webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 4583 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp b/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
new file mode 100644
index 000000000..c4e0bc583
--- /dev/null
+++ b/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
@@ -0,0 +1,4583 @@
+/*
+ * Copyright (C) 2011-2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "DFGByteCodeParser.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "ArrayConstructor.h"
+#include "BasicBlockLocation.h"
+#include "CallLinkStatus.h"
+#include "CodeBlock.h"
+#include "CodeBlockWithJITType.h"
+#include "DFGArrayMode.h"
+#include "DFGCapabilities.h"
+#include "DFGGraph.h"
+#include "DFGJITCode.h"
+#include "GetByIdStatus.h"
+#include "Heap.h"
+#include "JSLexicalEnvironment.h"
+#include "JSCInlines.h"
+#include "PreciseJumpTargets.h"
+#include "PutByIdStatus.h"
+#include "StackAlignment.h"
+#include "StringConstructor.h"
+#include "Watchdog.h"
+#include <wtf/CommaPrinter.h>
+#include <wtf/HashMap.h>
+#include <wtf/MathExtras.h>
+#include <wtf/StdLibExtras.h>
+
+namespace JSC { namespace DFG {
+
+static const bool verbose = false;
+
+class ConstantBufferKey {
+public:
+    ConstantBufferKey()
+        : m_codeBlock(0)
+        , m_index(0)
+    {
+    }
+    
+    ConstantBufferKey(WTF::HashTableDeletedValueType)
+        : m_codeBlock(0)
+        , m_index(1)
+    {
+    }
+    
+    ConstantBufferKey(CodeBlock* codeBlock, unsigned index)
+        : m_codeBlock(codeBlock)
+        , m_index(index)
+    {
+    }
+    
+    bool operator==(const ConstantBufferKey& other) const
+    {
+        return m_codeBlock == other.m_codeBlock
+            && m_index == other.m_index;
+    }
+    
+    unsigned hash() const
+    {
+        return WTF::PtrHash<CodeBlock*>::hash(m_codeBlock) ^ m_index;
+    }
+    
+    bool isHashTableDeletedValue() const
+    {
+        return !m_codeBlock && m_index;
+    }
+    
+    CodeBlock* codeBlock() const { return m_codeBlock; }
+    unsigned index() const { return m_index; }
+    
+private:
+    CodeBlock* m_codeBlock;
+    unsigned m_index;
+};
+
+struct ConstantBufferKeyHash {
+    static unsigned hash(const ConstantBufferKey& key) { return key.hash(); }
+    static bool equal(const ConstantBufferKey& a, const ConstantBufferKey& b)
+    {
+        return a == b;
+    }
+    
+    static const bool safeToCompareToEmptyOrDeleted = true;
+};
+
+} } // namespace JSC::DFG
+
+namespace WTF {
+
+template<typename T> struct DefaultHash;
+template<> struct DefaultHash<JSC::DFG::ConstantBufferKey> {
+    typedef JSC::DFG::ConstantBufferKeyHash Hash;
+};
+
+template<typename T> struct HashTraits;
+template<> struct HashTraits<JSC::DFG::ConstantBufferKey> : SimpleClassHashTraits<JSC::DFG::ConstantBufferKey> { };
+
+} // namespace WTF
+
+namespace JSC { namespace DFG {
+
+// === ByteCodeParser ===
+//
+// This class is used to compile the dataflow graph from a CodeBlock.
+class ByteCodeParser {
+public:
+    ByteCodeParser(Graph& graph)
+        : m_vm(&graph.m_vm)
+        , m_codeBlock(graph.m_codeBlock)
+        , m_profiledBlock(graph.m_profiledBlock)
+        , m_graph(graph)
+        , m_currentBlock(0)
+        , m_currentIndex(0)
+        , m_constantUndefined(graph.freeze(jsUndefined()))
+        , m_constantNull(graph.freeze(jsNull()))
+        , m_constantNaN(graph.freeze(jsNumber(PNaN)))
+        , m_constantOne(graph.freeze(jsNumber(1)))
+        , m_numArguments(m_codeBlock->numParameters())
+        , m_numLocals(m_codeBlock->m_numCalleeRegisters)
+        , m_parameterSlots(0)
+        , m_numPassedVarArgs(0)
+        , m_inlineStackTop(0)
+        , m_currentInstruction(0)
+        , m_hasDebuggerEnabled(graph.hasDebuggerEnabled())
+    {
+        ASSERT(m_profiledBlock);
+    }
+    
+    // Parse a full CodeBlock of bytecode.
+    bool parse();
+    
+private:
+    struct InlineStackEntry;
+
+    // Just parse from m_currentIndex to the end of the current CodeBlock.
+    void parseCodeBlock();
+    
+    void ensureLocals(unsigned newNumLocals)
+    {
+        if (newNumLocals <= m_numLocals)
+            return;
+        m_numLocals = newNumLocals;
+        for (size_t i = 0; i < m_graph.numBlocks(); ++i)
+            m_graph.block(i)->ensureLocals(newNumLocals);
+    }
+
+    // Helper for min and max.
+    template<typename ChecksFunctor>
+    bool handleMinMax(int resultOperand, NodeType op, int registerOffset, int argumentCountIncludingThis, const ChecksFunctor& insertChecks);
+    
+    // Handle calls. This resolves issues surrounding inlining and intrinsics.
+    void handleCall(
+        int result, NodeType op, InlineCallFrame::Kind, unsigned instructionSize,
+        Node* callTarget, int argCount, int registerOffset, CallLinkStatus,
+        SpeculatedType prediction);
+    void handleCall(
+        int result, NodeType op, InlineCallFrame::Kind, unsigned instructionSize,
+        Node* callTarget, int argCount, int registerOffset, CallLinkStatus);
+    void handleCall(int result, NodeType op, CodeSpecializationKind, unsigned instructionSize, int callee, int argCount, int registerOffset);
+    void handleCall(Instruction* pc, NodeType op, CodeSpecializationKind);
+    void handleVarargsCall(Instruction* pc, NodeType op, CodeSpecializationKind);
+    void emitFunctionChecks(CallVariant, Node* callTarget, VirtualRegister thisArgumnt);
+    void emitArgumentPhantoms(int registerOffset, int argumentCountIncludingThis);
+    unsigned inliningCost(CallVariant, int argumentCountIncludingThis, CodeSpecializationKind); // Return UINT_MAX if it's not an inlining candidate. By convention, intrinsics have a cost of 1.
+    // Handle inlining. Return true if it succeeded, false if we need to plant a call.
+    bool handleInlining(Node* callTargetNode, int resultOperand, const CallLinkStatus&, int registerOffset, VirtualRegister thisArgument, VirtualRegister argumentsArgument, unsigned argumentsOffset, int argumentCountIncludingThis, unsigned nextOffset, NodeType callOp, InlineCallFrame::Kind, SpeculatedType prediction);
+    enum CallerLinkability { CallerDoesNormalLinking, CallerLinksManually };
+    template<typename ChecksFunctor>
+    bool attemptToInlineCall(Node* callTargetNode, int resultOperand, CallVariant, int registerOffset, int argumentCountIncludingThis, unsigned nextOffset, InlineCallFrame::Kind, CallerLinkability, SpeculatedType prediction, unsigned& inliningBalance, const ChecksFunctor& insertChecks);
+    template<typename ChecksFunctor>
+    void inlineCall(Node* callTargetNode, int resultOperand, CallVariant, int registerOffset, int argumentCountIncludingThis, unsigned nextOffset, InlineCallFrame::Kind, CallerLinkability, const ChecksFunctor& insertChecks);
+    void cancelLinkingForBlock(InlineStackEntry*, BasicBlock*); // Only works when the given block is the last one to have been added for that inline stack entry.
+    // Handle intrinsic functions. Return true if it succeeded, false if we need to plant a call.
+    template<typename ChecksFunctor>
+    bool handleIntrinsic(int resultOperand, Intrinsic, int registerOffset, int argumentCountIncludingThis, SpeculatedType prediction, const ChecksFunctor& insertChecks);
+    template<typename ChecksFunctor>
+    bool handleTypedArrayConstructor(int resultOperand, InternalFunction*, int registerOffset, int argumentCountIncludingThis, TypedArrayType, const ChecksFunctor& insertChecks);
+    template<typename ChecksFunctor>
+    bool handleConstantInternalFunction(int resultOperand, InternalFunction*, int registerOffset, int argumentCountIncludingThis, CodeSpecializationKind, const ChecksFunctor& insertChecks);
+    Node* handlePutByOffset(Node* base, unsigned identifier, PropertyOffset, Node* value);
+    Node* handleGetByOffset(SpeculatedType, Node* base, unsigned identifierNumber, PropertyOffset, NodeType = GetByOffset);
+    Node* handleGetByOffset(SpeculatedType, Node* base, UniquedStringImpl*, PropertyOffset, NodeType = GetByOffset);
+
+    // Create a presence ObjectPropertyCondition based on some known offset and structure set. Does not
+    // check the validity of the condition, but it may return a null one if it encounters a contradiction.
+    ObjectPropertyCondition presenceLike(
+        JSObject* knownBase, UniquedStringImpl*, PropertyOffset, const StructureSet&);
+    
+    // Attempt to watch the presence of a property. It will watch that the property is present in the same
+    // way as in all of the structures in the set. It may emit code instead of just setting a watchpoint.
+    // Returns true if this all works out.
+    bool checkPresenceLike(JSObject* knownBase, UniquedStringImpl*, PropertyOffset, const StructureSet&);
+    void checkPresenceLike(Node* base, UniquedStringImpl*, PropertyOffset, const StructureSet&);
+    
+    // Works with both GetByIdVariant and the setter form of PutByIdVariant.
+    template<typename VariantType>
+    Node* load(SpeculatedType, Node* base, unsigned identifierNumber, const VariantType&);
+
+    Node* store(Node* base, unsigned identifier, const PutByIdVariant&, Node* value);
+        
+    void handleGetById(
+        int destinationOperand, SpeculatedType, Node* base, unsigned identifierNumber,
+        const GetByIdStatus&);
+    void emitPutById(
+        Node* base, unsigned identifierNumber, Node* value,  const PutByIdStatus&, bool isDirect);
+    void handlePutById(
+        Node* base, unsigned identifierNumber, Node* value, const PutByIdStatus&,
+        bool isDirect);
+    
+    // Either register a watchpoint or emit a check for this condition. Returns false if the
+    // condition no longer holds, and therefore no reasonable check can be emitted.
+    bool check(const ObjectPropertyCondition&);
+    
+    GetByOffsetMethod promoteToConstant(GetByOffsetMethod);
+    
+    // Either register a watchpoint or emit a check for this condition. It must be a Presence
+    // condition. It will attempt to promote a Presence condition to an Equivalence condition.
+    // Emits code for the loaded value that the condition guards, and returns a node containing
+    // the loaded value. Returns null if the condition no longer holds.
+    GetByOffsetMethod planLoad(const ObjectPropertyCondition&);
+    Node* load(SpeculatedType, unsigned identifierNumber, const GetByOffsetMethod&, NodeType = GetByOffset);
+    Node* load(SpeculatedType, const ObjectPropertyCondition&, NodeType = GetByOffset);
+    
+    // Calls check() for each condition in the set: that is, it either emits checks or registers
+    // watchpoints (or a combination of the two) to make the conditions hold. If any of those
+    // conditions are no longer checkable, returns false.
+    bool check(const ObjectPropertyConditionSet&);
+    
+    // Calls check() for those conditions that aren't the slot base, and calls load() for the slot
+    // base. Does a combination of watchpoint registration and check emission to guard the
+    // conditions, and emits code to load the value from the slot base. Returns a node containing
+    // the loaded value. Returns null if any of the conditions were no longer checkable.
+    GetByOffsetMethod planLoad(const ObjectPropertyConditionSet&);
+    Node* load(SpeculatedType, const ObjectPropertyConditionSet&, NodeType = GetByOffset);
+
+    void prepareToParseBlock();
+    void clearCaches();
+
+    // Parse a single basic block of bytecode instructions.
+    bool parseBlock(unsigned limit);
+    // Link block successors.
+    void linkBlock(BasicBlock*, Vector<BasicBlock*>& possibleTargets);
+    void linkBlocks(Vector<UnlinkedBlock>& unlinkedBlocks, Vector<BasicBlock*>& possibleTargets);
+    
+    VariableAccessData* newVariableAccessData(VirtualRegister operand)
+    {
+        ASSERT(!operand.isConstant());
+        
+        m_graph.m_variableAccessData.append(VariableAccessData(operand));
+        return &m_graph.m_variableAccessData.last();
+    }
+    
+    // Get/Set the operands/result of a bytecode instruction.
+    Node* getDirect(VirtualRegister operand)
+    {
+        ASSERT(!operand.isConstant());
+
+        // Is this an argument?
+        if (operand.isArgument())
+            return getArgument(operand);
+
+        // Must be a local.
+        return getLocal(operand);
+    }
+
+    Node* get(VirtualRegister operand)
+    {
+        if (operand.isConstant()) {
+            unsigned constantIndex = operand.toConstantIndex();
+            unsigned oldSize = m_constants.size();
+            if (constantIndex >= oldSize || !m_constants[constantIndex]) {
+                const CodeBlock& codeBlock = *m_inlineStackTop->m_codeBlock;
+                JSValue value = codeBlock.getConstant(operand.offset());
+                SourceCodeRepresentation sourceCodeRepresentation = codeBlock.constantSourceCodeRepresentation(operand.offset());
+                if (constantIndex >= oldSize) {
+                    m_constants.grow(constantIndex + 1);
+                    for (unsigned i = oldSize; i < m_constants.size(); ++i)
+                        m_constants[i] = nullptr;
+                }
+
+                Node* constantNode = nullptr;
+                if (sourceCodeRepresentation == SourceCodeRepresentation::Double)
+                    constantNode = addToGraph(DoubleConstant, OpInfo(m_graph.freezeStrong(jsDoubleNumber(value.asNumber()))));
+                else
+                    constantNode = addToGraph(JSConstant, OpInfo(m_graph.freezeStrong(value)));
+                m_constants[constantIndex] = constantNode;
+            }
+            ASSERT(m_constants[constantIndex]);
+            return m_constants[constantIndex];
+        }
+        
+        if (inlineCallFrame()) {
+            if (!inlineCallFrame()->isClosureCall) {
+                JSFunction* callee = inlineCallFrame()->calleeConstant();
+                if (operand.offset() == JSStack::Callee)
+                    return weakJSConstant(callee);
+            }
+        } else if (operand.offset() == JSStack::Callee) {
+            // We have to do some constant-folding here because this enables CreateThis folding. Note
+            // that we don't have such watchpoint-based folding for inlined uses of Callee, since in that
+            // case if the function is a singleton then we already know it.
+            if (FunctionExecutable* executable = jsDynamicCast<FunctionExecutable*>(m_codeBlock->ownerExecutable())) {
+                InferredValue* singleton = executable->singletonFunction();
+                if (JSValue value = singleton->inferredValue()) {
+                    m_graph.watchpoints().addLazily(singleton);
+                    JSFunction* function = jsCast<JSFunction*>(value);
+                    return weakJSConstant(function);
+                }
+            }
+            return addToGraph(GetCallee);
+        }
+        
+        return getDirect(m_inlineStackTop->remapOperand(operand));
+    }
+    
+    enum SetMode {
+        // A normal set which follows a two-phase commit that spans code origins. During
+        // the current code origin it issues a MovHint, and at the start of the next
+        // code origin there will be a SetLocal. If the local needs flushing, the second
+        // SetLocal will be preceded with a Flush.
+        NormalSet,
+        
+        // A set where the SetLocal happens immediately and there is still a Flush. This
+        // is relevant when assigning to a local in tricky situations for the delayed
+        // SetLocal logic but where we know that we have not performed any side effects
+        // within this code origin. This is a safe replacement for NormalSet anytime we
+        // know that we have not yet performed side effects in this code origin.
+        ImmediateSetWithFlush,
+        
+        // A set where the SetLocal happens immediately and we do not Flush it even if
+        // this is a local that is marked as needing it. This is relevant when
+        // initializing locals at the top of a function.
+        ImmediateNakedSet
+    };
+    Node* setDirect(VirtualRegister operand, Node* value, SetMode setMode = NormalSet)
+    {
+        addToGraph(MovHint, OpInfo(operand.offset()), value);
+
+        DelayedSetLocal delayed(currentCodeOrigin(), operand, value);
+        
+        if (setMode == NormalSet) {
+            m_setLocalQueue.append(delayed);
+            return 0;
+        }
+        
+        return delayed.execute(this, setMode);
+    }
+    
+    void processSetLocalQueue()
+    {
+        for (unsigned i = 0; i < m_setLocalQueue.size(); ++i)
+            m_setLocalQueue[i].execute(this);
+        m_setLocalQueue.resize(0);
+    }
+
+    Node* set(VirtualRegister operand, Node* value, SetMode setMode = NormalSet)
+    {
+        return setDirect(m_inlineStackTop->remapOperand(operand), value, setMode);
+    }
+    
+    Node* injectLazyOperandSpeculation(Node* node)
+    {
+        ASSERT(node->op() == GetLocal);
+        ASSERT(node->origin.semantic.bytecodeIndex == m_currentIndex);
+        ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+        LazyOperandValueProfileKey key(m_currentIndex, node->local());
+        SpeculatedType prediction = m_inlineStackTop->m_lazyOperands.prediction(locker, key);
+        node->variableAccessData()->predict(prediction);
+        return node;
+    }
+
+    // Used in implementing get/set, above, where the operand is a local variable.
+    Node* getLocal(VirtualRegister operand)
+    {
+        unsigned local = operand.toLocal();
+
+        Node* node = m_currentBlock->variablesAtTail.local(local);
+        
+        // This has two goals: 1) link together variable access datas, and 2)
+        // try to avoid creating redundant GetLocals. (1) is required for
+        // correctness - no other phase will ensure that block-local variable
+        // access data unification is done correctly. (2) is purely opportunistic
+        // and is meant as an compile-time optimization only.
+        
+        VariableAccessData* variable;
+        
+        if (node) {
+            variable = node->variableAccessData();
+            
+            switch (node->op()) {
+            case GetLocal:
+                return node;
+            case SetLocal:
+                return node->child1().node();
+            default:
+                break;
+            }
+        } else
+            variable = newVariableAccessData(operand);
+        
+        node = injectLazyOperandSpeculation(addToGraph(GetLocal, OpInfo(variable)));
+        m_currentBlock->variablesAtTail.local(local) = node;
+        return node;
+    }
+
+    Node* setLocal(const CodeOrigin& semanticOrigin, VirtualRegister operand, Node* value, SetMode setMode = NormalSet)
+    {
+        CodeOrigin oldSemanticOrigin = m_currentSemanticOrigin;
+        m_currentSemanticOrigin = semanticOrigin;
+
+        unsigned local = operand.toLocal();
+        
+        if (setMode != ImmediateNakedSet) {
+            ArgumentPosition* argumentPosition = findArgumentPositionForLocal(operand);
+            if (argumentPosition)
+                flushDirect(operand, argumentPosition);
+            else if (m_hasDebuggerEnabled && operand == m_codeBlock->scopeRegister())
+                flush(operand);
+        }
+
+        VariableAccessData* variableAccessData = newVariableAccessData(operand);
+        variableAccessData->mergeStructureCheckHoistingFailed(
+            m_inlineStackTop->m_exitProfile.hasExitSite(semanticOrigin.bytecodeIndex, BadCache));
+        variableAccessData->mergeCheckArrayHoistingFailed(
+            m_inlineStackTop->m_exitProfile.hasExitSite(semanticOrigin.bytecodeIndex, BadIndexingType));
+        Node* node = addToGraph(SetLocal, OpInfo(variableAccessData), value);
+        m_currentBlock->variablesAtTail.local(local) = node;
+
+        m_currentSemanticOrigin = oldSemanticOrigin;
+        return node;
+    }
+
+    // Used in implementing get/set, above, where the operand is an argument.
+    Node* getArgument(VirtualRegister operand)
+    {
+        unsigned argument = operand.toArgument();
+        ASSERT(argument < m_numArguments);
+        
+        Node* node = m_currentBlock->variablesAtTail.argument(argument);
+
+        VariableAccessData* variable;
+        
+        if (node) {
+            variable = node->variableAccessData();
+            
+            switch (node->op()) {
+            case GetLocal:
+                return node;
+            case SetLocal:
+                return node->child1().node();
+            default:
+                break;
+            }
+        } else
+            variable = newVariableAccessData(operand);
+        
+        node = injectLazyOperandSpeculation(addToGraph(GetLocal, OpInfo(variable)));
+        m_currentBlock->variablesAtTail.argument(argument) = node;
+        return node;
+    }
+    Node* setArgument(const CodeOrigin& semanticOrigin, VirtualRegister operand, Node* value, SetMode setMode = NormalSet)
+    {
+        CodeOrigin oldSemanticOrigin = m_currentSemanticOrigin;
+        m_currentSemanticOrigin = semanticOrigin;
+
+        unsigned argument = operand.toArgument();
+        ASSERT(argument < m_numArguments);
+        
+        VariableAccessData* variableAccessData = newVariableAccessData(operand);
+
+        // Always flush arguments, except for 'this'. If 'this' is created by us,
+        // then make sure that it's never unboxed.
+        if (argument) {
+            if (setMode != ImmediateNakedSet)
+                flushDirect(operand);
+        } else if (m_codeBlock->specializationKind() == CodeForConstruct)
+            variableAccessData->mergeShouldNeverUnbox(true);
+        
+        variableAccessData->mergeStructureCheckHoistingFailed(
+            m_inlineStackTop->m_exitProfile.hasExitSite(semanticOrigin.bytecodeIndex, BadCache));
+        variableAccessData->mergeCheckArrayHoistingFailed(
+            m_inlineStackTop->m_exitProfile.hasExitSite(semanticOrigin.bytecodeIndex, BadIndexingType));
+        Node* node = addToGraph(SetLocal, OpInfo(variableAccessData), value);
+        m_currentBlock->variablesAtTail.argument(argument) = node;
+
+        m_currentSemanticOrigin = oldSemanticOrigin;
+        return node;
+    }
+    
+    ArgumentPosition* findArgumentPositionForArgument(int argument)
+    {
+        InlineStackEntry* stack = m_inlineStackTop;
+        while (stack->m_inlineCallFrame)
+            stack = stack->m_caller;
+        return stack->m_argumentPositions[argument];
+    }
+    
+    ArgumentPosition* findArgumentPositionForLocal(VirtualRegister operand)
+    {
+        for (InlineStackEntry* stack = m_inlineStackTop; ; stack = stack->m_caller) {
+            InlineCallFrame* inlineCallFrame = stack->m_inlineCallFrame;
+            if (!inlineCallFrame)
+                break;
+            if (operand.offset() < static_cast<int>(inlineCallFrame->stackOffset + JSStack::CallFrameHeaderSize))
+                continue;
+            if (operand.offset() == inlineCallFrame->stackOffset + CallFrame::thisArgumentOffset())
+                continue;
+            if (operand.offset() >= static_cast<int>(inlineCallFrame->stackOffset + CallFrame::thisArgumentOffset() + inlineCallFrame->arguments.size()))
+                continue;
+            int argument = VirtualRegister(operand.offset() - inlineCallFrame->stackOffset).toArgument();
+            return stack->m_argumentPositions[argument];
+        }
+        return 0;
+    }
+    
+    ArgumentPosition* findArgumentPosition(VirtualRegister operand)
+    {
+        if (operand.isArgument())
+            return findArgumentPositionForArgument(operand.toArgument());
+        return findArgumentPositionForLocal(operand);
+    }
+
+    void flush(VirtualRegister operand)
+    {
+        flushDirect(m_inlineStackTop->remapOperand(operand));
+    }
+    
+    void flushDirect(VirtualRegister operand)
+    {
+        flushDirect(operand, findArgumentPosition(operand));
+    }
+    
+    void flushDirect(VirtualRegister operand, ArgumentPosition* argumentPosition)
+    {
+        ASSERT(!operand.isConstant());
+        
+        Node* node = m_currentBlock->variablesAtTail.operand(operand);
+        
+        VariableAccessData* variable;
+        
+        if (node)
+            variable = node->variableAccessData();
+        else
+            variable = newVariableAccessData(operand);
+        
+        node = addToGraph(Flush, OpInfo(variable));
+        m_currentBlock->variablesAtTail.operand(operand) = node;
+        if (argumentPosition)
+            argumentPosition->addVariable(variable);
+    }
+    
+    void flush(InlineStackEntry* inlineStackEntry)
+    {
+        int numArguments;
+        if (InlineCallFrame* inlineCallFrame = inlineStackEntry->m_inlineCallFrame) {
+            ASSERT(!m_hasDebuggerEnabled);
+            numArguments = inlineCallFrame->arguments.size();
+            if (inlineCallFrame->isClosureCall)
+                flushDirect(inlineStackEntry->remapOperand(VirtualRegister(JSStack::Callee)));
+            if (inlineCallFrame->isVarargs())
+                flushDirect(inlineStackEntry->remapOperand(VirtualRegister(JSStack::ArgumentCount)));
+        } else
+            numArguments = inlineStackEntry->m_codeBlock->numParameters();
+        for (unsigned argument = numArguments; argument-- > 1;)
+            flushDirect(inlineStackEntry->remapOperand(virtualRegisterForArgument(argument)));
+        if (m_hasDebuggerEnabled)
+            flush(m_codeBlock->scopeRegister());
+    }
+
+    void flushForTerminal()
+    {
+        for (InlineStackEntry* inlineStackEntry = m_inlineStackTop; inlineStackEntry; inlineStackEntry = inlineStackEntry->m_caller)
+            flush(inlineStackEntry);
+    }
+
+    void flushForReturn()
+    {
+        flush(m_inlineStackTop);
+    }
+    
+    void flushIfTerminal(SwitchData& data)
+    {
+        if (data.fallThrough.bytecodeIndex() > m_currentIndex)
+            return;
+        
+        for (unsigned i = data.cases.size(); i--;) {
+            if (data.cases[i].target.bytecodeIndex() > m_currentIndex)
+                return;
+        }
+        
+        flushForTerminal();
+    }
+
+    // Assumes that the constant should be strongly marked.
