webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 3976 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
new file mode 100644
index 000000000..394974eaa
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -0,0 +1,3976 @@
+/*
+ * Copyright (C) 2008-2010, 2012-2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "CodeBlock.h"
+
+#include "BasicBlockLocation.h"
+#include "BytecodeGenerator.h"
+#include "BytecodeUseDef.h"
+#include "CallLinkStatus.h"
+#include "DFGCapabilities.h"
+#include "DFGCommon.h"
+#include "DFGDriver.h"
+#include "DFGJITCode.h"
+#include "DFGWorklist.h"
+#include "Debugger.h"
+#include "FunctionExecutableDump.h"
+#include "Interpreter.h"
+#include "JIT.h"
+#include "JITStubs.h"
+#include "JSCJSValue.h"
+#include "JSFunction.h"
+#include "JSLexicalEnvironment.h"
+#include "LLIntEntrypoint.h"
+#include "LowLevelInterpreter.h"
+#include "JSCInlines.h"
+#include "PolymorphicGetByIdList.h"
+#include "PolymorphicPutByIdList.h"
+#include "ProfilerDatabase.h"
+#include "ReduceWhitespace.h"
+#include "Repatch.h"
+#include "RepatchBuffer.h"
+#include "SlotVisitorInlines.h"
+#include "StackVisitor.h"
+#include "TypeLocationCache.h"
+#include "TypeProfiler.h"
+#include "UnlinkedInstructionStream.h"
+#include <wtf/BagToHashMap.h>
+#include <wtf/CommaPrinter.h>
+#include <wtf/StringExtras.h>
+#include <wtf/StringPrintStream.h>
+#include <wtf/text/UniquedStringImpl.h>
+
+#if ENABLE(DFG_JIT)
+#include "DFGOperations.h"
+#endif
+
+#if ENABLE(FTL_JIT)
+#include "FTLJITCode.h"
+#endif
+
+namespace JSC {
+
+CString CodeBlock::inferredName() const
+{
+    switch (codeType()) {
+    case GlobalCode:
+        return "<global>";
+    case EvalCode:
+        return "<eval>";
+    case FunctionCode:
+        return jsCast<FunctionExecutable*>(ownerExecutable())->inferredName().utf8();
+    default:
+        CRASH();
+        return CString("", 0);
+    }
+}
+
+bool CodeBlock::hasHash() const
+{
+    return !!m_hash;
+}
+
+bool CodeBlock::isSafeToComputeHash() const
+{
+    return !isCompilationThread();
+}
+
+CodeBlockHash CodeBlock::hash() const
+{
+    if (!m_hash) {
+        RELEASE_ASSERT(isSafeToComputeHash());
+        m_hash = CodeBlockHash(ownerExecutable()->source(), specializationKind());
+    }
+    return m_hash;
+}
+
+CString CodeBlock::sourceCodeForTools() const
+{
+    if (codeType() != FunctionCode)
+        return ownerExecutable()->source().toUTF8();
+    
+    SourceProvider* provider = source();
+    FunctionExecutable* executable = jsCast<FunctionExecutable*>(ownerExecutable());
+    UnlinkedFunctionExecutable* unlinked = executable->unlinkedExecutable();
+    unsigned unlinkedStartOffset = unlinked->startOffset();
+    unsigned linkedStartOffset = executable->source().startOffset();
+    int delta = linkedStartOffset - unlinkedStartOffset;
+    unsigned rangeStart = delta + unlinked->unlinkedFunctionNameStart();
+    unsigned rangeEnd = delta + unlinked->startOffset() + unlinked->sourceLength();
+    return toCString(
+        "function ",
+        provider->source().impl()->utf8ForRange(rangeStart, rangeEnd - rangeStart));
+}
+
+CString CodeBlock::sourceCodeOnOneLine() const
+{
+    return reduceWhitespace(sourceCodeForTools());
+}
+
+CString CodeBlock::hashAsStringIfPossible() const
+{
+    if (hasHash() || isSafeToComputeHash())
+        return toCString(hash());
+    return "<no-hash>";
+}
+
+void CodeBlock::dumpAssumingJITType(PrintStream& out, JITCode::JITType jitType) const
+{
+    out.print(inferredName(), "#", hashAsStringIfPossible());
+    out.print(":[", RawPointer(this), "->");
+    if (!!m_alternative)
+        out.print(RawPointer(m_alternative.get()), "->");
+    out.print(RawPointer(ownerExecutable()), ", ", jitType, codeType());
+
+    if (codeType() == FunctionCode)
+        out.print(specializationKind());
+    out.print(", ", instructionCount());
+    if (this->jitType() == JITCode::BaselineJIT && m_shouldAlwaysBeInlined)
+        out.print(" (ShouldAlwaysBeInlined)");
+    if (ownerExecutable()->neverInline())
+        out.print(" (NeverInline)");
+    if (ownerExecutable()->didTryToEnterInLoop())
+        out.print(" (DidTryToEnterInLoop)");
+    if (ownerExecutable()->isStrictMode())
+        out.print(" (StrictMode)");
+    if (this->jitType() == JITCode::BaselineJIT && m_didFailFTLCompilation)
+        out.print(" (FTLFail)");
+    if (this->jitType() == JITCode::BaselineJIT && m_hasBeenCompiledWithFTL)
+        out.print(" (HadFTLReplacement)");
+    out.print("]");
+}
+
+void CodeBlock::dump(PrintStream& out) const
+{
+    dumpAssumingJITType(out, jitType());
+}
+
+static CString idName(int id0, const Identifier& ident)
+{
+    return toCString(ident.impl(), "(@id", id0, ")");
+}
+
+CString CodeBlock::registerName(int r) const
+{
+    if (isConstantRegisterIndex(r))
+        return constantName(r);
+
+    return toCString(VirtualRegister(r));
+}
+
+CString CodeBlock::constantName(int index) const
+{
+    JSValue value = getConstant(index);
+    return toCString(value, "(", VirtualRegister(index), ")");
+}
+
+static CString regexpToSourceString(RegExp* regExp)
+{
+    char postfix[5] = { '/', 0, 0, 0, 0 };
+    int index = 1;
+    if (regExp->global())
+        postfix[index++] = 'g';
+    if (regExp->ignoreCase())
+        postfix[index++] = 'i';
+    if (regExp->multiline())
+        postfix[index] = 'm';
+
+    return toCString("/", regExp->pattern().impl(), postfix);
+}
+
+static CString regexpName(int re, RegExp* regexp)
+{
+    return toCString(regexpToSourceString(regexp), "(@re", re, ")");
+}
+
+NEVER_INLINE static const char* debugHookName(int debugHookID)
+{
+    switch (static_cast<DebugHookID>(debugHookID)) {
+        case DidEnterCallFrame:
+            return "didEnterCallFrame";
+        case WillLeaveCallFrame:
+            return "willLeaveCallFrame";
+        case WillExecuteStatement:
+            return "willExecuteStatement";
+        case WillExecuteProgram:
+            return "willExecuteProgram";
+        case DidExecuteProgram:
+            return "didExecuteProgram";
+        case DidReachBreakpoint:
+            return "didReachBreakpoint";
+    }
+
+    RELEASE_ASSERT_NOT_REACHED();
+    return "";
+}
+
+void CodeBlock::printUnaryOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
+{
+    int r0 = (++it)->u.operand;
+    int r1 = (++it)->u.operand;
+
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+}
+
+void CodeBlock::printBinaryOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
+{
+    int r0 = (++it)->u.operand;
+    int r1 = (++it)->u.operand;
+    int r2 = (++it)->u.operand;
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+}
+
+void CodeBlock::printConditionalJump(PrintStream& out, ExecState* exec, const Instruction*, const Instruction*& it, int location, const char* op)
+{
+    int r0 = (++it)->u.operand;
+    int offset = (++it)->u.operand;
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %d(->%d)", registerName(r0).data(), offset, location + offset);
+}
+
+void CodeBlock::printGetByIdOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it)
+{
+    const char* op;
+    switch (exec->interpreter()->getOpcodeID(it->u.opcode)) {
+    case op_get_by_id:
+        op = "get_by_id";
+        break;
+    case op_get_by_id_out_of_line:
+        op = "get_by_id_out_of_line";
+        break;
+    case op_get_array_length:
+        op = "array_length";
+        break;
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+#if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
+        op = 0;
+#endif
+    }
+    int r0 = (++it)->u.operand;
+    int r1 = (++it)->u.operand;
+    int id0 = (++it)->u.operand;
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), idName(id0, identifier(id0)).data());
+    it += 4; // Increment up to the value profiler.
