSTANTS_EACH_NAME(JSC_DECLARE_BYTECODE_INTRINSIC_CONSTANT_GENERATORS)
+#undef JSC_DECLARE_BYTECODE_INTRINSIC_CONSTANT_GENERATORS
+
 // ------------------------------ FunctionCallBracketNode ----------------------------------
 
 RegisterID* FunctionCallBracketNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RefPtr<RegisterID> base = generator.emitNode(m_base);
-    RegisterID* property = generator.emitNode(m_subscript);
-    generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
-    RefPtr<RegisterID> function = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property);
+    bool baseIsSuper = m_base->isSuperNode();
+    bool subscriptIsNonIndexString = isNonIndexStringElement(*m_subscript);
+
+    RefPtr<RegisterID> base;
+    if (baseIsSuper)
+        base = emitSuperBaseForCallee(generator);
+    else {
+        if (subscriptIsNonIndexString)
+            base = generator.emitNode(m_base);
+        else
+            base = generator.emitNodeForLeftHandSide(m_base, m_subscriptHasAssignments, m_subscript->isPure(generator));
+    }
+
+    RefPtr<RegisterID> function;
+    if (subscriptIsNonIndexString) {
+        generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
+        function = generator.emitGetById(generator.tempDestination(dst), base.get(), static_cast<StringNode*>(m_subscript)->value());
+    } else {
+        RefPtr<RegisterID> property = generator.emitNode(m_subscript);
+        generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
+        function = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property.get());
+    }
+
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, function.get());
     CallArguments callArguments(generator, m_args);
-    generator.emitMove(callArguments.thisRegister(), base.get());
-    return generator.emitCall(generator.finalDestinationOrIgnored(dst, function.get()), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    if (baseIsSuper)
+        generator.emitMove(callArguments.thisRegister(), generator.thisRegister());
+    else
+        generator.emitMove(callArguments.thisRegister(), base.get());
+    RegisterID* ret = generator.emitCallInTailPosition(returnValue.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return ret;
 }
 
 // ------------------------------ FunctionCallDotNode ----------------------------------
@@ -476,11 +915,19 @@ RegisterID* FunctionCallBracketNode::emitBytecode(BytecodeGenerator& generator,
 RegisterID* FunctionCallDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> function = generator.tempDestination(dst);
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, function.get());
     CallArguments callArguments(generator, m_args);
-    generator.emitNode(callArguments.thisRegister(), m_base);
+    bool baseIsSuper = m_base->isSuperNode();
+    if (baseIsSuper) {
+        generator.emitTDZCheck(generator.thisRegister());
+        generator.emitMove(callArguments.thisRegister(), generator.thisRegister());
+    } else
+        generator.emitNode(callArguments.thisRegister(), m_base);
     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
-    generator.emitGetById(function.get(), callArguments.thisRegister(), m_ident);
-    return generator.emitCall(generator.finalDestinationOrIgnored(dst, function.get()), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitGetById(function.get(), baseIsSuper ? emitSuperBaseForCallee(generator) : callArguments.thisRegister(), m_ident);
+    RegisterID* ret = generator.emitCallInTailPosition(returnValue.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return ret;
 }
 
 RegisterID* CallFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
@@ -489,37 +936,53 @@ RegisterID* CallFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator,
     RefPtr<Label> end = generator.newLabel();
     RefPtr<RegisterID> base = generator.emitNode(m_base);
     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
-    RefPtr<RegisterID> function = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RefPtr<RegisterID> finalDestinationOrIgnored = generator.finalDestinationOrIgnored(dst, function.get());
-    generator.emitJumpIfNotFunctionCall(function.get(), realCall.get());
+    RefPtr<RegisterID> function;
+    bool emitCallCheck = !generator.isBuiltinFunction();
+    if (emitCallCheck) {
+        function = generator.emitGetById(generator.tempDestination(dst), base.get(), generator.propertyNames().builtinNames().callPublicName());
+        generator.emitJumpIfNotFunctionCall(function.get(), realCall.get());
+    }
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst);
     {
-        if (m_args->m_listNode && m_args->m_listNode->m_expr) {
+        if (m_args->m_listNode && m_args->m_listNode->m_expr && m_args->m_listNode->m_expr->isSpreadExpression()) {
+            RefPtr<RegisterID> profileHookRegister;
+            if (generator.shouldEmitProfileHooks())
+                profileHookRegister = generator.newTemporary();
+            SpreadExpressionNode* spread = static_cast<SpreadExpressionNode*>(m_args->m_listNode->m_expr);
+            ExpressionNode* subject = spread->expression();
+            RefPtr<RegisterID> argumentsRegister;
+            argumentsRegister = generator.emitNode(subject);
+            generator.emitExpressionInfo(spread->divot(), spread->divotStart(), spread->divotEnd());
+            RefPtr<RegisterID> thisRegister = generator.emitGetByVal(generator.newTemporary(), argumentsRegister.get(), generator.emitLoad(0, jsNumber(0)));
+            generator.emitCallVarargsInTailPosition(returnValue.get(), base.get(), thisRegister.get(), argumentsRegister.get(), generator.newTemporary(), 1, profileHookRegister.get(), divot(), divotStart(), divotEnd());
+        } else if (m_args->m_listNode && m_args->m_listNode->m_expr) {
             ArgumentListNode* oldList = m_args->m_listNode;
             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(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
-            generator.emitJump(end.get());
-
+            generator.emitCallInTailPosition(returnValue.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
             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(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
-            generator.emitJump(end.get());
+            generator.emitCallInTailPosition(returnValue.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
         }
     }
-    generator.emitLabel(realCall.get());
-    {
-        CallArguments callArguments(generator, m_args);
-        generator.emitMove(callArguments.thisRegister(), base.get());
-        generator.emitCall(finalDestinationOrIgnored.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+    if (emitCallCheck) {
+        generator.emitJump(end.get());
+        generator.emitLabel(realCall.get());
+        {
+            CallArguments callArguments(generator, m_args);
+            generator.emitMove(callArguments.thisRegister(), base.get());
+            generator.emitCallInTailPosition(returnValue.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        }
+        generator.emitLabel(end.get());
     }
-    generator.emitLabel(end.get());
-    return finalDestinationOrIgnored.get();
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return returnValue.get();
 }
 
 static bool areTrivialApplyArguments(ArgumentsNode* args)
@@ -539,66 +1002,95 @@ RegisterID* ApplyFunctionCallDotNode::emitBytecode(BytecodeGenerator& generator,
     RefPtr<Label> end = generator.newLabel();
     RefPtr<RegisterID> base = generator.emitNode(m_base);
     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
-    RefPtr<RegisterID> function = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RefPtr<RegisterID> finalDestinationOrIgnored = generator.finalDestinationOrIgnored(dst, function.get());
-    generator.emitJumpIfNotFunctionApply(function.get(), realCall.get());
-    {
-        if (mayBeCall) {
-            if (m_args->m_listNode && m_args->m_listNode->m_expr) {
-                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.vm(), 0, 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(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
-                } 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(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
-                }
-                m_args->m_listNode = oldList;
+    RefPtr<RegisterID> function;
+    RefPtr<RegisterID> returnValue = generator.finalDestination(dst, function.get());
+    bool emitCallCheck = !generator.isBuiltinFunction();
+    if (emitCallCheck) {
+        function = generator.emitGetById(generator.tempDestination(dst), base.get(), generator.propertyNames().builtinNames().applyPublicName());
+        generator.emitJumpIfNotFunctionApply(function.get(), realCall.get());
+    }
+    if (mayBeCall) {
+        if (m_args->m_listNode && m_args->m_listNode->m_expr) {
+            ArgumentListNode* oldList = m_args->m_listNode;
+            if (m_args->m_listNode->m_expr->isSpreadExpression()) {
+                SpreadExpressionNode* spread = static_cast<SpreadExpressionNode*>(m_args->m_listNode->m_expr);
+                RefPtr<RegisterID> profileHookRegister;
+                if (generator.shouldEmitProfileHooks())
+                    profileHookRegister = generator.newTemporary();
+                RefPtr<RegisterID> realFunction = generator.emitMove(generator.newTemporary(), base.get());
+                RefPtr<RegisterID> index = generator.emitLoad(generator.newTemporary(), jsNumber(0));
+                RefPtr<RegisterID> thisRegister = generator.emitLoad(generator.newTemporary(), jsUndefined());
+                RefPtr<RegisterID> argumentsRegister = generator.emitLoad(generator.newTemporary(), jsUndefined());
+                
+                auto extractor = [&thisRegister, &argumentsRegister, &index](BytecodeGenerator& generator, RegisterID* value)
+                {
+                    RefPtr<Label> haveThis = generator.newLabel();
+                    RefPtr<Label> end = generator.newLabel();
+                    RefPtr<RegisterID> compareResult = generator.newTemporary();
+                    RefPtr<RegisterID> indexZeroCompareResult = generator.emitBinaryOp(op_eq, compareResult.get(), index.get(), generator.emitLoad(0, jsNumber(0)), OperandTypes(ResultType::numberTypeIsInt32(), ResultType::numberTypeIsInt32()));
+                    generator.emitJumpIfFalse(indexZeroCompareResult.get(), haveThis.get());
+                    generator.emitMove(thisRegister.get(), value);
+                    generator.emitLoad(index.get(), jsNumber(1));
+                    generator.emitJump(end.get());
+                    generator.emitLabel(haveThis.get());
+                    RefPtr<RegisterID> indexOneCompareResult = generator.emitBinaryOp(op_eq, compareResult.get(), index.get(), generator.emitLoad(0, jsNumber(1)), OperandTypes(ResultType::numberTypeIsInt32(), ResultType::numberTypeIsInt32()));
+                    generator.emitJumpIfFalse(indexOneCompareResult.get(), end.get());
+                    generator.emitMove(argumentsRegister.get(), value);
+                    generator.emitLoad(index.get(), jsNumber(2));
+                    generator.emitLabel(end.get());
+                };
+                generator.emitEnumeration(this, spread->expression(), extractor);
+                generator.emitCallVarargsInTailPosition(returnValue.get(), realFunction.get(), thisRegister.get(), argumentsRegister.get(), generator.newTemporary(), 0, profileHookRegister.get(), divot(), divotStart(), divotEnd());
+            } else 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.parserArena(), 0, 0);
+                RefPtr<RegisterID> realFunction = generator.emitMove(generator.tempDestination(dst), base.get());
+                CallArguments callArguments(generator, m_args);
+                generator.emitNode(callArguments.thisRegister(), oldList->m_expr);
+                generator.emitCallInTailPosition(returnValue.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
             } 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.emitLoad(callArguments.thisRegister(), jsUndefined());
-                generator.emitCall(finalDestinationOrIgnored.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+                generator.emitNode(callArguments.thisRegister(), oldList->m_expr);
+                generator.emitCallInTailPosition(returnValue.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
             }
+            m_args->m_listNode = oldList;
         } else {
-            ASSERT(m_args->m_listNode && m_args->m_listNode->m_next);
-            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;
-            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.emitCallVarargs(finalDestinationOrIgnored.get(), realFunction.get(), thisRegister.get(), argsRegister.get(), generator.newTemporary(), profileHookRegister.get(), divot(), divotStart(), divotEnd());
+            CallArguments callArguments(generator, m_args);
+            generator.emitLoad(callArguments.thisRegister(), jsUndefined());
+            generator.emitCallInTailPosition(returnValue.get(), realFunction.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
         }
-        generator.emitJump(end.get());
+    } else {
+        ASSERT(m_args->m_listNode && m_args->m_listNode->m_next);
+        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;
+        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.emitCallVarargsInTailPosition(returnValue.get(), realFunction.get(), thisRegister.get(), argsRegister.get(), generator.newTemporary(), 0, profileHookRegister.get(), divot(), divotStart(), divotEnd());
     }
-    generator.emitLabel(realCall.get());
-    {
+    if (emitCallCheck) {
+        generator.emitJump(end.get());
+        generator.emitLabel(realCall.get());
         CallArguments callArguments(generator, m_args);
         generator.emitMove(callArguments.thisRegister(), base.get());
-        generator.emitCall(finalDestinationOrIgnored.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        generator.emitCallInTailPosition(returnValue.get(), function.get(), NoExpectedFunction, callArguments, divot(), divotStart(), divotEnd());
+        generator.emitLabel(end.get());
     }
-    generator.emitLabel(end.get());
-    return finalDestinationOrIgnored.get();
+    generator.emitProfileType(returnValue.get(), divotStart(), divotEnd());
+    return returnValue.get();
 }
 
 // ------------------------------ PostfixNode ----------------------------------
@@ -626,29 +1118,34 @@ RegisterID* PostfixNode::emitResolve(BytecodeGenerator& generator, RegisterID* d
     ResolveNode* resolve = static_cast<ResolveNode*>(m_expr);
     const Identifier& ident = resolve->identifier();
 
-    ResolveResult resolveResult = generator.resolve(ident);
-
-    if (RefPtr<RegisterID> local = resolveResult.local()) {
-        if (resolveResult.isReadOnly()) {
-            generator.emitReadOnlyExceptionIfNeeded();
-            local = generator.emitMove(generator.tempDestination(dst), local.get());
+    Variable var = generator.variable(ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
+        RefPtr<RegisterID> localReg = local;
+        if (var.isReadOnly()) {
+            generator.emitReadOnlyExceptionIfNeeded(var);
+            localReg = generator.emitMove(generator.tempDestination(dst), local);
         }
-        return emitPostIncOrDec(generator, generator.finalDestination(dst), local.get(), m_operator);
-    }
-
-    if (resolveResult.isStatic() && !resolveResult.isReadOnly()) {
-        RefPtr<RegisterID> value = generator.emitGetStaticVar(generator.newTemporary(), resolveResult, ident);
-        RefPtr<RegisterID> oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
-        generator.emitPutStaticVar(resolveResult, ident, value.get());
+        RefPtr<RegisterID> oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), localReg.get(), m_operator);
+        generator.emitProfileType(localReg.get(), var, divotStart(), divotEnd());
         return oldValue.get();
     }
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RefPtr<RegisterID> value = generator.newTemporary();
-    NonlocalResolveInfo resolveInfo;
-    RefPtr<RegisterID> base = generator.emitResolveWithBaseForPut(generator.newTemporary(), value.get(), resolveResult, ident, resolveInfo);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+    RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), var, ThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, value.get(), nullptr);
+    if (var.isReadOnly()) {
+        bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
+        if (threwException)
+            return value.get();
+    }
     RefPtr<RegisterID> oldValue = emitPostIncOrDec(generator, generator.finalDestination(dst), value.get(), m_operator);
-    generator.emitPutToBase(base.get(), ident, value.get(), resolveInfo);
+    if (!var.isReadOnly()) {
+        generator.emitPutToScope(scope.get(), var, value.get(), ThrowIfNotFound, NotInitialization);
+        generator.emitProfileType(value.get(), var, divotStart(), divotEnd());
+    }
+
     return oldValue.get();
 }
 