+    Node* jsConstant(JSValue constantValue)
+    {
+        return addToGraph(JSConstant, OpInfo(m_graph.freezeStrong(constantValue)));
+    }
+
+    Node* weakJSConstant(JSValue constantValue)
+    {
+        return addToGraph(JSConstant, OpInfo(m_graph.freeze(constantValue)));
+    }
+
+    // Helper functions to get/set the this value.
+    Node* getThis()
+    {
+        return get(m_inlineStackTop->m_codeBlock->thisRegister());
+    }
+
+    void setThis(Node* value)
+    {
+        set(m_inlineStackTop->m_codeBlock->thisRegister(), value);
+    }
+
+    InlineCallFrame* inlineCallFrame()
+    {
+        return m_inlineStackTop->m_inlineCallFrame;
+    }
+
+    CodeOrigin currentCodeOrigin()
+    {
+        return CodeOrigin(m_currentIndex, inlineCallFrame());
+    }
+
+    NodeOrigin currentNodeOrigin()
+    {
+        // FIXME: We should set the forExit origin only on those nodes that can exit.
+        // https://bugs.webkit.org/show_bug.cgi?id=145204
+        if (m_currentSemanticOrigin.isSet())
+            return NodeOrigin(m_currentSemanticOrigin, currentCodeOrigin());
+        return NodeOrigin(currentCodeOrigin());
+    }
+    
+    BranchData* branchData(unsigned taken, unsigned notTaken)
+    {
+        // We assume that branches originating from bytecode always have a fall-through. We
+        // use this assumption to avoid checking for the creation of terminal blocks.
+        ASSERT((taken > m_currentIndex) || (notTaken > m_currentIndex));
+        BranchData* data = m_graph.m_branchData.add();
+        *data = BranchData::withBytecodeIndices(taken, notTaken);
+        return data;
+    }
+    
+    Node* addToGraph(Node* node)
+    {
+        if (Options::verboseDFGByteCodeParsing())
+            dataLog("        appended ", node, " ", Graph::opName(node->op()), "\n");
+        m_currentBlock->append(node);
+        return node;
+    }
+    
+    Node* addToGraph(NodeType op, Node* child1 = 0, Node* child2 = 0, Node* child3 = 0)
+    {
+        Node* result = m_graph.addNode(
+            SpecNone, op, currentNodeOrigin(), Edge(child1), Edge(child2),
+            Edge(child3));
+        return addToGraph(result);
+    }
+    Node* addToGraph(NodeType op, Edge child1, Edge child2 = Edge(), Edge child3 = Edge())
+    {
+        Node* result = m_graph.addNode(
+            SpecNone, op, currentNodeOrigin(), child1, child2, child3);
+        return addToGraph(result);
+    }
+    Node* addToGraph(NodeType op, OpInfo info, Node* child1 = 0, Node* child2 = 0, Node* child3 = 0)
+    {
+        Node* result = m_graph.addNode(
+            SpecNone, op, currentNodeOrigin(), info, Edge(child1), Edge(child2),
+            Edge(child3));
+        return addToGraph(result);
+    }
+    Node* addToGraph(NodeType op, OpInfo info1, OpInfo info2, Node* child1 = 0, Node* child2 = 0, Node* child3 = 0)
+    {
+        Node* result = m_graph.addNode(
+            SpecNone, op, currentNodeOrigin(), info1, info2,
+            Edge(child1), Edge(child2), Edge(child3));
+        return addToGraph(result);
+    }
+    
+    Node* addToGraph(Node::VarArgTag, NodeType op, OpInfo info1, OpInfo info2)
+    {
+        Node* result = m_graph.addNode(
+            SpecNone, Node::VarArg, op, currentNodeOrigin(), info1, info2,
+            m_graph.m_varArgChildren.size() - m_numPassedVarArgs, m_numPassedVarArgs);
+        addToGraph(result);
+        
+        m_numPassedVarArgs = 0;
+        
+        return result;
+    }
+    
+    void addVarArgChild(Node* child)
+    {
+        m_graph.m_varArgChildren.append(Edge(child));
+        m_numPassedVarArgs++;
+    }
+    
+    Node* addCallWithoutSettingResult(
+        NodeType op, OpInfo opInfo, Node* callee, int argCount, int registerOffset,
+        SpeculatedType prediction)
+    {
+        addVarArgChild(callee);
+        size_t parameterSlots = JSStack::CallFrameHeaderSize - JSStack::CallerFrameAndPCSize + argCount;
+        if (parameterSlots > m_parameterSlots)
+            m_parameterSlots = parameterSlots;
+
+        for (int i = 0; i < argCount; ++i)
+            addVarArgChild(get(virtualRegisterForArgument(i, registerOffset)));
+
+        return addToGraph(Node::VarArg, op, opInfo, OpInfo(prediction));
+    }
+    
+    Node* addCall(
+        int result, NodeType op, OpInfo opInfo, Node* callee, int argCount, int registerOffset,
+        SpeculatedType prediction)
+    {
+        Node* call = addCallWithoutSettingResult(
+            op, opInfo, callee, argCount, registerOffset, prediction);
+        VirtualRegister resultReg(result);
+        if (resultReg.isValid())
+            set(resultReg, call);
+        return call;
+    }
+    
+    Node* cellConstantWithStructureCheck(JSCell* object, Structure* structure)
+    {
+        // FIXME: This should route to emitPropertyCheck, not the other way around. But currently,
+        // this gets no profit from using emitPropertyCheck() since we'll non-adaptively watch the
+        // object's structure as soon as we make it a weakJSCosntant.
+        Node* objectNode = weakJSConstant(object);
+        addToGraph(CheckStructure, OpInfo(m_graph.addStructureSet(structure)), objectNode);
+        return objectNode;
+    }
+    
+    SpeculatedType getPredictionWithoutOSRExit(unsigned bytecodeIndex)
+    {
+        ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+        return m_inlineStackTop->m_profiledBlock->valueProfilePredictionForBytecodeOffset(locker, bytecodeIndex);
+    }
+
+    SpeculatedType getPrediction(unsigned bytecodeIndex)
+    {
+        SpeculatedType prediction = getPredictionWithoutOSRExit(bytecodeIndex);
+        
+        if (prediction == SpecNone) {
+            // We have no information about what values this node generates. Give up
+            // on executing this code, since we're likely to do more damage than good.
+            addToGraph(ForceOSRExit);
+        }
+        
+        return prediction;
+    }
+    
+    SpeculatedType getPredictionWithoutOSRExit()
+    {
+        return getPredictionWithoutOSRExit(m_currentIndex);
+    }
+    
+    SpeculatedType getPrediction()
+    {
+        return getPrediction(m_currentIndex);
+    }
+    
+    ArrayMode getArrayMode(ArrayProfile* profile, Array::Action action)
+    {
+        ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+        profile->computeUpdatedPrediction(locker, m_inlineStackTop->m_profiledBlock);
+        bool makeSafe = profile->outOfBounds(locker);
+        return ArrayMode::fromObserved(locker, profile, action, makeSafe);
+    }
+    
+    ArrayMode getArrayMode(ArrayProfile* profile)
+    {
+        return getArrayMode(profile, Array::Read);
+    }
+    
+    Node* makeSafe(Node* node)
+    {
+        if (m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, Overflow))
+            node->mergeFlags(NodeMayOverflowInDFG);
+        if (m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, NegativeZero))
+            node->mergeFlags(NodeMayNegZeroInDFG);
+        
+        if (!isX86() && node->op() == ArithMod)
+            return node;
+
+        if (!m_inlineStackTop->m_profiledBlock->likelyToTakeSlowCase(m_currentIndex))
+            return node;
+        
+        switch (node->op()) {
+        case UInt32ToNumber:
+        case ArithAdd:
+        case ArithSub:
+        case ValueAdd:
+        case ArithMod: // for ArithMod "MayOverflow" means we tried to divide by zero, or we saw double.
+            node->mergeFlags(NodeMayOverflowInBaseline);
+            break;
+            
+        case ArithNegate:
+            // Currently we can't tell the difference between a negation overflowing
+            // (i.e. -(1 << 31)) or generating negative zero (i.e. -0). If it took slow
+            // path then we assume that it did both of those things.
+            node->mergeFlags(NodeMayOverflowInBaseline);
+            node->mergeFlags(NodeMayNegZeroInBaseline);
+            break;
+
+        case ArithMul:
+            // FIXME: We should detect cases where we only overflowed but never created
+            // negative zero.
+            // https://bugs.webkit.org/show_bug.cgi?id=132470
+            if (m_inlineStackTop->m_profiledBlock->likelyToTakeDeepestSlowCase(m_currentIndex)
+                || m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, Overflow))
+                node->mergeFlags(NodeMayOverflowInBaseline | NodeMayNegZeroInBaseline);
+            else if (m_inlineStackTop->m_profiledBlock->likelyToTakeSlowCase(m_currentIndex)
+                || m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, NegativeZero))
+                node->mergeFlags(NodeMayNegZeroInBaseline);
+            break;
+            
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            break;
+        }
+        
+        return node;
+    }
+    
+    Node* makeDivSafe(Node* node)
+    {
+        ASSERT(node->op() == ArithDiv);
+        
+        if (m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, Overflow))
+            node->mergeFlags(NodeMayOverflowInDFG);
+        if (m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, NegativeZero))
+            node->mergeFlags(NodeMayNegZeroInDFG);
+        
+        // The main slow case counter for op_div in the old JIT counts only when
+        // the operands are not numbers. We don't care about that since we already
+        // have speculations in place that take care of that separately. We only
+        // care about when the outcome of the division is not an integer, which
+        // is what the special fast case counter tells us.
+        
+        if (!m_inlineStackTop->m_profiledBlock->couldTakeSpecialFastCase(m_currentIndex))
+            return node;
+        
+        // FIXME: It might be possible to make this more granular.
+        node->mergeFlags(NodeMayOverflowInBaseline | NodeMayNegZeroInBaseline);
+        
+        return node;
+    }
+    
+    void noticeArgumentsUse()
+    {
+        // All of the arguments in this function need to be formatted as JSValues because we will
+        // load from them in a random-access fashion and we don't want to have to switch on
+        // format.
+        
+        for (ArgumentPosition* argument : m_inlineStackTop->m_argumentPositions)
+            argument->mergeShouldNeverUnbox(true);
+    }
+    
+    VM* m_vm;
+    CodeBlock* m_codeBlock;
+    CodeBlock* m_profiledBlock;
+    Graph& m_graph;
+
+    // The current block being generated.
+    BasicBlock* m_currentBlock;
+    // The bytecode index of the current instruction being generated.
+    unsigned m_currentIndex;
+    // The semantic origin of the current node if different from the current Index.
+    CodeOrigin m_currentSemanticOrigin;
+
+    FrozenValue* m_constantUndefined;
+    FrozenValue* m_constantNull;
+    FrozenValue* m_constantNaN;
+    FrozenValue* m_constantOne;
+    Vector<Node*, 16> m_constants;
+
+    // The number of arguments passed to the function.
+    unsigned m_numArguments;
+    // The number of locals (vars + temporaries) used in the function.
+    unsigned m_numLocals;
+    // The number of slots (in units of sizeof(Register)) that we need to
+    // preallocate for arguments to outgoing calls from this frame. This
+    // number includes the CallFrame slots that we initialize for the callee
+    // (but not the callee-initialized CallerFrame and ReturnPC slots).
+    // This number is 0 if and only if this function is a leaf.
+    unsigned m_parameterSlots;
+    // The number of var args passed to the next var arg node.
+    unsigned m_numPassedVarArgs;
+
+    HashMap<ConstantBufferKey, unsigned> m_constantBufferCache;
+    
+    struct InlineStackEntry {
+        ByteCodeParser* m_byteCodeParser;
+        
+        CodeBlock* m_codeBlock;
+        CodeBlock* m_profiledBlock;
+        InlineCallFrame* m_inlineCallFrame;
+        
+        ScriptExecutable* executable() { return m_codeBlock->ownerExecutable(); }
+        
+        QueryableExitProfile m_exitProfile;
+        
+        // Remapping of identifier and constant numbers from the code block being
+        // inlined (inline callee) to the code block that we're inlining into
+        // (the machine code block, which is the transitive, though not necessarily
+        // direct, caller).
+        Vector<unsigned> m_identifierRemap;
+        Vector<unsigned> m_constantBufferRemap;
+        Vector<unsigned> m_switchRemap;
+        
+        // Blocks introduced by this code block, which need successor linking.
+        // May include up to one basic block that includes the continuation after
+        // the callsite in the caller. These must be appended in the order that they
+        // are created, but their bytecodeBegin values need not be in order as they
+        // are ignored.
+        Vector<UnlinkedBlock> m_unlinkedBlocks;
+        
+        // Potential block linking targets. Must be sorted by bytecodeBegin, and
+        // cannot have two blocks that have the same bytecodeBegin.
+        Vector<BasicBlock*> m_blockLinkingTargets;
+        
+        // If the callsite's basic block was split into two, then this will be
+        // the head of the callsite block. It needs its successors linked to the
+        // m_unlinkedBlocks, but not the other way around: there's no way for
+        // any blocks in m_unlinkedBlocks to jump back into this block.
+        BasicBlock* m_callsiteBlockHead;
+        
+        // Does the callsite block head need linking? This is typically true
+        // but will be false for the machine code block's inline stack entry
+        // (since that one is not inlined) and for cases where an inline callee
+        // did the linking for us.
+        bool m_callsiteBlockHeadNeedsLinking;
+        
+        VirtualRegister m_returnValue;
+        
+        // Speculations about variable types collected from the profiled code block,
+        // which are based on OSR exit profiles that past DFG compilatins of this
+        // code block had gathered.
+        LazyOperandValueProfileParser m_lazyOperands;
+        
+        CallLinkInfoMap m_callLinkInfos;
+        StubInfoMap m_stubInfos;
+        ByValInfoMap m_byValInfos;
+        
+        // Did we see any returns? We need to handle the (uncommon but necessary)
+        // case where a procedure that does not return was inlined.
+        bool m_didReturn;
+        
+        // Did we have any early returns?
+        bool m_didEarlyReturn;
+        
+        // Pointers to the argument position trackers for this slice of code.
+        Vector<ArgumentPosition*> m_argumentPositions;
+        
+        InlineStackEntry* m_caller;
+        
+        InlineStackEntry(
+            ByteCodeParser*,
+            CodeBlock*,
+            CodeBlock* profiledBlock,
+            BasicBlock* callsiteBlockHead,
+            JSFunction* callee, // Null if this is a closure call.
+            VirtualRegister returnValueVR,
+            VirtualRegister inlineCallFrameStart,
+            int argumentCountIncludingThis,
+            InlineCallFrame::Kind);
+        
+        ~InlineStackEntry()
+        {
+            m_byteCodeParser->m_inlineStackTop = m_caller;
+        }
+        
+        VirtualRegister remapOperand(VirtualRegister operand) const
+        {
+            if (!m_inlineCallFrame)
+                return operand;
+            
+            ASSERT(!operand.isConstant());
+
+            return VirtualRegister(operand.offset() + m_inlineCallFrame->stackOffset);
+        }
+    };
+    
+    InlineStackEntry* m_inlineStackTop;
+    
+    struct DelayedSetLocal {
+        CodeOrigin m_origin;
+        VirtualRegister m_operand;
+        Node* m_value;
+        
+        DelayedSetLocal() { }
+        DelayedSetLocal(const CodeOrigin& origin, VirtualRegister operand, Node* value)
+            : m_origin(origin)
+            , m_operand(operand)
+            , m_value(value)
+        {
+        }
+        
+        Node* execute(ByteCodeParser* parser, SetMode setMode = NormalSet)
+        {
+            if (m_operand.isArgument())
+                return parser->setArgument(m_origin, m_operand, m_value, setMode);
+            return parser->setLocal(m_origin, m_operand, m_value, setMode);
+        }
+    };
+    
+    Vector<DelayedSetLocal, 2> m_setLocalQueue;
+
+    CodeBlock* m_dfgCodeBlock;
+    CallLinkStatus::ContextMap m_callContextMap;
+    StubInfoMap m_dfgStubInfos;
+    
+    Instruction* m_currentInstruction;
+    bool m_hasDebuggerEnabled;
+};
+
+#define NEXT_OPCODE(name) \
+    m_currentIndex += OPCODE_LENGTH(name); \
+    continue
+
+#define LAST_OPCODE(name) \
+    m_currentIndex += OPCODE_LENGTH(name); \
+    return shouldContinueParsing
+
+void ByteCodeParser::handleCall(Instruction* pc, NodeType op, CodeSpecializationKind kind)
+{
+    ASSERT(OPCODE_LENGTH(op_call) == OPCODE_LENGTH(op_construct));
+    handleCall(
+        pc[1].u.operand, op, kind, OPCODE_LENGTH(op_call),
+        pc[2].u.operand, pc[3].u.operand, -pc[4].u.operand);
+}
+
+void ByteCodeParser::handleCall(
+    int result, NodeType op, CodeSpecializationKind kind, unsigned instructionSize,
+    int callee, int argumentCountIncludingThis, int registerOffset)
+{
+    Node* callTarget = get(VirtualRegister(callee));
+    
+    CallLinkStatus callLinkStatus = CallLinkStatus::computeFor(
+        m_inlineStackTop->m_profiledBlock, currentCodeOrigin(),
+        m_inlineStackTop->m_callLinkInfos, m_callContextMap);
+    
+    handleCall(
+        result, op, InlineCallFrame::kindFor(kind), instructionSize, callTarget,
+        argumentCountIncludingThis, registerOffset, callLinkStatus);
+}
+    
+void ByteCodeParser::handleCall(
+    int result, NodeType op, InlineCallFrame::Kind kind, unsigned instructionSize,
+    Node* callTarget, int argumentCountIncludingThis, int registerOffset,
+    CallLinkStatus callLinkStatus)
+{
+    handleCall(
+        result, op, kind, instructionSize, callTarget, argumentCountIncludingThis,
+        registerOffset, callLinkStatus, getPrediction());
+}
+
+void ByteCodeParser::handleCall(
+    int result, NodeType op, InlineCallFrame::Kind kind, unsigned instructionSize,
+    Node* callTarget, int argumentCountIncludingThis, int registerOffset,
+    CallLinkStatus callLinkStatus, SpeculatedType prediction)
+{
+    ASSERT(registerOffset <= 0);
+    
+    if (callTarget->isCellConstant())
+        callLinkStatus.setProvenConstantCallee(CallVariant(callTarget->asCell()));
+    
+    if (Options::verboseDFGByteCodeParsing())
+        dataLog("    Handling call at ", currentCodeOrigin(), ": ", callLinkStatus, "\n");
+    
+    if (!callLinkStatus.canOptimize()) {
+        // Oddly, this conflates calls that haven't executed with calls that behaved sufficiently polymorphically
+        // that we cannot optimize them.
+        
+        addCall(result, op, OpInfo(), callTarget, argumentCountIncludingThis, registerOffset, prediction);
+        return;
+    }
+    
+    unsigned nextOffset = m_currentIndex + instructionSize;
+    
+    OpInfo callOpInfo;
+    
+    if (handleInlining(callTarget, result, callLinkStatus, registerOffset, virtualRegisterForArgument(0, registerOffset), VirtualRegister(), 0, argumentCountIncludingThis, nextOffset, op, kind, prediction)) {
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedCall();
+        return;
+    }
+    
+    addCall(result, op, callOpInfo, callTarget, argumentCountIncludingThis, registerOffset, prediction);
+}
+
+void ByteCodeParser::handleVarargsCall(Instruction* pc, NodeType op, CodeSpecializationKind kind)
+{
+    ASSERT(OPCODE_LENGTH(op_call_varargs) == OPCODE_LENGTH(op_construct_varargs));
+    
+    int result = pc[1].u.operand;
+    int callee = pc[2].u.operand;
+    int thisReg = pc[3].u.operand;
+    int arguments = pc[4].u.operand;
+    int firstFreeReg = pc[5].u.operand;
+    int firstVarArgOffset = pc[6].u.operand;
+    
+    SpeculatedType prediction = getPrediction();
+    
+    Node* callTarget = get(VirtualRegister(callee));
+    
+    CallLinkStatus callLinkStatus = CallLinkStatus::computeFor(
+        m_inlineStackTop->m_profiledBlock, currentCodeOrigin(),
+        m_inlineStackTop->m_callLinkInfos, m_callContextMap);
+    if (callTarget->isCellConstant())
+        callLinkStatus.setProvenConstantCallee(CallVariant(callTarget->asCell()));
+    
+    if (Options::verboseDFGByteCodeParsing())
+        dataLog("    Varargs call link status at ", currentCodeOrigin(), ": ", callLinkStatus, "\n");
+    
+    if (callLinkStatus.canOptimize()
+        && handleInlining(callTarget, result, callLinkStatus, firstFreeReg, VirtualRegister(thisReg), VirtualRegister(arguments), firstVarArgOffset, 0, m_currentIndex + OPCODE_LENGTH(op_call_varargs), op, InlineCallFrame::varargsKindFor(kind), prediction)) {
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedCall();
+        return;
+    }
+    
+    CallVarargsData* data = m_graph.m_callVarargsData.add();
+    data->firstVarArgOffset = firstVarArgOffset;
+    
+    Node* thisChild = get(VirtualRegister(thisReg));
+    
+    Node* call = addToGraph(op, OpInfo(data), OpInfo(prediction), callTarget, get(VirtualRegister(arguments)), thisChild);
+    VirtualRegister resultReg(result);
+    if (resultReg.isValid())
+        set(resultReg, call);
+}
+
+void ByteCodeParser::emitFunctionChecks(CallVariant callee, Node* callTarget, VirtualRegister thisArgumentReg)
+{
+    Node* thisArgument;
+    if (thisArgumentReg.isValid())
+        thisArgument = get(thisArgumentReg);
+    else
+        thisArgument = 0;
+
+    JSCell* calleeCell;
+    Node* callTargetForCheck;
+    if (callee.isClosureCall()) {
+        calleeCell = callee.executable();
+        callTargetForCheck = addToGraph(GetExecutable, callTarget);
+    } else {
+        calleeCell = callee.nonExecutableCallee();
+        callTargetForCheck = callTarget;
+    }
+    
+    ASSERT(calleeCell);
+    addToGraph(CheckCell, OpInfo(m_graph.freeze(calleeCell)), callTargetForCheck, thisArgument);
+}
+
+void ByteCodeParser::emitArgumentPhantoms(int registerOffset, int argumentCountIncludingThis)
+{
+    for (int i = 0; i < argumentCountIncludingThis; ++i)
+        addToGraph(Phantom, get(virtualRegisterForArgument(i, registerOffset)));
+}
+
+unsigned ByteCodeParser::inliningCost(CallVariant callee, int argumentCountIncludingThis, CodeSpecializationKind kind)
+{
+    if (verbose)
+        dataLog("Considering inlining ", callee, " into ", currentCodeOrigin(), "\n");
+    
+    if (m_hasDebuggerEnabled) {
+        if (verbose)
+            dataLog("    Failing because the debugger is in use.\n");
+        return UINT_MAX;
+    }
+
+    FunctionExecutable* executable = callee.functionExecutable();
+    if (!executable) {
+        if (verbose)
+            dataLog("    Failing because there is no function executable.\n");
+        return UINT_MAX;
+    }
+    
+    // Does the number of arguments we're passing match the arity of the target? We currently
+    // inline only if the number of arguments passed is greater than or equal to the number
+    // arguments expected.