+}
+
+static void dumpStructure(PrintStream& out, const char* name, Structure* structure, const Identifier& ident)
+{
+    if (!structure)
+        return;
+    
+    out.printf("%s = %p", name, structure);
+    
+    PropertyOffset offset = structure->getConcurrently(ident.impl());
+    if (offset != invalidOffset)
+        out.printf(" (offset = %d)", offset);
+}
+
+static void dumpChain(PrintStream& out, StructureChain* chain, const Identifier& ident)
+{
+    out.printf("chain = %p: [", chain);
+    bool first = true;
+    for (WriteBarrier<Structure>* currentStructure = chain->head();
+         *currentStructure;
+         ++currentStructure) {
+        if (first)
+            first = false;
+        else
+            out.printf(", ");
+        dumpStructure(out, "struct", currentStructure->get(), ident);
+    }
+    out.printf("]");
+}
+
+void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
+{
+    Instruction* instruction = instructions().begin() + location;
+
+    const Identifier& ident = identifier(instruction[3].u.operand);
+    
+    UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
+    
+    if (exec->interpreter()->getOpcodeID(instruction[0].u.opcode) == op_get_array_length)
+        out.printf(" llint(array_length)");
+    else if (Structure* structure = instruction[4].u.structure.get()) {
+        out.printf(" llint(");
+        dumpStructure(out, "struct", structure, ident);
+        out.printf(")");
+    }
+
+#if ENABLE(JIT)
+    if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
+        StructureStubInfo& stubInfo = *stubPtr;
+        if (stubInfo.resetByGC)
+            out.print(" (Reset By GC)");
+        
+        if (stubInfo.seen) {
+            out.printf(" jit(");
+            
+            Structure* baseStructure = 0;
+            Structure* prototypeStructure = 0;
+            PolymorphicGetByIdList* list = 0;
+            
+            switch (stubInfo.accessType) {
+            case access_get_by_id_self:
+                out.printf("self");
+                baseStructure = stubInfo.u.getByIdSelf.baseObjectStructure.get();
+                break;
+            case access_get_by_id_list:
+                out.printf("list");
+                list = stubInfo.u.getByIdList.list;
+                break;
+            case access_unset:
+                out.printf("unset");
+                break;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            
+            if (baseStructure) {
+                out.printf(", ");
+                dumpStructure(out, "struct", baseStructure, ident);
+            }
+            
+            if (prototypeStructure) {
+                out.printf(", ");
+                dumpStructure(out, "prototypeStruct", baseStructure, ident);
+            }
+            
+            if (list) {
+                out.printf(", list = %p: [", list);
+                for (unsigned i = 0; i < list->size(); ++i) {
+                    if (i)
+                        out.printf(", ");
+                    out.printf("(");
+                    dumpStructure(out, "base", list->at(i).structure(), ident);
+                    if (!list->at(i).conditionSet().isEmpty()) {
+                        out.printf(", ");
+                        out.print(list->at(i).conditionSet());
+                    }
+                    out.printf(")");
+                }
+                out.printf("]");
+            }
+            out.printf(")");
+        }
+    }
+#else
+    UNUSED_PARAM(map);
+#endif
+}
+
+void CodeBlock::printPutByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
+{
+    Instruction* instruction = instructions().begin() + location;
+
+    const Identifier& ident = identifier(instruction[2].u.operand);
+    
+    UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
+    
+    if (Structure* structure = instruction[4].u.structure.get()) {
+        switch (exec->interpreter()->getOpcodeID(instruction[0].u.opcode)) {
+        case op_put_by_id:
+        case op_put_by_id_out_of_line:
+            out.print(" llint(");
+            dumpStructure(out, "struct", structure, ident);
+            out.print(")");
+            break;
+            
+        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:
+            out.print(" llint(");
+            dumpStructure(out, "prev", structure, ident);
+            out.print(", ");
+            dumpStructure(out, "next", instruction[6].u.structure.get(), ident);
+            if (StructureChain* chain = instruction[7].u.structureChain.get()) {
+                out.print(", ");
+                dumpChain(out, chain, ident);
+            }
+            out.print(")");
+            break;
+            
+        default:
+            out.print(" llint(unknown)");
+            break;
+        }
+    }
+
+#if ENABLE(JIT)
+    if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
+        StructureStubInfo& stubInfo = *stubPtr;
+        if (stubInfo.resetByGC)
+            out.print(" (Reset By GC)");
+        
+        if (stubInfo.seen) {
+            out.printf(" jit(");
+            
+            switch (stubInfo.accessType) {
+            case access_put_by_id_replace:
+                out.print("replace, ");
+                dumpStructure(out, "struct", stubInfo.u.putByIdReplace.baseObjectStructure.get(), ident);
+                break;
+            case access_put_by_id_transition_normal:
+            case access_put_by_id_transition_direct:
+                out.print("transition, ");
+                dumpStructure(out, "prev", stubInfo.u.putByIdTransition.previousStructure.get(), ident);
+                out.print(", ");
+                dumpStructure(out, "next", stubInfo.u.putByIdTransition.structure.get(), ident);
+                if (stubInfo.u.putByIdTransition.rawConditionSet)
+                    out.print(", ", ObjectPropertyConditionSet::fromRawPointer(stubInfo.u.putByIdTransition.rawConditionSet));
+                break;
+            case access_put_by_id_list: {
+                out.printf("list = [");
+                PolymorphicPutByIdList* list = stubInfo.u.putByIdList.list;
+                CommaPrinter comma;
+                for (unsigned i = 0; i < list->size(); ++i) {
+                    out.print(comma, "(");
+                    const PutByIdAccess& access = list->at(i);
+                    
+                    if (access.isReplace()) {
+                        out.print("replace, ");
+                        dumpStructure(out, "struct", access.oldStructure(), ident);
+                    } else if (access.isSetter()) {
+                        out.print("setter, ");
+                        dumpStructure(out, "struct", access.oldStructure(), ident);
+                    } else if (access.isCustom()) {
+                        out.print("custom, ");
+                        dumpStructure(out, "struct", access.oldStructure(), ident);
+                    } else if (access.isTransition()) {
+                        out.print("transition, ");
+                        dumpStructure(out, "prev", access.oldStructure(), ident);
+                        out.print(", ");
+                        dumpStructure(out, "next", access.newStructure(), ident);
+                        if (!access.conditionSet().isEmpty())
+                            out.print(", ", access.conditionSet());
+                    } else
+                        out.print("unknown");
+                    
+                    out.print(")");
+                }
+                out.print("]");
+                break;
+            }
+            case access_unset:
+                out.printf("unset");
+                break;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            out.printf(")");
+        }
+    }
+#else
+    UNUSED_PARAM(map);
+#endif
+}
+
+void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, CacheDumpMode cacheDumpMode, bool& hasPrintedProfiling, const CallLinkInfoMap& map)
+{
+    int dst = (++it)->u.operand;
+    int func = (++it)->u.operand;
+    int argCount = (++it)->u.operand;
+    int registerOffset = (++it)->u.operand;
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %s, %d, %d", registerName(dst).data(), registerName(func).data(), argCount, registerOffset);
+    if (cacheDumpMode == DumpCaches) {
+        LLIntCallLinkInfo* callLinkInfo = it[1].u.callLinkInfo;
+        if (callLinkInfo->lastSeenCallee) {
+            out.printf(
+                " llint(%p, exec %p)",
+                callLinkInfo->lastSeenCallee.get(),
+                callLinkInfo->lastSeenCallee->executable());
+        }
+#if ENABLE(JIT)
+        if (CallLinkInfo* info = map.get(CodeOrigin(location))) {
+            JSFunction* target = info->lastSeenCallee();
+            if (target)
+                out.printf(" jit(%p, exec %p)", target, target->executable());
+        }
+        
+        if (jitType() != JITCode::FTLJIT)
+            out.print(" status(", CallLinkStatus::computeFor(this, location, map), ")");
+#else
+        UNUSED_PARAM(map);
+#endif
+    }
+    ++it;
+    ++it;
+    dumpArrayProfiling(out, it, hasPrintedProfiling);
+    dumpValueProfiling(out, it, hasPrintedProfiling);
+}
+
+void CodeBlock::printPutByIdOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
+{
+    int r0 = (++it)->u.operand;
+    int id0 = (++it)->u.operand;
+    int r1 = (++it)->u.operand;
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
+    it += 5;
+}
+
+void CodeBlock::dumpSource()
+{
+    dumpSource(WTF::dataFile());
+}
+
+void CodeBlock::dumpSource(PrintStream& out)
+{
+    ScriptExecutable* executable = ownerExecutable();
+    if (executable->isFunctionExecutable()) {
+        FunctionExecutable* functionExecutable = reinterpret_cast<FunctionExecutable*>(executable);
+        String source = functionExecutable->source().provider()->getRange(
+            functionExecutable->parametersStartOffset(),
+            functionExecutable->typeProfilingEndOffset() + 1); // Type profiling end offset is the character before the '}'.
+        
+        out.print("function ", inferredName(), source);
+        return;
+    }
+    out.print(executable->source().toString());
+}
+
+void CodeBlock::dumpBytecode()
+{
+    dumpBytecode(WTF::dataFile());
+}
+
+void CodeBlock::dumpBytecode(PrintStream& out)
+{
+    // We only use the ExecState* for things that don't actually lead to JS execution,
+    // like converting a JSString to a String. Hence the globalExec is appropriate.
+    ExecState* exec = m_globalObject->globalExec();
+    
+    size_t instructionCount = 0;
+
+    for (size_t i = 0; i < instructions().size(); i += opcodeLengths[exec->interpreter()->getOpcodeID(instructions()[i].u.opcode)])
+        ++instructionCount;
+
+    out.print(*this);
+    out.printf(
+        ": %lu m_instructions; %lu bytes; %d parameter(s); %d callee register(s); %d variable(s)",
+        static_cast<unsigned long>(instructions().size()),
+        static_cast<unsigned long>(instructions().size() * sizeof(Instruction)),
+        m_numParameters, m_numCalleeRegisters, m_numVars);
+    if (needsActivation() && codeType() == FunctionCode)
+        out.printf("; lexical environment in r%d", activationRegister().offset());
+    out.printf("\n");
+    
+    StubInfoMap stubInfos;
+    CallLinkInfoMap callLinkInfos;
+    getStubInfoMap(stubInfos);
+    getCallLinkInfoMap(callLinkInfos);
+    
+    const Instruction* begin = instructions().begin();
+    const Instruction* end = instructions().end();
+    for (const Instruction* it = begin; it != end; ++it)
+        dumpBytecode(out, exec, begin, it, stubInfos, callLinkInfos);
+    
+    if (numberOfIdentifiers()) {
+        out.printf("\nIdentifiers:\n");
+        size_t i = 0;
+        do {
+            out.printf("  id%u = %s\n", static_cast<unsigned>(i), identifier(i).string().utf8().data());
+            ++i;
+        } while (i != numberOfIdentifiers());
+    }
+
+    if (!m_constantRegisters.isEmpty()) {
+        out.printf("\nConstants:\n");
+        size_t i = 0;
+        do {
+            const char* sourceCodeRepresentationDescription = nullptr;
+            switch (m_constantsSourceCodeRepresentation[i]) {
+            case SourceCodeRepresentation::Double:
+                sourceCodeRepresentationDescription = ": in source as double";
+                break;
+            case SourceCodeRepresentation::Integer:
+                sourceCodeRepresentationDescription = ": in source as integer";
+                break;
+            case SourceCodeRepresentation::Other:
+                sourceCodeRepresentationDescription = "";
+                break;
+            }
+            out.printf("   k%u = %s%s\n", static_cast<unsigned>(i), toCString(m_constantRegisters[i].get()).data(), sourceCodeRepresentationDescription);
+            ++i;
+        } while (i < m_constantRegisters.size());
+    }
+
+    if (size_t count = m_unlinkedCode->numberOfRegExps()) {
+        out.printf("\nm_regexps:\n");
+        size_t i = 0;
+        do {
+            out.printf("  re%u = %s\n", static_cast<unsigned>(i), regexpToSourceString(m_unlinkedCode->regexp(i)).data());
+            ++i;
+        } while (i < count);
+    }
+
+    if (m_rareData && !m_rareData->m_exceptionHandlers.isEmpty()) {
+        out.printf("\nException Handlers:\n");
+        unsigned i = 0;
+        do {
+            HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
+            out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] } %s\n",
+                i + 1, handler.start, handler.end, handler.target, handler.typeName());
+            ++i;
+        } while (i < m_rareData->m_exceptionHandlers.size());
+    }
+    
+    if (m_rareData && !m_rareData->m_switchJumpTables.isEmpty()) {
+        out.printf("Switch Jump Tables:\n");
+        unsigned i = 0;
+        do {
+            out.printf("  %1d = {\n", i);
+            int entry = 0;