@@ -670,6 +1167,7 @@ RegisterID* PostfixNode::emitBracket(BytecodeGenerator& generator, RegisterID* d
     RegisterID* oldValue = emitPostIncOrDec(generator, generator.tempDestination(dst), value.get(), m_operator);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitPutByVal(base.get(), property.get(), value.get());
+    generator.emitProfileType(value.get(), divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, oldValue);
 }
 
@@ -690,6 +1188,7 @@ RegisterID* PostfixNode::emitDot(BytecodeGenerator& generator, RegisterID* dst)
     RegisterID* oldValue = emitPostIncOrDec(generator, generator.tempDestination(dst), value.get(), m_operator);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitPutById(base.get(), ident, value.get());
+    generator.emitProfileType(value.get(), divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, oldValue);
 }
 
@@ -705,21 +1204,24 @@ RegisterID* PostfixNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
         return emitDot(generator, dst);
 
     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.");
+        ? ASCIILiteral("Postfix ++ operator applied to value that is not a reference.")
+        : ASCIILiteral("Postfix -- operator applied to value that is not a reference."));
 }
 
 // ------------------------------ DeleteResolveNode -----------------------------------
 
 RegisterID* DeleteResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ResolveResult resolveResult = generator.resolve(m_ident);
-    if (resolveResult.isRegister())
+    Variable var = generator.variable(m_ident);
+    if (var.local()) {
+        generator.emitTDZCheckIfNecessary(var, var.local(), nullptr);
         return generator.emitLoad(generator.finalDestination(dst), false);
+    }
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RegisterID* base = generator.emitResolveBase(generator.tempDestination(dst), resolveResult, m_ident);
-    return generator.emitDeleteById(generator.finalDestination(dst, base), base, m_ident);
+    RefPtr<RegisterID> base = generator.emitResolveScope(dst, var);
+    generator.emitTDZCheckIfNecessary(var, nullptr, base.get());
+    return generator.emitDeleteById(generator.finalDestination(dst, base.get()), base.get(), m_ident);
 }
 
 // ------------------------------ DeleteBracketNode -----------------------------------
@@ -727,20 +1229,24 @@ RegisterID* DeleteResolveNode::emitBytecode(BytecodeGenerator& generator, Regist
 RegisterID* DeleteBracketNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> r0 = generator.emitNode(m_base);
-    RegisterID* r1 = generator.emitNode(m_subscript);
+    RefPtr<RegisterID> r1 = generator.emitNode(m_subscript);
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitDeleteByVal(generator.finalDestination(dst), r0.get(), r1);
+    if (m_base->isSuperNode())
+        return emitThrowReferenceError(generator, "Cannot delete a super property");
+    return generator.emitDeleteByVal(generator.finalDestination(dst), r0.get(), r1.get());
 }
 
 // ------------------------------ DeleteDotNode -----------------------------------
 
 RegisterID* DeleteDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RegisterID* r0 = generator.emitNode(m_base);
+    RefPtr<RegisterID> r0 = generator.emitNode(m_base);
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitDeleteById(generator.finalDestination(dst), r0, m_ident);
+    if (m_base->isSuperNode())
+        return emitThrowReferenceError(generator, "Cannot delete a super property");
+    return generator.emitDeleteById(generator.finalDestination(dst), r0.get(), m_ident);
 }
 
 // ------------------------------ DeleteValueNode -----------------------------------
@@ -765,27 +1271,24 @@ RegisterID* VoidNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst
     return generator.emitLoad(dst, jsUndefined());
 }
 
-// ------------------------------ TypeOfValueNode -----------------------------------
+// ------------------------------ TypeOfResolveNode -----------------------------------
 
 RegisterID* TypeOfResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ResolveResult resolveResult = generator.resolve(m_ident);
-    if (RegisterID* local = resolveResult.local()) {
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
         if (dst == generator.ignoredResult())
             return 0;
         return generator.emitTypeOf(generator.finalDestination(dst), local);
     }
 
-    if (resolveResult.isStatic()) {
-        RefPtr<RegisterID> scratch = generator.emitGetStaticVar(generator.tempDestination(dst), resolveResult, m_ident);
-        return generator.emitTypeOf(generator.finalDestination(dst, scratch.get()), scratch.get());
-    }
-
-    RefPtr<RegisterID> scratch = generator.emitResolveBase(generator.tempDestination(dst), resolveResult, m_ident);
-    generator.emitGetById(scratch.get(), scratch.get(), m_ident);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(dst, var);
+    RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), var, DoNotThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, value.get(), nullptr);
     if (dst == generator.ignoredResult())
         return 0;
-    return generator.emitTypeOf(generator.finalDestination(dst, scratch.get()), scratch.get());
+    return generator.emitTypeOf(generator.finalDestination(dst, scope.get()), value.get());
 }
 
 // ------------------------------ TypeOfValueNode -----------------------------------
@@ -808,30 +1311,41 @@ RegisterID* PrefixNode::emitResolve(BytecodeGenerator& generator, RegisterID* ds
     ResolveNode* resolve = static_cast<ResolveNode*>(m_expr);
     const Identifier& ident = resolve->identifier();
 
-    ResolveResult resolveResult = generator.resolve(ident);
-    if (RefPtr<RegisterID> local = resolveResult.local()) {
-        if (resolveResult.isReadOnly()) {
-            generator.emitReadOnlyExceptionIfNeeded();
-            local = generator.emitMove(generator.tempDestination(dst), local.get());
+    Variable var = generator.variable(ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
+        RefPtr<RegisterID> localReg = local;
+        if (var.isReadOnly()) {
+            generator.emitReadOnlyExceptionIfNeeded(var);
+            localReg = generator.emitMove(generator.tempDestination(dst), localReg.get());
+        } else if (generator.vm()->typeProfiler()) {
+            RefPtr<RegisterID> tempDst = generator.tempDestination(dst);
+            generator.emitMove(tempDst.get(), localReg.get());
+            emitIncOrDec(generator, tempDst.get(), m_operator);
+            generator.emitMove(localReg.get(), tempDst.get());
+            generator.emitProfileType(localReg.get(), var, divotStart(), divotEnd());
+            return generator.moveToDestinationIfNeeded(dst, tempDst.get());
         }
-        emitIncOrDec(generator, local.get(), m_operator);
-        return generator.moveToDestinationIfNeeded(dst, local.get());
+        emitIncOrDec(generator, localReg.get(), m_operator);
+        return generator.moveToDestinationIfNeeded(dst, localReg.get());
     }
 
-    if (resolveResult.isStatic() && !resolveResult.isReadOnly()) {
-        RefPtr<RegisterID> propDst = generator.emitGetStaticVar(generator.tempDestination(dst), resolveResult, ident);
-        emitIncOrDec(generator, propDst.get(), m_operator);
-        generator.emitPutStaticVar(resolveResult, ident, propDst.get());
-        return generator.moveToDestinationIfNeeded(dst, propDst.get());
+    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+    RefPtr<RegisterID> scope = generator.emitResolveScope(dst, var);
+    RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), var, ThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, value.get(), nullptr);
+    if (var.isReadOnly()) {
+        bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
+        if (threwException)
+            return value.get();
     }
 
-    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RefPtr<RegisterID> propDst = generator.tempDestination(dst);
-    NonlocalResolveInfo resolveVerifier;
-    RefPtr<RegisterID> base = generator.emitResolveWithBaseForPut(generator.newTemporary(), propDst.get(), resolveResult, ident, resolveVerifier);
-    emitIncOrDec(generator, propDst.get(), m_operator);
-    generator.emitPutToBase(base.get(), ident, propDst.get(), resolveVerifier);
-    return generator.moveToDestinationIfNeeded(dst, propDst.get());
+    emitIncOrDec(generator, value.get(), m_operator);
+    if (!var.isReadOnly()) {
+        generator.emitPutToScope(scope.get(), var, value.get(), ThrowIfNotFound, NotInitialization);
+        generator.emitProfileType(value.get(), var, divotStart(), divotEnd());
+    }
+    return generator.moveToDestinationIfNeeded(dst, value.get());
 }
 
 RegisterID* PrefixNode::emitBracket(BytecodeGenerator& generator, RegisterID* dst)
@@ -850,6 +1364,7 @@ RegisterID* PrefixNode::emitBracket(BytecodeGenerator& generator, RegisterID* ds
     emitIncOrDec(generator, value, m_operator);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitPutByVal(base.get(), property.get(), value);
+    generator.emitProfileType(value, divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, propDst.get());
 }
 
@@ -868,6 +1383,7 @@ RegisterID* PrefixNode::emitDot(BytecodeGenerator& generator, RegisterID* dst)
     emitIncOrDec(generator, value, m_operator);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitPutById(base.get(), ident, value);
+    generator.emitProfileType(value, divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, propDst.get());
 }
 
@@ -883,17 +1399,17 @@ RegisterID* PrefixNode::emitBytecode(BytecodeGenerator& generator, RegisterID* d
         return emitDot(generator, dst);
 
     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.");
+        ? ASCIILiteral("Prefix ++ operator applied to value that is not a reference.")
+        : ASCIILiteral("Prefix -- operator applied to value that is not a reference."));
 }
 
 // ------------------------------ Unary Operation Nodes -----------------------------------
 
 RegisterID* UnaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RegisterID* src = generator.emitNode(m_expr);
+    RefPtr<RegisterID> src = generator.emitNode(m_expr);
     generator.emitExpressionInfo(position(), position(), position());
-    return generator.emitUnaryOp(opcodeID(), generator.finalDestination(dst), src);
+    return generator.emitUnaryOp(opcodeID(), generator.finalDestination(dst), src.get());
 }
 
 // ------------------------------ BitwiseNotNode -----------------------------------
@@ -901,8 +1417,8 @@ RegisterID* UnaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
 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()));
+    RefPtr<RegisterID> src1 = generator.emitNode(m_expr);
+    return generator.emitBinaryOp(op_bitxor, generator.finalDestination(dst, src1.get()), src1.get(), src2.get(), OperandTypes(m_expr->resultDescriptor(), ResultType::numberTypeIsInt32()));
 }
  
 // ------------------------------ LogicalNotNode -----------------------------------
@@ -1116,20 +1632,23 @@ RegisterID* BinaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
     }
 
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(left, m_rightHasAssignments, right->isPure(generator));
-    bool wasTypeof = generator.m_lastOpcodeID == op_typeof;
-    RegisterID* src2 = generator.emitNode(right);
+    bool wasTypeof = generator.lastOpcodeID() == op_typeof;
+    RefPtr<RegisterID> src2 = generator.emitNode(right);
     generator.emitExpressionInfo(position(), position(), position());
     if (wasTypeof && (opcodeID == op_neq || opcodeID == op_nstricteq)) {
         RefPtr<RegisterID> tmp = generator.tempDestination(dst);
         if (opcodeID == op_neq)
-            generator.emitEqualityOp(op_eq, generator.finalDestination(tmp.get(), src1.get()), src1.get(), src2);
+            generator.emitEqualityOp(op_eq, generator.finalDestination(tmp.get(), src1.get()), src1.get(), src2.get());
         else if (opcodeID == op_nstricteq)
-            generator.emitEqualityOp(op_stricteq, generator.finalDestination(tmp.get(), src1.get()), src1.get(), src2);
+            generator.emitEqualityOp(op_stricteq, generator.finalDestination(tmp.get(), src1.get()), src1.get(), src2.get());
         else
             RELEASE_ASSERT_NOT_REACHED();
         return generator.emitUnaryOp(op_not, generator.finalDestination(dst, tmp.get()), tmp.get());
     }
-    return generator.emitBinaryOp(opcodeID, generator.finalDestination(dst, src1.get()), src1.get(), src2, OperandTypes(left->resultDescriptor(), right->resultDescriptor()));
+    RegisterID* result = generator.emitBinaryOp(opcodeID, generator.finalDestination(dst, src1.get()), src1.get(), src2.get(), OperandTypes(left->resultDescriptor(), right->resultDescriptor()));
+    if (opcodeID == op_urshift && dst != generator.ignoredResult())
+        return generator.emitUnaryOp(op_unsigned, result, result);
+    return result;
 }
 
 RegisterID* EqualNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
@@ -1146,8 +1665,8 @@ RegisterID* EqualNode::emitBytecode(BytecodeGenerator& generator, RegisterID* ds
         std::swap(left, right);
 
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(left, m_rightHasAssignments, m_expr2->isPure(generator));
-    RegisterID* src2 = generator.emitNode(right);
-    return generator.emitEqualityOp(op_eq, generator.finalDestination(dst, src1.get()), src1.get(), src2);
+    RefPtr<RegisterID> src2 = generator.emitNode(right);
+    return generator.emitEqualityOp(op_eq, generator.finalDestination(dst, src1.get()), src1.get(), src2.get());
 }
 
 RegisterID* StrictEqualNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
@@ -1158,36 +1677,63 @@ RegisterID* StrictEqualNode::emitBytecode(BytecodeGenerator& generator, Register
         std::swap(left, right);
 