+    if (static_cast<int>(executable->parameterCount()) + 1 > argumentCountIncludingThis) {
+        if (verbose)
+            dataLog("    Failing because of arity mismatch.\n");
+        return UINT_MAX;
+    }
+    
+    // Do we have a code block, and does the code block's size match the heuristics/requirements for
+    // being an inline candidate? We might not have a code block (1) if code was thrown away,
+    // (2) if we simply hadn't actually made this call yet or (3) code is a builtin function and
+    // specialization kind is construct. In the former 2 cases, we could still theoretically attempt
+    // to inline it if we had a static proof of what was being called; this might happen for example
+    // if you call a global function, where watchpointing gives us static information. Overall,
+    // it's a rare case because we expect that any hot callees would have already been compiled.
+    CodeBlock* codeBlock = executable->baselineCodeBlockFor(kind);
+    if (!codeBlock) {
+        if (verbose)
+            dataLog("    Failing because no code block available.\n");
+        return UINT_MAX;
+    }
+    CapabilityLevel capabilityLevel = inlineFunctionForCapabilityLevel(
+        codeBlock, kind, callee.isClosureCall());
+    if (verbose) {
+        dataLog("    Kind: ", kind, "\n");
+        dataLog("    Is closure call: ", callee.isClosureCall(), "\n");
+        dataLog("    Capability level: ", capabilityLevel, "\n");
+        dataLog("    Might inline function: ", mightInlineFunctionFor(codeBlock, kind), "\n");
+        dataLog("    Might compile function: ", mightCompileFunctionFor(codeBlock, kind), "\n");
+        dataLog("    Is supported for inlining: ", isSupportedForInlining(codeBlock), "\n");
+        dataLog("    Needs activation: ", codeBlock->ownerExecutable()->needsActivation(), "\n");
+        dataLog("    Is inlining candidate: ", codeBlock->ownerExecutable()->isInliningCandidate(), "\n");
+    }
+    if (!canInline(capabilityLevel)) {
+        if (verbose)
+            dataLog("    Failing because the function is not inlineable.\n");
+        return UINT_MAX;
+    }
+    
+    // Check if the caller is already too large. We do this check here because that's just
+    // where we happen to also have the callee's code block, and we want that for the
+    // purpose of unsetting SABI.
+    if (!isSmallEnoughToInlineCodeInto(m_codeBlock)) {
+        codeBlock->m_shouldAlwaysBeInlined = false;
+        if (verbose)
+            dataLog("    Failing because the caller is too large.\n");
+        return UINT_MAX;
+    }
+    
+    // FIXME: this should be better at predicting how much bloat we will introduce by inlining
+    // this function.
+    // https://bugs.webkit.org/show_bug.cgi?id=127627
+    
+    // FIXME: We currently inline functions that have run in LLInt but not in Baseline. These
+    // functions have very low fidelity profiling, and presumably they weren't very hot if they
+    // haven't gotten to Baseline yet. Consider not inlining these functions.
+    // https://bugs.webkit.org/show_bug.cgi?id=145503
+    
+    // Have we exceeded inline stack depth, or are we trying to inline a recursive call to
+    // too many levels? If either of these are detected, then don't inline. We adjust our
+    // heuristics if we are dealing with a function that cannot otherwise be compiled.
+    
+    unsigned depth = 0;
+    unsigned recursion = 0;
+    
+    for (InlineStackEntry* entry = m_inlineStackTop; entry; entry = entry->m_caller) {
+        ++depth;
+        if (depth >= Options::maximumInliningDepth()) {
+            if (verbose)
+                dataLog("    Failing because depth exceeded.\n");
+            return UINT_MAX;
+        }
+        
+        if (entry->executable() == executable) {
+            ++recursion;
+            if (recursion >= Options::maximumInliningRecursion()) {
+                if (verbose)
+                    dataLog("    Failing because recursion detected.\n");
+                return UINT_MAX;
+            }
+        }
+    }
+    
+    if (verbose)
+        dataLog("    Inlining should be possible.\n");
+    
+    // It might be possible to inline.
+    return codeBlock->instructionCount();
+}
+
+template<typename ChecksFunctor>
+void ByteCodeParser::inlineCall(Node* callTargetNode, int resultOperand, CallVariant callee, int registerOffset, int argumentCountIncludingThis, unsigned nextOffset, InlineCallFrame::Kind kind, CallerLinkability callerLinkability, const ChecksFunctor& insertChecks)
+{
+    CodeSpecializationKind specializationKind = InlineCallFrame::specializationKindFor(kind);
+    
+    ASSERT(inliningCost(callee, argumentCountIncludingThis, specializationKind) != UINT_MAX);
+    
+    CodeBlock* codeBlock = callee.functionExecutable()->baselineCodeBlockFor(specializationKind);
+    insertChecks(codeBlock);
+
+    // FIXME: Don't flush constants!
+    
+    int inlineCallFrameStart = m_inlineStackTop->remapOperand(VirtualRegister(registerOffset)).offset() + JSStack::CallFrameHeaderSize;
+    
+    ensureLocals(
+        VirtualRegister(inlineCallFrameStart).toLocal() + 1 +
+        JSStack::CallFrameHeaderSize + codeBlock->m_numCalleeRegisters);
+    
+    size_t argumentPositionStart = m_graph.m_argumentPositions.size();
+
+    VirtualRegister resultReg(resultOperand);
+    if (resultReg.isValid())
+        resultReg = m_inlineStackTop->remapOperand(resultReg);
+    
+    InlineStackEntry inlineStackEntry(
+        this, codeBlock, codeBlock, m_graph.lastBlock(), callee.function(), resultReg,
+        (VirtualRegister)inlineCallFrameStart, argumentCountIncludingThis, kind);
+    
+    // This is where the actual inlining really happens.
+    unsigned oldIndex = m_currentIndex;
+    m_currentIndex = 0;
+
+    InlineVariableData inlineVariableData;
+    inlineVariableData.inlineCallFrame = m_inlineStackTop->m_inlineCallFrame;
+    inlineVariableData.argumentPositionStart = argumentPositionStart;
+    inlineVariableData.calleeVariable = 0;
+    
+    RELEASE_ASSERT(
+        m_inlineStackTop->m_inlineCallFrame->isClosureCall
+        == callee.isClosureCall());
+    if (callee.isClosureCall()) {
+        VariableAccessData* calleeVariable =
+            set(VirtualRegister(JSStack::Callee), callTargetNode, ImmediateNakedSet)->variableAccessData();
+        
+        calleeVariable->mergeShouldNeverUnbox(true);
+        
+        inlineVariableData.calleeVariable = calleeVariable;
+    }
+    
+    m_graph.m_inlineVariableData.append(inlineVariableData);
+    
+    parseCodeBlock();
+    clearCaches(); // Reset our state now that we're back to the outer code.
+    
+    m_currentIndex = oldIndex;
+    
+    // If the inlined code created some new basic blocks, then we have linking to do.
+    if (inlineStackEntry.m_callsiteBlockHead != m_graph.lastBlock()) {
+        
+        ASSERT(!inlineStackEntry.m_unlinkedBlocks.isEmpty());
+        if (inlineStackEntry.m_callsiteBlockHeadNeedsLinking)
+            linkBlock(inlineStackEntry.m_callsiteBlockHead, inlineStackEntry.m_blockLinkingTargets);
+        else
+            ASSERT(inlineStackEntry.m_callsiteBlockHead->isLinked);
+        
+        if (callerLinkability == CallerDoesNormalLinking)
+            cancelLinkingForBlock(inlineStackEntry.m_caller, inlineStackEntry.m_callsiteBlockHead);
+        
+        linkBlocks(inlineStackEntry.m_unlinkedBlocks, inlineStackEntry.m_blockLinkingTargets);
+    } else
+        ASSERT(inlineStackEntry.m_unlinkedBlocks.isEmpty());
+    
+    BasicBlock* lastBlock = m_graph.lastBlock();
+    // If there was a return, but no early returns, then we're done. We allow parsing of
+    // the caller to continue in whatever basic block we're in right now.
+    if (!inlineStackEntry.m_didEarlyReturn && inlineStackEntry.m_didReturn) {
+        if (Options::verboseDFGByteCodeParsing())
+            dataLog("    Allowing parsing to continue in last inlined block.\n");
+        
+        ASSERT(lastBlock->isEmpty() || !lastBlock->terminal());
+        
+        // If we created new blocks then the last block needs linking, but in the
+        // caller. It doesn't need to be linked to, but it needs outgoing links.
+        if (!inlineStackEntry.m_unlinkedBlocks.isEmpty()) {
+            // For debugging purposes, set the bytecodeBegin. Note that this doesn't matter
+            // for release builds because this block will never serve as a potential target
+            // in the linker's binary search.
+            if (Options::verboseDFGByteCodeParsing())
+                dataLog("        Repurposing last block from ", lastBlock->bytecodeBegin, " to ", m_currentIndex, "\n");
+            lastBlock->bytecodeBegin = m_currentIndex;
+            if (callerLinkability == CallerDoesNormalLinking) {
+                if (verbose)
+                    dataLog("Adding unlinked block ", RawPointer(m_graph.lastBlock()), " (one return)\n");
+                m_inlineStackTop->m_caller->m_unlinkedBlocks.append(UnlinkedBlock(m_graph.lastBlock()));
+            }
+        }
+        
+        m_currentBlock = m_graph.lastBlock();
+        return;
+    }
+    
+    if (Options::verboseDFGByteCodeParsing())
+        dataLog("    Creating new block after inlining.\n");
+
+    // If we get to this point then all blocks must end in some sort of terminals.
+    ASSERT(lastBlock->terminal());
+
+    // Need to create a new basic block for the continuation at the caller.
+    RefPtr<BasicBlock> block = adoptRef(new BasicBlock(nextOffset, m_numArguments, m_numLocals, PNaN));
+
+    // Link the early returns to the basic block we're about to create.
+    for (size_t i = 0; i < inlineStackEntry.m_unlinkedBlocks.size(); ++i) {
+        if (!inlineStackEntry.m_unlinkedBlocks[i].m_needsEarlyReturnLinking)
+            continue;
+        BasicBlock* blockToLink = inlineStackEntry.m_unlinkedBlocks[i].m_block;
+        ASSERT(!blockToLink->isLinked);
+        Node* node = blockToLink->terminal();
+        ASSERT(node->op() == Jump);
+        ASSERT(!node->targetBlock());
+        node->targetBlock() = block.get();
+        inlineStackEntry.m_unlinkedBlocks[i].m_needsEarlyReturnLinking = false;
+        if (verbose)
+            dataLog("Marking ", RawPointer(blockToLink), " as linked (jumps to return)\n");
+        blockToLink->didLink();
+    }
+    
+    m_currentBlock = block.get();
+    ASSERT(m_inlineStackTop->m_caller->m_blockLinkingTargets.isEmpty() || m_inlineStackTop->m_caller->m_blockLinkingTargets.last()->bytecodeBegin < nextOffset);
+    if (verbose)
+        dataLog("Adding unlinked block ", RawPointer(block.get()), " (many returns)\n");
+    if (callerLinkability == CallerDoesNormalLinking) {
+        m_inlineStackTop->m_caller->m_unlinkedBlocks.append(UnlinkedBlock(block.get()));
+        m_inlineStackTop->m_caller->m_blockLinkingTargets.append(block.get());
+    }
+    m_graph.appendBlock(block);
+    prepareToParseBlock();
+}
+
+void ByteCodeParser::cancelLinkingForBlock(InlineStackEntry* inlineStackEntry, BasicBlock* block)
+{
+    // It's possible that the callsite block head is not owned by the caller.
+    if (!inlineStackEntry->m_unlinkedBlocks.isEmpty()) {
+        // It's definitely owned by the caller, because the caller created new blocks.
+        // Assert that this all adds up.
+        ASSERT_UNUSED(block, inlineStackEntry->m_unlinkedBlocks.last().m_block == block);
+        ASSERT(inlineStackEntry->m_unlinkedBlocks.last().m_needsNormalLinking);
+        inlineStackEntry->m_unlinkedBlocks.last().m_needsNormalLinking = false;
+    } else {
+        // It's definitely not owned by the caller. Tell the caller that he does not
+        // need to link his callsite block head, because we did it for him.
+        ASSERT(inlineStackEntry->m_callsiteBlockHeadNeedsLinking);
+        ASSERT_UNUSED(block, inlineStackEntry->m_callsiteBlockHead == block);
+        inlineStackEntry->m_callsiteBlockHeadNeedsLinking = false;
+    }
+}
+
+template<typename ChecksFunctor>
+bool ByteCodeParser::attemptToInlineCall(Node* callTargetNode, int resultOperand, CallVariant callee, int registerOffset, int argumentCountIncludingThis, unsigned nextOffset, InlineCallFrame::Kind kind, CallerLinkability callerLinkability, SpeculatedType prediction, unsigned& inliningBalance, const ChecksFunctor& insertChecks)
+{
+    CodeSpecializationKind specializationKind = InlineCallFrame::specializationKindFor(kind);
+    
+    if (!inliningBalance)
+        return false;
+    
+    bool didInsertChecks = false;
+    auto insertChecksWithAccounting = [&] () {
+        insertChecks(nullptr);
+        didInsertChecks = true;
+    };
+    
+    if (verbose)
+        dataLog("    Considering callee ", callee, "\n");
+    
+    // Intrinsics and internal functions can only be inlined if we're not doing varargs. This is because
+    // we currently don't have any way of getting profiling information for arguments to non-JS varargs
+    // calls. The prediction propagator won't be of any help because LoadVarargs obscures the data flow,
+    // and there are no callsite value profiles and native function won't have callee value profiles for
+    // those arguments. Even worse, if the intrinsic decides to exit, it won't really have anywhere to
+    // exit to: LoadVarargs is effectful and it's part of the op_call_varargs, so we can't exit without
+    // calling LoadVarargs twice.
+    if (!InlineCallFrame::isVarargs(kind)) {
+        if (InternalFunction* function = callee.internalFunction()) {
+            if (handleConstantInternalFunction(resultOperand, function, registerOffset, argumentCountIncludingThis, specializationKind, insertChecksWithAccounting)) {
+                RELEASE_ASSERT(didInsertChecks);
+                addToGraph(Phantom, callTargetNode);
+                emitArgumentPhantoms(registerOffset, argumentCountIncludingThis);
+                inliningBalance--;
+                return true;
+            }
+            RELEASE_ASSERT(!didInsertChecks);
+            return false;
+        }
+    
+        Intrinsic intrinsic = callee.intrinsicFor(specializationKind);
+        if (intrinsic != NoIntrinsic) {
+            if (handleIntrinsic(resultOperand, intrinsic, registerOffset, argumentCountIncludingThis, prediction, insertChecksWithAccounting)) {
+                RELEASE_ASSERT(didInsertChecks);
+                addToGraph(Phantom, callTargetNode);
+                emitArgumentPhantoms(registerOffset, argumentCountIncludingThis);
+                inliningBalance--;
+                return true;
+            }
+            RELEASE_ASSERT(!didInsertChecks);
+            return false;
+        }
+    }
+    
+    unsigned myInliningCost = inliningCost(callee, argumentCountIncludingThis, specializationKind);
+    if (myInliningCost > inliningBalance)
+        return false;
+
+    Instruction* savedCurrentInstruction = m_currentInstruction;
+    inlineCall(callTargetNode, resultOperand, callee, registerOffset, argumentCountIncludingThis, nextOffset, kind, callerLinkability, insertChecks);
+    inliningBalance -= myInliningCost;
+    m_currentInstruction = savedCurrentInstruction;
+    return true;
+}
+
+bool ByteCodeParser::handleInlining(
+    Node* callTargetNode, int resultOperand, const CallLinkStatus& callLinkStatus,
+    int registerOffsetOrFirstFreeReg, VirtualRegister thisArgument,
+    VirtualRegister argumentsArgument, unsigned argumentsOffset, int argumentCountIncludingThis,
+    unsigned nextOffset, NodeType callOp, InlineCallFrame::Kind kind, SpeculatedType prediction)
+{
+    if (verbose) {
+        dataLog("Handling inlining...\n");
+        dataLog("Stack: ", currentCodeOrigin(), "\n");
+    }
+    CodeSpecializationKind specializationKind = InlineCallFrame::specializationKindFor(kind);
+    
+    if (!callLinkStatus.size()) {
+        if (verbose)
+            dataLog("Bailing inlining.\n");
+        return false;
+    }
+    
+    if (InlineCallFrame::isVarargs(kind)
+        && callLinkStatus.maxNumArguments() > Options::maximumVarargsForInlining()) {
+        if (verbose)
+            dataLog("Bailing inlining because of varargs.\n");
+        return false;
+    }
+        
+    unsigned inliningBalance = Options::maximumFunctionForCallInlineCandidateInstructionCount();
+    if (specializationKind == CodeForConstruct)
+        inliningBalance = std::min(inliningBalance, Options::maximumFunctionForConstructInlineCandidateInstructionCount());
+    if (callLinkStatus.isClosureCall())
+        inliningBalance = std::min(inliningBalance, Options::maximumFunctionForClosureCallInlineCandidateInstructionCount());
+    
+    // First check if we can avoid creating control flow. Our inliner does some CFG
+    // simplification on the fly and this helps reduce compile times, but we can only leverage
+    // this in cases where we don't need control flow diamonds to check the callee.
+    if (!callLinkStatus.couldTakeSlowPath() && callLinkStatus.size() == 1) {
+        int registerOffset;
+        
+        // Only used for varargs calls.
+        unsigned mandatoryMinimum = 0;
+        unsigned maxNumArguments = 0;
+
+        if (InlineCallFrame::isVarargs(kind)) {
+            if (FunctionExecutable* functionExecutable = callLinkStatus[0].functionExecutable())
+                mandatoryMinimum = functionExecutable->parameterCount();
+            else
+                mandatoryMinimum = 0;
+            
+            // includes "this"
+            maxNumArguments = std::max(
+                callLinkStatus.maxNumArguments(),
+                mandatoryMinimum + 1);
+            
+            // We sort of pretend that this *is* the number of arguments that were passed.
+            argumentCountIncludingThis = maxNumArguments;
+            
+            registerOffset = registerOffsetOrFirstFreeReg + 1;
+            registerOffset -= maxNumArguments; // includes "this"
+            registerOffset -= JSStack::CallFrameHeaderSize;
+            registerOffset = -WTF::roundUpToMultipleOf(
+                stackAlignmentRegisters(),
+                -registerOffset);
+        } else
+            registerOffset = registerOffsetOrFirstFreeReg;
+        
+        bool result = attemptToInlineCall(
+            callTargetNode, resultOperand, callLinkStatus[0], registerOffset,
+            argumentCountIncludingThis, nextOffset, kind, CallerDoesNormalLinking, prediction,
+            inliningBalance, [&] (CodeBlock* codeBlock) {
+                emitFunctionChecks(callLinkStatus[0], callTargetNode, thisArgument);
+
+                // If we have a varargs call, we want to extract the arguments right now.
+                if (InlineCallFrame::isVarargs(kind)) {
+                    int remappedRegisterOffset =
+                        m_inlineStackTop->remapOperand(VirtualRegister(registerOffset)).offset();
+                    
+                    ensureLocals(VirtualRegister(remappedRegisterOffset).toLocal());
+                    
+                    int argumentStart = registerOffset + JSStack::CallFrameHeaderSize;
+                    int remappedArgumentStart =
+                        m_inlineStackTop->remapOperand(VirtualRegister(argumentStart)).offset();
+
+                    LoadVarargsData* data = m_graph.m_loadVarargsData.add();
+                    data->start = VirtualRegister(remappedArgumentStart + 1);
+                    data->count = VirtualRegister(remappedRegisterOffset + JSStack::ArgumentCount);
+                    data->offset = argumentsOffset;
+                    data->limit = maxNumArguments;
+                    data->mandatoryMinimum = mandatoryMinimum;
+            
+                    addToGraph(LoadVarargs, OpInfo(data), get(argumentsArgument));
+
+                    // LoadVarargs may OSR exit. Hence, we need to keep alive callTargetNode, thisArgument
+                    // and argumentsArgument for the baseline JIT. However, we only need a Phantom for
+                    // callTargetNode because the other 2 are still in use and alive at this point.
+                    addToGraph(Phantom, callTargetNode);
+
+                    // In DFG IR before SSA, we cannot insert control flow between after the
+                    // LoadVarargs and the last SetArgument. This isn't a problem once we get to DFG
+                    // SSA. Fortunately, we also have other reasons for not inserting control flow
+                    // before SSA.
+            
+                    VariableAccessData* countVariable = newVariableAccessData(
+                        VirtualRegister(remappedRegisterOffset + JSStack::ArgumentCount));
+                    // This is pretty lame, but it will force the count to be flushed as an int. This doesn't
+                    // matter very much, since our use of a SetArgument and Flushes for this local slot is
+                    // mostly just a formality.
+                    countVariable->predict(SpecInt32);
+                    countVariable->mergeIsProfitableToUnbox(true);
+                    Node* setArgumentCount = addToGraph(SetArgument, OpInfo(countVariable));
+                    m_currentBlock->variablesAtTail.setOperand(countVariable->local(), setArgumentCount);
+
+                    set(VirtualRegister(argumentStart), get(thisArgument), ImmediateNakedSet);
+                    for (unsigned argument = 1; argument < maxNumArguments; ++argument) {
+                        VariableAccessData* variable = newVariableAccessData(
+                            VirtualRegister(remappedArgumentStart + argument));
+                        variable->mergeShouldNeverUnbox(true); // We currently have nowhere to put the type check on the LoadVarargs. LoadVarargs is effectful, so after it finishes, we cannot exit.
+                        
+                        // For a while it had been my intention to do things like this inside the
+                        // prediction injection phase. But in this case it's really best to do it here,
+                        // because it's here that we have access to the variable access datas for the
+                        // inlining we're about to do.