+            Vector<int32_t>::const_iterator end = m_rareData->m_switchJumpTables[i].branchOffsets.end();
+            for (Vector<int32_t>::const_iterator iter = m_rareData->m_switchJumpTables[i].branchOffsets.begin(); iter != end; ++iter, ++entry) {
+                if (!*iter)
+                    continue;
+                out.printf("\t\t%4d => %04d\n", entry + m_rareData->m_switchJumpTables[i].min, *iter);
+            }
+            out.printf("      }\n");
+            ++i;
+        } while (i < m_rareData->m_switchJumpTables.size());
+    }
+    
+    if (m_rareData && !m_rareData->m_stringSwitchJumpTables.isEmpty()) {
+        out.printf("\nString Switch Jump Tables:\n");
+        unsigned i = 0;
+        do {
+            out.printf("  %1d = {\n", i);
+            StringJumpTable::StringOffsetTable::const_iterator end = m_rareData->m_stringSwitchJumpTables[i].offsetTable.end();
+            for (StringJumpTable::StringOffsetTable::const_iterator iter = m_rareData->m_stringSwitchJumpTables[i].offsetTable.begin(); iter != end; ++iter)
+                out.printf("\t\t\"%s\" => %04d\n", iter->key->utf8().data(), iter->value.branchOffset);
+            out.printf("      }\n");
+            ++i;
+        } while (i < m_rareData->m_stringSwitchJumpTables.size());
+    }
+
+    out.printf("\n");
+}
+
+void CodeBlock::beginDumpProfiling(PrintStream& out, bool& hasPrintedProfiling)
+{
+    if (hasPrintedProfiling) {
+        out.print("; ");
+        return;
+    }
+    
+    out.print("    ");
+    hasPrintedProfiling = true;
+}
+
+void CodeBlock::dumpValueProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
+{
+    ConcurrentJITLocker locker(m_lock);
+    
+    ++it;
+    CString description = it->u.profile->briefDescription(locker);
+    if (!description.length())
+        return;
+    beginDumpProfiling(out, hasPrintedProfiling);
+    out.print(description);
+}
+
+void CodeBlock::dumpArrayProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
+{
+    ConcurrentJITLocker locker(m_lock);
+    
+    ++it;
+    if (!it->u.arrayProfile)
+        return;
+    CString description = it->u.arrayProfile->briefDescription(locker, this);
+    if (!description.length())
+        return;
+    beginDumpProfiling(out, hasPrintedProfiling);
+    out.print(description);
+}
+
+void CodeBlock::dumpRareCaseProfile(PrintStream& out, const char* name, RareCaseProfile* profile, bool& hasPrintedProfiling)
+{
+    if (!profile || !profile->m_counter)
+        return;
+
+    beginDumpProfiling(out, hasPrintedProfiling);
+    out.print(name, profile->m_counter);
+}
+
+void CodeBlock::printLocationAndOp(PrintStream& out, ExecState*, int location, const Instruction*&, const char* op)
+{
+    out.printf("[%4d] %-17s ", location, op);
+}
+
+void CodeBlock::printLocationOpAndRegisterOperand(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, int operand)
+{
+    printLocationAndOp(out, exec, location, it, op);
+    out.printf("%s", registerName(operand).data());
+}
+
+void CodeBlock::dumpBytecode(
+    PrintStream& out, ExecState* exec, const Instruction* begin, const Instruction*& it,
+    const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
+{
+    int location = it - begin;
+    bool hasPrintedProfiling = false;
+    OpcodeID opcode = exec->interpreter()->getOpcodeID(it->u.opcode);
+    switch (opcode) {
+        case op_enter: {
+            printLocationAndOp(out, exec, location, it, "enter");
+            break;
+        }
+        case op_get_scope: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "get_scope", r0);
+            break;
+        }
+        case op_create_direct_arguments: {
+            int r0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "create_direct_arguments");
+            out.printf("%s", registerName(r0).data());
+            break;
+        }
+        case op_create_scoped_arguments: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "create_scoped_arguments");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
+        case op_create_out_of_band_arguments: {
+            int r0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "create_out_of_band_arguments");
+            out.printf("%s", registerName(r0).data());
+            break;
+        }
+        case op_create_this: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            unsigned inferredInlineCapacity = (++it)->u.operand;
+            unsigned cachedFunction = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "create_this");
+            out.printf("%s, %s, %u, %u", registerName(r0).data(), registerName(r1).data(), inferredInlineCapacity, cachedFunction);
+            break;
+        }
+        case op_to_this: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "to_this", r0);
+            Structure* structure = (++it)->u.structure.get();
+            if (structure)
+                out.print(", cache(struct = ", RawPointer(structure), ")");
+            out.print(", ", (++it)->u.toThisStatus);
+            break;
+        }
+        case op_check_tdz: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "op_check_tdz", r0);
+            break;
+        }
+        case op_new_object: {
+            int r0 = (++it)->u.operand;
+            unsigned inferredInlineCapacity = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_object");
+            out.printf("%s, %u", registerName(r0).data(), inferredInlineCapacity);
+            ++it; // Skip object allocation profile.
+            break;
+        }
+        case op_new_array: {
+            int dst = (++it)->u.operand;
+            int argv = (++it)->u.operand;
+            int argc = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_array");
+            out.printf("%s, %s, %d", registerName(dst).data(), registerName(argv).data(), argc);
+            ++it; // Skip array allocation profile.
+            break;
+        }
+        case op_new_array_with_size: {
+            int dst = (++it)->u.operand;
+            int length = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_array_with_size");
+            out.printf("%s, %s", registerName(dst).data(), registerName(length).data());
+            ++it; // Skip array allocation profile.
+            break;
+        }
+        case op_new_array_buffer: {
+            int dst = (++it)->u.operand;
+            int argv = (++it)->u.operand;
+            int argc = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_array_buffer");
+            out.printf("%s, %d, %d", registerName(dst).data(), argv, argc);
+            ++it; // Skip array allocation profile.
+            break;
+        }
+        case op_new_regexp: {
+            int r0 = (++it)->u.operand;
+            int re0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_regexp");
+            out.printf("%s, ", registerName(r0).data());
+            if (r0 >=0 && r0 < (int)m_unlinkedCode->numberOfRegExps())
+                out.printf("%s", regexpName(re0, regexp(re0)).data());
+            else
+                out.printf("bad_regexp(%d)", re0);
+            break;
+        }
+        case op_mov: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "mov");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
+        case op_profile_type: {
+            int r0 = (++it)->u.operand;
+            ++it;
+            ++it;
+            ++it;
+            ++it;
+            printLocationAndOp(out, exec, location, it, "op_profile_type");
+            out.printf("%s", registerName(r0).data());
+            break;
+        }
+        case op_profile_control_flow: {
+            BasicBlockLocation* basicBlockLocation = (++it)->u.basicBlockLocation;
+            printLocationAndOp(out, exec, location, it, "profile_control_flow");
+            out.printf("[%d, %d]", basicBlockLocation->startOffset(), basicBlockLocation->endOffset());
+            break;
+        }
+        case op_not: {
+            printUnaryOp(out, exec, location, it, "not");
+            break;
+        }
+        case op_eq: {
+            printBinaryOp(out, exec, location, it, "eq");
+            break;
+        }
+        case op_eq_null: {
+            printUnaryOp(out, exec, location, it, "eq_null");
+            break;
+        }
+        case op_neq: {
+            printBinaryOp(out, exec, location, it, "neq");
+            break;
+        }
+        case op_neq_null: {
+            printUnaryOp(out, exec, location, it, "neq_null");
+            break;
+        }
+        case op_stricteq: {
+            printBinaryOp(out, exec, location, it, "stricteq");
+            break;
+        }
+        case op_nstricteq: {
+            printBinaryOp(out, exec, location, it, "nstricteq");
+            break;
+        }
+        case op_less: {
+            printBinaryOp(out, exec, location, it, "less");
+            break;
+        }
+        case op_lesseq: {
+            printBinaryOp(out, exec, location, it, "lesseq");
+            break;
+        }
+        case op_greater: {
+            printBinaryOp(out, exec, location, it, "greater");
+            break;
+        }
+        case op_greatereq: {
+            printBinaryOp(out, exec, location, it, "greatereq");
+            break;
+        }
+        case op_inc: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "inc", r0);
+            break;
+        }
+        case op_dec: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "dec", r0);
+            break;
+        }
+        case op_to_number: {
+            printUnaryOp(out, exec, location, it, "to_number");
+            break;
+        }
+        case op_to_string: {
+            printUnaryOp(out, exec, location, it, "to_string");
+            break;
+        }
+        case op_negate: {
+            printUnaryOp(out, exec, location, it, "negate");
+            break;
+        }
+        case op_add: {
+            printBinaryOp(out, exec, location, it, "add");
+            ++it;
+            break;
+        }
+        case op_mul: {
+            printBinaryOp(out, exec, location, it, "mul");
+            ++it;
+            break;
+        }
+        case op_div: {
+            printBinaryOp(out, exec, location, it, "div");
+            ++it;
+            break;
+        }
+        case op_mod: {
+            printBinaryOp(out, exec, location, it, "mod");
+            break;
+        }
+        case op_sub: {
+            printBinaryOp(out, exec, location, it, "sub");
+            ++it;
+            break;
+        }
+        case op_lshift: {
+            printBinaryOp(out, exec, location, it, "lshift");
+            break;            
+        }
+        case op_rshift: {
+            printBinaryOp(out, exec, location, it, "rshift");
+            break;
+        }
+        case op_urshift: {
+            printBinaryOp(out, exec, location, it, "urshift");
+            break;
+        }
+        case op_bitand: {
+            printBinaryOp(out, exec, location, it, "bitand");
+            ++it;
+            break;
+        }
+        case op_bitxor: {
+            printBinaryOp(out, exec, location, it, "bitxor");
+            ++it;
+            break;
+        }
+        case op_bitor: {
+            printBinaryOp(out, exec, location, it, "bitor");
+            ++it;
+            break;
+        }
+        case op_check_has_instance: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "check_has_instance");
+            out.printf("%s, %s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), registerName(r2).data(), offset, location + offset);
+            break;
+        }
+        case op_instanceof: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "instanceof");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            break;
+        }
+        case op_unsigned: {
+            printUnaryOp(out, exec, location, it, "unsigned");
+            break;
+        }
+        case op_typeof: {
+            printUnaryOp(out, exec, location, it, "typeof");
+            break;
+        }
+        case op_is_undefined: {
+            printUnaryOp(out, exec, location, it, "is_undefined");
+            break;
+        }
+        case op_is_boolean: {
+            printUnaryOp(out, exec, location, it, "is_boolean");
+            break;
+        }
+        case op_is_number: {
+            printUnaryOp(out, exec, location, it, "is_number");
+            break;
+        }
+        case op_is_string: {
+            printUnaryOp(out, exec, location, it, "is_string");
+            break;
+        }
+        case op_is_object: {
+            printUnaryOp(out, exec, location, it, "is_object");
+            break;
+        }
+        case op_is_object_or_null: {
+            printUnaryOp(out, exec, location, it, "is_object_or_null");
+            break;
+        }
+        case op_is_function: {
+            printUnaryOp(out, exec, location, it, "is_function");
+            break;
+        }
+        case op_in: {
+            printBinaryOp(out, exec, location, it, "in");
+            break;
+        }
+        case op_get_by_id:
+        case op_get_by_id_out_of_line:
+        case op_get_array_length: {
+            printGetByIdOp(out, exec, location, it);
+            printGetByIdCacheStatus(out, exec, location, stubInfos);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_put_by_id: {
+            printPutByIdOp(out, exec, location, it, "put_by_id");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_out_of_line");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_transition_direct: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_transition_direct_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct_out_of_line");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_transition_normal: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_transition_normal_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal_out_of_line");
+            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_getter_by_id: {
+            int r0 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_getter_by_id");