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(left, m_rightHasAssignments, m_expr2->isPure(generator));
-    RegisterID* src2 = generator.emitNode(right);
-    return generator.emitEqualityOp(op_stricteq, generator.finalDestination(dst, src1.get()), src1.get(), src2);
+    RefPtr<RegisterID> src2 = generator.emitNode(right);
+    return generator.emitEqualityOp(op_stricteq, generator.finalDestination(dst, src1.get()), src1.get(), src2.get());
 }
 
 RegisterID* ThrowableBinaryOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1, m_rightHasAssignments, m_expr2->isPure(generator));
-    RegisterID* src2 = generator.emitNode(m_expr2);
+    RefPtr<RegisterID> src2 = generator.emitNode(m_expr2);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitBinaryOp(opcodeID(), generator.finalDestination(dst, src1.get()), src1.get(), src2, OperandTypes(m_expr1->resultDescriptor(), m_expr2->resultDescriptor()));
+    return generator.emitBinaryOp(opcodeID(), generator.finalDestination(dst, src1.get()), src1.get(), src2.get(), OperandTypes(m_expr1->resultDescriptor(), m_expr2->resultDescriptor()));
 }
 
 RegisterID* InstanceOfNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1, m_rightHasAssignments, m_expr2->isPure(generator));
-    RefPtr<RegisterID> src2 = generator.emitNode(m_expr2);
+    RefPtr<RegisterID> hasInstanceValue = generator.newTemporary();
+    RefPtr<RegisterID> isObject = generator.newTemporary();
+    RefPtr<RegisterID> isCustom = generator.newTemporary();
     RefPtr<RegisterID> prototype = generator.newTemporary();
-    RefPtr<RegisterID> dstReg = generator.finalDestination(dst, src1.get());
-    RefPtr<Label> target = generator.newLabel();
+    RefPtr<RegisterID> value = generator.emitNodeForLeftHandSide(m_expr1, m_rightHasAssignments, m_expr2->isPure(generator));
+    RefPtr<RegisterID> constructor = generator.emitNode(m_expr2);
+    RefPtr<RegisterID> dstReg = generator.finalDestination(dst, value.get());
+    RefPtr<Label> custom = generator.newLabel();
+    RefPtr<Label> done = generator.newLabel();
+    RefPtr<Label> typeError = generator.newLabel();
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    generator.emitCheckHasInstance(dstReg.get(), src1.get(), src2.get(), target.get());
+    generator.emitIsObject(isObject.get(), constructor.get());
+    generator.emitJumpIfFalse(isObject.get(), typeError.get());
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    generator.emitGetById(prototype.get(), src2.get(), generator.vm()->propertyNames->prototype);
+    generator.emitGetById(hasInstanceValue.get(), constructor.get(), generator.vm()->propertyNames->hasInstanceSymbol);
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RegisterID* result = generator.emitInstanceOf(dstReg.get(), src1.get(), prototype.get());
-    generator.emitLabel(target.get());
-    return result;
+    generator.emitOverridesHasInstance(isCustom.get(), constructor.get(), hasInstanceValue.get());
+
+    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+    generator.emitJumpIfTrue(isCustom.get(), custom.get());
+
+    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+    generator.emitGetById(prototype.get(), constructor.get(), generator.vm()->propertyNames->prototype);
+
+    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+    generator.emitInstanceOf(dstReg.get(), value.get(), prototype.get());
+
+    generator.emitJump(done.get());
+
+    generator.emitLabel(typeError.get());
+    generator.emitThrowTypeError("Right hand side of instanceof is not an object");
+
+    generator.emitLabel(custom.get());
+
+    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+    generator.emitInstanceOfCustom(dstReg.get(), value.get(), constructor.get(), hasInstanceValue.get());
+
+    generator.emitLabel(done.get());
+
+    return dstReg.get();
 }
 
 // ------------------------------ LogicalOpNode ----------------------------
@@ -1202,7 +1748,7 @@ RegisterID* LogicalOpNode::emitBytecode(BytecodeGenerator& generator, RegisterID
         generator.emitJumpIfFalse(temp.get(), target.get());
     else
         generator.emitJumpIfTrue(temp.get(), target.get());
-    generator.emitNode(temp.get(), m_expr2);
+    generator.emitNodeInTailPosition(temp.get(), m_expr2);
     generator.emitLabel(target.get());
 
     return generator.moveToDestinationIfNeeded(dst, temp.get());
@@ -1232,14 +1778,18 @@ RegisterID* ConditionalNode::emitBytecode(BytecodeGenerator& generator, Register
     generator.emitNodeInConditionContext(m_logical, beforeThen.get(), beforeElse.get(), FallThroughMeansTrue);
     generator.emitLabel(beforeThen.get());
 
-    generator.emitNode(newDst.get(), m_expr1);
+    generator.emitProfileControlFlow(m_expr1->startOffset());
+    generator.emitNodeInTailPosition(newDst.get(), m_expr1);
     generator.emitJump(afterElse.get());
 
     generator.emitLabel(beforeElse.get());
-    generator.emitNode(newDst.get(), m_expr2);
+    generator.emitProfileControlFlow(m_expr1->endOffset() + 1);
+    generator.emitNodeInTailPosition(newDst.get(), m_expr2);
 
     generator.emitLabel(afterElse.get());
 
+    generator.emitProfileControlFlow(m_expr2->endOffset() + 1);
+
     return newDst.get();
 }
 
@@ -1296,17 +1846,23 @@ static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(BytecodeGenerator& gen
     // If this is required the node is passed as 'emitExpressionInfoForMe'; do so now.
     if (emitExpressionInfoForMe)
         generator.emitExpressionInfo(emitExpressionInfoForMe->divot(), emitExpressionInfoForMe->divotStart(), emitExpressionInfoForMe->divotEnd());
-    return generator.emitBinaryOp(opcodeID, dst, src1, src2, types);
+    RegisterID* result = generator.emitBinaryOp(opcodeID, dst, src1, src2, types);
+    if (oper == OpURShift)
+        return generator.emitUnaryOp(op_unsigned, result, result);
+    return result;
 }
 
 RegisterID* ReadModifyResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ResolveResult resolveResult = generator.resolve(m_ident);
-
-    if (RegisterID *local = resolveResult.local()) {
-        if (resolveResult.isReadOnly()) {
-            generator.emitReadOnlyExceptionIfNeeded();
-            return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    JSTextPosition newDivot = divotStart() + m_ident.length();
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitTDZCheckIfNecessary(var, local, nullptr);
+        if (var.isReadOnly()) {
+            generator.emitReadOnlyExceptionIfNeeded(var);
+            RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst), local, m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+            generator.emitProfileType(result, divotStart(), divotEnd());
+            return result;
         }
         
         if (generator.leftHandSideNeedsCopy(m_rightHasAssignments, m_right->isPure(generator))) {
@@ -1314,61 +1870,94 @@ RegisterID* ReadModifyResolveNode::emitBytecode(BytecodeGenerator& generator, Re
             generator.emitMove(result.get(), local);
             emitReadModifyAssignment(generator, result.get(), result.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
             generator.emitMove(local, result.get());
+            generator.invalidateForInContextForLocal(local);
+            generator.emitProfileType(local, divotStart(), divotEnd());
             return generator.moveToDestinationIfNeeded(dst, result.get());
         }
         
         RegisterID* result = emitReadModifyAssignment(generator, local, local, m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+        generator.invalidateForInContextForLocal(local);
+        generator.emitProfileType(result, divotStart(), divotEnd());
         return generator.moveToDestinationIfNeeded(dst, result);
     }
 
-    if (resolveResult.isStatic() && !resolveResult.isReadOnly()) {
-        RefPtr<RegisterID> src1 = generator.emitGetStaticVar(generator.tempDestination(dst), resolveResult, m_ident);
-        RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
-        generator.emitPutStaticVar(resolveResult, m_ident, result);
-        return result;
-    }
-
-    RefPtr<RegisterID> src1 = generator.tempDestination(dst);
-    JSTextPosition newDivot = divotStart() + m_ident.length();
     generator.emitExpressionInfo(newDivot, divotStart(), newDivot);
-    NonlocalResolveInfo resolveVerifier;
-    RefPtr<RegisterID> base = generator.emitResolveWithBaseForPut(generator.newTemporary(), src1.get(), resolveResult, m_ident, resolveVerifier);
-    RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()), this);
-    return generator.emitPutToBase(base.get(), m_ident, result, resolveVerifier);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+    RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), var, ThrowIfNotFound);
+    generator.emitTDZCheckIfNecessary(var, value.get(), nullptr);
+    if (var.isReadOnly()) {
+        bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
+        if (threwException)
+            return value.get();
+    }
+    RefPtr<RegisterID> result = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()), this);
+    RegisterID* returnResult = result.get();
+    if (!var.isReadOnly()) {
+        returnResult = generator.emitPutToScope(scope.get(), var, result.get(), ThrowIfNotFound, NotInitialization);
+        generator.emitProfileType(result.get(), var, divotStart(), divotEnd());
+    }
+    return returnResult;
 }
 
 // ------------------------------ AssignResolveNode -----------------------------------
 
 RegisterID* AssignResolveNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ResolveResult resolveResult = generator.resolve(m_ident);
-
-    if (RegisterID* local = resolveResult.local()) {
-        if (resolveResult.isReadOnly()) {
-            generator.emitReadOnlyExceptionIfNeeded();
-            return generator.emitNode(dst, m_right);
+    Variable var = generator.variable(m_ident);
+    bool isReadOnly = var.isReadOnly() && m_assignmentContext != AssignmentContext::ConstDeclarationStatement;
+    if (RegisterID* local = var.local()) {
+        RegisterID* result = nullptr;
+        if (m_assignmentContext == AssignmentContext::AssignmentExpression)
+            generator.emitTDZCheckIfNecessary(var, local, nullptr);
+
+        if (isReadOnly) {
+            result = generator.emitNode(dst, m_right); // Execute side effects first.
+            generator.emitReadOnlyExceptionIfNeeded(var);
+            generator.emitProfileType(result, var, divotStart(), divotEnd());
+        } else if (var.isSpecial()) {
+            RefPtr<RegisterID> tempDst = generator.tempDestination(dst);
+            generator.emitNode(tempDst.get(), m_right);
+            generator.emitMove(local, tempDst.get());
+            generator.emitProfileType(local, var, divotStart(), divotEnd());
+            generator.invalidateForInContextForLocal(local);
+            result = generator.moveToDestinationIfNeeded(dst, tempDst.get());
+        } else {
+            RegisterID* right = generator.emitNode(local, m_right);
+            generator.emitProfileType(right, var, divotStart(), divotEnd());
+            generator.invalidateForInContextForLocal(local);
+            result = generator.moveToDestinationIfNeeded(dst, right);
         }
-        RegisterID* result = generator.emitNode(local, m_right);
-        return generator.moveToDestinationIfNeeded(dst, result);
-    }
 
-    if (resolveResult.isStatic() && !resolveResult.isReadOnly()) {
-        if (dst == generator.ignoredResult())
-            dst = 0;
-        RegisterID* value = generator.emitNode(dst, m_right);
-        generator.emitPutStaticVar(resolveResult, m_ident, value);
-        return value;
+        if (m_assignmentContext == AssignmentContext::DeclarationStatement || m_assignmentContext == AssignmentContext::ConstDeclarationStatement)
+            generator.liftTDZCheckIfPossible(var);
+        return result;
     }
 
-    NonlocalResolveInfo resolveVerifier;
     if (generator.isStrictMode())
         generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RefPtr<RegisterID> base = generator.emitResolveBaseForPut(generator.newTemporary(), resolveResult, m_ident, resolveVerifier);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+    if (m_assignmentContext == AssignmentContext::AssignmentExpression)
+        generator.emitTDZCheckIfNecessary(var, nullptr, scope.get());
     if (dst == generator.ignoredResult())
         dst = 0;
-    RegisterID* value = generator.emitNode(dst, m_right);
+    RefPtr<RegisterID> result = generator.emitNode(dst, m_right);
+    if (isReadOnly) {
+        RegisterID* result = generator.emitNode(dst, m_right); // Execute side effects first.
+        bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
+        if (threwException)
+            return result;
+    }
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitPutToBase(base.get(), m_ident, value, resolveVerifier);
+    RegisterID* returnResult = result.get();
+    if (!isReadOnly) {
+        returnResult = generator.emitPutToScope(scope.get(), var, result.get(), generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, 
+            m_assignmentContext == AssignmentContext::ConstDeclarationStatement || m_assignmentContext == AssignmentContext::DeclarationStatement  ? Initialization : NotInitialization);
+        generator.emitProfileType(result.get(), var, divotStart(), divotEnd());
+    }
+
+    if (m_assignmentContext == AssignmentContext::DeclarationStatement || m_assignmentContext == AssignmentContext::ConstDeclarationStatement)
+        generator.liftTDZCheckIfPossible(var);
+    return returnResult;
 }
 
 // ------------------------------ AssignDotNode -----------------------------------
@@ -1377,10 +1966,11 @@ RegisterID* AssignDotNode::emitBytecode(BytecodeGenerator& generator, RegisterID
 {
     RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_rightHasAssignments, m_right->isPure(generator));
     RefPtr<RegisterID> value = generator.destinationForAssignResult(dst);
-    RegisterID* result = generator.emitNode(value.get(), m_right);
+    RefPtr<RegisterID> result = generator.emitNode(value.get(), m_right);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result : generator.moveToDestinationIfNeeded(generator.tempDestination(result), result);
+    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result.get() : generator.moveToDestinationIfNeeded(generator.tempDestination(result.get()), result.get());
     generator.emitPutById(base.get(), m_ident, forwardResult);
+    generator.emitProfileType(forwardResult, divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, forwardResult);
 }
 
@@ -1392,17 +1982,19 @@ RegisterID* ReadModifyDotNode::emitBytecode(BytecodeGenerator& generator, Regist
 
     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
     RefPtr<RegisterID> value = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right, static_cast<JSC::Operator>(m_operator), OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    return generator.emitPutById(base.get(), m_ident, updatedValue);
+    RegisterID* ret = generator.emitPutById(base.get(), m_ident, updatedValue);
+    generator.emitProfileType(updatedValue, divotStart(), divotEnd());
+    return ret;
 }
 