+                        //
+                        // Something else that's interesting here is that we'd really love to get
+                        // predictions from the arguments loaded at the callsite, rather than the
+                        // arguments received inside the callee. But that probably won't matter for most
+                        // calls.
+                        if (codeBlock && argument < static_cast<unsigned>(codeBlock->numParameters())) {
+                            ConcurrentJITLocker locker(codeBlock->m_lock);
+                            if (ValueProfile* profile = codeBlock->valueProfileForArgument(argument))
+                                variable->predict(profile->computeUpdatedPrediction(locker));
+                        }
+                        
+                        Node* setArgument = addToGraph(SetArgument, OpInfo(variable));
+                        m_currentBlock->variablesAtTail.setOperand(variable->local(), setArgument);
+                    }
+                }
+            });
+        if (verbose) {
+            dataLog("Done inlining (simple).\n");
+            dataLog("Stack: ", currentCodeOrigin(), "\n");
+            dataLog("Result: ", result, "\n");
+        }
+        return result;
+    }
+    
+    // We need to create some kind of switch over callee. For now we only do this if we believe that
+    // we're in the top tier. We have two reasons for this: first, it provides us an opportunity to
+    // do more detailed polyvariant/polymorphic profiling; and second, it reduces compile times in
+    // the DFG. And by polyvariant profiling we mean polyvariant profiling of *this* call. Note that
+    // we could improve that aspect of this by doing polymorphic inlining but having the profiling
+    // also.
+    if (!isFTL(m_graph.m_plan.mode) || !Options::enablePolymorphicCallInlining()
+        || InlineCallFrame::isVarargs(kind)) {
+        if (verbose) {
+            dataLog("Bailing inlining (hard).\n");
+            dataLog("Stack: ", currentCodeOrigin(), "\n");
+        }
+        return false;
+    }
+    
+    unsigned oldOffset = m_currentIndex;
+    
+    bool allAreClosureCalls = true;
+    bool allAreDirectCalls = true;
+    for (unsigned i = callLinkStatus.size(); i--;) {
+        if (callLinkStatus[i].isClosureCall())
+            allAreDirectCalls = false;
+        else
+            allAreClosureCalls = false;
+    }
+    
+    Node* thingToSwitchOn;
+    if (allAreDirectCalls)
+        thingToSwitchOn = callTargetNode;
+    else if (allAreClosureCalls)
+        thingToSwitchOn = addToGraph(GetExecutable, callTargetNode);
+    else {
+        // FIXME: We should be able to handle this case, but it's tricky and we don't know of cases
+        // where it would be beneficial. It might be best to handle these cases as if all calls were
+        // closure calls.
+        // https://bugs.webkit.org/show_bug.cgi?id=136020
+        if (verbose) {
+            dataLog("Bailing inlining (mix).\n");
+            dataLog("Stack: ", currentCodeOrigin(), "\n");
+        }
+        return false;
+    }
+    
+    if (verbose) {
+        dataLog("Doing hard inlining...\n");
+        dataLog("Stack: ", currentCodeOrigin(), "\n");
+    }
+    
+    int registerOffset = registerOffsetOrFirstFreeReg;
+    
+    // This makes me wish that we were in SSA all the time. We need to pick a variable into which to
+    // store the callee so that it will be accessible to all of the blocks we're about to create. We
+    // get away with doing an immediate-set here because we wouldn't have performed any side effects
+    // yet.
+    if (verbose)
+        dataLog("Register offset: ", registerOffset);
+    VirtualRegister calleeReg(registerOffset + JSStack::Callee);
+    calleeReg = m_inlineStackTop->remapOperand(calleeReg);
+    if (verbose)
+        dataLog("Callee is going to be ", calleeReg, "\n");
+    setDirect(calleeReg, callTargetNode, ImmediateSetWithFlush);
+    
+    SwitchData& data = *m_graph.m_switchData.add();
+    data.kind = SwitchCell;
+    addToGraph(Switch, OpInfo(&data), thingToSwitchOn);
+    
+    BasicBlock* originBlock = m_currentBlock;
+    if (verbose)
+        dataLog("Marking ", RawPointer(originBlock), " as linked (origin of poly inline)\n");
+    originBlock->didLink();
+    cancelLinkingForBlock(m_inlineStackTop, originBlock);
+    
+    // Each inlined callee will have a landing block that it returns at. They should all have jumps
+    // to the continuation block, which we create last.
+    Vector<BasicBlock*> landingBlocks;
+    
+    // We may force this true if we give up on inlining any of the edges.
+    bool couldTakeSlowPath = callLinkStatus.couldTakeSlowPath();
+    
+    if (verbose)
+        dataLog("About to loop over functions at ", currentCodeOrigin(), ".\n");
+    
+    for (unsigned i = 0; i < callLinkStatus.size(); ++i) {
+        m_currentIndex = oldOffset;
+        RefPtr<BasicBlock> block = adoptRef(new BasicBlock(UINT_MAX, m_numArguments, m_numLocals, PNaN));
+        m_currentBlock = block.get();
+        m_graph.appendBlock(block);
+        prepareToParseBlock();
+        
+        Node* myCallTargetNode = getDirect(calleeReg);
+        
+        bool inliningResult = attemptToInlineCall(
+            myCallTargetNode, resultOperand, callLinkStatus[i], registerOffset,
+            argumentCountIncludingThis, nextOffset, kind, CallerLinksManually, prediction,
+            inliningBalance, [&] (CodeBlock*) { });
+        
+        if (!inliningResult) {
+            // That failed so we let the block die. Nothing interesting should have been added to
+            // the block. We also give up on inlining any of the (less frequent) callees.
+            ASSERT(m_currentBlock == block.get());
+            ASSERT(m_graph.m_blocks.last() == block);
+            m_graph.killBlockAndItsContents(block.get());
+            m_graph.m_blocks.removeLast();
+            
+            // The fact that inlining failed means we need a slow path.
+            couldTakeSlowPath = true;
+            break;
+        }
+        
+        JSCell* thingToCaseOn;
+        if (allAreDirectCalls)
+            thingToCaseOn = callLinkStatus[i].nonExecutableCallee();
+        else {
+            ASSERT(allAreClosureCalls);
+            thingToCaseOn = callLinkStatus[i].executable();
+        }
+        data.cases.append(SwitchCase(m_graph.freeze(thingToCaseOn), block.get()));
+        m_currentIndex = nextOffset;
+        processSetLocalQueue(); // This only comes into play for intrinsics, since normal inlined code will leave an empty queue.
+        addToGraph(Jump);
+        if (verbose)
+            dataLog("Marking ", RawPointer(m_currentBlock), " as linked (tail of poly inlinee)\n");
+        m_currentBlock->didLink();
+        landingBlocks.append(m_currentBlock);
+
+        if (verbose)
+            dataLog("Finished inlining ", callLinkStatus[i], " at ", currentCodeOrigin(), ".\n");
+    }
+    
+    RefPtr<BasicBlock> slowPathBlock = adoptRef(
+        new BasicBlock(UINT_MAX, m_numArguments, m_numLocals, PNaN));
+    m_currentIndex = oldOffset;
+    data.fallThrough = BranchTarget(slowPathBlock.get());
+    m_graph.appendBlock(slowPathBlock);
+    if (verbose)
+        dataLog("Marking ", RawPointer(slowPathBlock.get()), " as linked (slow path block)\n");
+    slowPathBlock->didLink();
+    prepareToParseBlock();
+    m_currentBlock = slowPathBlock.get();
+    Node* myCallTargetNode = getDirect(calleeReg);
+    if (couldTakeSlowPath) {
+        addCall(
+            resultOperand, callOp, OpInfo(), myCallTargetNode, argumentCountIncludingThis,
+            registerOffset, prediction);
+    } else {
+        addToGraph(CheckBadCell);
+        addToGraph(Phantom, myCallTargetNode);
+        emitArgumentPhantoms(registerOffset, argumentCountIncludingThis);
+        
+        set(VirtualRegister(resultOperand), addToGraph(BottomValue));
+    }
+
+    m_currentIndex = nextOffset;
+    processSetLocalQueue();
+    addToGraph(Jump);
+    landingBlocks.append(m_currentBlock);
+    
+    RefPtr<BasicBlock> continuationBlock = adoptRef(
+        new BasicBlock(UINT_MAX, m_numArguments, m_numLocals, PNaN));
+    m_graph.appendBlock(continuationBlock);
+    if (verbose)
+        dataLog("Adding unlinked block ", RawPointer(continuationBlock.get()), " (continuation)\n");
+    m_inlineStackTop->m_unlinkedBlocks.append(UnlinkedBlock(continuationBlock.get()));
+    prepareToParseBlock();
+    m_currentBlock = continuationBlock.get();
+    
+    for (unsigned i = landingBlocks.size(); i--;)
+        landingBlocks[i]->terminal()->targetBlock() = continuationBlock.get();
+    
+    m_currentIndex = oldOffset;
+    
+    if (verbose) {
+        dataLog("Done inlining (hard).\n");
+        dataLog("Stack: ", currentCodeOrigin(), "\n");
+    }
+    return true;
+}
+
+template<typename ChecksFunctor>
+bool ByteCodeParser::handleMinMax(int resultOperand, NodeType op, int registerOffset, int argumentCountIncludingThis, const ChecksFunctor& insertChecks)
+{
+    if (argumentCountIncludingThis == 1) { // Math.min()
+        insertChecks();
+        set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantNaN)));
+        return true;
+    }
+     
+    if (argumentCountIncludingThis == 2) { // Math.min(x)
+        insertChecks();
+        Node* result = get(VirtualRegister(virtualRegisterForArgument(1, registerOffset)));
+        addToGraph(Phantom, Edge(result, NumberUse));
+        set(VirtualRegister(resultOperand), result);
+        return true;
+    }
+    
+    if (argumentCountIncludingThis == 3) { // Math.min(x, y)
+        insertChecks();
+        set(VirtualRegister(resultOperand), addToGraph(op, get(virtualRegisterForArgument(1, registerOffset)), get(virtualRegisterForArgument(2, registerOffset))));
+        return true;
+    }
+    
+    // Don't handle >=3 arguments for now.
+    return false;
+}
+
+template<typename ChecksFunctor>
+bool ByteCodeParser::handleIntrinsic(int resultOperand, Intrinsic intrinsic, int registerOffset, int argumentCountIncludingThis, SpeculatedType prediction, const ChecksFunctor& insertChecks)
+{
+    switch (intrinsic) {
+    case AbsIntrinsic: {
+        if (argumentCountIncludingThis == 1) { // Math.abs()
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantNaN)));
+            return true;
+        }
+
+        if (!MacroAssembler::supportsFloatingPointAbs())
+            return false;
+
+        insertChecks();
+        Node* node = addToGraph(ArithAbs, get(virtualRegisterForArgument(1, registerOffset)));
+        if (m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, Overflow))
+            node->mergeFlags(NodeMayOverflowInDFG);
+        set(VirtualRegister(resultOperand), node);
+        return true;
+    }
+
+    case MinIntrinsic:
+        return handleMinMax(resultOperand, ArithMin, registerOffset, argumentCountIncludingThis, insertChecks);
+        
+    case MaxIntrinsic:
+        return handleMinMax(resultOperand, ArithMax, registerOffset, argumentCountIncludingThis, insertChecks);
+
+    case SqrtIntrinsic:
+    case CosIntrinsic:
+    case SinIntrinsic:
+    case LogIntrinsic: {
+        if (argumentCountIncludingThis == 1) {
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantNaN)));
+            return true;
+        }
+        
+        switch (intrinsic) {
+        case SqrtIntrinsic:
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(ArithSqrt, get(virtualRegisterForArgument(1, registerOffset))));
+            return true;
+            
+        case CosIntrinsic:
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(ArithCos, get(virtualRegisterForArgument(1, registerOffset))));
+            return true;
+            
+        case SinIntrinsic:
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(ArithSin, get(virtualRegisterForArgument(1, registerOffset))));
+            return true;
+
+        case LogIntrinsic:
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(ArithLog, get(virtualRegisterForArgument(1, registerOffset))));
+            return true;
+            
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            return false;
+        }
+    }
+
+    case PowIntrinsic: {
+        if (argumentCountIncludingThis < 3) {
+            // Math.pow() and Math.pow(x) return NaN.
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantNaN)));
+            return true;
+        }
+        insertChecks();
+        VirtualRegister xOperand = virtualRegisterForArgument(1, registerOffset);
+        VirtualRegister yOperand = virtualRegisterForArgument(2, registerOffset);
+        set(VirtualRegister(resultOperand), addToGraph(ArithPow, get(xOperand), get(yOperand)));
+        return true;
+    }
+        
+    case ArrayPushIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+        
+        ArrayMode arrayMode = getArrayMode(m_currentInstruction[OPCODE_LENGTH(op_call) - 2].u.arrayProfile);
+        if (!arrayMode.isJSArray())
+            return false;
+        switch (arrayMode.type()) {
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous:
+        case Array::ArrayStorage: {
+            insertChecks();
+            Node* arrayPush = addToGraph(ArrayPush, OpInfo(arrayMode.asWord()), OpInfo(prediction), get(virtualRegisterForArgument(0, registerOffset)), get(virtualRegisterForArgument(1, registerOffset)));
+            set(VirtualRegister(resultOperand), arrayPush);
+            
+            return true;
+        }
+            
+        default:
+            return false;
+        }
+    }
+        
+    case ArrayPopIntrinsic: {
+        if (argumentCountIncludingThis != 1)
+            return false;
+        
+        ArrayMode arrayMode = getArrayMode(m_currentInstruction[OPCODE_LENGTH(op_call) - 2].u.arrayProfile);
+        if (!arrayMode.isJSArray())
+            return false;
+        switch (arrayMode.type()) {
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous:
+        case Array::ArrayStorage: {
+            insertChecks();
+            Node* arrayPop = addToGraph(ArrayPop, OpInfo(arrayMode.asWord()), OpInfo(prediction), get(virtualRegisterForArgument(0, registerOffset)));
+            set(VirtualRegister(resultOperand), arrayPop);
+            return true;
+        }
+            
+        default:
+            return false;
+        }
+    }
+
+    case CharCodeAtIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+
+        insertChecks();
+        VirtualRegister thisOperand = virtualRegisterForArgument(0, registerOffset);
+        VirtualRegister indexOperand = virtualRegisterForArgument(1, registerOffset);
+        Node* charCode = addToGraph(StringCharCodeAt, OpInfo(ArrayMode(Array::String).asWord()), get(thisOperand), get(indexOperand));
+
+        set(VirtualRegister(resultOperand), charCode);
+        return true;
+    }
+
+    case CharAtIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+
+        insertChecks();
+        VirtualRegister thisOperand = virtualRegisterForArgument(0, registerOffset);
+        VirtualRegister indexOperand = virtualRegisterForArgument(1, registerOffset);
+        Node* charCode = addToGraph(StringCharAt, OpInfo(ArrayMode(Array::String).asWord()), get(thisOperand), get(indexOperand));
+
+        set(VirtualRegister(resultOperand), charCode);
+        return true;
+    }
+    case Clz32Intrinsic: {
+        insertChecks();
+        if (argumentCountIncludingThis == 1)
+            set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_graph.freeze(jsNumber(32)))));
+        else {
+            Node* operand = get(virtualRegisterForArgument(1, registerOffset));
+            set(VirtualRegister(resultOperand), addToGraph(ArithClz32, operand));
+        }
+        return true;
+    }
+    case FromCharCodeIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+
+        insertChecks();
+        VirtualRegister indexOperand = virtualRegisterForArgument(1, registerOffset);
+        Node* charCode = addToGraph(StringFromCharCode, get(indexOperand));
+
+        set(VirtualRegister(resultOperand), charCode);
+
+        return true;
+    }
+
+    case RegExpExecIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+        
+        insertChecks();
+        Node* regExpExec = addToGraph(RegExpExec, OpInfo(0), OpInfo(prediction), get(virtualRegisterForArgument(0, registerOffset)), get(virtualRegisterForArgument(1, registerOffset)));
+        set(VirtualRegister(resultOperand), regExpExec);
+        
+        return true;
+    }
+        
+    case RegExpTestIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+        
+        insertChecks();
+        Node* regExpExec = addToGraph(RegExpTest, OpInfo(0), OpInfo(prediction), get(virtualRegisterForArgument(0, registerOffset)), get(virtualRegisterForArgument(1, registerOffset)));
+        set(VirtualRegister(resultOperand), regExpExec);
+        
+        return true;
+    }
+    case RoundIntrinsic: {
+        if (argumentCountIncludingThis == 1) {
+            insertChecks();
+            set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantNaN)));
+            return true;
+        }
+        if (argumentCountIncludingThis == 2) {
+            insertChecks();
+            Node* operand = get(virtualRegisterForArgument(1, registerOffset));
+            Node* roundNode = addToGraph(ArithRound, OpInfo(0), OpInfo(prediction), operand);
+            set(VirtualRegister(resultOperand), roundNode);
+            return true;
+        }
+        return false;
+    }
+    case IMulIntrinsic: {
+        if (argumentCountIncludingThis != 3)
+            return false;
+        insertChecks();
+        VirtualRegister leftOperand = virtualRegisterForArgument(1, registerOffset);
+        VirtualRegister rightOperand = virtualRegisterForArgument(2, registerOffset);
+        Node* left = get(leftOperand);
+        Node* right = get(rightOperand);
+        set(VirtualRegister(resultOperand), addToGraph(ArithIMul, left, right));
+        return true;
+    }
+        
+    case FRoundIntrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+        insertChecks();
+        VirtualRegister operand = virtualRegisterForArgument(1, registerOffset);
+        set(VirtualRegister(resultOperand), addToGraph(ArithFRound, get(operand)));
+        return true;
+    }
+        
+    case DFGTrueIntrinsic: {
+        insertChecks();
+        set(VirtualRegister(resultOperand), jsConstant(jsBoolean(true)));
+        return true;
+    }
+        
+    case OSRExitIntrinsic: {
+        insertChecks();
+        addToGraph(ForceOSRExit);
+        set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantUndefined)));
+        return true;
+    }
+        
+    case IsFinalTierIntrinsic: {
+        insertChecks();
+        set(VirtualRegister(resultOperand),
+            jsConstant(jsBoolean(Options::useFTLJIT() ? isFTL(m_graph.m_plan.mode) : true)));
+        return true;
+    }
+        
+    case SetInt32HeapPredictionIntrinsic: {
+        insertChecks();
+        for (int i = 1; i < argumentCountIncludingThis; ++i) {
+            Node* node = get(virtualRegisterForArgument(i, registerOffset));
+            if (node->hasHeapPrediction())
+                node->setHeapPrediction(SpecInt32);
+        }
+        set(VirtualRegister(resultOperand), addToGraph(JSConstant, OpInfo(m_constantUndefined)));
+        return true;
+    }
+        
+    case CheckInt32Intrinsic: {
+        insertChecks();
+        for (int i = 1; i < argumentCountIncludingThis; ++i) {
+            Node* node = get(virtualRegisterForArgument(i, registerOffset));
+            addToGraph(Phantom, Edge(node, Int32Use));
+        }
+        set(VirtualRegister(resultOperand), jsConstant(jsBoolean(true)));
+        return true;
+    }
+        
+    case FiatInt52Intrinsic: {
+        if (argumentCountIncludingThis != 2)
+            return false;
+        insertChecks();
+        VirtualRegister operand = virtualRegisterForArgument(1, registerOffset);
+        if (enableInt52())
+            set(VirtualRegister(resultOperand), addToGraph(FiatInt52, get(operand)));
+        else
+            set(VirtualRegister(resultOperand), get(operand));
+        return true;
+    }
+        
+    default:
+        return false;
+    }
+}
+
+template<typename ChecksFunctor>
+bool ByteCodeParser::handleTypedArrayConstructor(
+    int resultOperand, InternalFunction* function, int registerOffset,
+    int argumentCountIncludingThis, TypedArrayType type, const ChecksFunctor& insertChecks)
+{
+    if (!isTypedView(type))
+        return false;
+    
+    if (function->classInfo() != constructorClassInfoForType(type))
+        return false;
+    
+    if (function->globalObject() != m_inlineStackTop->m_codeBlock->globalObject())
+        return false;
+    
+    // We only have an intrinsic for the case where you say:
+    //
+    // new FooArray(blah);
+    //
+    // Of course, 'blah' could be any of the following:
+    //
+    // - Integer, indicating that you want to allocate an array of that length.
+    //   This is the thing we're hoping for, and what we can actually do meaningful
+    //   optimizations for.
+    //
+    // - Array buffer, indicating that you want to create a view onto that _entire_
+    //   buffer.
+    //
+    // - Non-buffer object, indicating that you want to create a copy of that
+    //   object by pretending that it quacks like an array.
+    //
+    // - Anything else, indicating that you want to have an exception thrown at
+    //   you.
+    //
+    // The intrinsic, NewTypedArray, will behave as if it could do any of these
+    // things up until we do Fixup. Thereafter, if child1 (i.e. 'blah') is
+    // predicted Int32, then we lock it in as a normal typed array allocation.
+    // Otherwise, NewTypedArray turns into a totally opaque function call that
+    // may clobber the world - by virtue of it accessing properties on what could
+    // be an object.
+    //
+    // Note that although the generic form of NewTypedArray sounds sort of awful,
+    // it is actually quite likely to be more efficient than a fully generic
+    // Construct. So, we might want to think about making NewTypedArray variadic,
+    // or else making Construct not super slow.
+    
+    if (argumentCountIncludingThis != 2)
+        return false;
+
+    insertChecks();
+    set(VirtualRegister(resultOperand),
+        addToGraph(NewTypedArray, OpInfo(type), get(virtualRegisterForArgument(1, registerOffset))));
+    return true;
+}
+
+template<typename ChecksFunctor>
+bool ByteCodeParser::handleConstantInternalFunction(
+    int resultOperand, InternalFunction* function, int registerOffset,
+    int argumentCountIncludingThis, CodeSpecializationKind kind, const ChecksFunctor& insertChecks)
+{
+    if (verbose)
+        dataLog("    Handling constant internal function ", JSValue(function), "\n");
+    
+    // If we ever find that we have a lot of internal functions that we specialize for,
+    // then we should probably have some sort of hashtable dispatch, or maybe even
+    // dispatch straight through the MethodTable of the InternalFunction. But for now,
+    // it seems that this case is hit infrequently enough, and the number of functions
+    // we know about is small enough, that having just a linear cascade of if statements
+    // is good enough.
+    
+    if (function->classInfo() == ArrayConstructor::info()) {
+        if (function->globalObject() != m_inlineStackTop->m_codeBlock->globalObject())
+            return false;
+        
+        insertChecks();
+        if (argumentCountIncludingThis == 2) {
+            set(VirtualRegister(resultOperand),
+                addToGraph(NewArrayWithSize, OpInfo(ArrayWithUndecided), get(virtualRegisterForArgument(1, registerOffset))));
+            return true;
+        }
+        
+        // FIXME: Array constructor should use "this" as newTarget.