+            out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
+            break;
+        }
+        case op_put_setter_by_id: {
+            int r0 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_setter_by_id");
+            out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
+            break;
+        }
+        case op_put_getter_setter: {
+            int r0 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_getter_setter");
+            out.printf("%s, %s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data(), registerName(r2).data());
+            break;
+        }
+        case op_del_by_id: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "del_by_id");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), idName(id0, identifier(id0)).data());
+            break;
+        }
+        case op_get_by_val: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "get_by_val");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            dumpArrayProfiling(out, it, hasPrintedProfiling);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_put_by_val: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_by_val");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            dumpArrayProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_put_by_val_direct: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_by_val_direct");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            dumpArrayProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_del_by_val: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "del_by_val");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            break;
+        }
+        case op_put_by_index: {
+            int r0 = (++it)->u.operand;
+            unsigned n0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_by_index");
+            out.printf("%s, %u, %s", registerName(r0).data(), n0, registerName(r1).data());
+            break;
+        }
+        case op_jmp: {
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jmp");
+            out.printf("%d(->%d)", offset, location + offset);
+            break;
+        }
+        case op_jtrue: {
+            printConditionalJump(out, exec, begin, it, location, "jtrue");
+            break;
+        }
+        case op_jfalse: {
+            printConditionalJump(out, exec, begin, it, location, "jfalse");
+            break;
+        }
+        case op_jeq_null: {
+            printConditionalJump(out, exec, begin, it, location, "jeq_null");
+            break;
+        }
+        case op_jneq_null: {
+            printConditionalJump(out, exec, begin, it, location, "jneq_null");
+            break;
+        }
+        case op_jneq_ptr: {
+            int r0 = (++it)->u.operand;
+            Special::Pointer pointer = (++it)->u.specialPointer;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jneq_ptr");
+            out.printf("%s, %d (%p), %d(->%d)", registerName(r0).data(), pointer, m_globalObject->actualPointerFor(pointer), offset, location + offset);
+            break;
+        }
+        case op_jless: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jless");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jlesseq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jlesseq");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jgreater: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jgreater");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jgreatereq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jgreatereq");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jnless: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jnless");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jnlesseq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jnlesseq");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jngreater: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jngreater");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jngreatereq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "jngreatereq");
+            out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
+            break;
+        }
+        case op_loop_hint: {
+            printLocationAndOp(out, exec, location, it, "loop_hint");
+            break;
+        }
+        case op_switch_imm: {
+            int tableIndex = (++it)->u.operand;
+            int defaultTarget = (++it)->u.operand;
+            int scrutineeRegister = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "switch_imm");
+            out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
+            break;
+        }
+        case op_switch_char: {
+            int tableIndex = (++it)->u.operand;
+            int defaultTarget = (++it)->u.operand;
+            int scrutineeRegister = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "switch_char");
+            out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
+            break;
+        }
+        case op_switch_string: {
+            int tableIndex = (++it)->u.operand;
+            int defaultTarget = (++it)->u.operand;
+            int scrutineeRegister = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "switch_string");
+            out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
+            break;
+        }
+        case op_new_func: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int f0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_func");
+            out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
+            break;
+        }
+        case op_new_func_exp: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int f0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_func_exp");
+            out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
+            break;
+        }
+        case op_call: {
+            printCallOp(out, exec, location, it, "call", DumpCaches, hasPrintedProfiling, callLinkInfos);
+            break;
+        }
+        case op_call_eval: {
+            printCallOp(out, exec, location, it, "call_eval", DontDumpCaches, hasPrintedProfiling, callLinkInfos);
+            break;
+        }
+            
+        case op_construct_varargs:
+        case op_call_varargs: {
+            int result = (++it)->u.operand;
+            int callee = (++it)->u.operand;
+            int thisValue = (++it)->u.operand;
+            int arguments = (++it)->u.operand;
+            int firstFreeRegister = (++it)->u.operand;
+            int varArgOffset = (++it)->u.operand;
+            ++it;
+            printLocationAndOp(out, exec, location, it, opcode == op_call_varargs ? "call_varargs" : "construct_varargs");
+            out.printf("%s, %s, %s, %s, %d, %d", registerName(result).data(), registerName(callee).data(), registerName(thisValue).data(), registerName(arguments).data(), firstFreeRegister, varArgOffset);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+
+        case op_ret: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "ret", r0);
+            break;
+        }
+        case op_construct: {
+            printCallOp(out, exec, location, it, "construct", DumpCaches, hasPrintedProfiling, callLinkInfos);
+            break;
+        }
+        case op_strcat: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int count = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "strcat");
+            out.printf("%s, %s, %d", registerName(r0).data(), registerName(r1).data(), count);
+            break;
+        }
+        case op_to_primitive: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "to_primitive");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
+        case op_get_enumerable_length: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_get_enumerable_length");
+            out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
+            it += OPCODE_LENGTH(op_get_enumerable_length) - 1;
+            break;
+        }
+        case op_has_indexed_property: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            int propertyName = it[3].u.operand;
+            ArrayProfile* arrayProfile = it[4].u.arrayProfile;
+            printLocationAndOp(out, exec, location, it, "op_has_indexed_property");
+            out.printf("%s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), arrayProfile);
+            it += OPCODE_LENGTH(op_has_indexed_property) - 1;
+            break;
+        }
+        case op_has_structure_property: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            int propertyName = it[3].u.operand;
+            int enumerator = it[4].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_has_structure_property");
+            out.printf("%s, %s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(enumerator).data());
+            it += OPCODE_LENGTH(op_has_structure_property) - 1;
+            break;
+        }
+        case op_has_generic_property: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            int propertyName = it[3].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_has_generic_property");
+            out.printf("%s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data());
+            it += OPCODE_LENGTH(op_has_generic_property) - 1;
+            break;
+        }
+        case op_get_direct_pname: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            int propertyName = it[3].u.operand;
+            int index = it[4].u.operand;
+            int enumerator = it[5].u.operand;
+            ValueProfile* profile = it[6].u.profile;
+            printLocationAndOp(out, exec, location, it, "op_get_direct_pname");
+            out.printf("%s, %s, %s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(index).data(), registerName(enumerator).data(), profile);
+            it += OPCODE_LENGTH(op_get_direct_pname) - 1;
+            break;
+
+        }
+        case op_get_property_enumerator: {
+            int dst = it[1].u.operand;
+            int base = it[2].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_get_property_enumerator");
+            out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
+            it += OPCODE_LENGTH(op_get_property_enumerator) - 1;
+            break;
+        }
+        case op_enumerator_structure_pname: {
+            int dst = it[1].u.operand;
+            int enumerator = it[2].u.operand;
+            int index = it[3].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_enumerator_structure_pname");
+            out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
+            it += OPCODE_LENGTH(op_enumerator_structure_pname) - 1;
+            break;
+        }
+        case op_enumerator_generic_pname: {
+            int dst = it[1].u.operand;
+            int enumerator = it[2].u.operand;
+            int index = it[3].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_enumerator_generic_pname");
+            out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
+            it += OPCODE_LENGTH(op_enumerator_generic_pname) - 1;
+            break;
+        }
+        case op_to_index_string: {
+            int dst = it[1].u.operand;
+            int index = it[2].u.operand;
+            printLocationAndOp(out, exec, location, it, "op_to_index_string");
+            out.printf("%s, %s", registerName(dst).data(), registerName(index).data());
+            it += OPCODE_LENGTH(op_to_index_string) - 1;
+            break;
+        }
+        case op_push_with_scope: {
+            int dst = (++it)->u.operand;
+            int newScope = (++it)->u.operand;
+            int currentScope = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "push_with_scope");
+            out.printf("%s, %s, %s", registerName(dst).data(), registerName(newScope).data(), registerName(currentScope).data());
+            break;
+        }
+        case op_get_parent_scope: {
+            int dst = (++it)->u.operand;
+            int parentScope = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "get_parent_scope");
+            out.printf("%s, %s", registerName(dst).data(), registerName(parentScope).data());
+            break;
+        }
+        case op_create_lexical_environment: {
+            int dst = (++it)->u.operand;
+            int scope = (++it)->u.operand;
+            int symbolTable = (++it)->u.operand;
+            int initialValue = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "create_lexical_environment");
+            out.printf("%s, %s, %s, %s", 
+                registerName(dst).data(), registerName(scope).data(), registerName(symbolTable).data(), registerName(initialValue).data());
+            break;
+        }
+        case op_catch: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "catch");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
+        case op_throw: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "throw", r0);
+            break;
+        }
+        case op_throw_static_error: {
+            int k0 = (++it)->u.operand;
+            int k1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "throw_static_error");
+            out.printf("%s, %s", constantName(k0).data(), k1 ? "true" : "false");
+            break;
+        }
+        case op_debug: {
+            int debugHookID = (++it)->u.operand;
+            int hasBreakpointFlag = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "debug");
+            out.printf("%s %d", debugHookName(debugHookID), hasBreakpointFlag);
+            break;
+        }
+        case op_profile_will_call: {
+            int function = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "profile_will_call", function);
+            break;
+        }
+        case op_profile_did_call: {
+            int function = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "profile_did_call", function);
+            break;
+        }
+        case op_end: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "end", r0);