 // ------------------------------ AssignErrorNode -----------------------------------
 
 RegisterID* AssignErrorNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    return emitThrowReferenceError(generator, "Left side of assignment is not a reference.");
+    return emitThrowReferenceError(generator, ASCIILiteral("Left side of assignment is not a reference."));
 }
 
 // ------------------------------ AssignBracketNode -----------------------------------
@@ -1412,11 +2004,17 @@ RegisterID* AssignBracketNode::emitBytecode(BytecodeGenerator& generator, Regist
     RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_subscriptHasAssignments || m_rightHasAssignments, m_subscript->isPure(generator) && m_right->isPure(generator));
     RefPtr<RegisterID> property = generator.emitNodeForLeftHandSide(m_subscript, m_rightHasAssignments, m_right->isPure(generator));
     RefPtr<RegisterID> value = generator.destinationForAssignResult(dst);
-    RegisterID* result = generator.emitNode(value.get(), m_right);
+    RefPtr<RegisterID> result = generator.emitNode(value.get(), m_right);
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result : generator.moveToDestinationIfNeeded(generator.tempDestination(result), result);
-    generator.emitPutByVal(base.get(), property.get(), forwardResult);
+    RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result.get() : generator.moveToDestinationIfNeeded(generator.tempDestination(result.get()), result.get());
+
+    if (isNonIndexStringElement(*m_subscript))
+        generator.emitPutById(base.get(), static_cast<StringNode*>(m_subscript)->value(), forwardResult);
+    else
+        generator.emitPutByVal(base.get(), property.get(), forwardResult);
+
+    generator.emitProfileType(forwardResult, divotStart(), divotEnd());
     return generator.moveToDestinationIfNeeded(dst, forwardResult);
 }
 
@@ -1429,10 +2027,11 @@ RegisterID* ReadModifyBracketNode::emitBytecode(BytecodeGenerator& generator, Re
 
     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
     RefPtr<RegisterID> value = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property.get());
-    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right, static_cast<JSC::Operator>(m_operator), OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitPutByVal(base.get(), property.get(), updatedValue);
+    generator.emitProfileType(updatedValue, divotStart(), divotEnd());
 
     return updatedValue;
 }
@@ -1441,54 +2040,10 @@ RegisterID* ReadModifyBracketNode::emitBytecode(BytecodeGenerator& generator, Re
 
 RegisterID* CommaNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    ASSERT(m_expressions.size() > 1);
-    for (size_t i = 0; i < m_expressions.size() - 1; i++)
-        generator.emitNode(generator.ignoredResult(), m_expressions[i]);
-    return generator.emitNode(dst, m_expressions.last());
-}
-
-// ------------------------------ ConstDeclNode ------------------------------------
-
-RegisterID* ConstDeclNode::emitCodeSingle(BytecodeGenerator& generator)
-{
-    ResolveResult resolveResult = generator.resolveConstDecl(m_ident);
-
-    // FIXME: This code does not match the behavior of const in Firefox.
-    if (RegisterID* local = resolveResult.local()) {
-        if (!m_init)
-            return local;
-
-        return generator.emitNode(local, m_init);
-    }
-
-    RefPtr<RegisterID> value = m_init ? generator.emitNode(m_init) : generator.emitLoad(0, jsUndefined());
-
-    if (generator.codeType() == GlobalCode)
-        return generator.emitInitGlobalConst(m_ident, value.get());
-
-    if (generator.codeType() != EvalCode)
-        return value.get();
-
-    // FIXME: This will result in incorrect assignment if m_ident exists in an intervening with scope.
-    RefPtr<RegisterID> base = generator.emitResolveBase(generator.newTemporary(), resolveResult, m_ident);
-    return generator.emitPutById(base.get(), m_ident, value.get());
-}
-
-RegisterID* ConstDeclNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
-{
-    RegisterID* result = 0;
-    for (ConstDeclNode* n = this; n; n = n->m_next)
-        result = n->emitCodeSingle(generator);
-
-    return result;
-}
-
-// ------------------------------ ConstStatementNode -----------------------------
-
-void ConstStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
-{
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
-    generator.emitNode(m_next);
+    CommaNode* node = this;
+    for (; node && node->next(); node = node->next())
+        generator.emitNode(generator.ignoredResult(), node->m_expr);
+    return generator.emitNodeInTailPosition(dst, node->m_expr);
 }
 
 // ------------------------------ SourceElements -------------------------------
@@ -1496,15 +2051,13 @@ void ConstStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 
 inline StatementNode* SourceElements::lastStatement() const
 {
-    size_t size = m_statements.size();
-    return size ? m_statements[size - 1] : 0;
+    return m_tail;
 }
 
 inline void SourceElements::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    size_t size = m_statements.size();
-    for (size_t i = 0; i < size; ++i)
-        generator.emitNode(dst, m_statements[i]);
+    for (StatementNode* statement = m_head; statement; statement = statement->next())
+        generator.emitNodeInTailPosition(dst, statement);
 }
 
 // ------------------------------ BlockNode ------------------------------------
@@ -1514,7 +2067,7 @@ inline StatementNode* BlockNode::lastStatement() const
     return m_statements ? m_statements->lastStatement() : 0;
 }
 
-inline StatementNode* BlockNode::singleStatement() const
+StatementNode* BlockNode::singleStatement() const
 {
     return m_statements ? m_statements->singleStatement() : 0;
 }
@@ -1523,21 +2076,23 @@ void BlockNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     if (!m_statements)
         return;
+    generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::Optimize, BytecodeGenerator::NestedScopeType::IsNested);
     m_statements->emitBytecode(generator, dst);
+    generator.popLexicalScope(this);
 }
 
 // ------------------------------ EmptyStatementNode ---------------------------
 
 void EmptyStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 }
 
 // ------------------------------ DebuggerStatementNode ---------------------------
 
 void DebuggerStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(DidReachBreakpoint, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(DidReachBreakpoint, lastLine(), startOffset(), lineStartOffset());
 }
 
 // ------------------------------ ExprStatementNode ----------------------------
@@ -1545,19 +2100,60 @@ void DebuggerStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterI
 void ExprStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     ASSERT(m_expr);
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     generator.emitNode(dst, m_expr);
 }
 
-// ------------------------------ VarStatementNode ----------------------------
+// ------------------------------ DeclarationStatement ----------------------------
 
-void VarStatementNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+void DeclarationStatement::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
     ASSERT(m_expr);
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     generator.emitNode(m_expr);
 }
 
+// ------------------------------ EmptyVarExpression ----------------------------
+
+RegisterID* EmptyVarExpression::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+{
+    // It's safe to return null here because this node will always be a child node of DeclarationStatement which ignores our return value.
+    if (!generator.vm()->typeProfiler())
+        return nullptr;
+
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local())
+        generator.emitProfileType(local, var, position(), JSTextPosition(-1, position().offset + m_ident.length(), -1));
+    else {
+        RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+        RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), var, DoNotThrowIfNotFound);
+        generator.emitProfileType(value.get(), var, position(), JSTextPosition(-1, position().offset + m_ident.length(), -1));
+    }
+
+    return nullptr;
+}
+
+// ------------------------------ EmptyLetExpression ----------------------------
+
+RegisterID* EmptyLetExpression::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+{
+    // Lexical declarations like 'let' must move undefined into their variables so we don't
+    // get TDZ errors for situations like this: `let x; x;`
+    Variable var = generator.variable(m_ident);
+    if (RegisterID* local = var.local()) {
+        generator.emitLoad(local, jsUndefined());
+        generator.emitProfileType(local, var, position(), JSTextPosition(-1, position().offset + m_ident.length(), -1));
+    } else {
+        RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+        RefPtr<RegisterID> value = generator.emitLoad(nullptr, jsUndefined());
+        generator.emitPutToScope(scope.get(), var, value.get(), generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, Initialization);
+        generator.emitProfileType(value.get(), var, position(), JSTextPosition(-1, position().offset + m_ident.length(), -1)); 
+    }
+
+    // It's safe to return null here because this node will always be a child node of DeclarationStatement which ignores our return value.
+    return nullptr;
+}
+
 // ------------------------------ IfElseNode ---------------------------------------
 
 static inline StatementNode* singleStatement(StatementNode* statementNode)
@@ -1599,7 +2195,7 @@ bool IfElseNode::tryFoldBreakAndContinue(BytecodeGenerator& generator, Statement
 
 void IfElseNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     
     RefPtr<Label> beforeThen = generator.newLabel();
     RefPtr<Label> beforeElse = generator.newLabel();
@@ -1612,19 +2208,24 @@ void IfElseNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
     generator.emitNodeInConditionContext(m_condition, trueTarget, falseTarget, fallThroughMode);
     generator.emitLabel(beforeThen.get());
+    generator.emitProfileControlFlow(m_ifBlock->startOffset());
 
     if (!didFoldIfBlock) {
-        generator.emitNode(dst, m_ifBlock);
+        generator.emitNodeInTailPosition(dst, m_ifBlock);
         if (m_elseBlock)
             generator.emitJump(afterElse.get());
     }
 
     generator.emitLabel(beforeElse.get());
 
-    if (m_elseBlock)
-        generator.emitNode(dst, m_elseBlock);
+    if (m_elseBlock) {
+        generator.emitProfileControlFlow(m_ifBlock->endOffset() + (m_ifBlock->isBlock() ? 1 : 0));
+        generator.emitNodeInTailPosition(dst, m_elseBlock);
+    }
 
     generator.emitLabel(afterElse.get());
+    StatementNode* endingBlock = m_elseBlock ? m_elseBlock : m_ifBlock;
+    generator.emitProfileControlFlow(endingBlock->endOffset() + (endingBlock->isBlock() ? 1 : 0));
 }
 
 // ------------------------------ DoWhileNode ----------------------------------
@@ -1636,12 +2237,12 @@ void DoWhileNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
     RefPtr<Label> topOfLoop = generator.newLabel();
     generator.emitLabel(topOfLoop.get());
     generator.emitLoopHint();
-    generator.emitDebugHook(WillExecuteStatement, lastLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, lastLine(), startOffset(), lineStartOffset());
 
-    generator.emitNode(dst, m_statement);
+    generator.emitNodeInTailPosition(dst, m_statement);
 
     generator.emitLabel(scope->continueTarget());
-    generator.emitDebugHook(WillExecuteStatement, lastLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, lastLine(), startOffset(), lineStartOffset());
     generator.emitNodeInConditionContext(m_expr, topOfLoop.get(), scope->breakTarget(), FallThroughMeansFalse);
 
     generator.emitLabel(scope->breakTarget());
@@ -1654,20 +2255,23 @@ void WhileNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
     LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
     RefPtr<Label> topOfLoop = generator.newLabel();
 
-    generator.emitDebugHook(WillExecuteStatement, m_expr->lineNo(), m_expr->lineNo(), m_expr->startOffset(), m_expr->lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, m_expr->firstLine(), m_expr->startOffset(), m_expr->lineStartOffset());
     generator.emitNodeInConditionContext(m_expr, topOfLoop.get(), scope->breakTarget(), FallThroughMeansTrue);
 
     generator.emitLabel(topOfLoop.get());
     generator.emitLoopHint();
     
-    generator.emitNode(dst, m_statement);
+    generator.emitProfileControlFlow(m_statement->startOffset());
+    generator.emitNodeInTailPosition(dst, m_statement);
 
     generator.emitLabel(scope->continueTarget());
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     generator.emitNodeInConditionContext(m_expr, topOfLoop.get(), scope->breakTarget(), FallThroughMeansFalse);
 
     generator.emitLabel(scope->breakTarget());
+
+    generator.emitProfileControlFlow(m_statement->endOffset() + (m_statement->isBlock() ? 1 : 0));
 }
 
 // ------------------------------ ForNode --------------------------------------
@@ -1676,7 +2280,10 @@ void ForNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
     LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
 
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    RegisterID* forLoopSymbolTable = nullptr;
+    generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::Optimize, BytecodeGenerator::NestedScopeType::IsNested, &forLoopSymbolTable);
+
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     if (m_expr1)
         generator.emitNode(generator.ignoredResult(), m_expr1);
@@ -1687,11 +2294,13 @@ void ForNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
     generator.emitLabel(topOfLoop.get());
     generator.emitLoopHint();
+    generator.emitProfileControlFlow(m_statement->startOffset());
 
-    generator.emitNode(dst, m_statement);
+    generator.emitNodeInTailPosition(dst, m_statement);
 
     generator.emitLabel(scope->continueTarget());
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
+    generator.prepareLexicalScopeForNextForLoopIteration(this, forLoopSymbolTable);
     if (m_expr3)
         generator.emitNode(generator.ignoredResult(), m_expr3);
 
@@ -1701,87 +2310,299 @@ void ForNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
         generator.emitJump(topOfLoop.get());
 
     generator.emitLabel(scope->breakTarget());
+    generator.popLexicalScope(this);
+    generator.emitProfileControlFlow(m_statement->endOffset() + (m_statement->isBlock() ? 1 : 0));
 }
 
 // ------------------------------ ForInNode ------------------------------------
 
-void ForInNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+RegisterID* ForInNode::tryGetBoundLocal(BytecodeGenerator& generator)
 {
-    LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
-
-    if (!m_lexpr->isLocation()) {
-        emitThrowReferenceError(generator, "Left side of for-in statement is not a reference.");
-        return;
+    if (m_lexpr->isResolveNode()) {
+        const Identifier& ident = static_cast<ResolveNode*>(m_lexpr)->identifier();
+        return generator.variable(ident).local();
     }
 