+        for (int i = 1; i < argumentCountIncludingThis; ++i)
+            addVarArgChild(get(virtualRegisterForArgument(i, registerOffset)));
+        set(VirtualRegister(resultOperand),
+            addToGraph(Node::VarArg, NewArray, OpInfo(ArrayWithUndecided), OpInfo(0)));
+        return true;
+    }
+    
+    if (function->classInfo() == StringConstructor::info()) {
+        insertChecks();
+        
+        Node* result;
+        
+        if (argumentCountIncludingThis <= 1)
+            result = jsConstant(m_vm->smallStrings.emptyString());
+        else
+            result = addToGraph(CallStringConstructor, get(virtualRegisterForArgument(1, registerOffset)));
+        
+        if (kind == CodeForConstruct)
+            result = addToGraph(NewStringObject, OpInfo(function->globalObject()->stringObjectStructure()), result);
+        
+        set(VirtualRegister(resultOperand), result);
+        return true;
+    }
+    
+    for (unsigned typeIndex = 0; typeIndex < NUMBER_OF_TYPED_ARRAY_TYPES; ++typeIndex) {
+        bool result = handleTypedArrayConstructor(
+            resultOperand, function, registerOffset, argumentCountIncludingThis,
+            indexToTypedArrayType(typeIndex), insertChecks);
+        if (result)
+            return true;
+    }
+    
+    return false;
+}
+
+Node* ByteCodeParser::handleGetByOffset(SpeculatedType prediction, Node* base, unsigned identifierNumber, PropertyOffset offset, NodeType op)
+{
+    Node* propertyStorage;
+    if (isInlineOffset(offset))
+        propertyStorage = base;
+    else
+        propertyStorage = addToGraph(GetButterfly, base);
+    
+    StorageAccessData* data = m_graph.m_storageAccessData.add();
+    data->offset = offset;
+    data->identifierNumber = identifierNumber;
+    
+    Node* getByOffset = addToGraph(op, OpInfo(data), OpInfo(prediction), propertyStorage, base);
+
+    return getByOffset;
+}
+
+Node* ByteCodeParser::handlePutByOffset(Node* base, unsigned identifier, PropertyOffset offset, Node* value)
+{
+    Node* propertyStorage;
+    if (isInlineOffset(offset))
+        propertyStorage = base;
+    else
+        propertyStorage = addToGraph(GetButterfly, base);
+    
+    StorageAccessData* data = m_graph.m_storageAccessData.add();
+    data->offset = offset;
+    data->identifierNumber = identifier;
+    
+    Node* result = addToGraph(PutByOffset, OpInfo(data), propertyStorage, base, value);
+    
+    return result;
+}
+
+bool ByteCodeParser::check(const ObjectPropertyCondition& condition)
+{
+    if (m_graph.watchCondition(condition))
+        return true;
+    
+    Structure* structure = condition.object()->structure();
+    if (!condition.structureEnsuresValidity(structure))
+        return false;
+    
+    addToGraph(
+        CheckStructure,
+        OpInfo(m_graph.addStructureSet(structure)),
+        weakJSConstant(condition.object()));
+    return true;
+}
+
+GetByOffsetMethod ByteCodeParser::promoteToConstant(GetByOffsetMethod method)
+{
+    if (method.kind() == GetByOffsetMethod::LoadFromPrototype
+        && method.prototype()->structure()->dfgShouldWatch()) {
+        if (JSValue constant = m_graph.tryGetConstantProperty(method.prototype()->value(), method.prototype()->structure(), method.offset()))
+            return GetByOffsetMethod::constant(m_graph.freeze(constant));
+    }
+    
+    return method;
+}
+
+GetByOffsetMethod ByteCodeParser::planLoad(const ObjectPropertyCondition& condition)
+{
+    if (verbose)
+        dataLog("Planning a load: ", condition, "\n");
+    
+    // We might promote this to Equivalence, and a later DFG pass might also do such promotion
+    // even if we fail, but for simplicity this cannot be asked to load an equivalence condition.
+    // None of the clients of this method will request a load of an Equivalence condition anyway,
+    // and supporting it would complicate the heuristics below.
+    RELEASE_ASSERT(condition.kind() == PropertyCondition::Presence);
+    
+    // Here's the ranking of how to handle this, from most preferred to least preferred:
+    //
+    // 1) Watchpoint on an equivalence condition and return a constant node for the loaded value.
+    //    No other code is emitted, and the structure of the base object is never registered.
+    //    Hence this results in zero code and we won't jettison this compilation if the object
+    //    transitions, even if the structure is watchable right now.
+    //
+    // 2) Need to emit a load, and the current structure of the base is going to be watched by the
+    //    DFG anyway (i.e. dfgShouldWatch). Watch the structure and emit the load. Don't watch the
+    //    condition, since the act of turning the base into a constant in IR will cause the DFG to
+    //    watch the structure anyway and doing so would subsume watching the condition.
+    //
+    // 3) Need to emit a load, and the current structure of the base is watchable but not by the
+    //    DFG (i.e. transitionWatchpointSetIsStillValid() and !dfgShouldWatchIfPossible()). Watch
+    //    the condition, and emit a load.
+    //
+    // 4) Need to emit a load, and the current structure of the base is not watchable. Emit a
+    //    structure check, and emit a load.
+    //
+    // 5) The condition does not hold. Give up and return null.
+    
+    // First, try to promote Presence to Equivalence. We do this before doing anything else
+    // because it's the most profitable. Also, there are cases where the presence is watchable but
+    // we don't want to watch it unless it became an equivalence (see the relationship between
+    // (1), (2), and (3) above).
+    ObjectPropertyCondition equivalenceCondition = condition.attemptToMakeEquivalenceWithoutBarrier();
+    if (m_graph.watchCondition(equivalenceCondition))
+        return GetByOffsetMethod::constant(m_graph.freeze(equivalenceCondition.requiredValue()));
+    
+    // At this point, we'll have to materialize the condition's base as a constant in DFG IR. Once
+    // we do this, the frozen value will have its own idea of what the structure is. Use that from
+    // now on just because it's less confusing.
+    FrozenValue* base = m_graph.freeze(condition.object());
+    Structure* structure = base->structure();
+    
+    // Check if the structure that we've registered makes the condition hold. If not, just give
+    // up. This is case (5) above.
+    if (!condition.structureEnsuresValidity(structure))
+        return GetByOffsetMethod();
+    
+    // If the structure is watched by the DFG already, then just use this fact to emit the load.
+    // This is case (2) above.
+    if (structure->dfgShouldWatch())
+        return promoteToConstant(GetByOffsetMethod::loadFromPrototype(base, condition.offset()));
+    
+    // If we can watch the condition right now, then we can emit the load after watching it. This
+    // is case (3) above.
+    if (m_graph.watchCondition(condition))
+        return promoteToConstant(GetByOffsetMethod::loadFromPrototype(base, condition.offset()));
+    
+    // We can't watch anything but we know that the current structure satisfies the condition. So,
+    // check for that structure and then emit the load.
+    addToGraph(
+        CheckStructure, 
+        OpInfo(m_graph.addStructureSet(structure)),
+        addToGraph(JSConstant, OpInfo(base)));
+    return promoteToConstant(GetByOffsetMethod::loadFromPrototype(base, condition.offset()));
+}
+
+Node* ByteCodeParser::load(
+    SpeculatedType prediction, unsigned identifierNumber, const GetByOffsetMethod& method,
+    NodeType op)
+{
+    switch (method.kind()) {
+    case GetByOffsetMethod::Invalid:
+        return nullptr;
+    case GetByOffsetMethod::Constant:
+        return addToGraph(JSConstant, OpInfo(method.constant()));
+    case GetByOffsetMethod::LoadFromPrototype: {
+        Node* baseNode = addToGraph(JSConstant, OpInfo(method.prototype()));
+        return handleGetByOffset(prediction, baseNode, identifierNumber, method.offset(), op);
+    }
+    case GetByOffsetMethod::Load:
+        // Will never see this from planLoad().
+        RELEASE_ASSERT_NOT_REACHED();
+        return nullptr;
+    }
+    
+    RELEASE_ASSERT_NOT_REACHED();
+    return nullptr;
+}
+
+Node* ByteCodeParser::load(
+    SpeculatedType prediction, const ObjectPropertyCondition& condition, NodeType op)
+{
+    GetByOffsetMethod method = planLoad(condition);
+    return load(prediction, m_graph.identifiers().ensure(condition.uid()), method, op);
+}
+
+bool ByteCodeParser::check(const ObjectPropertyConditionSet& conditionSet)
+{
+    for (const ObjectPropertyCondition condition : conditionSet) {
+        if (!check(condition))
+            return false;
+    }
+    return true;
+}
+
+GetByOffsetMethod ByteCodeParser::planLoad(const ObjectPropertyConditionSet& conditionSet)
+{
+    if (verbose)
+        dataLog("conditionSet = ", conditionSet, "\n");
+    
+    GetByOffsetMethod result;
+    for (const ObjectPropertyCondition condition : conditionSet) {
+        switch (condition.kind()) {
+        case PropertyCondition::Presence:
+            RELEASE_ASSERT(!result); // Should only see exactly one of these.
+            result = planLoad(condition);
+            if (!result)
+                return GetByOffsetMethod();
+            break;
+        default:
+            if (!check(condition))
+                return GetByOffsetMethod();
+            break;
+        }
+    }
+    RELEASE_ASSERT(!!result);
+    return result;
+}
+
+Node* ByteCodeParser::load(
+    SpeculatedType prediction, const ObjectPropertyConditionSet& conditionSet, NodeType op)
+{
+    GetByOffsetMethod method = planLoad(conditionSet);
+    return load(
+        prediction,
+        m_graph.identifiers().ensure(conditionSet.slotBaseCondition().uid()),
+        method, op);
+}
+
+ObjectPropertyCondition ByteCodeParser::presenceLike(
+    JSObject* knownBase, UniquedStringImpl* uid, PropertyOffset offset, const StructureSet& set)
+{
+    if (set.isEmpty())
+        return ObjectPropertyCondition();
+    unsigned attributes;
+    PropertyOffset firstOffset = set[0]->getConcurrently(uid, attributes);
+    if (firstOffset != offset)
+        return ObjectPropertyCondition();
+    for (unsigned i = 1; i < set.size(); ++i) {
+        unsigned otherAttributes;
+        PropertyOffset otherOffset = set[i]->getConcurrently(uid, otherAttributes);
+        if (otherOffset != offset || otherAttributes != attributes)
+            return ObjectPropertyCondition();
+    }
+    return ObjectPropertyCondition::presenceWithoutBarrier(knownBase, uid, offset, attributes);
+}
+
+bool ByteCodeParser::checkPresenceLike(
+    JSObject* knownBase, UniquedStringImpl* uid, PropertyOffset offset, const StructureSet& set)
+{
+    return check(presenceLike(knownBase, uid, offset, set));
+}
+
+void ByteCodeParser::checkPresenceLike(
+    Node* base, UniquedStringImpl* uid, PropertyOffset offset, const StructureSet& set)
+{
+    if (JSObject* knownBase = base->dynamicCastConstant<JSObject*>()) {
+        if (checkPresenceLike(knownBase, uid, offset, set))
+            return;
+    }
+
+    addToGraph(CheckStructure, OpInfo(m_graph.addStructureSet(set)), base);
+}
+
+template<typename VariantType>
+Node* ByteCodeParser::load(
+    SpeculatedType prediction, Node* base, unsigned identifierNumber, const VariantType& variant)
+{
+    // Make sure backwards propagation knows that we've used base.
+    addToGraph(Phantom, base);
+    
+    bool needStructureCheck = true;
+    
+    if (JSObject* knownBase = base->dynamicCastConstant<JSObject*>()) {
+        // Try to optimize away the structure check. Note that it's not worth doing anything about this
+        // if the base's structure is watched.
+        Structure* structure = base->constant()->structure();
+        if (!structure->dfgShouldWatch()) {
+            UniquedStringImpl* uid = m_graph.identifiers()[identifierNumber];
+            
+            if (!variant.conditionSet().isEmpty()) {
+                // This means that we're loading from a prototype. We expect the base not to have the
+                // property. We can only use ObjectPropertyCondition if all of the structures in the
+                // variant.structureSet() agree on the prototype (it would be hilariously rare if they
+                // didn't). Note that we are relying on structureSet() having at least one element. That
+                // will always be true here because of how GetByIdStatus/PutByIdStatus work.
+                JSObject* prototype = variant.structureSet()[0]->storedPrototypeObject();
+                bool allAgree = true;
+                for (unsigned i = 1; i < variant.structureSet().size(); ++i) {
+                    if (variant.structureSet()[i]->storedPrototypeObject() != prototype) {
+                        allAgree = false;
+                        break;
+                    }
+                }
+                if (allAgree) {
+                    ObjectPropertyCondition condition = ObjectPropertyCondition::absenceWithoutBarrier(
+                        knownBase, uid, prototype);
+                    if (check(condition))
+                        needStructureCheck = false;
+                }
+            } else {
+                // This means we're loading directly from base. We can avoid all of the code that follows
+                // if we can prove that the property is a constant. Otherwise, we try to prove that the
+                // property is watchably present, in which case we get rid of the structure check.
+
+                ObjectPropertyCondition presenceCondition =
+                    presenceLike(knownBase, uid, variant.offset(), variant.structureSet());
+
+                ObjectPropertyCondition equivalenceCondition =
+                    presenceCondition.attemptToMakeEquivalenceWithoutBarrier();
+                if (m_graph.watchCondition(equivalenceCondition))
+                    return weakJSConstant(equivalenceCondition.requiredValue());
+
+                if (check(presenceCondition))
+                    needStructureCheck = false;
+            }
+        }
+    }
+
+    if (needStructureCheck)
+        addToGraph(CheckStructure, OpInfo(m_graph.addStructureSet(variant.structureSet())), base);
+    
+    SpeculatedType loadPrediction;
+    NodeType loadOp;
+    if (variant.callLinkStatus()) {
+        loadPrediction = SpecCellOther;
+        loadOp = GetGetterSetterByOffset;
+    } else {
+        loadPrediction = prediction;
+        loadOp = GetByOffset;
+    }
+    
+    Node* loadedValue;
+    if (!variant.conditionSet().isEmpty())
+        loadedValue = load(loadPrediction, variant.conditionSet(), loadOp);
+    else {
+        if (needStructureCheck && base->hasConstant()) {
+            // We did emit a structure check. That means that we have an opportunity to do constant folding
+            // here, since we didn't do it above.
+            JSValue constant = m_graph.tryGetConstantProperty(
+                base->asJSValue(), variant.structureSet(), variant.offset());
+            if (constant)
+                return weakJSConstant(constant);
+        }
+        
+        loadedValue = handleGetByOffset(
+            loadPrediction, base, identifierNumber, variant.offset(), loadOp);
+    }
+
+    return loadedValue;
+}
+
+Node* ByteCodeParser::store(Node* base, unsigned identifier, const PutByIdVariant& variant, Node* value)
+{
+    RELEASE_ASSERT(variant.kind() == PutByIdVariant::Replace);
+
+    checkPresenceLike(base, m_graph.identifiers()[identifier], variant.offset(), variant.structure());
+    return handlePutByOffset(base, identifier, variant.offset(), value);
+}
+
+void ByteCodeParser::handleGetById(
+    int destinationOperand, SpeculatedType prediction, Node* base, unsigned identifierNumber,
+    const GetByIdStatus& getByIdStatus)
+{
+    NodeType getById = getByIdStatus.makesCalls() ? GetByIdFlush : GetById;
+    
+    if (!getByIdStatus.isSimple() || !getByIdStatus.numVariants() || !Options::enableAccessInlining()) {
+        set(VirtualRegister(destinationOperand),
+            addToGraph(getById, OpInfo(identifierNumber), OpInfo(prediction), base));
+        return;
+    }
+    
+    if (getByIdStatus.numVariants() > 1) {
+        if (getByIdStatus.makesCalls() || !isFTL(m_graph.m_plan.mode)
+            || !Options::enablePolymorphicAccessInlining()) {
+            set(VirtualRegister(destinationOperand),
+                addToGraph(getById, OpInfo(identifierNumber), OpInfo(prediction), base));
+            return;
+        }
+        
+        Vector<MultiGetByOffsetCase, 2> cases;
+        
+        // 1) Emit prototype structure checks for all chains. This could sort of maybe not be
+        //    optimal, if there is some rarely executed case in the chain that requires a lot
+        //    of checks and those checks are not watchpointable.
+        for (const GetByIdVariant& variant : getByIdStatus.variants()) {
+            if (variant.conditionSet().isEmpty()) {
+                cases.append(
+                    MultiGetByOffsetCase(
+                        variant.structureSet(),
+                        GetByOffsetMethod::load(variant.offset())));
+                continue;
+            }
+            
+            GetByOffsetMethod method = planLoad(variant.conditionSet());
+            if (!method) {
+                set(VirtualRegister(destinationOperand),
+                    addToGraph(getById, OpInfo(identifierNumber), OpInfo(prediction), base));
+                return;
+            }
+            
+            cases.append(MultiGetByOffsetCase(variant.structureSet(), method));
+        }
+
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedGetById();
+    
+        // 2) Emit a MultiGetByOffset
+        MultiGetByOffsetData* data = m_graph.m_multiGetByOffsetData.add();
+        data->cases = cases;
+        data->identifierNumber = identifierNumber;
+        set(VirtualRegister(destinationOperand),
+            addToGraph(MultiGetByOffset, OpInfo(data), OpInfo(prediction), base));
+        return;
+    }
+    
+    ASSERT(getByIdStatus.numVariants() == 1);
+    GetByIdVariant variant = getByIdStatus[0];
+                
+    Node* loadedValue = load(prediction, base, identifierNumber, variant);
+    if (!loadedValue) {
+        set(VirtualRegister(destinationOperand),
+            addToGraph(getById, OpInfo(identifierNumber), OpInfo(prediction), base));
+        return;
+    }
+
+    if (m_graph.compilation())
+        m_graph.compilation()->noticeInlinedGetById();
+    
+    if (!variant.callLinkStatus()) {
+        set(VirtualRegister(destinationOperand), loadedValue);
+        return;
+    }
+    
+    Node* getter = addToGraph(GetGetter, loadedValue);
+    
+    // Make a call. We don't try to get fancy with using the smallest operand number because
+    // the stack layout phase should compress the stack anyway.
+    
+    unsigned numberOfParameters = 0;
+    numberOfParameters++; // The 'this' argument.
+    numberOfParameters++; // True return PC.
+    
+    // Start with a register offset that corresponds to the last in-use register.
+    int registerOffset = virtualRegisterForLocal(
+        m_inlineStackTop->m_profiledBlock->m_numCalleeRegisters - 1).offset();
+    registerOffset -= numberOfParameters;
+    registerOffset -= JSStack::CallFrameHeaderSize;
+    
+    // Get the alignment right.
+    registerOffset = -WTF::roundUpToMultipleOf(
+        stackAlignmentRegisters(),
+        -registerOffset);
+    
+    ensureLocals(
+        m_inlineStackTop->remapOperand(
+            VirtualRegister(registerOffset)).toLocal());
+    
+    // Issue SetLocals. This has two effects:
+    // 1) That's how handleCall() sees the arguments.
+    // 2) If we inline then this ensures that the arguments are flushed so that if you use
+    //    the dreaded arguments object on the getter, the right things happen. Well, sort of -
+    //    since we only really care about 'this' in this case. But we're not going to take that
+    //    shortcut.
+    int nextRegister = registerOffset + JSStack::CallFrameHeaderSize;
+    set(VirtualRegister(nextRegister++), base, ImmediateNakedSet);
+    
+    handleCall(
+        destinationOperand, Call, InlineCallFrame::GetterCall, OPCODE_LENGTH(op_get_by_id),
+        getter, numberOfParameters - 1, registerOffset, *variant.callLinkStatus(), prediction);
+}
+
+void ByteCodeParser::emitPutById(
+    Node* base, unsigned identifierNumber, Node* value, const PutByIdStatus& putByIdStatus, bool isDirect)
+{
+    if (isDirect)
+        addToGraph(PutByIdDirect, OpInfo(identifierNumber), base, value);
+    else
+        addToGraph(putByIdStatus.makesCalls() ? PutByIdFlush : PutById, OpInfo(identifierNumber), base, value);
+}
+
+void ByteCodeParser::handlePutById(
+    Node* base, unsigned identifierNumber, Node* value,
+    const PutByIdStatus& putByIdStatus, bool isDirect)
+{
+    if (!putByIdStatus.isSimple() || !putByIdStatus.numVariants() || !Options::enableAccessInlining()) {
+        if (!putByIdStatus.isSet())
+            addToGraph(ForceOSRExit);
+        emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+        return;
+    }
+    
+    if (putByIdStatus.numVariants() > 1) {
+        if (!isFTL(m_graph.m_plan.mode) || putByIdStatus.makesCalls()
+            || !Options::enablePolymorphicAccessInlining()) {
+            emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+            return;
+        }
+        
+        if (!isDirect) {
+            for (unsigned variantIndex = putByIdStatus.numVariants(); variantIndex--;) {
+                if (putByIdStatus[variantIndex].kind() != PutByIdVariant::Transition)
+                    continue;
+                if (!check(putByIdStatus[variantIndex].conditionSet())) {
+                    emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+                    return;
+                }
+            }
+        }
+        
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedPutById();
+        
+        MultiPutByOffsetData* data = m_graph.m_multiPutByOffsetData.add();
+        data->variants = putByIdStatus.variants();
+        data->identifierNumber = identifierNumber;
+        addToGraph(MultiPutByOffset, OpInfo(data), base, value);
+        return;
+    }
+    
+    ASSERT(putByIdStatus.numVariants() == 1);
+    const PutByIdVariant& variant = putByIdStatus[0];
+    
+    switch (variant.kind()) {
+    case PutByIdVariant::Replace: {
+        store(base, identifierNumber, variant, value);
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedPutById();
+        return;
+    }
+    
+    case PutByIdVariant::Transition: {
+        addToGraph(CheckStructure, OpInfo(m_graph.addStructureSet(variant.oldStructure())), base);
+        if (!check(variant.conditionSet())) {
+            emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+            return;
+        }
+
+        ASSERT(variant.oldStructureForTransition()->transitionWatchpointSetHasBeenInvalidated());
+    
+        Node* propertyStorage;
+        Transition* transition = m_graph.m_transitions.add(
+            variant.oldStructureForTransition(), variant.newStructure());
+
+        if (variant.reallocatesStorage()) {
+
+            // If we're growing the property storage then it must be because we're
+            // storing into the out-of-line storage.
+            ASSERT(!isInlineOffset(variant.offset()));
+
+            if (!variant.oldStructureForTransition()->outOfLineCapacity()) {
+                propertyStorage = addToGraph(
+                    AllocatePropertyStorage, OpInfo(transition), base);
+            } else {
+                propertyStorage = addToGraph(
+                    ReallocatePropertyStorage, OpInfo(transition),
+                    base, addToGraph(GetButterfly, base));
+            }
+        } else {
+            if (isInlineOffset(variant.offset()))
+                propertyStorage = base;
+            else
+                propertyStorage = addToGraph(GetButterfly, base);
+        }
+
+        StorageAccessData* data = m_graph.m_storageAccessData.add();
+        data->offset = variant.offset();
+        data->identifierNumber = identifierNumber;
+        
+        addToGraph(
+            PutByOffset,
+            OpInfo(data),
+            propertyStorage,
+            base,
+            value);
+
+        // FIXME: PutStructure goes last until we fix either
+        // https://bugs.webkit.org/show_bug.cgi?id=142921 or
+        // https://bugs.webkit.org/show_bug.cgi?id=142924.
+        addToGraph(PutStructure, OpInfo(transition), base);
+
+        if (m_graph.compilation())
+            m_graph.compilation()->noticeInlinedPutById();
+        return;
+    }
+        
+    case PutByIdVariant::Setter: {
+        Node* loadedValue = load(SpecCellOther, base, identifierNumber, variant);
+        if (!loadedValue) {
+            emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+            return;
+        }
+        
+        Node* setter = addToGraph(GetSetter, loadedValue);
+        
+        // Make a call. We don't try to get fancy with using the smallest operand number because
+        // the stack layout phase should compress the stack anyway.
+    
+        unsigned numberOfParameters = 0;
+        numberOfParameters++; // The 'this' argument.
+        numberOfParameters++; // The new value.
+        numberOfParameters++; // True return PC.
+    
+        // Start with a register offset that corresponds to the last in-use register.
+        int registerOffset = virtualRegisterForLocal(
+            m_inlineStackTop->m_profiledBlock->m_numCalleeRegisters - 1).offset();
+        registerOffset -= numberOfParameters;
+        registerOffset -= JSStack::CallFrameHeaderSize;
+    
+        // Get the alignment right.