+            break;
+        }
+        case op_resolve_scope: {
+            int r0 = (++it)->u.operand;
+            int scope = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
+            int depth = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "resolve_scope");
+            out.printf("%s, %s, %s, %u<%s|%s>, %d", registerName(r0).data(), registerName(scope).data(), idName(id0, identifier(id0)).data(),
+                modeAndType.operand(), resolveModeName(modeAndType.mode()), resolveTypeName(modeAndType.type()),
+                depth);
+            ++it;
+            break;
+        }
+        case op_get_from_scope: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
+            ++it; // Structure
+            int operand = (++it)->u.operand; // Operand
+            printLocationAndOp(out, exec, location, it, "get_from_scope");
+            out.print(registerName(r0), ", ", registerName(r1));
+            if (static_cast<unsigned>(id0) == UINT_MAX)
+                out.print(", anonymous");
+            else
+                out.print(", ", idName(id0, identifier(id0)));
+            out.print(", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, ", operand);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_put_to_scope: {
+            int r0 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
+            ++it; // Structure
+            int operand = (++it)->u.operand; // Operand
+            printLocationAndOp(out, exec, location, it, "put_to_scope");
+            out.print(registerName(r0));
+            if (static_cast<unsigned>(id0) == UINT_MAX)
+                out.print(", anonymous");
+            else
+                out.print(", ", idName(id0, identifier(id0)));
+            out.print(", ", registerName(r1), ", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, <structure>, ", operand);
+            break;
+        }
+        case op_get_from_arguments: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "get_from_arguments");
+            out.printf("%s, %s, %d", registerName(r0).data(), registerName(r1).data(), offset);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_put_to_arguments: {
+            int r0 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "put_to_arguments");
+            out.printf("%s, %d, %s", registerName(r0).data(), offset, registerName(r1).data());
+            break;
+        }
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+    }
+
+    dumpRareCaseProfile(out, "rare case: ", rareCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
+    dumpRareCaseProfile(out, "special fast case: ", specialFastCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
+    
+#if ENABLE(DFG_JIT)
+    Vector<DFG::FrequentExitSite> exitSites = exitProfile().exitSitesFor(location);
+    if (!exitSites.isEmpty()) {
+        out.print(" !! frequent exits: ");
+        CommaPrinter comma;
+        for (unsigned i = 0; i < exitSites.size(); ++i)
+            out.print(comma, exitSites[i].kind(), " ", exitSites[i].jitType());
+    }
+#else // ENABLE(DFG_JIT)
+    UNUSED_PARAM(location);
+#endif // ENABLE(DFG_JIT)
+    out.print("\n");
+}
+
+void CodeBlock::dumpBytecode(
+    PrintStream& out, unsigned bytecodeOffset,
+    const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
+{
+    ExecState* exec = m_globalObject->globalExec();
+    const Instruction* it = instructions().begin() + bytecodeOffset;
+    dumpBytecode(out, exec, instructions().begin(), it, stubInfos, callLinkInfos);
+}
+
+#define FOR_EACH_MEMBER_VECTOR(macro) \
+    macro(instructions) \
+    macro(callLinkInfos) \
+    macro(linkedCallerList) \
+    macro(identifiers) \
+    macro(functionExpressions) \
+    macro(constantRegisters)
+
+#define FOR_EACH_MEMBER_VECTOR_RARE_DATA(macro) \
+    macro(regexps) \
+    macro(functions) \
+    macro(exceptionHandlers) \
+    macro(switchJumpTables) \
+    macro(stringSwitchJumpTables) \
+    macro(evalCodeCache) \
+    macro(expressionInfo) \
+    macro(lineInfo) \
+    macro(callReturnIndexVector)
+
+template<typename T>
+static size_t sizeInBytes(const Vector<T>& vector)
+{
+    return vector.capacity() * sizeof(T);
+}
+
+namespace {
+
+class PutToScopeFireDetail : public FireDetail {
+public:
+    PutToScopeFireDetail(CodeBlock* codeBlock, const Identifier& ident)
+        : m_codeBlock(codeBlock)
+        , m_ident(ident)
+    {
+    }
+    
+    virtual void dump(PrintStream& out) const override
+    {
+        out.print("Linking put_to_scope in ", FunctionExecutableDump(jsCast<FunctionExecutable*>(m_codeBlock->ownerExecutable())), " for ", m_ident);
+    }
+    
+private:
+    CodeBlock* m_codeBlock;
+    const Identifier& m_ident;
+};
+
+} // anonymous namespace
+
+CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
+    : m_globalObject(other.m_globalObject)
+    , m_heap(other.m_heap)
+    , m_numCalleeRegisters(other.m_numCalleeRegisters)
+    , m_numVars(other.m_numVars)
+    , m_isConstructor(other.m_isConstructor)
+    , m_shouldAlwaysBeInlined(true)
+    , m_didFailFTLCompilation(false)
+    , m_hasBeenCompiledWithFTL(false)
+    , m_unlinkedCode(*other.m_vm, other.m_ownerExecutable.get(), other.m_unlinkedCode.get())
+    , m_hasDebuggerStatement(false)
+    , m_steppingMode(SteppingModeDisabled)
+    , m_numBreakpoints(0)
+    , m_ownerExecutable(*other.m_vm, other.m_ownerExecutable.get(), other.m_ownerExecutable.get())
+    , m_vm(other.m_vm)
+    , m_instructions(other.m_instructions)
+    , m_thisRegister(other.m_thisRegister)
+    , m_scopeRegister(other.m_scopeRegister)
+    , m_lexicalEnvironmentRegister(other.m_lexicalEnvironmentRegister)
+    , m_isStrictMode(other.m_isStrictMode)
+    , m_needsActivation(other.m_needsActivation)
+    , m_mayBeExecuting(false)
+    , m_source(other.m_source)
+    , m_sourceOffset(other.m_sourceOffset)
+    , m_firstLineColumnOffset(other.m_firstLineColumnOffset)
+    , m_codeType(other.m_codeType)
+    , m_constantRegisters(other.m_constantRegisters)
+    , m_constantsSourceCodeRepresentation(other.m_constantsSourceCodeRepresentation)
+    , m_functionDecls(other.m_functionDecls)
+    , m_functionExprs(other.m_functionExprs)
+    , m_osrExitCounter(0)
+    , m_optimizationDelayCounter(0)
+    , m_reoptimizationRetryCounter(0)
+    , m_hash(other.m_hash)
+#if ENABLE(JIT)
+    , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
+#endif
+{
+    m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
+
+    ASSERT(m_heap->isDeferred());
+    ASSERT(m_scopeRegister.isLocal());
+
+    setNumParameters(other.numParameters());
+    optimizeAfterWarmUp();
+    jitAfterWarmUp();
+
+    if (other.m_rareData) {
+        createRareDataIfNecessary();
+        
+        m_rareData->m_exceptionHandlers = other.m_rareData->m_exceptionHandlers;
+        m_rareData->m_constantBuffers = other.m_rareData->m_constantBuffers;
+        m_rareData->m_switchJumpTables = other.m_rareData->m_switchJumpTables;
+        m_rareData->m_stringSwitchJumpTables = other.m_rareData->m_stringSwitchJumpTables;
+    }
+    
+    m_heap->m_codeBlocks.add(this);
+    m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock));
+}
+
+CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
+    : m_globalObject(scope->globalObject()->vm(), ownerExecutable, scope->globalObject())
+    , m_heap(&m_globalObject->vm().heap)
+    , m_numCalleeRegisters(unlinkedCodeBlock->m_numCalleeRegisters)
+    , m_numVars(unlinkedCodeBlock->m_numVars)
+    , m_isConstructor(unlinkedCodeBlock->isConstructor())
+    , m_shouldAlwaysBeInlined(true)
+    , m_didFailFTLCompilation(false)
+    , m_hasBeenCompiledWithFTL(false)
+    , m_unlinkedCode(m_globalObject->vm(), ownerExecutable, unlinkedCodeBlock)
+    , m_hasDebuggerStatement(false)
+    , m_steppingMode(SteppingModeDisabled)
+    , m_numBreakpoints(0)
+    , m_ownerExecutable(m_globalObject->vm(), ownerExecutable, ownerExecutable)
+    , m_vm(unlinkedCodeBlock->vm())
+    , m_thisRegister(unlinkedCodeBlock->thisRegister())
+    , m_scopeRegister(unlinkedCodeBlock->scopeRegister())
+    , m_lexicalEnvironmentRegister(unlinkedCodeBlock->activationRegister())
+    , m_isStrictMode(unlinkedCodeBlock->isStrictMode())
+    , m_needsActivation(unlinkedCodeBlock->hasActivationRegister() && unlinkedCodeBlock->codeType() == FunctionCode)
+    , m_mayBeExecuting(false)
+    , m_source(sourceProvider)
+    , m_sourceOffset(sourceOffset)
+    , m_firstLineColumnOffset(firstLineColumnOffset)
+    , m_codeType(unlinkedCodeBlock->codeType())
+    , m_osrExitCounter(0)
+    , m_optimizationDelayCounter(0)
+    , m_reoptimizationRetryCounter(0)
+#if ENABLE(JIT)
+    , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
+#endif
+{
+    m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
+
+    ASSERT(m_heap->isDeferred());
+    ASSERT(m_scopeRegister.isLocal());
+
+    ASSERT(m_source);
+    setNumParameters(unlinkedCodeBlock->numParameters());
+
+    if (vm()->typeProfiler() || vm()->controlFlowProfiler())
+        vm()->functionHasExecutedCache()->removeUnexecutedRange(m_ownerExecutable->sourceID(), m_ownerExecutable->typeProfilingStartOffset(), m_ownerExecutable->typeProfilingEndOffset());
+
+    setConstantRegisters(unlinkedCodeBlock->constantRegisters(), unlinkedCodeBlock->constantsSourceCodeRepresentation());
+    if (unlinkedCodeBlock->usesGlobalObject())
+        m_constantRegisters[unlinkedCodeBlock->globalObjectRegister().toConstantIndex()].set(*m_vm, ownerExecutable, m_globalObject.get());
+
+    for (unsigned i = 0; i < LinkTimeConstantCount; i++) {
+        LinkTimeConstant type = static_cast<LinkTimeConstant>(i);
+        if (unsigned registerIndex = unlinkedCodeBlock->registerIndexForLinkTimeConstant(type))
+            m_constantRegisters[registerIndex].set(*m_vm, ownerExecutable, m_globalObject->jsCellForLinkTimeConstant(type));
+    }
+
+    HashSet<int, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>> clonedConstantSymbolTables;
+    {
+        HashSet<SymbolTable*> clonedSymbolTables;
+        for (unsigned i = 0; i < m_constantRegisters.size(); i++) {
+            if (m_constantRegisters[i].get().isEmpty())
+                continue;
+            if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(m_constantRegisters[i].get())) {
+                RELEASE_ASSERT(clonedSymbolTables.add(symbolTable).isNewEntry);
+                if (m_vm->typeProfiler()) {
+                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    symbolTable->prepareForTypeProfiling(locker);
+                }
+                m_constantRegisters[i].set(*m_vm, ownerExecutable, symbolTable->cloneScopePart(*m_vm));
+                clonedConstantSymbolTables.add(i + FirstConstantRegisterIndex);
+            }
+        }
+    }
+
+    m_functionDecls.resizeToFit(unlinkedCodeBlock->numberOfFunctionDecls());
+    for (size_t count = unlinkedCodeBlock->numberOfFunctionDecls(), i = 0; i < count; ++i) {
+        UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionDecl(i);
+        if (vm()->typeProfiler() || vm()->controlFlowProfiler())
+            vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
+        m_functionDecls[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
+    }
+
+    m_functionExprs.resizeToFit(unlinkedCodeBlock->numberOfFunctionExprs());
+    for (size_t count = unlinkedCodeBlock->numberOfFunctionExprs(), i = 0; i < count; ++i) {
+        UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionExpr(i);
+        if (vm()->typeProfiler() || vm()->controlFlowProfiler())
+            vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
+        m_functionExprs[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
+    }
+
+    if (unlinkedCodeBlock->hasRareData()) {
+        createRareDataIfNecessary();
+        if (size_t count = unlinkedCodeBlock->constantBufferCount()) {
+            m_rareData->m_constantBuffers.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                const UnlinkedCodeBlock::ConstantBuffer& buffer = unlinkedCodeBlock->constantBuffer(i);
+                m_rareData->m_constantBuffers[i] = buffer;
+            }
+        }
+        if (size_t count = unlinkedCodeBlock->numberOfExceptionHandlers()) {
+            m_rareData->m_exceptionHandlers.resizeToFit(count);
+            for (size_t i = 0; i < count; i++) {
+                const UnlinkedHandlerInfo& unlinkedHandler = unlinkedCodeBlock->exceptionHandler(i);
+                HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
+#if ENABLE(JIT)
+                handler.initialize(unlinkedHandler, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(LLInt::getCodePtr(op_catch))));
+#else
+                handler.initialize(unlinkedHandler);
+#endif
+            }
+        }
+
+        if (size_t count = unlinkedCodeBlock->numberOfStringSwitchJumpTables()) {
+            m_rareData->m_stringSwitchJumpTables.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                UnlinkedStringJumpTable::StringOffsetTable::iterator ptr = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.begin();
+                UnlinkedStringJumpTable::StringOffsetTable::iterator end = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.end();
+                for (; ptr != end; ++ptr) {
+                    OffsetLocation offset;
+                    offset.branchOffset = ptr->value;
+                    m_rareData->m_stringSwitchJumpTables[i].offsetTable.add(ptr->key, offset);
+                }
+            }
+        }
+
+        if (size_t count = unlinkedCodeBlock->numberOfSwitchJumpTables()) {
+            m_rareData->m_switchJumpTables.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                UnlinkedSimpleJumpTable& sourceTable = unlinkedCodeBlock->switchJumpTable(i);
+                SimpleJumpTable& destTable = m_rareData->m_switchJumpTables[i];
+                destTable.branchOffsets = sourceTable.branchOffsets;