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
-
-    if (m_init)
-        generator.emitNode(generator.ignoredResult(), m_init);
-
-    RefPtr<RegisterID> base = generator.newTemporary();
-    generator.emitNode(base.get(), m_expr);
-    RefPtr<RegisterID> i = generator.newTemporary();
-    RefPtr<RegisterID> size = generator.newTemporary();
-    RefPtr<RegisterID> expectedSubscript;
-    RefPtr<RegisterID> iter = generator.emitGetPropertyNames(generator.newTemporary(), base.get(), i.get(), size.get(), scope->breakTarget());
-    generator.emitJump(scope->continueTarget());
+    if (m_lexpr->isDestructuringNode()) {
+        DestructuringAssignmentNode* assignNode = static_cast<DestructuringAssignmentNode*>(m_lexpr);
+        auto binding = assignNode->bindings();
+        if (!binding->isBindingNode())
+            return nullptr;
+
+        auto simpleBinding = static_cast<BindingNode*>(binding);
+        const Identifier& ident = simpleBinding->boundProperty();
+        Variable var = generator.variable(ident);
+        if (var.isSpecial())
+            return nullptr;
+        return var.local();
+    }
 
-    RefPtr<Label> loopStart = generator.newLabel();
-    generator.emitLabel(loopStart.get());
-    generator.emitLoopHint();
+    return nullptr;
+}
 
-    RegisterID* propertyName;
-    bool optimizedForinAccess = false;
+void ForInNode::emitLoopHeader(BytecodeGenerator& generator, RegisterID* propertyName)
+{
     if (m_lexpr->isResolveNode()) {
         const Identifier& ident = static_cast<ResolveNode*>(m_lexpr)->identifier();
-        ResolveResult resolveResult = generator.resolve(ident);
-        propertyName = resolveResult.local();
-        if (!propertyName) {
-            propertyName = generator.newTemporary();
-            RefPtr<RegisterID> protect = propertyName;
-            NonlocalResolveInfo resolveVerifier;
+        Variable var = generator.variable(ident);
+        if (RegisterID* local = var.local())
+            generator.emitMove(local, propertyName);
+        else {
             if (generator.isStrictMode())
                 generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-            RegisterID* base = generator.emitResolveBaseForPut(generator.newTemporary(), resolveResult, ident, resolveVerifier);
-
+            RegisterID* scope = generator.emitResolveScope(nullptr, var);
             generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
-            generator.emitPutToBase(base, ident, propertyName, resolveVerifier);
-        } else {
-            expectedSubscript = generator.emitMove(generator.newTemporary(), propertyName);
-            generator.pushOptimisedForIn(expectedSubscript.get(), iter.get(), i.get(), propertyName);
-            optimizedForinAccess = true;
+            generator.emitPutToScope(scope, var, propertyName, generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, NotInitialization);
         }
-    } else if (m_lexpr->isDotAccessorNode()) {
+        generator.emitProfileType(propertyName, var, m_lexpr->position(), JSTextPosition(-1, m_lexpr->position().offset + ident.length(), -1));
+        return;
+    }
+    if (m_lexpr->isDotAccessorNode()) {
         DotAccessorNode* assignNode = static_cast<DotAccessorNode*>(m_lexpr);
         const Identifier& ident = assignNode->identifier();
-        propertyName = generator.newTemporary();
-        RefPtr<RegisterID> protect = propertyName;
         RegisterID* base = generator.emitNode(assignNode->base());
-
         generator.emitExpressionInfo(assignNode->divot(), assignNode->divotStart(), assignNode->divotEnd());
         generator.emitPutById(base, ident, propertyName);
-    } else {
-        ASSERT(m_lexpr->isBracketAccessorNode());
+        generator.emitProfileType(propertyName, assignNode->divotStart(), assignNode->divotEnd());
+        return;
+    }
+    if (m_lexpr->isBracketAccessorNode()) {
         BracketAccessorNode* assignNode = static_cast<BracketAccessorNode*>(m_lexpr);
-        propertyName = generator.newTemporary();
-        RefPtr<RegisterID> protect = propertyName;
         RefPtr<RegisterID> base = generator.emitNode(assignNode->base());
         RegisterID* subscript = generator.emitNode(assignNode->subscript());
-        
         generator.emitExpressionInfo(assignNode->divot(), assignNode->divotStart(), assignNode->divotEnd());
         generator.emitPutByVal(base.get(), subscript, propertyName);
-    }   
+        generator.emitProfileType(propertyName, assignNode->divotStart(), assignNode->divotEnd());
+        return;
+    }
 
-    generator.emitNode(dst, m_statement);
+    if (m_lexpr->isDestructuringNode()) {
+        DestructuringAssignmentNode* assignNode = static_cast<DestructuringAssignmentNode*>(m_lexpr);
+        auto binding = assignNode->bindings();
+        if (!binding->isBindingNode()) {
+            assignNode->bindings()->bindValue(generator, propertyName);
+            return;
+        }
 
-    if (optimizedForinAccess)
-        generator.popOptimisedForIn();
+        auto simpleBinding = static_cast<BindingNode*>(binding);
+        const Identifier& ident = simpleBinding->boundProperty();
+        Variable var = generator.variable(ident);
+        if (!var.local() || var.isSpecial()) {
+            assignNode->bindings()->bindValue(generator, propertyName);
+            return;
+        }
+        generator.emitMove(var.local(), propertyName);
+        generator.emitProfileType(propertyName, var, simpleBinding->divotStart(), simpleBinding->divotEnd());
+        return;
+    }
 
-    generator.emitLabel(scope->continueTarget());
-    generator.emitNextPropertyName(propertyName, base.get(), i.get(), size.get(), iter.get(), loopStart.get());
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
-    generator.emitLabel(scope->breakTarget());
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+void ForInNode::emitMultiLoopBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (!m_lexpr->isAssignmentLocation()) {
+        emitThrowReferenceError(generator, ASCIILiteral("Left side of for-in statement is not a reference."));
+        return;
+    }
+
+    RefPtr<Label> end = generator.newLabel();
+
+    RegisterID* forLoopSymbolTable = nullptr;
+    generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::Optimize, BytecodeGenerator::NestedScopeType::IsNested, &forLoopSymbolTable);
+
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
+
+    RefPtr<RegisterID> base = generator.newTemporary();
+    RefPtr<RegisterID> length;
+    RefPtr<RegisterID> enumerator;
+    generator.emitNode(base.get(), m_expr);
+    RefPtr<RegisterID> local = this->tryGetBoundLocal(generator);
+    RefPtr<RegisterID> enumeratorIndex;
+
+    int profilerStartOffset = m_statement->startOffset();
+    int profilerEndOffset = m_statement->endOffset() + (m_statement->isBlock() ? 1 : 0);
+
+    enumerator = generator.emitGetPropertyEnumerator(generator.newTemporary(), base.get());
+
+    // Indexed property loop.
+    {
+        LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
+        RefPtr<Label> loopStart = generator.newLabel();
+        RefPtr<Label> loopEnd = generator.newLabel();
+
+        length = generator.emitGetEnumerableLength(generator.newTemporary(), enumerator.get());
+        RefPtr<RegisterID> i = generator.emitLoad(generator.newTemporary(), jsNumber(0));
+        RefPtr<RegisterID> propertyName = generator.newTemporary();
+
+        generator.emitLabel(loopStart.get());
+        generator.emitLoopHint();
+
+        RefPtr<RegisterID> result = generator.emitEqualityOp(op_less, generator.newTemporary(), i.get(), length.get());
+        generator.emitJumpIfFalse(result.get(), loopEnd.get());
+        generator.emitHasIndexedProperty(result.get(), base.get(), i.get());
+        generator.emitJumpIfFalse(result.get(), scope->continueTarget());
+
+        generator.emitToIndexString(propertyName.get(), i.get());
+        this->emitLoopHeader(generator, propertyName.get());
+
+        generator.emitProfileControlFlow(profilerStartOffset);
+
+        generator.pushIndexedForInScope(local.get(), i.get());
+        generator.emitNode(dst, m_statement);
+        generator.popIndexedForInScope(local.get());
+
+        generator.emitProfileControlFlow(profilerEndOffset);
+
+        generator.emitLabel(scope->continueTarget());
+        generator.prepareLexicalScopeForNextForLoopIteration(this, forLoopSymbolTable);
+        generator.emitInc(i.get());
+        generator.emitJump(loopStart.get());
+
+        generator.emitLabel(scope->breakTarget());
+        generator.emitJump(end.get());
+        generator.emitLabel(loopEnd.get());
+    }
+
+    // Structure property loop.
+    {
+        LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
+        RefPtr<Label> loopStart = generator.newLabel();
+        RefPtr<Label> loopEnd = generator.newLabel();
+
+        enumeratorIndex = generator.emitLoad(generator.newTemporary(), jsNumber(0));
+        RefPtr<RegisterID> propertyName = generator.newTemporary();
+        generator.emitEnumeratorStructurePropertyName(propertyName.get(), enumerator.get(), enumeratorIndex.get());
+
+        generator.emitLabel(loopStart.get());
+        generator.emitLoopHint();
+
+        RefPtr<RegisterID> result = generator.emitUnaryOp(op_eq_null, generator.newTemporary(), propertyName.get());
+        generator.emitJumpIfTrue(result.get(), loopEnd.get());
+        generator.emitHasStructureProperty(result.get(), base.get(), propertyName.get(), enumerator.get());
+        generator.emitJumpIfFalse(result.get(), scope->continueTarget());
+
+        this->emitLoopHeader(generator, propertyName.get());
+
+        generator.emitProfileControlFlow(profilerStartOffset);
+
+        generator.pushStructureForInScope(local.get(), enumeratorIndex.get(), propertyName.get(), enumerator.get());
+        generator.emitNode(dst, m_statement);
+        generator.popStructureForInScope(local.get());
+
+        generator.emitProfileControlFlow(profilerEndOffset);
+
+        generator.emitLabel(scope->continueTarget());
+        generator.prepareLexicalScopeForNextForLoopIteration(this, forLoopSymbolTable);
+        generator.emitInc(enumeratorIndex.get());
+        generator.emitEnumeratorStructurePropertyName(propertyName.get(), enumerator.get(), enumeratorIndex.get());
+        generator.emitJump(loopStart.get());
+        
+        generator.emitLabel(scope->breakTarget());
+        generator.emitJump(end.get());
+        generator.emitLabel(loopEnd.get());
+    }
+
+    // Generic property loop.
+    {
+        LabelScopePtr scope = generator.newLabelScope(LabelScope::Loop);
+        RefPtr<Label> loopStart = generator.newLabel();
+        RefPtr<Label> loopEnd = generator.newLabel();
+
+        RefPtr<RegisterID> propertyName = generator.newTemporary();
+
+        generator.emitEnumeratorGenericPropertyName(propertyName.get(), enumerator.get(), enumeratorIndex.get());
+
+        generator.emitLabel(loopStart.get());
+        generator.emitLoopHint();
+
+        RefPtr<RegisterID> result = generator.emitUnaryOp(op_eq_null, generator.newTemporary(), propertyName.get());
+        generator.emitJumpIfTrue(result.get(), loopEnd.get());
+
+        generator.emitHasGenericProperty(result.get(), base.get(), propertyName.get());
+        generator.emitJumpIfFalse(result.get(), scope->continueTarget());
+
+        this->emitLoopHeader(generator, propertyName.get());
+
+        generator.emitProfileControlFlow(profilerStartOffset);
+
+        generator.emitNode(dst, m_statement);
+
+        generator.emitLabel(scope->continueTarget());
+        generator.prepareLexicalScopeForNextForLoopIteration(this, forLoopSymbolTable);
+        generator.emitInc(enumeratorIndex.get());
+        generator.emitEnumeratorGenericPropertyName(propertyName.get(), enumerator.get(), enumeratorIndex.get());
+        generator.emitJump(loopStart.get());
+
+        generator.emitLabel(scope->breakTarget());
+        generator.emitJump(end.get());
+        generator.emitLabel(loopEnd.get());
+    }
+
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
+    generator.emitLabel(end.get());
+    generator.popLexicalScope(this);
+    generator.emitProfileControlFlow(profilerEndOffset);
+}
+
+void ForInNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    this->emitMultiLoopBytecode(generator, dst);
+}
+
+// ------------------------------ ForOfNode ------------------------------------
+void ForOfNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (!m_lexpr->isAssignmentLocation()) {
+        emitThrowReferenceError(generator, ASCIILiteral("Left side of for-of statement is not a reference."));
+        return;
+    }
+
+    RegisterID* forLoopSymbolTable = nullptr;
+    generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::Optimize, BytecodeGenerator::NestedScopeType::IsNested, &forLoopSymbolTable);
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
+    auto extractor = [this, dst](BytecodeGenerator& generator, RegisterID* value)
+    {
+        if (m_lexpr->isResolveNode()) {
+            const Identifier& ident = static_cast<ResolveNode*>(m_lexpr)->identifier();
+            Variable var = generator.variable(ident);
+            if (RegisterID* local = var.local())
+                generator.emitMove(local, value);
+            else {
+                if (generator.isStrictMode())
+                    generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+                RegisterID* scope = generator.emitResolveScope(nullptr, var);
+                generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
+                generator.emitPutToScope(scope, var, value, generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, NotInitialization);
+            }
+            generator.emitProfileType(value, var, m_lexpr->position(), JSTextPosition(-1, m_lexpr->position().offset + ident.length(), -1));
+        } else if (m_lexpr->isDotAccessorNode()) {
+            DotAccessorNode* assignNode = static_cast<DotAccessorNode*>(m_lexpr);
+            const Identifier& ident = assignNode->identifier();
+            RefPtr<RegisterID> base = generator.emitNode(assignNode->base());
+            
+            generator.emitExpressionInfo(assignNode->divot(), assignNode->divotStart(), assignNode->divotEnd());
+            generator.emitPutById(base.get(), ident, value);
+            generator.emitProfileType(value, assignNode->divotStart(), assignNode->divotEnd());
+        } else if (m_lexpr->isBracketAccessorNode()) {
+            BracketAccessorNode* assignNode = static_cast<BracketAccessorNode*>(m_lexpr);
+            RefPtr<RegisterID> base = generator.emitNode(assignNode->base());
+            RegisterID* subscript = generator.emitNode(assignNode->subscript());
+            
+            generator.emitExpressionInfo(assignNode->divot(), assignNode->divotStart(), assignNode->divotEnd());
+            generator.emitPutByVal(base.get(), subscript, value);
+            generator.emitProfileType(value, assignNode->divotStart(), assignNode->divotEnd());
+        } else {
+            ASSERT(m_lexpr->isDestructuringNode());
+            DestructuringAssignmentNode* assignNode = static_cast<DestructuringAssignmentNode*>(m_lexpr);
+            assignNode->bindings()->bindValue(generator, value);
+        }
+        generator.emitProfileControlFlow(m_statement->startOffset());
+        generator.emitNode(dst, m_statement);
+    };
+    generator.emitEnumeration(this, m_expr, extractor, this, forLoopSymbolTable);
+    generator.popLexicalScope(this);
+    generator.emitProfileControlFlow(m_statement->endOffset() + (m_statement->isBlock() ? 1 : 0));
 }
 