+        registerOffset = -WTF::roundUpToMultipleOf(
+            stackAlignmentRegisters(),
+            -registerOffset);
+    
+        ensureLocals(
+            m_inlineStackTop->remapOperand(
+                VirtualRegister(registerOffset)).toLocal());
+    
+        int nextRegister = registerOffset + JSStack::CallFrameHeaderSize;
+        set(VirtualRegister(nextRegister++), base, ImmediateNakedSet);
+        set(VirtualRegister(nextRegister++), value, ImmediateNakedSet);
+    
+        handleCall(
+            VirtualRegister().offset(), Call, InlineCallFrame::SetterCall,
+            OPCODE_LENGTH(op_put_by_id), setter, numberOfParameters - 1, registerOffset,
+            *variant.callLinkStatus(), SpecOther);
+        return;
+    }
+    
+    default: {
+        emitPutById(base, identifierNumber, value, putByIdStatus, isDirect);
+        return;
+    } }
+}
+
+void ByteCodeParser::prepareToParseBlock()
+{
+    clearCaches();
+    ASSERT(m_setLocalQueue.isEmpty());
+}
+
+void ByteCodeParser::clearCaches()
+{
+    m_constants.resize(0);
+}
+
+bool ByteCodeParser::parseBlock(unsigned limit)
+{
+    bool shouldContinueParsing = true;
+
+    Interpreter* interpreter = m_vm->interpreter;
+    Instruction* instructionsBegin = m_inlineStackTop->m_codeBlock->instructions().begin();
+    unsigned blockBegin = m_currentIndex;
+    
+    // If we are the first basic block, introduce markers for arguments. This allows
+    // us to track if a use of an argument may use the actual argument passed, as
+    // opposed to using a value we set explicitly.
+    if (m_currentBlock == m_graph.block(0) && !inlineCallFrame()) {
+        m_graph.m_arguments.resize(m_numArguments);
+        for (unsigned argument = 0; argument < m_numArguments; ++argument) {
+            VariableAccessData* variable = newVariableAccessData(
+                virtualRegisterForArgument(argument));
+            variable->mergeStructureCheckHoistingFailed(
+                m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, BadCache));
+            variable->mergeCheckArrayHoistingFailed(
+                m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, BadIndexingType));
+            
+            Node* setArgument = addToGraph(SetArgument, OpInfo(variable));
+            m_graph.m_arguments[argument] = setArgument;
+            m_currentBlock->variablesAtTail.setArgumentFirstTime(argument, setArgument);
+        }
+    }
+
+    while (true) {
+        processSetLocalQueue();
+        
+        // Don't extend over jump destinations.
+        if (m_currentIndex == limit) {
+            // Ordinarily we want to plant a jump. But refuse to do this if the block is
+            // empty. This is a special case for inlining, which might otherwise create
+            // some empty blocks in some cases. When parseBlock() returns with an empty
+            // block, it will get repurposed instead of creating a new one. Note that this
+            // logic relies on every bytecode resulting in one or more nodes, which would
+            // be true anyway except for op_loop_hint, which emits a Phantom to force this
+            // to be true.
+            if (!m_currentBlock->isEmpty())
+                addToGraph(Jump, OpInfo(m_currentIndex));
+            return shouldContinueParsing;
+        }
+        
+        // Switch on the current bytecode opcode.
+        Instruction* currentInstruction = instructionsBegin + m_currentIndex;
+        m_currentInstruction = currentInstruction; // Some methods want to use this, and we'd rather not thread it through calls.
+        OpcodeID opcodeID = interpreter->getOpcodeID(currentInstruction->u.opcode);
+        
+        if (Options::verboseDFGByteCodeParsing())
+            dataLog("    parsing ", currentCodeOrigin(), "\n");
+        
+        if (m_graph.compilation()) {
+            addToGraph(CountExecution, OpInfo(m_graph.compilation()->executionCounterFor(
+                Profiler::OriginStack(*m_vm->m_perBytecodeProfiler, m_codeBlock, currentCodeOrigin()))));
+        }
+        
+        switch (opcodeID) {
+
+        // === Function entry opcodes ===
+
+        case op_enter: {
+            Node* undefined = addToGraph(JSConstant, OpInfo(m_constantUndefined));
+            // Initialize all locals to undefined.
+            for (int i = 0; i < m_inlineStackTop->m_codeBlock->m_numVars; ++i)
+                set(virtualRegisterForLocal(i), undefined, ImmediateNakedSet);
+            NEXT_OPCODE(op_enter);
+        }
+            
+        case op_to_this: {
+            Node* op1 = getThis();
+            if (op1->op() != ToThis) {
+                Structure* cachedStructure = currentInstruction[2].u.structure.get();
+                if (currentInstruction[2].u.toThisStatus != ToThisOK
+                    || !cachedStructure
+                    || cachedStructure->classInfo()->methodTable.toThis != JSObject::info()->methodTable.toThis
+                    || m_inlineStackTop->m_profiledBlock->couldTakeSlowCase(m_currentIndex)
+                    || m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, BadCache)
+                    || (op1->op() == GetLocal && op1->variableAccessData()->structureCheckHoistingFailed())) {
+                    setThis(addToGraph(ToThis, op1));
+                } else {
+                    addToGraph(
+                        CheckStructure,
+                        OpInfo(m_graph.addStructureSet(cachedStructure)),
+                        op1);
+                }
+            }
+            NEXT_OPCODE(op_to_this);
+        }
+
+        case op_create_this: {
+            int calleeOperand = currentInstruction[2].u.operand;
+            Node* callee = get(VirtualRegister(calleeOperand));
+
+            JSFunction* function = callee->dynamicCastConstant<JSFunction*>();
+            if (!function) {
+                JSCell* cachedFunction = currentInstruction[4].u.jsCell.unvalidatedGet();
+                if (cachedFunction
+                    && cachedFunction != JSCell::seenMultipleCalleeObjects()
+                    && !m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, BadCell)) {
+                    ASSERT(cachedFunction->inherits(JSFunction::info()));
+
+                    FrozenValue* frozen = m_graph.freeze(cachedFunction);
+                    addToGraph(CheckCell, OpInfo(frozen), callee);
+                    set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(JSConstant, OpInfo(frozen)));
+
+                    function = static_cast<JSFunction*>(cachedFunction);
+                }
+            }
+
+            bool alreadyEmitted = false;
+            if (function) {
+                if (FunctionRareData* rareData = function->rareData()) {
+                    if (Structure* structure = rareData->allocationStructure()) {
+                        m_graph.freeze(rareData);
+                        m_graph.watchpoints().addLazily(rareData->allocationProfileWatchpointSet());
+                        // The callee is still live up to this point.
+                        addToGraph(Phantom, callee);
+                        set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(NewObject, OpInfo(structure)));
+                        alreadyEmitted = true;
+                    }
+                }
+            }
+            if (!alreadyEmitted) {
+                set(VirtualRegister(currentInstruction[1].u.operand),
+                    addToGraph(CreateThis, OpInfo(currentInstruction[3].u.operand), callee));
+            }
+            NEXT_OPCODE(op_create_this);
+        }
+
+        case op_new_object: {
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(NewObject,
+                    OpInfo(currentInstruction[3].u.objectAllocationProfile->structure())));
+            NEXT_OPCODE(op_new_object);
+        }
+            
+        case op_new_array: {
+            int startOperand = currentInstruction[2].u.operand;
+            int numOperands = currentInstruction[3].u.operand;
+            ArrayAllocationProfile* profile = currentInstruction[4].u.arrayAllocationProfile;
+            for (int operandIdx = startOperand; operandIdx > startOperand - numOperands; --operandIdx)
+                addVarArgChild(get(VirtualRegister(operandIdx)));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(Node::VarArg, NewArray, OpInfo(profile->selectIndexingType()), OpInfo(0)));
+            NEXT_OPCODE(op_new_array);
+        }
+            
+        case op_new_array_with_size: {
+            int lengthOperand = currentInstruction[2].u.operand;
+            ArrayAllocationProfile* profile = currentInstruction[3].u.arrayAllocationProfile;
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(NewArrayWithSize, OpInfo(profile->selectIndexingType()), get(VirtualRegister(lengthOperand))));
+            NEXT_OPCODE(op_new_array_with_size);
+        }
+            
+        case op_new_array_buffer: {
+            int startConstant = currentInstruction[2].u.operand;
+            int numConstants = currentInstruction[3].u.operand;
+            ArrayAllocationProfile* profile = currentInstruction[4].u.arrayAllocationProfile;
+            NewArrayBufferData data;
+            data.startConstant = m_inlineStackTop->m_constantBufferRemap[startConstant];
+            data.numConstants = numConstants;
+            data.indexingType = profile->selectIndexingType();
+
+            // If this statement has never executed, we'll have the wrong indexing type in the profile.
+            for (int i = 0; i < numConstants; ++i) {
+                data.indexingType =
+                    leastUpperBoundOfIndexingTypeAndValue(
+                        data.indexingType,
+                        m_codeBlock->constantBuffer(data.startConstant)[i]);
+            }
+            
+            m_graph.m_newArrayBufferData.append(data);
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(NewArrayBuffer, OpInfo(&m_graph.m_newArrayBufferData.last())));
+            NEXT_OPCODE(op_new_array_buffer);
+        }
+            
+        case op_new_regexp: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(NewRegexp, OpInfo(currentInstruction[2].u.operand)));
+            NEXT_OPCODE(op_new_regexp);
+        }
+            
+        // === Bitwise operations ===
+
+        case op_bitand: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(BitAnd, op1, op2));
+            NEXT_OPCODE(op_bitand);
+        }
+
+        case op_bitor: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(BitOr, op1, op2));
+            NEXT_OPCODE(op_bitor);
+        }
+
+        case op_bitxor: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(BitXor, op1, op2));
+            NEXT_OPCODE(op_bitxor);
+        }
+
+        case op_rshift: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(BitRShift, op1, op2));
+            NEXT_OPCODE(op_rshift);
+        }
+
+        case op_lshift: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(BitLShift, op1, op2));
+            NEXT_OPCODE(op_lshift);
+        }
+
+        case op_urshift: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(BitURShift, op1, op2));
+            NEXT_OPCODE(op_urshift);
+        }
+            
+        case op_unsigned: {
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                makeSafe(addToGraph(UInt32ToNumber, get(VirtualRegister(currentInstruction[2].u.operand)))));
+            NEXT_OPCODE(op_unsigned);
+        }
+
+        // === Increment/Decrement opcodes ===
+
+        case op_inc: {
+            int srcDst = currentInstruction[1].u.operand;
+            VirtualRegister srcDstVirtualRegister = VirtualRegister(srcDst);
+            Node* op = get(srcDstVirtualRegister);
+            set(srcDstVirtualRegister, makeSafe(addToGraph(ArithAdd, op, addToGraph(JSConstant, OpInfo(m_constantOne)))));
+            NEXT_OPCODE(op_inc);
+        }
+
+        case op_dec: {
+            int srcDst = currentInstruction[1].u.operand;
+            VirtualRegister srcDstVirtualRegister = VirtualRegister(srcDst);
+            Node* op = get(srcDstVirtualRegister);
+            set(srcDstVirtualRegister, makeSafe(addToGraph(ArithSub, op, addToGraph(JSConstant, OpInfo(m_constantOne)))));
+            NEXT_OPCODE(op_dec);
+        }
+
+        // === Arithmetic operations ===
+
+        case op_add: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            if (op1->hasNumberResult() && op2->hasNumberResult())
+                set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ArithAdd, op1, op2)));
+            else
+                set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ValueAdd, op1, op2)));
+            NEXT_OPCODE(op_add);
+        }
+
+        case op_sub: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ArithSub, op1, op2)));
+            NEXT_OPCODE(op_sub);
+        }
+
+        case op_negate: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ArithNegate, op1)));
+            NEXT_OPCODE(op_negate);
+        }
+
+        case op_mul: {
+            // Multiply requires that the inputs are not truncated, unfortunately.
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ArithMul, op1, op2)));
+            NEXT_OPCODE(op_mul);
+        }
+
+        case op_mod: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), makeSafe(addToGraph(ArithMod, op1, op2)));
+            NEXT_OPCODE(op_mod);
+        }
+
+        case op_div: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), makeDivSafe(addToGraph(ArithDiv, op1, op2)));
+            NEXT_OPCODE(op_div);
+        }
+
+        // === Misc operations ===
+
+        case op_debug:
+            addToGraph(Breakpoint);
+            NEXT_OPCODE(op_debug);
+
+        case op_profile_will_call: {
+            addToGraph(ProfileWillCall);
+            NEXT_OPCODE(op_profile_will_call);
+        }
+
+        case op_profile_did_call: {
+            addToGraph(ProfileDidCall);
+            NEXT_OPCODE(op_profile_did_call);
+        }
+
+        case op_mov: {
+            Node* op = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), op);
+            NEXT_OPCODE(op_mov);
+        }
+
+        case op_check_tdz: {
+            addToGraph(CheckNotEmpty, get(VirtualRegister(currentInstruction[1].u.operand)));
+            NEXT_OPCODE(op_check_tdz);
+        }
+
+        case op_check_has_instance:
+            addToGraph(CheckHasInstance, get(VirtualRegister(currentInstruction[3].u.operand)));
+            NEXT_OPCODE(op_check_has_instance);
+
+        case op_instanceof: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* prototype = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(InstanceOf, value, prototype));
+            NEXT_OPCODE(op_instanceof);
+        }
+            
+        case op_is_undefined: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsUndefined, value));
+            NEXT_OPCODE(op_is_undefined);
+        }
+
+        case op_is_boolean: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsBoolean, value));
+            NEXT_OPCODE(op_is_boolean);
+        }
+
+        case op_is_number: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsNumber, value));
+            NEXT_OPCODE(op_is_number);
+        }
+
+        case op_is_string: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsString, value));
+            NEXT_OPCODE(op_is_string);
+        }
+
+        case op_is_object: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsObject, value));
+            NEXT_OPCODE(op_is_object);
+        }
+
+        case op_is_object_or_null: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsObjectOrNull, value));
+            NEXT_OPCODE(op_is_object_or_null);
+        }
+
+        case op_is_function: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(IsFunction, value));
+            NEXT_OPCODE(op_is_function);
+        }
+
+        case op_not: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(LogicalNot, value));
+            NEXT_OPCODE(op_not);
+        }
+            
+        case op_to_primitive: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(ToPrimitive, value));
+            NEXT_OPCODE(op_to_primitive);
+        }
+            
+        case op_strcat: {
+            int startOperand = currentInstruction[2].u.operand;
+            int numOperands = currentInstruction[3].u.operand;
+#if CPU(X86)
+            // X86 doesn't have enough registers to compile MakeRope with three arguments.
+            // Rather than try to be clever, we just make MakeRope dumber on this processor.
+            const unsigned maxRopeArguments = 2;
+#else
+            const unsigned maxRopeArguments = 3;
+#endif
+            auto toStringNodes = std::make_unique<Node*[]>(numOperands);
+            for (int i = 0; i < numOperands; i++)
+                toStringNodes[i] = addToGraph(ToString, get(VirtualRegister(startOperand - i)));
+
+            for (int i = 0; i < numOperands; i++)
+                addToGraph(Phantom, toStringNodes[i]);
+
+            Node* operands[AdjacencyList::Size];
+            unsigned indexInOperands = 0;
+            for (unsigned i = 0; i < AdjacencyList::Size; ++i)
+                operands[i] = 0;
+            for (int operandIdx = 0; operandIdx < numOperands; ++operandIdx) {
+                if (indexInOperands == maxRopeArguments) {
+                    operands[0] = addToGraph(MakeRope, operands[0], operands[1], operands[2]);
+                    for (unsigned i = 1; i < AdjacencyList::Size; ++i)
+                        operands[i] = 0;
+                    indexInOperands = 1;
+                }
+                
+                ASSERT(indexInOperands < AdjacencyList::Size);
+                ASSERT(indexInOperands < maxRopeArguments);
+                operands[indexInOperands++] = toStringNodes[operandIdx];
+            }
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(MakeRope, operands[0], operands[1], operands[2]));
+            NEXT_OPCODE(op_strcat);
+        }
+
+        case op_less: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareLess, op1, op2));
+            NEXT_OPCODE(op_less);
+        }
+
+        case op_lesseq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareLessEq, op1, op2));
+            NEXT_OPCODE(op_lesseq);
+        }
+
+        case op_greater: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareGreater, op1, op2));
+            NEXT_OPCODE(op_greater);
+        }
+
+        case op_greatereq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareGreaterEq, op1, op2));
+            NEXT_OPCODE(op_greatereq);
+        }
+
+        case op_eq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareEq, op1, op2));
+            NEXT_OPCODE(op_eq);
+        }
+
+        case op_eq_null: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareEqConstant, value, addToGraph(JSConstant, OpInfo(m_constantNull))));
+            NEXT_OPCODE(op_eq_null);
+        }
+
+        case op_stricteq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(CompareStrictEq, op1, op2));
+            NEXT_OPCODE(op_stricteq);
+        }
+
+        case op_neq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(LogicalNot, addToGraph(CompareEq, op1, op2)));
+            NEXT_OPCODE(op_neq);
+        }
+
+        case op_neq_null: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(LogicalNot, addToGraph(CompareEqConstant, value, addToGraph(JSConstant, OpInfo(m_constantNull)))));
+            NEXT_OPCODE(op_neq_null);
+        }
+
+        case op_nstricteq: {
+            Node* op1 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[3].u.operand));
+            Node* invertedResult;
+            invertedResult = addToGraph(CompareStrictEq, op1, op2);
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(LogicalNot, invertedResult));
+            NEXT_OPCODE(op_nstricteq);
+        }
+
+        // === Property access operations ===
+
+        case op_get_by_val: {
+            SpeculatedType prediction = getPredictionWithoutOSRExit();
+
+            Node* base = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* property = get(VirtualRegister(currentInstruction[3].u.operand));
+            bool compiledAsGetById = false;
+            {
+                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                ByValInfo* byValInfo = m_inlineStackTop->m_byValInfos.get(CodeOrigin(currentCodeOrigin().bytecodeIndex));
+                // FIXME: When the bytecode is not compiled in the baseline JIT, byValInfo becomes null.
+                // At that time, there is no information.
+                if (byValInfo && byValInfo->stubInfo && !byValInfo->tookSlowPath && !m_inlineStackTop->m_exitProfile.hasExitSite(m_currentIndex, BadIdent)) {
+                    compiledAsGetById = true;
+                    unsigned identifierNumber = m_graph.identifiers().ensure(byValInfo->cachedId.impl());
+                    UniquedStringImpl* uid = m_graph.identifiers()[identifierNumber];
+
+                    addToGraph(CheckIdent, OpInfo(uid), property);
+
+                    GetByIdStatus getByIdStatus = GetByIdStatus::computeForStubInfo(
+                        locker, m_inlineStackTop->m_profiledBlock,
+                        byValInfo->stubInfo, currentCodeOrigin(), uid);
+
+                    handleGetById(currentInstruction[1].u.operand, prediction, base, identifierNumber, getByIdStatus);
+                }
+            }
+
+            if (!compiledAsGetById) {
+                ArrayMode arrayMode = getArrayMode(currentInstruction[4].u.arrayProfile, Array::Read);
+                Node* getByVal = addToGraph(GetByVal, OpInfo(arrayMode.asWord()), OpInfo(prediction), base, property);
+                set(VirtualRegister(currentInstruction[1].u.operand), getByVal);
+            }
+
+            NEXT_OPCODE(op_get_by_val);
+        }
+
+        case op_put_by_val_direct:
+        case op_put_by_val: {
+            Node* base = get(VirtualRegister(currentInstruction[1].u.operand));
+
+            ArrayMode arrayMode = getArrayMode(currentInstruction[4].u.arrayProfile, Array::Write);
+            
+            Node* property = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* value = get(VirtualRegister(currentInstruction[3].u.operand));
+            
+            addVarArgChild(base);
+            addVarArgChild(property);
+            addVarArgChild(value);
+            addVarArgChild(0); // Leave room for property storage.
+            addVarArgChild(0); // Leave room for length.