+                destTable.min = sourceTable.min;
+            }
+        }
+    }
+
+    // Allocate metadata buffers for the bytecode
+    if (size_t size = unlinkedCodeBlock->numberOfLLintCallLinkInfos())
+        m_llintCallLinkInfos.resizeToFit(size);
+    if (size_t size = unlinkedCodeBlock->numberOfArrayProfiles())
+        m_arrayProfiles.grow(size);
+    if (size_t size = unlinkedCodeBlock->numberOfArrayAllocationProfiles())
+        m_arrayAllocationProfiles.resizeToFit(size);
+    if (size_t size = unlinkedCodeBlock->numberOfValueProfiles())
+        m_valueProfiles.resizeToFit(size);
+    if (size_t size = unlinkedCodeBlock->numberOfObjectAllocationProfiles())
+        m_objectAllocationProfiles.resizeToFit(size);
+
+    // Copy and translate the UnlinkedInstructions
+    unsigned instructionCount = unlinkedCodeBlock->instructions().count();
+    UnlinkedInstructionStream::Reader instructionReader(unlinkedCodeBlock->instructions());
+
+    RefCountedArray<Instruction> instructions(instructionCount);
+
+    for (unsigned i = 0; !instructionReader.atEnd(); ) {
+        const UnlinkedInstruction* pc = instructionReader.next();
+
+        unsigned opLength = opcodeLength(pc[0].u.opcode);
+
+        instructions[i] = vm()->interpreter->getOpcode(pc[0].u.opcode);
+        for (size_t j = 1; j < opLength; ++j) {
+            if (sizeof(int32_t) != sizeof(intptr_t))
+                instructions[i + j].u.pointer = 0;
+            instructions[i + j].u.operand = pc[j].u.operand;
+        }
+        switch (pc[0].u.opcode) {
+        case op_has_indexed_property: {
+            int arrayProfileIndex = pc[opLength - 1].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+
+            instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
+            break;
+        }
+        case op_call_varargs:
+        case op_construct_varargs:
+        case op_get_by_val: {
+            int arrayProfileIndex = pc[opLength - 2].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+
+            instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
+            FALLTHROUGH;
+        }
+        case op_get_direct_pname:
+        case op_get_by_id:
+        case op_get_from_arguments: {
+            ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+            break;
+        }
+        case op_put_by_val: {
+            int arrayProfileIndex = pc[opLength - 1].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+            instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
+            break;
+        }
+        case op_put_by_val_direct: {
+            int arrayProfileIndex = pc[opLength - 1].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+            instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
+            break;
+        }
+
+        case op_new_array:
+        case op_new_array_buffer:
+        case op_new_array_with_size: {
+            int arrayAllocationProfileIndex = pc[opLength - 1].u.operand;
+            instructions[i + opLength - 1] = &m_arrayAllocationProfiles[arrayAllocationProfileIndex];
+            break;
+        }
+        case op_new_object: {
+            int objectAllocationProfileIndex = pc[opLength - 1].u.operand;
+            ObjectAllocationProfile* objectAllocationProfile = &m_objectAllocationProfiles[objectAllocationProfileIndex];
+            int inferredInlineCapacity = pc[opLength - 2].u.operand;
+
+            instructions[i + opLength - 1] = objectAllocationProfile;
+            objectAllocationProfile->initialize(*vm(),
+                m_ownerExecutable.get(), m_globalObject->objectPrototype(), inferredInlineCapacity);
+            break;
+        }
+
+        case op_call:
+        case op_call_eval: {
+            ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+            int arrayProfileIndex = pc[opLength - 2].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+            instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
+            instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
+            break;
+        }
+        case op_construct: {
+            instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
+            ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+            break;
+        }
+        case op_get_by_id_out_of_line:
+        case op_get_array_length:
+            CRASH();
+
+        case op_create_lexical_environment: {
+            int symbolTableIndex = pc[3].u.operand;
+            RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
+            break;
+        }
+
+        case op_resolve_scope: {
+            const Identifier& ident = identifier(pc[3].u.operand);
+            ResolveType type = static_cast<ResolveType>(pc[4].u.operand);
+            RELEASE_ASSERT(type != LocalClosureVar);
+            int localScopeDepth = pc[5].u.operand;
+
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type);
+            instructions[i + 4].u.operand = op.type;
+            instructions[i + 5].u.operand = op.depth;
+            if (op.lexicalEnvironment)
+                instructions[i + 6].u.symbolTable.set(*vm(), ownerExecutable, op.lexicalEnvironment->symbolTable());
+            else
+                instructions[i + 6].u.pointer = nullptr;
+            break;
+        }
+
+        case op_get_from_scope: {
+            ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+
+            // get_from_scope dst, scope, id, ResolveModeAndType, Structure, Operand
+
+            int localScopeDepth = pc[5].u.operand;
+            instructions[i + 5].u.pointer = nullptr;
+
+            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
+            if (modeAndType.type() == LocalClosureVar) {
+                instructions[i + 4] = ResolveModeAndType(modeAndType.mode(), ClosureVar).operand();
+                break;
+            }
+
+            const Identifier& ident = identifier(pc[3].u.operand);
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, modeAndType.type());
+
+            instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
+            if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
+                instructions[i + 5].u.watchpointSet = op.watchpointSet;
+            else if (op.structure)
+                instructions[i + 5].u.structure.set(*vm(), ownerExecutable, op.structure);
+            instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
+            break;
+        }
+
+        case op_put_to_scope: {
+            // put_to_scope scope, id, value, ResolveModeAndType, Structure, Operand
+            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
+            if (modeAndType.type() == LocalClosureVar) {
+                // Only do watching if the property we're putting to is not anonymous.
+                if (static_cast<unsigned>(pc[2].u.operand) != UINT_MAX) {
+                    int symbolTableIndex = pc[5].u.operand;
+                    RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
+                    SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
+                    const Identifier& ident = identifier(pc[2].u.operand);
+                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    auto iter = symbolTable->find(locker, ident.impl());
+                    RELEASE_ASSERT(iter != symbolTable->end(locker));
+                    iter->value.prepareToWatch();
+                    instructions[i + 5].u.watchpointSet = iter->value.watchpointSet();
+                } else
+                    instructions[i + 5].u.watchpointSet = nullptr;
+                break;
+            }
+
+            const Identifier& ident = identifier(pc[2].u.operand);
+            int localScopeDepth = pc[5].u.operand;
+            instructions[i + 5].u.pointer = nullptr;
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Put, modeAndType.type());
+
+            instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
+            if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
+                instructions[i + 5].u.watchpointSet = op.watchpointSet;
+            else if (op.type == ClosureVar || op.type == ClosureVarWithVarInjectionChecks) {
+                if (op.watchpointSet)
+                    op.watchpointSet->invalidate(PutToScopeFireDetail(this, ident));
+            } else if (op.structure)
+                instructions[i + 5].u.structure.set(*vm(), ownerExecutable, op.structure);
+            instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
+
+            break;
+        }
+
+        case op_profile_type: {
+            RELEASE_ASSERT(vm()->typeProfiler());
+            // The format of this instruction is: op_profile_type regToProfile, TypeLocation*, flag, identifier?, resolveType?
+            size_t instructionOffset = i + opLength - 1;
+            unsigned divotStart, divotEnd;
+            GlobalVariableID globalVariableID = 0;
+            RefPtr<TypeSet> globalTypeSet;
+            bool shouldAnalyze = m_unlinkedCode->typeProfilerExpressionInfoForBytecodeOffset(instructionOffset, divotStart, divotEnd);
+            VirtualRegister profileRegister(pc[1].u.operand);
+            ProfileTypeBytecodeFlag flag = static_cast<ProfileTypeBytecodeFlag>(pc[3].u.operand);
+            SymbolTable* symbolTable = nullptr;
+
+            switch (flag) {
+            case ProfileTypeBytecodeClosureVar: {
+                const Identifier& ident = identifier(pc[4].u.operand);
+                int localScopeDepth = pc[2].u.operand;
+                ResolveType type = static_cast<ResolveType>(pc[5].u.operand);
+                // Even though type profiling may be profiling either a Get or a Put, we can always claim a Get because
+                // we're abstractly "read"ing from a JSScope.
+                ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type);
+
+                if (op.type == ClosureVar)
+                    symbolTable = op.lexicalEnvironment->symbolTable();
+                else if (op.type == GlobalVar)
+                    symbolTable = m_globalObject.get()->symbolTable();
+                
+                if (symbolTable) {
+                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
+                    symbolTable->prepareForTypeProfiling(locker);
+                    globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
+                    globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
+                } else
+                    globalVariableID = TypeProfilerNoGlobalIDExists;
+
+                break;
+            }
+            case ProfileTypeBytecodeLocallyResolved: {
+                int symbolTableIndex = pc[2].u.operand;
+                RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
+                SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
+                const Identifier& ident = identifier(pc[4].u.operand);
+                ConcurrentJITLocker locker(symbolTable->m_lock);
+                // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
+                globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
+                globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
+
+                break;
+            }
+            case ProfileTypeBytecodeDoesNotHaveGlobalID: 
+            case ProfileTypeBytecodeFunctionArgument: {
+                globalVariableID = TypeProfilerNoGlobalIDExists;
+                break;
+            }
+            case ProfileTypeBytecodeFunctionReturnStatement: {
+                RELEASE_ASSERT(ownerExecutable->isFunctionExecutable());
+                globalTypeSet = jsCast<FunctionExecutable*>(ownerExecutable)->returnStatementTypeSet();
+                globalVariableID = TypeProfilerReturnStatement;
+                if (!shouldAnalyze) {
+                    // Because a return statement can be added implicitly to return undefined at the end of a function,
+                    // and these nodes don't emit expression ranges because they aren't in the actual source text of
+                    // the user's program, give the type profiler some range to identify these return statements.
+                    // Currently, the text offset that is used as identification is on the open brace of the function 
+                    // and is stored on TypeLocation's m_divotForFunctionOffsetIfReturnStatement member variable.
+                    divotStart = divotEnd = m_sourceOffset;
+                    shouldAnalyze = true;
+                }
+                break;
+            }
+            }
+
+            std::pair<TypeLocation*, bool> locationPair = vm()->typeProfiler()->typeLocationCache()->getTypeLocation(globalVariableID,
+                m_ownerExecutable->sourceID(), divotStart, divotEnd, globalTypeSet, vm());
+            TypeLocation* location = locationPair.first;
+            bool isNewLocation = locationPair.second;
+
+            if (flag == ProfileTypeBytecodeFunctionReturnStatement)
+                location->m_divotForFunctionOffsetIfReturnStatement = m_sourceOffset;
+
+            if (shouldAnalyze && isNewLocation)
+                vm()->typeProfiler()->insertNewLocation(location);
+
+            instructions[i + 2].u.location = location;
+            break;
+        }
+
+        case op_debug: {
+            if (pc[1].u.index == DidReachBreakpoint)
+                m_hasDebuggerStatement = true;
+            break;
+        }
+
+        default:
+            break;
+        }
+        i += opLength;
+    }
+
+    if (vm()->controlFlowProfiler())
+        insertBasicBlockBoundariesForControlFlowProfiler(instructions);
+
+    m_instructions = WTF::move(instructions);
+
+    // Set optimization thresholds only after m_instructions is initialized, since these
+    // rely on the instruction count (and are in theory permitted to also inspect the
+    // instruction stream to more accurate assess the cost of tier-up).