 // ------------------------------ ContinueNode ---------------------------------
@@ -1791,10 +2612,10 @@ Label* ContinueNode::trivialTarget(BytecodeGenerator& generator)
     if (generator.shouldEmitDebugHooks())
         return 0;
 
-    LabelScope* scope = generator.continueTarget(m_ident);
+    LabelScopePtr scope = generator.continueTarget(m_ident);
     ASSERT(scope);
 
-    if (generator.scopeDepth() != scope->scopeDepth())
+    if (generator.labelScopeDepth() != scope->scopeDepth())
         return 0;
 
     return scope->continueTarget();
@@ -1802,13 +2623,15 @@ Label* ContinueNode::trivialTarget(BytecodeGenerator& generator)
 
 void ContinueNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     
-    LabelScope* scope = generator.continueTarget(m_ident);
+    LabelScopePtr scope = generator.continueTarget(m_ident);
     ASSERT(scope);
 
-    generator.emitPopScopes(scope->scopeDepth());
+    generator.emitPopScopes(generator.scopeRegister(), scope->scopeDepth());
     generator.emitJump(scope->continueTarget());
+
+    generator.emitProfileControlFlow(endOffset());
 }
 
 // ------------------------------ BreakNode ------------------------------------
@@ -1818,10 +2641,10 @@ Label* BreakNode::trivialTarget(BytecodeGenerator& generator)
     if (generator.shouldEmitDebugHooks())
         return 0;
 
-    LabelScope* scope = generator.breakTarget(m_ident);
+    LabelScopePtr scope = generator.breakTarget(m_ident);
     ASSERT(scope);
 
-    if (generator.scopeDepth() != scope->scopeDepth())
+    if (generator.labelScopeDepth() != scope->scopeDepth())
         return 0;
 
     return scope->breakTarget();
@@ -1829,52 +2652,62 @@ Label* BreakNode::trivialTarget(BytecodeGenerator& generator)
 
 void BreakNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     
-    LabelScope* scope = generator.breakTarget(m_ident);
+    LabelScopePtr scope = generator.breakTarget(m_ident);
     ASSERT(scope);
 
-    generator.emitPopScopes(scope->scopeDepth());
+    generator.emitPopScopes(generator.scopeRegister(), scope->scopeDepth());
     generator.emitJump(scope->breakTarget());
+
+    generator.emitProfileControlFlow(endOffset());
 }
 
 // ------------------------------ ReturnNode -----------------------------------
 
 void ReturnNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     ASSERT(generator.codeType() == FunctionCode);
 
     if (dst == generator.ignoredResult())
         dst = 0;
 
-    RefPtr<RegisterID> returnRegister = m_value ? generator.emitNode(dst, m_value) : generator.emitLoad(dst, jsUndefined());
-    if (generator.scopeDepth()) {
+    RefPtr<RegisterID> returnRegister = m_value ? generator.emitNodeInTailPosition(dst, m_value) : generator.emitLoad(dst, jsUndefined());
+
+    generator.emitProfileType(returnRegister.get(), ProfileTypeBytecodeFunctionReturnStatement, divotStart(), divotEnd());
+    if (generator.isInFinallyBlock()) {
         returnRegister = generator.emitMove(generator.newTemporary(), returnRegister.get());
-        generator.emitPopScopes(0);
+        generator.emitPopScopes(generator.scopeRegister(), 0);
     }
 
-    generator.emitDebugHook(WillLeaveCallFrame, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillLeaveCallFrame, lastLine(), startOffset(), lineStartOffset());
     generator.emitReturn(returnRegister.get());
+    generator.emitProfileControlFlow(endOffset()); 
+    // Emitting an unreachable return here is needed in case this op_profile_control_flow is the 
+    // last opcode in a CodeBlock because a CodeBlock's instructions must end with a terminal opcode.
+    if (generator.vm()->controlFlowProfiler())
+        generator.emitReturn(generator.emitLoad(nullptr, jsUndefined()));
 }
 
 // ------------------------------ WithNode -------------------------------------
 
 void WithNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     RefPtr<RegisterID> scope = generator.emitNode(m_expr);
     generator.emitExpressionInfo(m_divot, m_divot - m_expressionLength, m_divot);
     generator.emitPushWithScope(scope.get());
-    generator.emitNode(dst, m_statement);
-    generator.emitPopScope();
+    generator.emitNodeInTailPosition(dst, m_statement);
+    generator.emitPopWithScope();
 }
 
 // ------------------------------ CaseClauseNode --------------------------------
 
 inline void CaseClauseNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
+    generator.emitProfileControlFlow(m_startOffset);
     if (!m_statements)
         return;
     m_statements->emitBytecode(generator, dst);
@@ -2036,26 +2869,30 @@ void CaseBlockNode::emitBytecodeForBlock(BytecodeGenerator& generator, RegisterI
 
 void SwitchNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
     
     LabelScopePtr scope = generator.newLabelScope(LabelScope::Switch);
 
     RefPtr<RegisterID> r0 = generator.emitNode(m_expr);
+
+    generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::DoNotOptimize, BytecodeGenerator::NestedScopeType::IsNested);
     m_block->emitBytecodeForBlock(generator, r0.get(), dst);
+    generator.popLexicalScope(this);
 
     generator.emitLabel(scope->breakTarget());
+    generator.emitProfileControlFlow(endOffset());
 }
 
 // ------------------------------ LabelNode ------------------------------------
 
 void LabelNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     ASSERT(!generator.breakTarget(m_name));
 
     LabelScopePtr scope = generator.newLabelScope(LabelScope::NamedLabel, &m_name);
-    generator.emitNode(dst, m_statement);
+    generator.emitNodeInTailPosition(dst, m_statement);
 
     generator.emitLabel(scope->breakTarget());
 }
@@ -2064,13 +2901,15 @@ void LabelNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
 void ThrowNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 {
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     if (dst == generator.ignoredResult())
         dst = 0;
     RefPtr<RegisterID> expr = generator.emitNode(m_expr);
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     generator.emitThrow(expr.get());
+
+    generator.emitProfileControlFlow(endOffset()); 
 }
 
 // ------------------------------ TryNode --------------------------------------
@@ -2080,7 +2919,7 @@ void 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.
 
-    generator.emitDebugHook(WillExecuteStatement, firstLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(WillExecuteStatement, firstLine(), startOffset(), lineStartOffset());
 
     ASSERT(m_catchBlock || m_finallyBlock);
 
@@ -2101,17 +2940,24 @@ void TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
         // Uncaught exception path: the catch block.
         RefPtr<Label> here = generator.emitLabel(generator.newLabel().get());
-        RefPtr<RegisterID> exceptionRegister = generator.popTryAndEmitCatch(tryData, generator.newTemporary(), here.get());
+        RefPtr<RegisterID> exceptionRegister = generator.newTemporary();
+        RefPtr<RegisterID> thrownValueRegister = generator.newTemporary();
+        generator.popTryAndEmitCatch(tryData, exceptionRegister.get(), thrownValueRegister.get(), here.get(), HandlerType::Catch);
         
         if (m_finallyBlock) {
             // If the catch block throws an exception and we have a finally block, then the finally
             // block should "catch" that exception.
             tryData = generator.pushTry(here.get());
         }
-        
-        generator.emitPushNameScope(m_exceptionIdent, exceptionRegister.get(), DontDelete);
-        generator.emitNode(dst, m_catchBlock);
-        generator.emitPopScope();
+
+        generator.emitPushCatchScope(m_lexicalVariables);
+        m_catchPattern->bindValue(generator, thrownValueRegister.get());
+        generator.emitProfileControlFlow(m_tryBlock->endOffset() + 1);
+        if (m_finallyBlock)
+            generator.emitNode(dst, m_catchBlock);
+        else
+            generator.emitNodeInTailPosition(dst, m_catchBlock);
+        generator.emitPopCatchScope(m_lexicalVariables);
         generator.emitLabel(catchEndLabel.get());
     }
 
@@ -2122,17 +2968,27 @@ void TryNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
 
         RefPtr<Label> finallyEndLabel = generator.newLabel();
 
+        int finallyStartOffset = m_catchBlock ? m_catchBlock->endOffset() + 1 : m_tryBlock->endOffset() + 1;
+
         // Normal path: run the finally code, and jump to the end.
-        generator.emitNode(dst, m_finallyBlock);
+        generator.emitProfileControlFlow(finallyStartOffset);
+        generator.emitNodeInTailPosition(dst, m_finallyBlock);
+        generator.emitProfileControlFlow(m_finallyBlock->endOffset() + 1);
         generator.emitJump(finallyEndLabel.get());
 
         // Uncaught exception path: invoke the finally block, then re-throw the exception.
-        RefPtr<RegisterID> tempExceptionRegister = generator.popTryAndEmitCatch(tryData, generator.newTemporary(), preFinallyLabel.get());
-        generator.emitNode(dst, m_finallyBlock);
-        generator.emitThrow(tempExceptionRegister.get());
+        RefPtr<RegisterID> exceptionRegister = generator.newTemporary();
+        RefPtr<RegisterID> thrownValueRegister = generator.newTemporary();
+        generator.popTryAndEmitCatch(tryData, exceptionRegister.get(), thrownValueRegister.get(), preFinallyLabel.get(), HandlerType::Finally);
+        generator.emitProfileControlFlow(finallyStartOffset);
+        generator.emitNodeInTailPosition(dst, m_finallyBlock);
+        generator.emitThrow(exceptionRegister.get());
 
         generator.emitLabel(finallyEndLabel.get());
-    }
+        generator.emitProfileControlFlow(m_finallyBlock->endOffset() + 1);
+    } else
+        generator.emitProfileControlFlow(m_catchBlock->endOffset() + 1);
+
 }
 
 // ------------------------------ ScopeNode -----------------------------
@@ -2144,74 +3000,156 @@ inline void ScopeNode::emitStatementsBytecode(BytecodeGenerator& generator, Regi
     m_statements->emitBytecode(generator, dst);
 }
 
-// ------------------------------ ProgramNode -----------------------------
-
-void ProgramNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+static void emitProgramNodeBytecode(BytecodeGenerator& generator, ScopeNode& scopeNode)
 {
-    generator.emitDebugHook(WillExecuteProgram, startLine(), startLine(), startStartOffset(), startLineStartOffset());
+    generator.emitDebugHook(WillExecuteProgram, scopeNode.startLine(), scopeNode.startStartOffset(), scopeNode.startLineStartOffset());
 
     RefPtr<RegisterID> dstRegister = generator.newTemporary();
     generator.emitLoad(dstRegister.get(), jsUndefined());
-    emitStatementsBytecode(generator, dstRegister.get());
+    generator.emitProfileControlFlow(scopeNode.startStartOffset());
+    scopeNode.emitStatementsBytecode(generator, dstRegister.get());
 
-    generator.emitDebugHook(DidExecuteProgram, lastLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(DidExecuteProgram, scopeNode.lastLine(), scopeNode.startOffset(), scopeNode.lineStartOffset());
     generator.emitEnd(dstRegister.get());
 }
 
+// ------------------------------ ProgramNode -----------------------------
+
+void ProgramNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+{
+    emitProgramNodeBytecode(generator, *this);
+}
+
+// ------------------------------ ModuleProgramNode --------------------
+
+void ModuleProgramNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+{
+    emitProgramNodeBytecode(generator, *this);
+}
+
 // ------------------------------ EvalNode -----------------------------
 
 void EvalNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(WillExecuteProgram, startLine(), startLine(), startStartOffset(), startLineStartOffset());
+    generator.emitDebugHook(WillExecuteProgram, startLine(), startStartOffset(), startLineStartOffset());
 
     RefPtr<RegisterID> dstRegister = generator.newTemporary();
     generator.emitLoad(dstRegister.get(), jsUndefined());
     emitStatementsBytecode(generator, dstRegister.get());
 
-    generator.emitDebugHook(DidExecuteProgram, lastLine(), lastLine(), startOffset(), lineStartOffset());
+    generator.emitDebugHook(DidExecuteProgram, lastLine(), startOffset(), lineStartOffset());
     generator.emitEnd(dstRegister.get());
 }
 
-// ------------------------------ FunctionBodyNode -----------------------------
+// ------------------------------ FunctionNode -----------------------------
 
-void FunctionBodyNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+void FunctionNode::emitBytecode(BytecodeGenerator& generator, RegisterID*)
 {
-    generator.emitDebugHook(DidEnterCallFrame, startLine(), startLine(), startStartOffset(), startLineStartOffset());
-    emitStatementsBytecode(generator, generator.ignoredResult());
+    if (generator.vm()->typeProfiler()) {
+        for (size_t i = 0; i < m_parameters->size(); i++) {
+            // Destructuring parameters are handled in destructuring nodes.
+            if (!m_parameters->at(i).first->isBindingNode())
+                continue;
+            BindingNode* parameter = static_cast<BindingNode*>(m_parameters->at(i).first);
+            RegisterID reg(CallFrame::argumentOffset(i));
+            generator.emitProfileType(&reg, ProfileTypeBytecodeFunctionArgument, parameter->divotStart(), parameter->divotEnd());
+        }
+    }
+
+    generator.emitProfileControlFlow(startStartOffset());
+    generator.emitDebugHook(DidEnterCallFrame, startLine(), startStartOffset(), startLineStartOffset());
+
+    switch (generator.parseMode()) {
+    case SourceParseMode::GeneratorWrapperFunctionMode: {
+        StatementNode* singleStatement = this->singleStatement();
+        ASSERT(singleStatement->isExprStatement());
+        ExprStatementNode* exprStatement = static_cast<ExprStatementNode*>(singleStatement);
+        ExpressionNode* expr = exprStatement->expr();
+        ASSERT(expr->isFuncExprNode());
+        FuncExprNode* funcExpr = static_cast<FuncExprNode*>(expr);
 