+            addToGraph(Node::VarArg, opcodeID == op_put_by_val_direct ? PutByValDirect : PutByVal, OpInfo(arrayMode.asWord()), OpInfo(0));
+
+            NEXT_OPCODE(op_put_by_val);
+        }
+            
+        case op_get_by_id:
+        case op_get_by_id_out_of_line:
+        case op_get_array_length: {
+            SpeculatedType prediction = getPrediction();
+            
+            Node* base = get(VirtualRegister(currentInstruction[2].u.operand));
+            unsigned identifierNumber = m_inlineStackTop->m_identifierRemap[currentInstruction[3].u.operand];
+            
+            UniquedStringImpl* uid = m_graph.identifiers()[identifierNumber];
+            GetByIdStatus getByIdStatus = GetByIdStatus::computeFor(
+                m_inlineStackTop->m_profiledBlock, m_dfgCodeBlock,
+                m_inlineStackTop->m_stubInfos, m_dfgStubInfos,
+                currentCodeOrigin(), uid);
+            
+            handleGetById(
+                currentInstruction[1].u.operand, prediction, base, identifierNumber, getByIdStatus);
+
+            NEXT_OPCODE(op_get_by_id);
+        }
+        case op_put_by_id:
+        case op_put_by_id_out_of_line:
+        case op_put_by_id_transition_direct:
+        case op_put_by_id_transition_normal:
+        case op_put_by_id_transition_direct_out_of_line:
+        case op_put_by_id_transition_normal_out_of_line: {
+            Node* value = get(VirtualRegister(currentInstruction[3].u.operand));
+            Node* base = get(VirtualRegister(currentInstruction[1].u.operand));
+            unsigned identifierNumber = m_inlineStackTop->m_identifierRemap[currentInstruction[2].u.operand];
+            bool direct = currentInstruction[8].u.operand;
+
+            PutByIdStatus putByIdStatus = PutByIdStatus::computeFor(
+                m_inlineStackTop->m_profiledBlock, m_dfgCodeBlock,
+                m_inlineStackTop->m_stubInfos, m_dfgStubInfos,
+                currentCodeOrigin(), m_graph.identifiers()[identifierNumber]);
+            
+            handlePutById(base, identifierNumber, value, putByIdStatus, direct);
+            NEXT_OPCODE(op_put_by_id);
+        }
+
+        case op_profile_type: {
+            Node* valueToProfile = get(VirtualRegister(currentInstruction[1].u.operand));
+            addToGraph(ProfileType, OpInfo(currentInstruction[2].u.location), valueToProfile);
+            NEXT_OPCODE(op_profile_type);
+        }
+
+        case op_profile_control_flow: {
+            BasicBlockLocation* basicBlockLocation = currentInstruction[1].u.basicBlockLocation;
+            addToGraph(ProfileControlFlow, OpInfo(basicBlockLocation));
+            NEXT_OPCODE(op_profile_control_flow);
+        }
+
+        // === Block terminators. ===
+
+        case op_jmp: {
+            int relativeOffset = currentInstruction[1].u.operand;
+            addToGraph(Jump, OpInfo(m_currentIndex + relativeOffset));
+            if (relativeOffset <= 0)
+                flushForTerminal();
+            LAST_OPCODE(op_jmp);
+        }
+
+        case op_jtrue: {
+            unsigned relativeOffset = currentInstruction[2].u.operand;
+            Node* condition = get(VirtualRegister(currentInstruction[1].u.operand));
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jtrue))), condition);
+            LAST_OPCODE(op_jtrue);
+        }
+
+        case op_jfalse: {
+            unsigned relativeOffset = currentInstruction[2].u.operand;
+            Node* condition = get(VirtualRegister(currentInstruction[1].u.operand));
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jfalse), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jfalse);
+        }
+
+        case op_jeq_null: {
+            unsigned relativeOffset = currentInstruction[2].u.operand;
+            Node* value = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* condition = addToGraph(CompareEqConstant, value, addToGraph(JSConstant, OpInfo(m_constantNull)));
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jeq_null))), condition);
+            LAST_OPCODE(op_jeq_null);
+        }
+
+        case op_jneq_null: {
+            unsigned relativeOffset = currentInstruction[2].u.operand;
+            Node* value = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* condition = addToGraph(CompareEqConstant, value, addToGraph(JSConstant, OpInfo(m_constantNull)));
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jneq_null), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jneq_null);
+        }
+
+        case op_jless: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareLess, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jless))), condition);
+            LAST_OPCODE(op_jless);
+        }
+
+        case op_jlesseq: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareLessEq, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jlesseq))), condition);
+            LAST_OPCODE(op_jlesseq);
+        }
+
+        case op_jgreater: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareGreater, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jgreater))), condition);
+            LAST_OPCODE(op_jgreater);
+        }
+
+        case op_jgreatereq: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareGreaterEq, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + relativeOffset, m_currentIndex + OPCODE_LENGTH(op_jgreatereq))), condition);
+            LAST_OPCODE(op_jgreatereq);
+        }
+
+        case op_jnless: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareLess, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jnless), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jnless);
+        }
+
+        case op_jnlesseq: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareLessEq, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jnlesseq), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jnlesseq);
+        }
+
+        case op_jngreater: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareGreater, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jngreater), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jngreater);
+        }
+
+        case op_jngreatereq: {
+            unsigned relativeOffset = currentInstruction[3].u.operand;
+            Node* op1 = get(VirtualRegister(currentInstruction[1].u.operand));
+            Node* op2 = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* condition = addToGraph(CompareGreaterEq, op1, op2);
+            addToGraph(Branch, OpInfo(branchData(m_currentIndex + OPCODE_LENGTH(op_jngreatereq), m_currentIndex + relativeOffset)), condition);
+            LAST_OPCODE(op_jngreatereq);
+        }
+            
+        case op_switch_imm: {
+            SwitchData& data = *m_graph.m_switchData.add();
+            data.kind = SwitchImm;
+            data.switchTableIndex = m_inlineStackTop->m_switchRemap[currentInstruction[1].u.operand];
+            data.fallThrough.setBytecodeIndex(m_currentIndex + currentInstruction[2].u.operand);
+            SimpleJumpTable& table = m_codeBlock->switchJumpTable(data.switchTableIndex);
+            for (unsigned i = 0; i < table.branchOffsets.size(); ++i) {
+                if (!table.branchOffsets[i])
+                    continue;
+                unsigned target = m_currentIndex + table.branchOffsets[i];
+                if (target == data.fallThrough.bytecodeIndex())
+                    continue;
+                data.cases.append(SwitchCase::withBytecodeIndex(m_graph.freeze(jsNumber(static_cast<int32_t>(table.min + i))), target));
+            }
+            addToGraph(Switch, OpInfo(&data), get(VirtualRegister(currentInstruction[3].u.operand)));
+            flushIfTerminal(data);
+            LAST_OPCODE(op_switch_imm);
+        }
+            
+        case op_switch_char: {
+            SwitchData& data = *m_graph.m_switchData.add();
+            data.kind = SwitchChar;
+            data.switchTableIndex = m_inlineStackTop->m_switchRemap[currentInstruction[1].u.operand];
+            data.fallThrough.setBytecodeIndex(m_currentIndex + currentInstruction[2].u.operand);
+            SimpleJumpTable& table = m_codeBlock->switchJumpTable(data.switchTableIndex);
+            for (unsigned i = 0; i < table.branchOffsets.size(); ++i) {
+                if (!table.branchOffsets[i])
+                    continue;
+                unsigned target = m_currentIndex + table.branchOffsets[i];
+                if (target == data.fallThrough.bytecodeIndex())
+                    continue;
+                data.cases.append(
+                    SwitchCase::withBytecodeIndex(LazyJSValue::singleCharacterString(table.min + i), target));
+            }
+            addToGraph(Switch, OpInfo(&data), get(VirtualRegister(currentInstruction[3].u.operand)));
+            flushIfTerminal(data);
+            LAST_OPCODE(op_switch_char);
+        }
+
+        case op_switch_string: {
+            SwitchData& data = *m_graph.m_switchData.add();
+            data.kind = SwitchString;
+            data.switchTableIndex = currentInstruction[1].u.operand;
+            data.fallThrough.setBytecodeIndex(m_currentIndex + currentInstruction[2].u.operand);
+            StringJumpTable& table = m_codeBlock->stringSwitchJumpTable(data.switchTableIndex);
+            StringJumpTable::StringOffsetTable::iterator iter;
+            StringJumpTable::StringOffsetTable::iterator end = table.offsetTable.end();
+            for (iter = table.offsetTable.begin(); iter != end; ++iter) {
+                unsigned target = m_currentIndex + iter->value.branchOffset;
+                if (target == data.fallThrough.bytecodeIndex())
+                    continue;
+                data.cases.append(
+                    SwitchCase::withBytecodeIndex(LazyJSValue::knownStringImpl(iter->key.get()), target));
+            }
+            addToGraph(Switch, OpInfo(&data), get(VirtualRegister(currentInstruction[3].u.operand)));
+            flushIfTerminal(data);
+            LAST_OPCODE(op_switch_string);
+        }
+
+        case op_ret:
+            if (inlineCallFrame()) {
+                flushForReturn();
+                if (m_inlineStackTop->m_returnValue.isValid())
+                    setDirect(m_inlineStackTop->m_returnValue, get(VirtualRegister(currentInstruction[1].u.operand)), ImmediateSetWithFlush);
+                m_inlineStackTop->m_didReturn = true;
+                if (m_inlineStackTop->m_unlinkedBlocks.isEmpty()) {
+                    // If we're returning from the first block, then we're done parsing.
+                    ASSERT(m_inlineStackTop->m_callsiteBlockHead == m_graph.lastBlock());
+                    shouldContinueParsing = false;
+                    LAST_OPCODE(op_ret);
+                } else {
+                    // If inlining created blocks, and we're doing a return, then we need some
+                    // special linking.
+                    ASSERT(m_inlineStackTop->m_unlinkedBlocks.last().m_block == m_graph.lastBlock());
+                    m_inlineStackTop->m_unlinkedBlocks.last().m_needsNormalLinking = false;
+                }
+                if (m_currentIndex + OPCODE_LENGTH(op_ret) != m_inlineStackTop->m_codeBlock->instructions().size() || m_inlineStackTop->m_didEarlyReturn) {
+                    ASSERT(m_currentIndex + OPCODE_LENGTH(op_ret) <= m_inlineStackTop->m_codeBlock->instructions().size());
+                    addToGraph(Jump, OpInfo(0));
+                    m_inlineStackTop->m_unlinkedBlocks.last().m_needsEarlyReturnLinking = true;
+                    m_inlineStackTop->m_didEarlyReturn = true;
+                }
+                LAST_OPCODE(op_ret);
+            }
+            addToGraph(Return, get(VirtualRegister(currentInstruction[1].u.operand)));
+            flushForReturn();
+            LAST_OPCODE(op_ret);
+            
+        case op_end:
+            ASSERT(!inlineCallFrame());
+            addToGraph(Return, get(VirtualRegister(currentInstruction[1].u.operand)));
+            flushForReturn();
+            LAST_OPCODE(op_end);
+
+        case op_throw:
+            addToGraph(Throw, get(VirtualRegister(currentInstruction[1].u.operand)));
+            flushForTerminal();
+            addToGraph(Unreachable);
+            LAST_OPCODE(op_throw);
+            
+        case op_throw_static_error:
+            addToGraph(ThrowReferenceError);
+            flushForTerminal();
+            addToGraph(Unreachable);
+            LAST_OPCODE(op_throw_static_error);
+            
+        case op_call:
+            handleCall(currentInstruction, Call, CodeForCall);
+            // Verify that handleCall(), which could have inlined the callee, didn't trash m_currentInstruction
+            ASSERT(m_currentInstruction == currentInstruction);
+            NEXT_OPCODE(op_call);
+            
+        case op_construct:
+            handleCall(currentInstruction, Construct, CodeForConstruct);
+            NEXT_OPCODE(op_construct);
+            
+        case op_call_varargs: {
+            handleVarargsCall(currentInstruction, CallVarargs, CodeForCall);
+            NEXT_OPCODE(op_call_varargs);
+        }
+            
+        case op_construct_varargs: {
+            handleVarargsCall(currentInstruction, ConstructVarargs, CodeForConstruct);
+            NEXT_OPCODE(op_construct_varargs);
+        }
+            
+        case op_jneq_ptr:
+            // Statically speculate for now. It makes sense to let speculate-only jneq_ptr
+            // support simmer for a while before making it more general, since it's
+            // already gnarly enough as it is.
+            ASSERT(pointerIsFunction(currentInstruction[2].u.specialPointer));
+            addToGraph(
+                CheckCell,
+                OpInfo(m_graph.freeze(static_cast<JSCell*>(actualPointerFor(
+                    m_inlineStackTop->m_codeBlock, currentInstruction[2].u.specialPointer)))),
+                get(VirtualRegister(currentInstruction[1].u.operand)));
+            addToGraph(Jump, OpInfo(m_currentIndex + OPCODE_LENGTH(op_jneq_ptr)));
+            LAST_OPCODE(op_jneq_ptr);
+
+        case op_resolve_scope: {
+            int dst = currentInstruction[1].u.operand;
+            ResolveType resolveType = static_cast<ResolveType>(currentInstruction[4].u.operand);
+            unsigned depth = currentInstruction[5].u.operand;
+
+            // get_from_scope and put_to_scope depend on this watchpoint forcing OSR exit, so they don't add their own watchpoints.
+            if (needsVarInjectionChecks(resolveType))
+                addToGraph(VarInjectionWatchpoint);
+
+            switch (resolveType) {
+            case GlobalProperty:
+            case GlobalVar:
+            case GlobalPropertyWithVarInjectionChecks:
+            case GlobalVarWithVarInjectionChecks:
+                set(VirtualRegister(dst), weakJSConstant(m_inlineStackTop->m_codeBlock->globalObject()));
+                if (resolveType == GlobalPropertyWithVarInjectionChecks || resolveType == GlobalVarWithVarInjectionChecks)
+                    addToGraph(Phantom, getDirect(m_inlineStackTop->remapOperand(VirtualRegister(currentInstruction[2].u.operand))));
+                break;
+            case LocalClosureVar:
+            case ClosureVar:
+            case ClosureVarWithVarInjectionChecks: {
+                Node* localBase = get(VirtualRegister(currentInstruction[2].u.operand));
+                addToGraph(Phantom, localBase); // OSR exit cannot handle resolve_scope on a DCE'd scope.
+                
+                // We have various forms of constant folding here. This is necessary to avoid
+                // spurious recompiles in dead-but-foldable code.
+                if (SymbolTable* symbolTable = currentInstruction[6].u.symbolTable.get()) {
+                    InferredValue* singleton = symbolTable->singletonScope();
+                    if (JSValue value = singleton->inferredValue()) {
+                        m_graph.watchpoints().addLazily(singleton);
+                        set(VirtualRegister(dst), weakJSConstant(value));
+                        break;
+                    }
+                }
+                if (JSScope* scope = localBase->dynamicCastConstant<JSScope*>()) {
+                    for (unsigned n = depth; n--;)
+                        scope = scope->next();
+                    set(VirtualRegister(dst), weakJSConstant(scope));
+                    break;
+                }
+                for (unsigned n = depth; n--;)
+                    localBase = addToGraph(SkipScope, localBase);
+                set(VirtualRegister(dst), localBase);
+                break;
+            }
+            case Dynamic:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            NEXT_OPCODE(op_resolve_scope);
+        }
+
+        case op_get_from_scope: {
+            int dst = currentInstruction[1].u.operand;
+            int scope = currentInstruction[2].u.operand;
+            unsigned identifierNumber = m_inlineStackTop->m_identifierRemap[currentInstruction[3].u.operand];
+            UniquedStringImpl* uid = m_graph.identifiers()[identifierNumber];
+            ResolveType resolveType = ResolveModeAndType(currentInstruction[4].u.operand).type();
+
+            Structure* structure = 0;
+            WatchpointSet* watchpoints = 0;
+            uintptr_t operand;
+            {
+                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                if (resolveType == GlobalVar || resolveType == GlobalVarWithVarInjectionChecks)
+                    watchpoints = currentInstruction[5].u.watchpointSet;
+                else
+                    structure = currentInstruction[5].u.structure.get();
+                operand = reinterpret_cast<uintptr_t>(currentInstruction[6].u.pointer);
+            }
+
+            UNUSED_PARAM(watchpoints); // We will use this in the future. For now we set it as a way of documenting the fact that that's what index 5 is in GlobalVar mode.
+
+            JSGlobalObject* globalObject = m_inlineStackTop->m_codeBlock->globalObject();
+
+            switch (resolveType) {
+            case GlobalProperty:
+            case GlobalPropertyWithVarInjectionChecks: {
+                SpeculatedType prediction = getPrediction();
+
+                GetByIdStatus status = GetByIdStatus::computeFor(structure, uid);
+                if (status.state() != GetByIdStatus::Simple
+                    || status.numVariants() != 1
+                    || status[0].structureSet().size() != 1) {
+                    set(VirtualRegister(dst), addToGraph(GetByIdFlush, OpInfo(identifierNumber), OpInfo(prediction), get(VirtualRegister(scope))));
+                    break;
+                }
+
+                Node* base = weakJSConstant(globalObject);
+                Node* result = load(prediction, base, identifierNumber, status[0]);
+                addToGraph(Phantom, get(VirtualRegister(scope)));
+                set(VirtualRegister(dst), result);
+                break;
+            }
+            case GlobalVar:
+            case GlobalVarWithVarInjectionChecks: {
+                addToGraph(Phantom, get(VirtualRegister(scope)));
+                WatchpointSet* watchpointSet;
+                ScopeOffset offset;
+                {
+                    ConcurrentJITLocker locker(globalObject->symbolTable()->m_lock);
+                    SymbolTableEntry entry = globalObject->symbolTable()->get(locker, uid);
+                    watchpointSet = entry.watchpointSet();
+                    offset = entry.scopeOffset();
+                }
+                if (watchpointSet && watchpointSet->state() == IsWatched) {
+                    // This has a fun concurrency story. There is the possibility of a race in two
+                    // directions:
+                    //
+                    // We see that the set IsWatched, but in the meantime it gets invalidated: this is
+                    // fine because if we saw that it IsWatched then we add a watchpoint. If it gets
+                    // invalidated, then this compilation is invalidated. Note that in the meantime we
+                    // may load an absurd value from the global object. It's fine to load an absurd
+                    // value if the compilation is invalidated anyway.
+                    //
+                    // We see that the set IsWatched, but the value isn't yet initialized: this isn't
+                    // possible because of the ordering of operations.
+                    //
+                    // Here's how we order operations:
+                    //
+                    // Main thread stores to the global object: always store a value first, and only
+                    // after that do we touch the watchpoint set. There is a fence in the touch, that
+                    // ensures that the store to the global object always happens before the touch on the
+                    // set.
+                    //
+                    // Compilation thread: always first load the state of the watchpoint set, and then
+                    // load the value. The WatchpointSet::state() method does fences for us to ensure
+                    // that the load of the state happens before our load of the value.
+                    //
+                    // Finalizing compilation: this happens on the main thread and synchronously checks
+                    // validity of all watchpoint sets.
+                    //
+                    // We will only perform optimizations if the load of the state yields IsWatched. That
+                    // means that at least one store would have happened to initialize the original value
+                    // of the variable (that is, the value we'd like to constant fold to). There may be
+                    // other stores that happen after that, but those stores will invalidate the
+                    // watchpoint set and also the compilation.
+                    
+                    // Note that we need to use the operand, which is a direct pointer at the global,
+                    // rather than looking up the global by doing variableAt(offset). That's because the
+                    // internal data structures of JSSegmentedVariableObject are not thread-safe even
+                    // though accessing the global itself is. The segmentation involves a vector spine
+                    // that resizes with malloc/free, so if new globals unrelated to the one we are
+                    // reading are added, we might access freed memory if we do variableAt().
+                    WriteBarrier<Unknown>* pointer = bitwise_cast<WriteBarrier<Unknown>*>(operand);
+                    
+                    ASSERT(globalObject->findVariableIndex(pointer) == offset);
+                    
+                    JSValue value = pointer->get();
+                    if (value) {
+                        m_graph.watchpoints().addLazily(watchpointSet);
+                        set(VirtualRegister(dst), weakJSConstant(value));
+                        break;
+                    }
+                }
+                
+                SpeculatedType prediction = getPrediction();
+                set(VirtualRegister(dst), addToGraph(GetGlobalVar, OpInfo(operand), OpInfo(prediction)));
+                break;
+            }
+            case LocalClosureVar:
+            case ClosureVar:
+            case ClosureVarWithVarInjectionChecks: {
+                Node* scopeNode = get(VirtualRegister(scope));
+                
+                // Ideally we wouldn't have to do this Phantom. But:
+                //
+                // For the constant case: we must do it because otherwise we would have no way of knowing
+                // that the scope is live at OSR here.
+                //
+                // For the non-constant case: GetClosureVar could be DCE'd, but baseline's implementation
+                // won't be able to handle an Undefined scope.
+                addToGraph(Phantom, scopeNode);
+                
+                // Constant folding in the bytecode parser is important for performance. This may not
+                // have executed yet. If it hasn't, then we won't have a prediction. Lacking a
+                // prediction, we'd otherwise think that it has to exit. Then when it did execute, we
+                // would recompile. But if we can fold it here, we avoid the exit.
+                if (JSValue value = m_graph.tryGetConstantClosureVar(scopeNode, ScopeOffset(operand))) {
+                    set(VirtualRegister(dst), weakJSConstant(value));
+                    break;
+                }
+                SpeculatedType prediction = getPrediction();
+                set(VirtualRegister(dst),
+                    addToGraph(GetClosureVar, OpInfo(operand), OpInfo(prediction), scopeNode));
+                break;
+            }
+            case Dynamic:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            NEXT_OPCODE(op_get_from_scope);
+        }
+
+        case op_put_to_scope: {
+            unsigned scope = currentInstruction[1].u.operand;
+            unsigned identifierNumber = currentInstruction[2].u.operand;
+            if (identifierNumber != UINT_MAX)
+                identifierNumber = m_inlineStackTop->m_identifierRemap[identifierNumber];
+            unsigned value = currentInstruction[3].u.operand;
+            ResolveType resolveType = ResolveModeAndType(currentInstruction[4].u.operand).type();
+            UniquedStringImpl* uid;
+            if (identifierNumber != UINT_MAX)
+                uid = m_graph.identifiers()[identifierNumber];
+            else
+                uid = nullptr;
+            
+            Structure* structure = nullptr;
+            WatchpointSet* watchpoints = nullptr;
+            uintptr_t operand;
+            {
+                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                if (resolveType == GlobalVar || resolveType == GlobalVarWithVarInjectionChecks || resolveType == LocalClosureVar)
+                    watchpoints = currentInstruction[5].u.watchpointSet;
+                else
+                    structure = currentInstruction[5].u.structure.get();
+                operand = reinterpret_cast<uintptr_t>(currentInstruction[6].u.pointer);
+            }
+
+            JSGlobalObject* globalObject = m_inlineStackTop->m_codeBlock->globalObject();
+
+            switch (resolveType) {
+            case GlobalProperty:
+            case GlobalPropertyWithVarInjectionChecks: {
+                PutByIdStatus status;
+                if (uid)
+                    status = PutByIdStatus::computeFor(globalObject, structure, uid, false);
+                else
+                    status = PutByIdStatus(PutByIdStatus::TakesSlowPath);
+                if (status.numVariants() != 1
+                    || status[0].kind() != PutByIdVariant::Replace
+                    || status[0].structure().size() != 1) {
+                    addToGraph(PutById, OpInfo(identifierNumber), get(VirtualRegister(scope)), get(VirtualRegister(value)));
+                    break;
+                }
+                Node* base = weakJSConstant(globalObject);
+                store(base, identifierNumber, status[0], get(VirtualRegister(value)));
+                // Keep scope alive until after put.
+                addToGraph(Phantom, get(VirtualRegister(scope)));
+                break;
+            }
+            case GlobalVar:
+            case GlobalVarWithVarInjectionChecks: {
+                if (watchpoints) {
+                    SymbolTableEntry entry = globalObject->symbolTable()->get(uid);
+                    ASSERT_UNUSED(entry, watchpoints == entry.watchpointSet());
+                }
+                Node* valueNode = get(VirtualRegister(value));
+                addToGraph(PutGlobalVar, OpInfo(operand), weakJSConstant(globalObject), valueNode);
+                if (watchpoints && watchpoints->state() != IsInvalidated) {
+                    // Must happen after the store. See comment for GetGlobalVar.
+                    addToGraph(NotifyWrite, OpInfo(watchpoints));
+                }
+                // Keep scope alive until after put.
+                addToGraph(Phantom, get(VirtualRegister(scope)));
+                break;
+            }
+            case LocalClosureVar:
+            case ClosureVar:
+            case ClosureVarWithVarInjectionChecks: {
+                Node* scopeNode = get(VirtualRegister(scope));
+                Node* valueNode = get(VirtualRegister(value));
+
+                addToGraph(PutClosureVar, OpInfo(operand), scopeNode, valueNode);
+
+                if (watchpoints && watchpoints->state() != IsInvalidated) {
+                    // Must happen after the store. See comment for GetGlobalVar.
+                    addToGraph(NotifyWrite, OpInfo(watchpoints));
+                }
+                break;
+            }
+            case Dynamic:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            NEXT_OPCODE(op_put_to_scope);
+        }
+
+        case op_loop_hint: {
+            // Baseline->DFG OSR jumps between loop hints. The DFG assumes that Baseline->DFG
+            // OSR can only happen at basic block boundaries. Assert that these two statements
+            // are compatible.
+            RELEASE_ASSERT(m_currentIndex == blockBegin);
+            
+            // We never do OSR into an inlined code block. That could not happen, since OSR
+            // looks up the code block that is the replacement for the baseline JIT code
+            // block. Hence, machine code block = true code block = not inline code block.
+            if (!m_inlineStackTop->m_caller)
+                m_currentBlock->isOSRTarget = true;
+
+            addToGraph(LoopHint);
+            
+            if (m_vm->watchdog)
+                addToGraph(CheckWatchdogTimer);
+            
+            NEXT_OPCODE(op_loop_hint);
+        }
+            
+        case op_create_lexical_environment: {
+            VirtualRegister symbolTableRegister(currentInstruction[3].u.operand);
+            VirtualRegister initialValueRegister(currentInstruction[4].u.operand);
+            ASSERT(symbolTableRegister.isConstant() && initialValueRegister.isConstant());
+            FrozenValue* symbolTable = m_graph.freezeStrong(m_inlineStackTop->m_codeBlock->getConstant(symbolTableRegister.offset()));
+            FrozenValue* initialValue = m_graph.freezeStrong(m_inlineStackTop->m_codeBlock->getConstant(initialValueRegister.offset()));
+            Node* scope = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* lexicalEnvironment = addToGraph(CreateActivation, OpInfo(symbolTable), OpInfo(initialValue), scope);
+            set(VirtualRegister(currentInstruction[1].u.operand), lexicalEnvironment);
+            NEXT_OPCODE(op_create_lexical_environment);
+        }
+
+        case op_get_parent_scope: {
+            Node* currentScope = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* newScope = addToGraph(SkipScope, currentScope);
+            set(VirtualRegister(currentInstruction[1].u.operand), newScope);
+            addToGraph(Phantom, currentScope);
+            NEXT_OPCODE(op_get_parent_scope);
+        }
+
+        case op_get_scope: {
+            // Help the later stages a bit by doing some small constant folding here. Note that this
+            // only helps for the first basic block. It's extremely important not to constant fold
+            // loads from the scope register later, as that would prevent the DFG from tracking the
+            // bytecode-level liveness of the scope register.