+    optimizeAfterWarmUp();
+    jitAfterWarmUp();
+
+    // If the concurrent thread will want the code block's hash, then compute it here
+    // synchronously.
+    if (Options::alwaysComputeHash())
+        hash();
+
+    if (Options::dumpGeneratedBytecodes())
+        dumpBytecode();
+    
+    m_heap->m_codeBlocks.add(this);
+    m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock) + m_instructions.size() * sizeof(Instruction));
+}
+
+CodeBlock::~CodeBlock()
+{
+    if (m_vm->m_perBytecodeProfiler)
+        m_vm->m_perBytecodeProfiler->notifyDestruction(this);
+    
+#if ENABLE(VERBOSE_VALUE_PROFILE)
+    dumpValueProfiles();
+#endif
+    while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
+        m_incomingLLIntCalls.begin()->remove();
+#if ENABLE(JIT)
+    // We may be destroyed before any CodeBlocks that refer to us are destroyed.
+    // Consider that two CodeBlocks become unreachable at the same time. There
+    // is no guarantee about the order in which the CodeBlocks are destroyed.
+    // So, if we don't remove incoming calls, and get destroyed before the
+    // CodeBlock(s) that have calls into us, then the CallLinkInfo vector's
+    // destructor will try to remove nodes from our (no longer valid) linked list.
+    while (m_incomingCalls.begin() != m_incomingCalls.end())
+        m_incomingCalls.begin()->remove();
+    while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
+        m_incomingPolymorphicCalls.begin()->remove();
+    
+    // Note that our outgoing calls will be removed from other CodeBlocks'
+    // m_incomingCalls linked lists through the execution of the ~CallLinkInfo
+    // destructors.
+
+    for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter)
+        (*iter)->deref();
+#endif // ENABLE(JIT)
+}
+
+void CodeBlock::setNumParameters(int newValue)
+{
+    m_numParameters = newValue;
+
+    m_argumentValueProfiles.resizeToFit(newValue);
+}
+
+void EvalCodeCache::visitAggregate(SlotVisitor& visitor)
+{
+    EvalCacheMap::iterator end = m_cacheMap.end();
+    for (EvalCacheMap::iterator ptr = m_cacheMap.begin(); ptr != end; ++ptr)
+        visitor.append(&ptr->value);
+}
+
+CodeBlock* CodeBlock::specialOSREntryBlockOrNull()
+{
+#if ENABLE(FTL_JIT)
+    if (jitType() != JITCode::DFGJIT)
+        return 0;
+    DFG::JITCode* jitCode = m_jitCode->dfg();
+    return jitCode->osrEntryBlock.get();
+#else // ENABLE(FTL_JIT)
+    return 0;
+#endif // ENABLE(FTL_JIT)
+}
+
+void CodeBlock::visitAggregate(SlotVisitor& visitor)
+{
+#if ENABLE(PARALLEL_GC)
+    // I may be asked to scan myself more than once, and it may even happen concurrently.
+    // To this end, use an atomic operation to check (and set) if I've been called already.
+    // Only one thread may proceed past this point - whichever one wins the atomic set race.
+    bool setByMe = m_visitAggregateHasBeenCalled.compareExchangeStrong(false, true);
+    if (!setByMe)
+        return;
+#endif // ENABLE(PARALLEL_GC)
+    
+    if (!!m_alternative)
+        m_alternative->visitAggregate(visitor);
+    
+    if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
+        otherBlock->visitAggregate(visitor);
+
+    visitor.reportExtraMemoryVisited(ownerExecutable(), sizeof(CodeBlock));
+    if (m_jitCode)
+        visitor.reportExtraMemoryVisited(ownerExecutable(), m_jitCode->size());
+    if (m_instructions.size()) {
+        // Divide by refCount() because m_instructions points to something that is shared
+        // by multiple CodeBlocks, and we only want to count it towards the heap size once.
+        // Having each CodeBlock report only its proportional share of the size is one way
+        // of accomplishing this.
+        visitor.reportExtraMemoryVisited(ownerExecutable(), m_instructions.size() * sizeof(Instruction) / m_instructions.refCount());
+    }
+
+    visitor.append(&m_unlinkedCode);
+
+    // There are three things that may use unconditional finalizers: lazy bytecode freeing,
+    // inline cache clearing, and jettisoning. The probability of us wanting to do at
+    // least one of those things is probably quite close to 1. So we add one no matter what
+    // and when it runs, it figures out whether it has any work to do.
+    visitor.addUnconditionalFinalizer(this);
+    
+    m_allTransitionsHaveBeenMarked = false;
+    
+    if (shouldImmediatelyAssumeLivenessDuringScan()) {
+        // This code block is live, so scan all references strongly and return.
+        stronglyVisitStrongReferences(visitor);
+        stronglyVisitWeakReferences(visitor);
+        propagateTransitions(visitor);
+        return;
+    }
+    
+    // There are two things that we use weak reference harvesters for: DFG fixpoint for
+    // jettisoning, and trying to find structures that would be live based on some
+    // inline cache. So it makes sense to register them regardless.
+    visitor.addWeakReferenceHarvester(this);
+
+#if ENABLE(DFG_JIT)
+    // We get here if we're live in the sense that our owner executable is live,
+    // but we're not yet live for sure in another sense: we may yet decide that this
+    // code block should be jettisoned based on its outgoing weak references being
+    // stale. Set a flag to indicate that we're still assuming that we're dead, and
+    // perform one round of determining if we're live. The GC may determine, based on
+    // either us marking additional objects, or by other objects being marked for
+    // other reasons, that this iteration should run again; it will notify us of this
+    // decision by calling harvestWeakReferences().
+    
+    m_jitCode->dfgCommon()->livenessHasBeenProved = false;
+    
+    propagateTransitions(visitor);
+    determineLiveness(visitor);
+#else // ENABLE(DFG_JIT)
+    RELEASE_ASSERT_NOT_REACHED();
+#endif // ENABLE(DFG_JIT)
+}
+
+bool CodeBlock::shouldImmediatelyAssumeLivenessDuringScan()
+{
+#if ENABLE(DFG_JIT)
+    // Interpreter and Baseline JIT CodeBlocks don't need to be jettisoned when
+    // their weak references go stale. So if a basline JIT CodeBlock gets
+    // scanned, we can assume that this means that it's live.
+    if (!JITCode::isOptimizingJIT(jitType()))
+        return true;
+
+    // For simplicity, we don't attempt to jettison code blocks during GC if
+    // they are executing. Instead we strongly mark their weak references to
+    // allow them to continue to execute soundly.
+    if (m_mayBeExecuting)
+        return true;
+
+    if (Options::forceDFGCodeBlockLiveness())
+        return true;
+
+    return false;
+#else
+    return true;
+#endif
+}
+
+bool CodeBlock::isKnownToBeLiveDuringGC()
+{
+#if ENABLE(DFG_JIT)
+    // This should return true for:
+    // - Code blocks that behave like normal objects - i.e. if they are referenced then they
+    //   are live.
+    // - Code blocks that were running on the stack.
+    // - Code blocks that survived the last GC if the current GC is an Eden GC. This is
+    //   because either livenessHasBeenProved would have survived as true or m_mayBeExecuting
+    //   would survive as true.
+    // - Code blocks that don't have any dead weak references.
+    
+    return shouldImmediatelyAssumeLivenessDuringScan()
+        || m_jitCode->dfgCommon()->livenessHasBeenProved;
+#else
+    return true;
+#endif
+}
+
+#if ENABLE(DFG_JIT)
+static bool shouldMarkTransition(DFG::WeakReferenceTransition& transition)
+{
+    if (transition.m_codeOrigin && !Heap::isMarked(transition.m_codeOrigin.get()))
+        return false;
+    
+    if (!Heap::isMarked(transition.m_from.get()))
+        return false;
+    
+    return true;
+}
+#endif // ENABLE(DFG_JIT)
+
+void CodeBlock::propagateTransitions(SlotVisitor& visitor)
+{
+    UNUSED_PARAM(visitor);
+
+    if (m_allTransitionsHaveBeenMarked)
+        return;
+
+    bool allAreMarkedSoFar = true;
+        
+    Interpreter* interpreter = m_vm->interpreter;
+    if (jitType() == JITCode::InterpreterThunk) {
+        const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
+        for (size_t i = 0; i < propertyAccessInstructions.size(); ++i) {
+            Instruction* instruction = &instructions()[propertyAccessInstructions[i]];
+            switch (interpreter->getOpcodeID(instruction[0].u.opcode)) {
+            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: {
+                if (Heap::isMarked(instruction[4].u.structure.get()))
+                    visitor.append(&instruction[6].u.structure);
+                else
+                    allAreMarkedSoFar = false;
+                break;
+            }
+            default:
+                break;
+            }
+        }
+    }
+
+#if ENABLE(JIT)
+    if (JITCode::isJIT(jitType())) {
+        for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter) {
+            StructureStubInfo& stubInfo = **iter;
+            switch (stubInfo.accessType) {
+            case access_put_by_id_transition_normal:
+            case access_put_by_id_transition_direct: {
+                JSCell* origin = stubInfo.codeOrigin.codeOriginOwner();
+                if ((!origin || Heap::isMarked(origin))
+                    && Heap::isMarked(stubInfo.u.putByIdTransition.previousStructure.get()))
+                    visitor.append(&stubInfo.u.putByIdTransition.structure);
+                else
+                    allAreMarkedSoFar = false;
+                break;
+            }
+
+            case access_put_by_id_list: {
+                PolymorphicPutByIdList* list = stubInfo.u.putByIdList.list;
+                JSCell* origin = stubInfo.codeOrigin.codeOriginOwner();
+                if (origin && !Heap::isMarked(origin)) {
+                    allAreMarkedSoFar = false;
+                    break;
+                }
+                for (unsigned j = list->size(); j--;) {
+                    PutByIdAccess& access = list->m_list[j];
+                    if (!access.isTransition())
+                        continue;
+                    if (Heap::isMarked(access.oldStructure()))
+                        visitor.append(&access.m_newStructure);
+                    else
+                        allAreMarkedSoFar = false;
+                }
+                break;
+            }
+            
+            default:
+                break;
+            }
+        }
+    }
+#endif // ENABLE(JIT)
+    
+#if ENABLE(DFG_JIT)
+    if (JITCode::isOptimizingJIT(jitType())) {
+        DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
+        
+        for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
+            if (shouldMarkTransition(dfgCommon->transitions[i])) {
+                // If the following three things are live, then the target of the
+                // transition is also live:
+                //
+                // - This code block. We know it's live already because otherwise
+                //   we wouldn't be scanning ourselves.
+                //
+                // - The code origin of the transition. Transitions may arise from
+                //   code that was inlined. They are not relevant if the user's
+                //   object that is required for the inlinee to run is no longer
+                //   live.