-    StatementNode* singleStatement = this->singleStatement();
-    ReturnNode* returnNode = 0;
+        RefPtr<RegisterID> next = generator.newTemporary();
+        generator.emitNode(next.get(), funcExpr);
 
-    // 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())
-            returnNode = static_cast<ReturnNode*>(lastStatementInBlock);
+        if (generator.superBinding() == SuperBinding::Needed) {
+            RefPtr<RegisterID> homeObject = emitHomeObjectForCallee(generator);
+            emitPutHomeObject(generator, next.get(), homeObject.get());
+        }
+
+        // FIXME: Currently, we just create an object and store generator related fields as its properties for ease.
+        // But to make it efficient, we will introduce JSGenerator class, add opcode new_generator and use its C++ fields instead of these private properties.
+        // https://bugs.webkit.org/show_bug.cgi?id=151545
+
+        generator.emitDirectPutById(generator.generatorRegister(), generator.propertyNames().generatorNextPrivateName, next.get(), PropertyNode::KnownDirect);
+
+        generator.emitDirectPutById(generator.generatorRegister(), generator.propertyNames().generatorThisPrivateName, generator.thisRegister(), PropertyNode::KnownDirect);
+
+        RegisterID* initialState = generator.emitLoad(nullptr, jsNumber(0));
+        generator.emitDirectPutById(generator.generatorRegister(), generator.propertyNames().generatorStatePrivateName, initialState, PropertyNode::KnownDirect);
+
+        generator.emitDirectPutById(generator.generatorRegister(), generator.propertyNames().generatorFramePrivateName, generator.emitLoad(nullptr, jsNull()), PropertyNode::KnownDirect);
+
+        ASSERT(startOffset() >= lineStartOffset());
+        generator.emitDebugHook(WillLeaveCallFrame, lastLine(), startOffset(), lineStartOffset());
+        generator.emitReturn(generator.generatorRegister());
+        break;
     }
 
-    // If there is no return we must automatically insert one.
-    if (!returnNode) {
-        RegisterID* r0 = generator.isConstructor() ? generator.thisRegister() : generator.emitLoad(0, jsUndefined());
-        ASSERT((startOffset() -  1) >= lineStartOffset());
-        generator.emitDebugHook(WillLeaveCallFrame, lastLine(), lastLine(), startOffset() - 1, lineStartOffset());
-        generator.emitReturn(r0);
-        return;
+    case SourceParseMode::GeneratorBodyMode: {
+        RefPtr<Label> generatorBodyLabel = generator.newLabel();
+        {
+            RefPtr<RegisterID> condition = generator.newTemporary();
+            generator.emitEqualityOp(op_stricteq, condition.get(), generator.generatorResumeModeRegister(), generator.emitLoad(nullptr, jsNumber(static_cast<int32_t>(JSGeneratorFunction::GeneratorResumeMode::NormalMode))));
+            generator.emitJumpIfTrue(condition.get(), generatorBodyLabel.get());
+
+            RefPtr<Label> throwLabel = generator.newLabel();
+            generator.emitEqualityOp(op_stricteq, condition.get(), generator.generatorResumeModeRegister(), generator.emitLoad(nullptr, jsNumber(static_cast<int32_t>(JSGeneratorFunction::GeneratorResumeMode::ThrowMode))));
+            generator.emitJumpIfTrue(condition.get(), throwLabel.get());
+
+            generator.emitReturn(generator.generatorValueRegister());
+
+            generator.emitLabel(throwLabel.get());
+            generator.emitThrow(generator.generatorValueRegister());
+        }
+
+        generator.emitLabel(generatorBodyLabel.get());
+
+        emitStatementsBytecode(generator, generator.ignoredResult());
+
+        RefPtr<Label> done = generator.newLabel();
+        generator.emitLabel(done.get());
+        generator.emitReturn(generator.emitLoad(nullptr, jsUndefined()));
+        generator.endGenerator(done.get());
+        break;
     }
 
-    // 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);
-            }
+    default: {
+        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())
+                returnNode = static_cast<ReturnNode*>(lastStatementInBlock);
+        }
+
+        // If there is no return we must automatically insert one.
+        if (!returnNode) {
+            if (generator.constructorKind() == ConstructorKind::Derived && generator.needsToUpdateArrowFunctionContext())
+                generator.emitLoadThisFromArrowFunctionLexicalEnvironment(); // Arrow function can invoke 'super' in constructor and before leave constructor we need load 'this' from lexical arrow function environment
+            
+            RegisterID* r0 = generator.isConstructor() ? generator.thisRegister() : generator.emitLoad(0, jsUndefined());
+            generator.emitProfileType(r0, ProfileTypeBytecodeFunctionReturnStatement); // Do not emit expression info for this profile because it's not in the user's source code.
+            ASSERT(startOffset() >= lineStartOffset());
+            generator.emitDebugHook(WillLeaveCallFrame, lastLine(), startOffset(), lineStartOffset());
+            generator.emitReturn(r0);
+            return;
         }
+        break;
+    }
     }
 }
 
@@ -2228,4 +3166,527 @@ RegisterID* FuncExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID*
     return generator.emitNewFunctionExpression(generator.finalDestination(dst), this);
 }
 