+            Node* callee = get(VirtualRegister(JSStack::Callee));
+            Node* result;
+            if (JSFunction* function = callee->dynamicCastConstant<JSFunction*>())
+                result = weakJSConstant(function->scope());
+            else
+                result = addToGraph(GetScope, callee);
+            set(VirtualRegister(currentInstruction[1].u.operand), result);
+            NEXT_OPCODE(op_get_scope);
+        }
+            
+        case op_create_direct_arguments: {
+            noticeArgumentsUse();
+            Node* createArguments = addToGraph(CreateDirectArguments);
+            set(VirtualRegister(currentInstruction[1].u.operand), createArguments);
+            NEXT_OPCODE(op_create_direct_arguments);
+        }
+            
+        case op_create_scoped_arguments: {
+            noticeArgumentsUse();
+            Node* createArguments = addToGraph(CreateScopedArguments, get(VirtualRegister(currentInstruction[2].u.operand)));
+            set(VirtualRegister(currentInstruction[1].u.operand), createArguments);
+            NEXT_OPCODE(op_create_scoped_arguments);
+        }
+
+        case op_create_out_of_band_arguments: {
+            noticeArgumentsUse();
+            Node* createArguments = addToGraph(CreateClonedArguments);
+            set(VirtualRegister(currentInstruction[1].u.operand), createArguments);
+            NEXT_OPCODE(op_create_out_of_band_arguments);
+        }
+            
+        case op_get_from_arguments: {
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(
+                    GetFromArguments,
+                    OpInfo(currentInstruction[3].u.operand),
+                    OpInfo(getPrediction()),
+                    get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_get_from_arguments);
+        }
+            
+        case op_put_to_arguments: {
+            addToGraph(
+                PutToArguments,
+                OpInfo(currentInstruction[2].u.operand),
+                get(VirtualRegister(currentInstruction[1].u.operand)),
+                get(VirtualRegister(currentInstruction[3].u.operand)));
+            NEXT_OPCODE(op_put_to_arguments);
+        }
+            
+        case op_new_func: {
+            FunctionExecutable* decl = m_inlineStackTop->m_profiledBlock->functionDecl(currentInstruction[3].u.operand);
+            FrozenValue* frozen = m_graph.freezeStrong(decl);
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(NewFunction, OpInfo(frozen), get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_new_func);
+        }
+
+        case op_new_func_exp: {
+            FunctionExecutable* expr = m_inlineStackTop->m_profiledBlock->functionExpr(currentInstruction[3].u.operand);
+            FrozenValue* frozen = m_graph.freezeStrong(expr);
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(NewFunction, OpInfo(frozen), get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_new_func_exp);
+        }
+
+        case op_typeof: {
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(TypeOf, get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_typeof);
+        }
+
+        case op_to_number: {
+            Node* node = get(VirtualRegister(currentInstruction[2].u.operand));
+            addToGraph(Phantom, Edge(node, NumberUse));
+            set(VirtualRegister(currentInstruction[1].u.operand), node);
+            NEXT_OPCODE(op_to_number);
+        }
+
+        case op_to_string: {
+            Node* value = get(VirtualRegister(currentInstruction[2].u.operand));
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(ToString, value));
+            NEXT_OPCODE(op_to_string);
+        }
+
+        case op_in: {
+            set(VirtualRegister(currentInstruction[1].u.operand),
+                addToGraph(In, get(VirtualRegister(currentInstruction[2].u.operand)), get(VirtualRegister(currentInstruction[3].u.operand))));
+            NEXT_OPCODE(op_in);
+        }
+
+        case op_get_enumerable_length: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(GetEnumerableLength, 
+                get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_get_enumerable_length);
+        }
+
+        case op_has_generic_property: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(HasGenericProperty, 
+                get(VirtualRegister(currentInstruction[2].u.operand)),
+                get(VirtualRegister(currentInstruction[3].u.operand))));
+            NEXT_OPCODE(op_has_generic_property);
+        }
+
+        case op_has_structure_property: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(HasStructureProperty, 
+                get(VirtualRegister(currentInstruction[2].u.operand)),
+                get(VirtualRegister(currentInstruction[3].u.operand)),
+                get(VirtualRegister(currentInstruction[4].u.operand))));
+            NEXT_OPCODE(op_has_structure_property);
+        }
+
+        case op_has_indexed_property: {
+            Node* base = get(VirtualRegister(currentInstruction[2].u.operand));
+            ArrayMode arrayMode = getArrayMode(currentInstruction[4].u.arrayProfile, Array::Read);
+            Node* property = get(VirtualRegister(currentInstruction[3].u.operand));
+            Node* hasIterableProperty = addToGraph(HasIndexedProperty, OpInfo(arrayMode.asWord()), base, property);
+            set(VirtualRegister(currentInstruction[1].u.operand), hasIterableProperty);
+            NEXT_OPCODE(op_has_indexed_property);
+        }
+
+        case op_get_direct_pname: {
+            SpeculatedType prediction = getPredictionWithoutOSRExit();
+            
+            Node* base = get(VirtualRegister(currentInstruction[2].u.operand));
+            Node* property = get(VirtualRegister(currentInstruction[3].u.operand));
+            Node* index = get(VirtualRegister(currentInstruction[4].u.operand));
+            Node* enumerator = get(VirtualRegister(currentInstruction[5].u.operand));
+
+            addVarArgChild(base);
+            addVarArgChild(property);
+            addVarArgChild(index);
+            addVarArgChild(enumerator);
+            set(VirtualRegister(currentInstruction[1].u.operand), 
+                addToGraph(Node::VarArg, GetDirectPname, OpInfo(0), OpInfo(prediction)));
+
+            NEXT_OPCODE(op_get_direct_pname);
+        }
+
+        case op_get_property_enumerator: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(GetPropertyEnumerator, 
+                get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_get_property_enumerator);
+        }
+
+        case op_enumerator_structure_pname: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(GetEnumeratorStructurePname,
+                get(VirtualRegister(currentInstruction[2].u.operand)),
+                get(VirtualRegister(currentInstruction[3].u.operand))));
+            NEXT_OPCODE(op_enumerator_structure_pname);
+        }
+
+        case op_enumerator_generic_pname: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(GetEnumeratorGenericPname,
+                get(VirtualRegister(currentInstruction[2].u.operand)),
+                get(VirtualRegister(currentInstruction[3].u.operand))));
+            NEXT_OPCODE(op_enumerator_generic_pname);
+        }
+            
+        case op_to_index_string: {
+            set(VirtualRegister(currentInstruction[1].u.operand), addToGraph(ToIndexString, 
+                get(VirtualRegister(currentInstruction[2].u.operand))));
+            NEXT_OPCODE(op_to_index_string);
+        }
+
+        default:
+            // Parse failed! This should not happen because the capabilities checker
+            // should have caught it.
+            RELEASE_ASSERT_NOT_REACHED();
+            return false;
+        }
+    }
+}
+
+void ByteCodeParser::linkBlock(BasicBlock* block, Vector<BasicBlock*>& possibleTargets)
+{
+    ASSERT(!block->isLinked);
+    ASSERT(!block->isEmpty());
+    Node* node = block->terminal();
+    ASSERT(node->isTerminal());
+    
+    switch (node->op()) {
+    case Jump:
+        node->targetBlock() = blockForBytecodeOffset(possibleTargets, node->targetBytecodeOffsetDuringParsing());
+        break;
+        
+    case Branch: {
+        BranchData* data = node->branchData();
+        data->taken.block = blockForBytecodeOffset(possibleTargets, data->takenBytecodeIndex());
+        data->notTaken.block = blockForBytecodeOffset(possibleTargets, data->notTakenBytecodeIndex());
+        break;
+    }
+        
+    case Switch: {
+        SwitchData* data = node->switchData();
+        for (unsigned i = node->switchData()->cases.size(); i--;)
+            data->cases[i].target.block = blockForBytecodeOffset(possibleTargets, data->cases[i].target.bytecodeIndex());
+        data->fallThrough.block = blockForBytecodeOffset(possibleTargets, data->fallThrough.bytecodeIndex());
+        break;
+    }
+        
+    default:
+        break;
+    }
+    
+    if (verbose)
+        dataLog("Marking ", RawPointer(block), " as linked (actually did linking)\n");
+    block->didLink();
+}
+
+void ByteCodeParser::linkBlocks(Vector<UnlinkedBlock>& unlinkedBlocks, Vector<BasicBlock*>& possibleTargets)
+{
+    for (size_t i = 0; i < unlinkedBlocks.size(); ++i) {
+        if (verbose)
+            dataLog("Attempting to link ", RawPointer(unlinkedBlocks[i].m_block), "\n");
+        if (unlinkedBlocks[i].m_needsNormalLinking) {
+            if (verbose)
+                dataLog("    Does need normal linking.\n");
+            linkBlock(unlinkedBlocks[i].m_block, possibleTargets);
+            unlinkedBlocks[i].m_needsNormalLinking = false;
+        }
+    }
+}
+
+ByteCodeParser::InlineStackEntry::InlineStackEntry(
+    ByteCodeParser* byteCodeParser,
+    CodeBlock* codeBlock,
+    CodeBlock* profiledBlock,
+    BasicBlock* callsiteBlockHead,
+    JSFunction* callee, // Null if this is a closure call.
+    VirtualRegister returnValueVR,
+    VirtualRegister inlineCallFrameStart,
+    int argumentCountIncludingThis,
+    InlineCallFrame::Kind kind)
+    : m_byteCodeParser(byteCodeParser)
+    , m_codeBlock(codeBlock)
+    , m_profiledBlock(profiledBlock)
+    , m_callsiteBlockHead(callsiteBlockHead)
+    , m_returnValue(returnValueVR)
+    , m_didReturn(false)
+    , m_didEarlyReturn(false)
+    , m_caller(byteCodeParser->m_inlineStackTop)
+{
+    {
+        ConcurrentJITLocker locker(m_profiledBlock->m_lock);
+        m_lazyOperands.initialize(locker, m_profiledBlock->lazyOperandValueProfiles());
+        m_exitProfile.initialize(locker, profiledBlock->exitProfile());
+        
+        // We do this while holding the lock because we want to encourage StructureStubInfo's
+        // to be potentially added to operations and because the profiled block could be in the
+        // middle of LLInt->JIT tier-up in which case we would be adding the info's right now.
+        if (m_profiledBlock->hasBaselineJITProfiling()) {
+            m_profiledBlock->getStubInfoMap(locker, m_stubInfos);
+            m_profiledBlock->getCallLinkInfoMap(locker, m_callLinkInfos);
+            m_profiledBlock->getByValInfoMap(locker, m_byValInfos);
+        }
+    }
+    
+    m_argumentPositions.resize(argumentCountIncludingThis);
+    for (int i = 0; i < argumentCountIncludingThis; ++i) {
+        byteCodeParser->m_graph.m_argumentPositions.append(ArgumentPosition());
+        ArgumentPosition* argumentPosition = &byteCodeParser->m_graph.m_argumentPositions.last();
+        m_argumentPositions[i] = argumentPosition;
+    }
+    
+    if (m_caller) {
+        // Inline case.
+        ASSERT(codeBlock != byteCodeParser->m_codeBlock);
+        ASSERT(inlineCallFrameStart.isValid());
+        ASSERT(callsiteBlockHead);
+        
+        m_inlineCallFrame = byteCodeParser->m_graph.m_plan.inlineCallFrames->add();
+        byteCodeParser->m_graph.freeze(codeBlock->ownerExecutable());
+        // The owner is the machine code block, and we already have a barrier on that when the
+        // plan finishes.
+        m_inlineCallFrame->executable.setWithoutWriteBarrier(codeBlock->ownerExecutable());
+        m_inlineCallFrame->setStackOffset(inlineCallFrameStart.offset() - JSStack::CallFrameHeaderSize);
+        if (callee) {
+            m_inlineCallFrame->calleeRecovery = ValueRecovery::constant(callee);
+            m_inlineCallFrame->isClosureCall = false;
+        } else
+            m_inlineCallFrame->isClosureCall = true;
+        m_inlineCallFrame->caller = byteCodeParser->currentCodeOrigin();
+        m_inlineCallFrame->arguments.resizeToFit(argumentCountIncludingThis); // Set the number of arguments including this, but don't configure the value recoveries, yet.
+        m_inlineCallFrame->kind = kind;
+        
+        m_identifierRemap.resize(codeBlock->numberOfIdentifiers());
+        m_constantBufferRemap.resize(codeBlock->numberOfConstantBuffers());
+        m_switchRemap.resize(codeBlock->numberOfSwitchJumpTables());
+
+        for (size_t i = 0; i < codeBlock->numberOfIdentifiers(); ++i) {
+            UniquedStringImpl* rep = codeBlock->identifier(i).impl();
+            unsigned index = byteCodeParser->m_graph.identifiers().ensure(rep);
+            m_identifierRemap[i] = index;
+        }
+        for (unsigned i = 0; i < codeBlock->numberOfConstantBuffers(); ++i) {
+            // If we inline the same code block multiple times, we don't want to needlessly
+            // duplicate its constant buffers.
+            HashMap<ConstantBufferKey, unsigned>::iterator iter =
+                byteCodeParser->m_constantBufferCache.find(ConstantBufferKey(codeBlock, i));
+            if (iter != byteCodeParser->m_constantBufferCache.end()) {
+                m_constantBufferRemap[i] = iter->value;
+                continue;
+            }
+            Vector<JSValue>& buffer = codeBlock->constantBufferAsVector(i);
+            unsigned newIndex = byteCodeParser->m_codeBlock->addConstantBuffer(buffer);
+            m_constantBufferRemap[i] = newIndex;
+            byteCodeParser->m_constantBufferCache.add(ConstantBufferKey(codeBlock, i), newIndex);
+        }
+        for (unsigned i = 0; i < codeBlock->numberOfSwitchJumpTables(); ++i) {
+            m_switchRemap[i] = byteCodeParser->m_codeBlock->numberOfSwitchJumpTables();
+            byteCodeParser->m_codeBlock->addSwitchJumpTable() = codeBlock->switchJumpTable(i);
+        }
+        m_callsiteBlockHeadNeedsLinking = true;
+    } else {
+        // Machine code block case.
+        ASSERT(codeBlock == byteCodeParser->m_codeBlock);
+        ASSERT(!callee);
+        ASSERT(!returnValueVR.isValid());
+        ASSERT(!inlineCallFrameStart.isValid());
+        ASSERT(!callsiteBlockHead);
+
+        m_inlineCallFrame = 0;
+
+        m_identifierRemap.resize(codeBlock->numberOfIdentifiers());
+        m_constantBufferRemap.resize(codeBlock->numberOfConstantBuffers());
+        m_switchRemap.resize(codeBlock->numberOfSwitchJumpTables());
+        for (size_t i = 0; i < codeBlock->numberOfIdentifiers(); ++i)
+            m_identifierRemap[i] = i;
+        for (size_t i = 0; i < codeBlock->numberOfConstantBuffers(); ++i)
+            m_constantBufferRemap[i] = i;
+        for (size_t i = 0; i < codeBlock->numberOfSwitchJumpTables(); ++i)
+            m_switchRemap[i] = i;
+        m_callsiteBlockHeadNeedsLinking = false;
+    }
+    
+    byteCodeParser->m_inlineStackTop = this;
+}
+
+void ByteCodeParser::parseCodeBlock()
+{
+    clearCaches();
+    
+    CodeBlock* codeBlock = m_inlineStackTop->m_codeBlock;
+    
+    if (m_graph.compilation()) {
+        m_graph.compilation()->addProfiledBytecodes(
+            *m_vm->m_perBytecodeProfiler, m_inlineStackTop->m_profiledBlock);
+    }
+    
+    if (UNLIKELY(Options::dumpSourceAtDFGTime())) {
+        Vector<DeferredSourceDump>& deferredSourceDump = m_graph.m_plan.callback->ensureDeferredSourceDump();
+        if (inlineCallFrame()) {
+            DeferredSourceDump dump(codeBlock->baselineVersion(), m_codeBlock, JITCode::DFGJIT, inlineCallFrame()->caller);
+            deferredSourceDump.append(dump);
+        } else
+            deferredSourceDump.append(DeferredSourceDump(codeBlock->baselineVersion()));
+    }
+
+    if (Options::dumpBytecodeAtDFGTime()) {
+        dataLog("Parsing ", *codeBlock);
+        if (inlineCallFrame()) {
+            dataLog(
+                " for inlining at ", CodeBlockWithJITType(m_codeBlock, JITCode::DFGJIT),
+                " ", inlineCallFrame()->caller);
+        }
+        dataLog(
+            ": needsActivation = ", codeBlock->needsActivation(),
+            ", isStrictMode = ", codeBlock->ownerExecutable()->isStrictMode(), "\n");
+        codeBlock->baselineVersion()->dumpBytecode();
+    }
+    
+    Vector<unsigned, 32> jumpTargets;
+    computePreciseJumpTargets(codeBlock, jumpTargets);
+    if (Options::dumpBytecodeAtDFGTime()) {
+        dataLog("Jump targets: ");
+        CommaPrinter comma;
+        for (unsigned i = 0; i < jumpTargets.size(); ++i)
+            dataLog(comma, jumpTargets[i]);
+        dataLog("\n");
+    }
+    
+    for (unsigned jumpTargetIndex = 0; jumpTargetIndex <= jumpTargets.size(); ++jumpTargetIndex) {
+        // The maximum bytecode offset to go into the current basicblock is either the next jump target, or the end of the instructions.
+        unsigned limit = jumpTargetIndex < jumpTargets.size() ? jumpTargets[jumpTargetIndex] : codeBlock->instructions().size();
+        ASSERT(m_currentIndex < limit);
+
+        // Loop until we reach the current limit (i.e. next jump target).
+        do {
+            if (!m_currentBlock) {
+                // Check if we can use the last block.
+                if (m_graph.numBlocks() && m_graph.lastBlock()->isEmpty()) {
+                    // This must be a block belonging to us.
+                    ASSERT(m_inlineStackTop->m_unlinkedBlocks.last().m_block == m_graph.lastBlock());
+                    // Either the block is linkable or it isn't. If it's linkable then it's the last
+                    // block in the blockLinkingTargets list. If it's not then the last block will
+                    // have a lower bytecode index that the one we're about to give to this block.
+                    if (m_inlineStackTop->m_blockLinkingTargets.isEmpty() || m_inlineStackTop->m_blockLinkingTargets.last()->bytecodeBegin != m_currentIndex) {
+                        // Make the block linkable.
+                        ASSERT(m_inlineStackTop->m_blockLinkingTargets.isEmpty() || m_inlineStackTop->m_blockLinkingTargets.last()->bytecodeBegin < m_currentIndex);
+                        m_inlineStackTop->m_blockLinkingTargets.append(m_graph.lastBlock());
+                    }
+                    // Change its bytecode begin and continue.
+                    m_currentBlock = m_graph.lastBlock();
+                    m_currentBlock->bytecodeBegin = m_currentIndex;
+                } else {
+                    RefPtr<BasicBlock> block = adoptRef(new BasicBlock(m_currentIndex, m_numArguments, m_numLocals, PNaN));
+                    m_currentBlock = block.get();
+                    // This assertion checks two things:
+                    // 1) If the bytecodeBegin is greater than currentIndex, then something has gone
+                    //    horribly wrong. So, we're probably generating incorrect code.
+                    // 2) If the bytecodeBegin is equal to the currentIndex, then we failed to do
+                    //    a peephole coalescing of this block in the if statement above. So, we're
+                    //    generating suboptimal code and leaving more work for the CFG simplifier.
+                    if (!m_inlineStackTop->m_unlinkedBlocks.isEmpty()) {
+                        unsigned lastBegin =
+                            m_inlineStackTop->m_unlinkedBlocks.last().m_block->bytecodeBegin;
+                        ASSERT_UNUSED(
+                            lastBegin, lastBegin == UINT_MAX || lastBegin < m_currentIndex);
+                    }
+                    m_inlineStackTop->m_unlinkedBlocks.append(UnlinkedBlock(block.get()));
+                    m_inlineStackTop->m_blockLinkingTargets.append(block.get());
+                    // The first block is definitely an OSR target.
+                    if (!m_graph.numBlocks())
+                        block->isOSRTarget = true;
+                    m_graph.appendBlock(block);
+                    prepareToParseBlock();
+                }
+            }
+
+            bool shouldContinueParsing = parseBlock(limit);
+
+            // We should not have gone beyond the limit.
+            ASSERT(m_currentIndex <= limit);
+            
+            // We should have planted a terminal, or we just gave up because
+            // we realized that the jump target information is imprecise, or we
+            // are at the end of an inline function, or we realized that we
+            // should stop parsing because there was a return in the first
+            // basic block.
+            ASSERT(m_currentBlock->isEmpty() || m_currentBlock->terminal() || (m_currentIndex == codeBlock->instructions().size() && inlineCallFrame()) || !shouldContinueParsing);
+
+            if (!shouldContinueParsing) {
+                if (Options::verboseDFGByteCodeParsing())
+                    dataLog("Done parsing ", *codeBlock, "\n");
+                return;
+            }
+            
+            m_currentBlock = 0;
+        } while (m_currentIndex < limit);
+    }
+
+    // Should have reached the end of the instructions.
+    ASSERT(m_currentIndex == codeBlock->instructions().size());
+    
+    if (Options::verboseDFGByteCodeParsing())
+        dataLog("Done parsing ", *codeBlock, " (fell off end)\n");
+}
+
+bool ByteCodeParser::parse()
+{
+    // Set during construction.
+    ASSERT(!m_currentIndex);
+    
+    if (Options::verboseDFGByteCodeParsing())
+        dataLog("Parsing ", *m_codeBlock, "\n");
+    
+    m_dfgCodeBlock = m_graph.m_plan.profiledDFGCodeBlock.get();
+    if (isFTL(m_graph.m_plan.mode) && m_dfgCodeBlock
+        && Options::enablePolyvariantDevirtualization()) {
+        if (Options::enablePolyvariantCallInlining())
+            CallLinkStatus::computeDFGStatuses(m_dfgCodeBlock, m_callContextMap);
+        if (Options::enablePolyvariantByIdInlining())
+            m_dfgCodeBlock->getStubInfoMap(m_dfgStubInfos);
+    }
+    
+    InlineStackEntry inlineStackEntry(
+        this, m_codeBlock, m_profiledBlock, 0, 0, VirtualRegister(), VirtualRegister(),
+        m_codeBlock->numParameters(), InlineCallFrame::Call);
+    
+    parseCodeBlock();
+
+    linkBlocks(inlineStackEntry.m_unlinkedBlocks, inlineStackEntry.m_blockLinkingTargets);
+    m_graph.determineReachability();
+    m_graph.killUnreachableBlocks();
+    
+    for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
+        BasicBlock* block = m_graph.block(blockIndex);
+        if (!block)
+            continue;
+        ASSERT(block->variablesAtHead.numberOfLocals() == m_graph.block(0)->variablesAtHead.numberOfLocals());
+        ASSERT(block->variablesAtHead.numberOfArguments() == m_graph.block(0)->variablesAtHead.numberOfArguments());
+        ASSERT(block->variablesAtTail.numberOfLocals() == m_graph.block(0)->variablesAtHead.numberOfLocals());
+        ASSERT(block->variablesAtTail.numberOfArguments() == m_graph.block(0)->variablesAtHead.numberOfArguments());
+    }
+    
+    m_graph.m_localVars = m_numLocals;
+    m_graph.m_parameterSlots = m_parameterSlots;
+
+    return true;
+}
+
+bool parse(Graph& graph)
+{
+    SamplingRegion samplingRegion("DFG Parsing");
+    return ByteCodeParser(graph).parse();
+}
+
+} } // namespace JSC::DFG
+
+#endif