+// ------------------------------ ArrowFuncExprNode ---------------------------------
+
+RegisterID* ArrowFuncExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    return generator.emitNewArrowFunctionExpression(generator.finalDestination(dst), this);
+}
+
+// ------------------------------ YieldExprNode --------------------------------
+
+RegisterID* YieldExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (!delegate()) {
+        RefPtr<RegisterID> arg = nullptr;
+        if (argument()) {
+            arg = generator.newTemporary();
+            generator.emitNode(arg.get(), argument());
+        } else
+            arg = generator.emitLoad(nullptr, jsUndefined());
+        RefPtr<RegisterID> value = generator.emitYield(arg.get());
+        if (dst == generator.ignoredResult())
+            return nullptr;
+        return generator.emitMove(generator.finalDestination(dst), value.get());
+    }
+    RefPtr<RegisterID> arg = generator.newTemporary();
+    generator.emitNode(arg.get(), argument());
+    RefPtr<RegisterID> value = generator.emitDelegateYield(arg.get(), this);
+    if (dst == generator.ignoredResult())
+        return nullptr;
+    return generator.emitMove(generator.finalDestination(dst), value.get());
+}
+
+// ------------------------------ ClassDeclNode ---------------------------------
+
+void ClassDeclNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    generator.emitNode(dst, m_classDeclaration);
+}
+
+// ------------------------------ ClassExprNode ---------------------------------
+
+RegisterID* ClassExprNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (!m_name.isNull())
+        generator.pushLexicalScope(this, BytecodeGenerator::TDZCheckOptimization::Optimize, BytecodeGenerator::NestedScopeType::IsNested);
+
+    RefPtr<RegisterID> superclass;
+    if (m_classHeritage) {
+        superclass = generator.newTemporary();
+        generator.emitNode(superclass.get(), m_classHeritage);
+    }
+
+    RefPtr<RegisterID> constructor;
+
+    // FIXME: Make the prototype non-configurable & non-writable.
+    if (m_constructorExpression)
+        constructor = generator.emitNode(dst, m_constructorExpression);
+    else {
+        constructor = generator.emitNewDefaultConstructor(generator.finalDestination(dst),
+            m_classHeritage ? ConstructorKind::Derived : ConstructorKind::Base, m_name);
+    }
+
+    const auto& propertyNames = generator.propertyNames();
+    RefPtr<RegisterID> prototype = generator.emitNewObject(generator.newTemporary());
+
+    if (superclass) {
+        RefPtr<RegisterID> protoParent = generator.newTemporary();
+        generator.emitLoad(protoParent.get(), jsNull());
+
+        RefPtr<RegisterID> tempRegister = generator.newTemporary();
+
+        // FIXME: Throw TypeError if it's a generator function.
+        RefPtr<Label> superclassIsUndefinedLabel = generator.newLabel();
+        generator.emitJumpIfTrue(generator.emitIsUndefined(tempRegister.get(), superclass.get()), superclassIsUndefinedLabel.get());
+
+        RefPtr<Label> superclassIsNullLabel = generator.newLabel();
+        generator.emitJumpIfTrue(generator.emitUnaryOp(op_eq_null, tempRegister.get(), superclass.get()), superclassIsNullLabel.get());
+
+        RefPtr<Label> superclassIsObjectLabel = generator.newLabel();
+        generator.emitJumpIfTrue(generator.emitIsObject(tempRegister.get(), superclass.get()), superclassIsObjectLabel.get());
+        generator.emitLabel(superclassIsUndefinedLabel.get());
+        generator.emitThrowTypeError(ASCIILiteral("The superclass is not an object."));
+        generator.emitLabel(superclassIsObjectLabel.get());
+        generator.emitGetById(protoParent.get(), superclass.get(), generator.propertyNames().prototype);
+
+        RefPtr<Label> protoParentIsObjectOrNullLabel = generator.newLabel();
+        generator.emitJumpIfTrue(generator.emitUnaryOp(op_is_object_or_null, tempRegister.get(), protoParent.get()), protoParentIsObjectOrNullLabel.get());
+        generator.emitJumpIfTrue(generator.emitUnaryOp(op_is_function, tempRegister.get(), protoParent.get()), protoParentIsObjectOrNullLabel.get());
+        generator.emitThrowTypeError(ASCIILiteral("The value of the superclass's prototype property is not an object."));
+        generator.emitLabel(protoParentIsObjectOrNullLabel.get());
+
+        generator.emitDirectPutById(constructor.get(), generator.propertyNames().underscoreProto, superclass.get(), PropertyNode::Unknown);
+        generator.emitLabel(superclassIsNullLabel.get());
+        generator.emitDirectPutById(prototype.get(), generator.propertyNames().underscoreProto, protoParent.get(), PropertyNode::Unknown);
+
+        emitPutHomeObject(generator, constructor.get(), prototype.get());
+    }
+
+    RefPtr<RegisterID> constructorNameRegister = generator.emitLoad(generator.newTemporary(), propertyNames.constructor);
+    generator.emitCallDefineProperty(prototype.get(), constructorNameRegister.get(), constructor.get(), nullptr, nullptr,
+        BytecodeGenerator::PropertyConfigurable | BytecodeGenerator::PropertyWritable, m_position);
+
+    RefPtr<RegisterID> prototypeNameRegister = generator.emitLoad(generator.newTemporary(), propertyNames.prototype);
+    generator.emitCallDefineProperty(constructor.get(), prototypeNameRegister.get(), prototype.get(), nullptr, nullptr, 0, m_position);
+
+    if (m_staticMethods)
+        generator.emitNode(constructor.get(), m_staticMethods);
+
+    if (m_instanceMethods)
+        generator.emitNode(prototype.get(), m_instanceMethods);
+
+    if (!m_name.isNull()) {
+        Variable classNameVar = generator.variable(m_name);
+        RELEASE_ASSERT(classNameVar.isResolved());
+        RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, classNameVar);
+        generator.emitPutToScope(scope.get(), classNameVar, constructor.get(), ThrowIfNotFound, Initialization);
+        generator.popLexicalScope(this);
+    }
+
+    return generator.moveToDestinationIfNeeded(dst, constructor.get());
+}
+
+// ------------------------------ ImportDeclarationNode -----------------------
+
+void ImportDeclarationNode::emitBytecode(BytecodeGenerator&, RegisterID*)
+{
+    // Do nothing at runtime.
+}
+
+// ------------------------------ ExportAllDeclarationNode --------------------
+
+void ExportAllDeclarationNode::emitBytecode(BytecodeGenerator&, RegisterID*)
+{
+    // Do nothing at runtime.
+}
+
+// ------------------------------ ExportDefaultDeclarationNode ----------------
+
+void ExportDefaultDeclarationNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ASSERT(m_declaration);
+    generator.emitNode(dst, m_declaration);
+}
+
+// ------------------------------ ExportLocalDeclarationNode ------------------
+
+void ExportLocalDeclarationNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    ASSERT(m_declaration);
+    generator.emitNode(dst, m_declaration);
+}
+
+// ------------------------------ ExportNamedDeclarationNode ------------------
+
+void ExportNamedDeclarationNode::emitBytecode(BytecodeGenerator&, RegisterID*)
+{
+    // Do nothing at runtime.
+}
+
+// ------------------------------ DestructuringAssignmentNode -----------------
+RegisterID* DestructuringAssignmentNode::emitBytecode(BytecodeGenerator& generator, RegisterID* dst)
+{
+    if (RegisterID* result = m_bindings->emitDirectBinding(generator, dst, m_initializer))
+        return result;
+    RefPtr<RegisterID> initializer = generator.tempDestination(dst);
+    generator.emitNode(initializer.get(), m_initializer);
+    m_bindings->bindValue(generator, initializer.get());
+    return generator.moveToDestinationIfNeeded(dst, initializer.get());
+}
+
+static void assignDefaultValueIfUndefined(BytecodeGenerator& generator, RegisterID* maybeUndefined, ExpressionNode* defaultValue)
+{
+    ASSERT(defaultValue);
+    RefPtr<Label> isNotUndefined = generator.newLabel();
+    generator.emitJumpIfFalse(generator.emitIsUndefined(generator.newTemporary(), maybeUndefined), isNotUndefined.get());
+    generator.emitNode(maybeUndefined, defaultValue);
+    generator.emitLabel(isNotUndefined.get());
+}
+
+void ArrayPatternNode::bindValue(BytecodeGenerator& generator, RegisterID* rhs) const
+{
+    RefPtr<RegisterID> iterator = generator.newTemporary();
+    {
+        generator.emitGetById(iterator.get(), rhs, generator.propertyNames().iteratorSymbol);
+        CallArguments args(generator, nullptr);
+        generator.emitMove(args.thisRegister(), rhs);
+        generator.emitCall(iterator.get(), iterator.get(), NoExpectedFunction, args, divot(), divotStart(), divotEnd());
+    }
+
+    if (m_targetPatterns.isEmpty()) {
+        generator.emitIteratorClose(iterator.get(), this);
+        return;
+    }
+
+    RefPtr<RegisterID> done;
+    for (auto& target : m_targetPatterns) {
+        switch (target.bindingType) {
+        case BindingType::Elision:
+        case BindingType::Element: {
+            RefPtr<Label> iterationSkipped = generator.newLabel();
+            if (!done)
+                done = generator.newTemporary();
+            else
+                generator.emitJumpIfTrue(done.get(), iterationSkipped.get());
+
+            RefPtr<RegisterID> value = generator.newTemporary();
+            generator.emitIteratorNext(value.get(), iterator.get(), this);
+            generator.emitGetById(done.get(), value.get(), generator.propertyNames().done);
+            generator.emitJumpIfTrue(done.get(), iterationSkipped.get());
+            generator.emitGetById(value.get(), value.get(), generator.propertyNames().value);
+
+            {
+                RefPtr<Label> valueIsSet = generator.newLabel();
+                generator.emitJump(valueIsSet.get());
+                generator.emitLabel(iterationSkipped.get());
+                generator.emitLoad(value.get(), jsUndefined());
+                generator.emitLabel(valueIsSet.get());
+            }
+
+            if (target.bindingType == BindingType::Element) {
+                if (target.defaultValue)
+                    assignDefaultValueIfUndefined(generator, value.get(), target.defaultValue);
+                target.pattern->bindValue(generator, value.get());
+            }
+            break;
+        }
+
+        case BindingType::RestElement: {
+            RefPtr<RegisterID> array = generator.emitNewArray(generator.newTemporary(), 0, 0);
+
+            RefPtr<Label> iterationDone = generator.newLabel();
+            if (!done)
+                done = generator.newTemporary();
+            else
+                generator.emitJumpIfTrue(done.get(), iterationDone.get());
+
+            RefPtr<RegisterID> index = generator.newTemporary();
+            generator.emitLoad(index.get(), jsNumber(0));
+            RefPtr<Label> loopStart = generator.newLabel();
+            generator.emitLabel(loopStart.get());
+
+            RefPtr<RegisterID> value = generator.newTemporary();
+            generator.emitIteratorNext(value.get(), iterator.get(), this);
+            generator.emitGetById(done.get(), value.get(), generator.propertyNames().done);
+            generator.emitJumpIfTrue(done.get(), iterationDone.get());
+            generator.emitGetById(value.get(), value.get(), generator.propertyNames().value);
+
+            generator.emitDirectPutByVal(array.get(), index.get(), value.get());
+            generator.emitInc(index.get());
+            generator.emitJump(loopStart.get());
+
+            generator.emitLabel(iterationDone.get());
+            target.pattern->bindValue(generator, array.get());
+            break;
+        }
+        }
+    }
+
+    RefPtr<Label> iteratorClosed = generator.newLabel();
+    generator.emitJumpIfTrue(done.get(), iteratorClosed.get());
+    generator.emitIteratorClose(iterator.get(), this);
+    generator.emitLabel(iteratorClosed.get());
+}
+
+RegisterID* ArrayPatternNode::emitDirectBinding(BytecodeGenerator& generator, RegisterID* dst, ExpressionNode* rhs)
+{
+    if (!rhs->isSimpleArray())
+        return nullptr;
+
+    ElementNode* elementNodes = static_cast<ArrayNode*>(rhs)->elements();
+    Vector<ExpressionNode*> elements;
+    for (; elementNodes; elementNodes = elementNodes->next()) {
+        ExpressionNode* value = elementNodes->value();
+        if (value->isSpreadExpression())
+            return nullptr;
+        elements.append(value);
+    }
+
+    RefPtr<RegisterID> resultRegister;
+    if (dst && dst != generator.ignoredResult())
+        resultRegister = generator.emitNewArray(generator.newTemporary(), 0, 0);
+    if (m_targetPatterns.size() != elements.size())
+        return nullptr;
+    Vector<RefPtr<RegisterID>> registers;
+    registers.reserveCapacity(m_targetPatterns.size());
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        registers.uncheckedAppend(generator.newTemporary());
+        generator.emitNode(registers.last().get(), elements[i]);
+        if (m_targetPatterns[i].defaultValue)
+            assignDefaultValueIfUndefined(generator, registers.last().get(), m_targetPatterns[i].defaultValue);
+        if (resultRegister)
+            generator.emitPutByIndex(resultRegister.get(), i, registers.last().get());
+    }
+    
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        if (m_targetPatterns[i].pattern)
+            m_targetPatterns[i].pattern->bindValue(generator, registers[i].get());
+    }
+    if (resultRegister)
+        return generator.moveToDestinationIfNeeded(dst, resultRegister.get());
+    return generator.emitLoad(generator.finalDestination(dst), jsUndefined());
+}
+
+void ArrayPatternNode::toString(StringBuilder& builder) const
+{
+    builder.append('[');
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        const auto& target = m_targetPatterns[i];
+
+        switch (target.bindingType) {
+        case BindingType::Elision:
+            builder.append(',');
+            break;
+
+        case BindingType::Element:
+            target.pattern->toString(builder);
+            if (i < m_targetPatterns.size() - 1)
+                builder.append(',');
+            break;
+
+        case BindingType::RestElement:
+            builder.append("...");
+            target.pattern->toString(builder);
+            break;
+        }
+    }
+    builder.append(']');
+}
+
+void ArrayPatternNode::collectBoundIdentifiers(Vector<Identifier>& identifiers) const
+{
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        if (DestructuringPatternNode* node = m_targetPatterns[i].pattern)
+            node->collectBoundIdentifiers(identifiers);
+    }
+}
+
+void ObjectPatternNode::toString(StringBuilder& builder) const
+{
+    builder.append('{');
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        if (m_targetPatterns[i].wasString)
+            builder.appendQuotedJSONString(m_targetPatterns[i].propertyName.string());
+        else
+            builder.append(m_targetPatterns[i].propertyName.string());
+        builder.append(':');
+        m_targetPatterns[i].pattern->toString(builder);
+        if (i < m_targetPatterns.size() - 1)
+            builder.append(',');
+    }
+    builder.append('}');
+}
+    
+void ObjectPatternNode::bindValue(BytecodeGenerator& generator, RegisterID* rhs) const
+{
+    generator.emitRequireObjectCoercible(rhs, ASCIILiteral("Right side of assignment cannot be destructured"));
+    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
+        auto& target = m_targetPatterns[i];
+        RefPtr<RegisterID> temp = generator.newTemporary();
+        if (!target.propertyExpression) {
+            // Should not emit get_by_id for indexed ones.
+            Optional<uint32_t> optionalIndex = parseIndex(target.propertyName);
+            if (!optionalIndex)
+                generator.emitGetById(temp.get(), rhs, target.propertyName);
+            else {
+                RefPtr<RegisterID> index = generator.emitLoad(generator.newTemporary(), jsNumber(optionalIndex.value()));
+                generator.emitGetByVal(temp.get(), rhs, index.get());
+            }
+        } else {
+            RefPtr<RegisterID> propertyName = generator.emitNode(target.propertyExpression);
+            generator.emitGetByVal(temp.get(), rhs, propertyName.get());
+        }
+
+        if (target.defaultValue)
+            assignDefaultValueIfUndefined(generator, temp.get(), target.defaultValue);
+        target.pattern->bindValue(generator, temp.get());
+    }
+}
+
+void ObjectPatternNode::collectBoundIdentifiers(Vector<Identifier>& identifiers) const
+{
+    for (size_t i = 0; i < m_targetPatterns.size(); i++)
+        m_targetPatterns[i].pattern->collectBoundIdentifiers(identifiers);
+}
+
+void BindingNode::bindValue(BytecodeGenerator& generator, RegisterID* value) const
+{
+    Variable var = generator.variable(m_boundProperty);
+    bool isReadOnly = var.isReadOnly() && m_bindingContext != AssignmentContext::ConstDeclarationStatement;
+    if (RegisterID* local = var.local()) {
+        if (m_bindingContext == AssignmentContext::AssignmentExpression)
+            generator.emitTDZCheckIfNecessary(var, local, nullptr);
+        if (isReadOnly) {
+            generator.emitReadOnlyExceptionIfNeeded(var);
+            return;
+        }
+        generator.emitMove(local, value);
+        generator.emitProfileType(local, var, divotStart(), divotEnd());
+        if (m_bindingContext == AssignmentContext::DeclarationStatement || m_bindingContext == AssignmentContext::ConstDeclarationStatement)
+            generator.liftTDZCheckIfPossible(var);
+        return;
+    }
+    if (generator.isStrictMode())
+        generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+    RegisterID* scope = generator.emitResolveScope(nullptr, var);
+    generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+    if (m_bindingContext == AssignmentContext::AssignmentExpression)
+        generator.emitTDZCheckIfNecessary(var, nullptr, scope);
+    if (isReadOnly) {
+        generator.emitReadOnlyExceptionIfNeeded(var);
+        return;
+    }
+    generator.emitPutToScope(scope, var, value, generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, 
+        m_bindingContext == AssignmentContext::ConstDeclarationStatement || m_bindingContext == AssignmentContext::DeclarationStatement ? Initialization : NotInitialization);
+    generator.emitProfileType(value, var, divotStart(), divotEnd());
+    if (m_bindingContext == AssignmentContext::DeclarationStatement || m_bindingContext == AssignmentContext::ConstDeclarationStatement)
+        generator.liftTDZCheckIfPossible(var);
+    return;
+}
+
+void BindingNode::toString(StringBuilder& builder) const
+{
+    builder.append(m_boundProperty.string());
+}
+
+void BindingNode::collectBoundIdentifiers(Vector<Identifier>& identifiers) const
+{
+    identifiers.append(m_boundProperty);
+}
+
+void AssignmentElementNode::collectBoundIdentifiers(Vector<Identifier>&) const
+{
+}
+
+void AssignmentElementNode::bindValue(BytecodeGenerator& generator, RegisterID* value) const
+{
+    if (m_assignmentTarget->isResolveNode()) {
+        ResolveNode* lhs = static_cast<ResolveNode*>(m_assignmentTarget);
+        Variable var = generator.variable(lhs->identifier());
+        bool isReadOnly = var.isReadOnly();
+        if (RegisterID* local = var.local()) {
+            generator.emitTDZCheckIfNecessary(var, local, nullptr);
+
+            if (isReadOnly)
+                generator.emitReadOnlyExceptionIfNeeded(var);
+            else {
+                generator.invalidateForInContextForLocal(local);
+                generator.moveToDestinationIfNeeded(local, value);
+                generator.emitProfileType(local, divotStart(), divotEnd());
+            }
+            return;
+        }
+        if (generator.isStrictMode())
+            generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+        RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+        generator.emitTDZCheckIfNecessary(var, nullptr, scope.get());
+        if (isReadOnly) {
+            bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
+            if (threwException)
+                return;
+        }
+        generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+        if (!isReadOnly) {
+            generator.emitPutToScope(scope.get(), var, value, generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, NotInitialization);
+            generator.emitProfileType(value, var, divotStart(), divotEnd());
+        }
+    } else if (m_assignmentTarget->isDotAccessorNode()) {
+        DotAccessorNode* lhs = static_cast<DotAccessorNode*>(m_assignmentTarget);
+        RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(lhs->base(), true, false);
+        generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+        generator.emitPutById(base.get(), lhs->identifier(), value);
+        generator.emitProfileType(value, divotStart(), divotEnd());
+    } else if (m_assignmentTarget->isBracketAccessorNode()) {
+        BracketAccessorNode* lhs = static_cast<BracketAccessorNode*>(m_assignmentTarget);
+        RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(lhs->base(), true, false);
+        RefPtr<RegisterID> property = generator.emitNodeForLeftHandSide(lhs->subscript(), true, false);
+        generator.emitExpressionInfo(divotEnd(), divotStart(), divotEnd());
+        generator.emitPutByVal(base.get(), property.get(), value);
+        generator.emitProfileType(value, divotStart(), divotEnd());
+    }
+}
+
+void AssignmentElementNode::toString(StringBuilder& builder) const
+{
+    if (m_assignmentTarget->isResolveNode())
+        builder.append(static_cast<ResolveNode*>(m_assignmentTarget)->identifier().string());
+}
+
+void RestParameterNode::collectBoundIdentifiers(Vector<Identifier>& identifiers) const
+{
+    identifiers.append(m_name);
+}
+void RestParameterNode::toString(StringBuilder& builder) const
+{
+    builder.append(m_name.string());
+}
+void RestParameterNode::bindValue(BytecodeGenerator&, RegisterID*) const
+{
+    RELEASE_ASSERT_NOT_REACHED();
+}
+void RestParameterNode::emit(BytecodeGenerator& generator)
+{
+    Variable var = generator.variable(m_name);
+    if (RegisterID* local = var.local()) {
+        generator.emitRestParameter(local, m_numParametersToSkip);
+        generator.emitProfileType(local, var, m_divotStart, m_divotEnd);
+        return;
+    }
+
+    RefPtr<RegisterID> restParameterArray = generator.newTemporary();
+    generator.emitRestParameter(restParameterArray.get(), m_numParametersToSkip);
+    generator.emitProfileType(restParameterArray.get(), var, m_divotStart, m_divotEnd);
+    RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
+    generator.emitExpressionInfo(m_divotEnd, m_divotStart, m_divotEnd);
+    generator.emitPutToScope(scope.get(), var, restParameterArray.get(), generator.isStrictMode() ? ThrowIfNotFound : DoNotThrowIfNotFound, Initialization);
+}
+
+
+RegisterID* SpreadExpressionNode::emitBytecode(BytecodeGenerator&, RegisterID*)
+{
+    RELEASE_ASSERT_NOT_REACHED();
+    return 0;
+}
+
 } // namespace JSC