+                //
+                // - The source of the transition. The transition checks if some
+                //   heap location holds the source, and if so, stores the target.
+                //   Hence the source must be live for the transition to be live.
+                //
+                // We also short-circuit the liveness if the structure is harmless
+                // to mark (i.e. its global object and prototype are both already
+                // live).
+                
+                visitor.append(&dfgCommon->transitions[i].m_to);
+            } else
+                allAreMarkedSoFar = false;
+        }
+    }
+#endif // ENABLE(DFG_JIT)
+    
+    if (allAreMarkedSoFar)
+        m_allTransitionsHaveBeenMarked = true;
+}
+
+void CodeBlock::determineLiveness(SlotVisitor& visitor)
+{
+    UNUSED_PARAM(visitor);
+    
+    if (shouldImmediatelyAssumeLivenessDuringScan())
+        return;
+    
+#if ENABLE(DFG_JIT)
+    // Check if we have any remaining work to do.
+    DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
+    if (dfgCommon->livenessHasBeenProved)
+        return;
+    
+    // Now check all of our weak references. If all of them are live, then we
+    // have proved liveness and so we scan our strong references. If at end of
+    // GC we still have not proved liveness, then this code block is toast.
+    bool allAreLiveSoFar = true;
+    for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
+        if (!Heap::isMarked(dfgCommon->weakReferences[i].get())) {
+            allAreLiveSoFar = false;
+            break;
+        }
+    }
+    if (allAreLiveSoFar) {
+        for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i) {
+            if (!Heap::isMarked(dfgCommon->weakStructureReferences[i].get())) {
+                allAreLiveSoFar = false;
+                break;
+            }
+        }
+    }
+    
+    // If some weak references are dead, then this fixpoint iteration was
+    // unsuccessful.
+    if (!allAreLiveSoFar)
+        return;
+    
+    // All weak references are live. Record this information so we don't
+    // come back here again, and scan the strong references.
+    dfgCommon->livenessHasBeenProved = true;
+    stronglyVisitStrongReferences(visitor);
+#endif // ENABLE(DFG_JIT)
+}
+
+void CodeBlock::visitWeakReferences(SlotVisitor& visitor)
+{
+    propagateTransitions(visitor);
+    determineLiveness(visitor);
+}
+
+void CodeBlock::finalizeUnconditionally()
+{
+    Interpreter* interpreter = m_vm->interpreter;
+    if (JITCode::couldBeInterpreted(jitType())) {
+        const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
+        for (size_t size = propertyAccessInstructions.size(), i = 0; i < size; ++i) {
+            Instruction* curInstruction = &instructions()[propertyAccessInstructions[i]];
+            switch (interpreter->getOpcodeID(curInstruction[0].u.opcode)) {
+            case op_get_by_id:
+            case op_get_by_id_out_of_line:
+            case op_put_by_id:
+            case op_put_by_id_out_of_line:
+                if (!curInstruction[4].u.structure || Heap::isMarked(curInstruction[4].u.structure.get()))
+                    break;
+                if (Options::verboseOSR())
+                    dataLogF("Clearing LLInt property access with structure %p.\n", curInstruction[4].u.structure.get());
+                curInstruction[4].u.structure.clear();
+                curInstruction[5].u.operand = 0;
+                break;
+            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:
+                if (Heap::isMarked(curInstruction[4].u.structure.get())
+                    && Heap::isMarked(curInstruction[6].u.structure.get())
+                    && Heap::isMarked(curInstruction[7].u.structureChain.get()))
+                    break;
+                if (Options::verboseOSR()) {
+                    dataLogF("Clearing LLInt put transition with structures %p -> %p, chain %p.\n",
+                            curInstruction[4].u.structure.get(),
+                            curInstruction[6].u.structure.get(),
+                            curInstruction[7].u.structureChain.get());
+                }
+                curInstruction[4].u.structure.clear();
+                curInstruction[6].u.structure.clear();
+                curInstruction[7].u.structureChain.clear();
+                curInstruction[0].u.opcode = interpreter->getOpcode(op_put_by_id);
+                break;
+            case op_get_array_length:
+                break;
+            case op_to_this:
+                if (!curInstruction[2].u.structure || Heap::isMarked(curInstruction[2].u.structure.get()))
+                    break;
+                if (Options::verboseOSR())
+                    dataLogF("Clearing LLInt to_this with structure %p.\n", curInstruction[2].u.structure.get());
+                curInstruction[2].u.structure.clear();
+                curInstruction[3].u.toThisStatus = merge(
+                    curInstruction[3].u.toThisStatus, ToThisClearedByGC);
+                break;
+            case op_create_this: {
+                auto& cacheWriteBarrier = curInstruction[4].u.jsCell;
+                if (!cacheWriteBarrier || cacheWriteBarrier.unvalidatedGet() == JSCell::seenMultipleCalleeObjects())
+                    break;
+                JSCell* cachedFunction = cacheWriteBarrier.get();
+                if (Heap::isMarked(cachedFunction))
+                    break;
+                if (Options::verboseOSR())
+                    dataLogF("Clearing LLInt create_this with cached callee %p.\n", cachedFunction);
+                cacheWriteBarrier.clear();
+                break;
+            }
+            case op_resolve_scope: {
+                // Right now this isn't strictly necessary. Any symbol tables that this will refer to
+                // are for outer functions, and we refer to those functions strongly, and they refer
+                // to the symbol table strongly. But it's nice to be on the safe side.
+                WriteBarrierBase<SymbolTable>& symbolTable = curInstruction[6].u.symbolTable;
+                if (!symbolTable || Heap::isMarked(symbolTable.get()))
+                    break;
+                if (Options::verboseOSR())
+                    dataLogF("Clearing dead symbolTable %p.\n", symbolTable.get());
+                symbolTable.clear();
+                break;
+            }
+            case op_get_from_scope:
+            case op_put_to_scope: {
+                ResolveModeAndType modeAndType =
+                    ResolveModeAndType(curInstruction[4].u.operand);
+                if (modeAndType.type() == GlobalVar || modeAndType.type() == GlobalVarWithVarInjectionChecks || modeAndType.type() == LocalClosureVar)
+                    continue;
+                WriteBarrierBase<Structure>& structure = curInstruction[5].u.structure;
+                if (!structure || Heap::isMarked(structure.get()))
+                    break;
+                if (Options::verboseOSR())
+                    dataLogF("Clearing scope access with structure %p.\n", structure.get());
+                structure.clear();
+                break;
+            }
+            default:
+                OpcodeID opcodeID = interpreter->getOpcodeID(curInstruction[0].u.opcode);
+                ASSERT_WITH_MESSAGE_UNUSED(opcodeID, false, "Unhandled opcode in CodeBlock::finalizeUnconditionally, %s(%d) at bc %u", opcodeNames[opcodeID], opcodeID, propertyAccessInstructions[i]);
+            }
+        }
+
+        for (unsigned i = 0; i < m_llintCallLinkInfos.size(); ++i) {
+            if (m_llintCallLinkInfos[i].isLinked() && !Heap::isMarked(m_llintCallLinkInfos[i].callee.get())) {
+                if (Options::verboseOSR())
+                    dataLog("Clearing LLInt call from ", *this, "\n");
+                m_llintCallLinkInfos[i].unlink();
+            }
+            if (!!m_llintCallLinkInfos[i].lastSeenCallee && !Heap::isMarked(m_llintCallLinkInfos[i].lastSeenCallee.get()))
+                m_llintCallLinkInfos[i].lastSeenCallee.clear();
+        }
+    }
+
+#if ENABLE(DFG_JIT)
+    // Check if we're not live. If we are, then jettison.
+    if (!isKnownToBeLiveDuringGC()) {
+        if (Options::verboseOSR())
+            dataLog(*this, " has dead weak references, jettisoning during GC.\n");
+
+        if (DFG::shouldShowDisassembly()) {
+            dataLog(*this, " will be jettisoned because of the following dead references:\n");
+            DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
+            for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
+                DFG::WeakReferenceTransition& transition = dfgCommon->transitions[i];
+                JSCell* origin = transition.m_codeOrigin.get();
+                JSCell* from = transition.m_from.get();
+                JSCell* to = transition.m_to.get();
+                if ((!origin || Heap::isMarked(origin)) && Heap::isMarked(from))
+                    continue;
+                dataLog("    Transition under ", RawPointer(origin), ", ", RawPointer(from), " -> ", RawPointer(to), ".\n");
+            }
+            for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
+                JSCell* weak = dfgCommon->weakReferences[i].get();
+                if (Heap::isMarked(weak))
+                    continue;
+                dataLog("    Weak reference ", RawPointer(weak), ".\n");
+            }
+        }
+        
+        jettison(Profiler::JettisonDueToWeakReference);
+        return;
+    }
+#endif // ENABLE(DFG_JIT)
+
+#if ENABLE(JIT)
+    // Handle inline caches.
+    if (!!jitCode()) {
+        RepatchBuffer repatchBuffer(this);
+        
+        for (auto iter = callLinkInfosBegin(); !!iter; ++iter)
+            (*iter)->visitWeak(repatchBuffer);
+
+        for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter) {
+            StructureStubInfo& stubInfo = **iter;
+            
+            if (stubInfo.visitWeakReferences(repatchBuffer))
+                continue;
+            
+            resetStubDuringGCInternal(repatchBuffer, stubInfo);
+        }
+    }
+#endif
+}
+
+void CodeBlock::getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result)
+{
+#if ENABLE(JIT)
+    toHashMap(m_stubInfos, getStructureStubInfoCodeOrigin, result);
+#else
+    UNUSED_PARAM(result);
+#endif
+}
+
+void CodeBlock::getStubInfoMap(StubInfoMap& result)
+{
+    ConcurrentJITLocker locker(m_lock);
+    getStubInfoMap(locker, result);
+}
+
+void CodeBlock::getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result)
+{
+#if ENABLE(JIT)
+    toHashMap(m_callLinkInfos, getCallLinkInfoCodeOrigin, result);
+#else
+    UNUSED_PARAM(result);
+#endif
+}
+
+void CodeBlock::getCallLinkInfoMap(CallLinkInfoMap& result)
+{
+    ConcurrentJITLocker locker(m_lock);
+    getCallLinkInfoMap(locker, result);
+}
+
+void CodeBlock::getByValInfoMap(const ConcurrentJITLocker&, ByValInfoMap& result)
+{
+#if ENABLE(JIT)
+    for (auto* byValInfo : m_byValInfos)
+        result.add(CodeOrigin(byValInfo->bytecodeIndex), byValInfo);
+#else
+    UNUSED_PARAM(result);
+#endif
+}
+
+void CodeBlock::getByValInfoMap(ByValInfoMap& result)
+{
+    ConcurrentJITLocker locker(m_lock);
+    getByValInfoMap(locker, result);
+}
+
+#if ENABLE(JIT)
+StructureStubInfo* CodeBlock::addStubInfo()
+{
+    ConcurrentJITLocker locker(m_lock);
+    return m_stubInfos.add();
+}
+
+StructureStubInfo* CodeBlock::findStubInfo(CodeOrigin codeOrigin)
+{
+    for (StructureStubInfo* stubInfo : m_stubInfos) {
+        if (stubInfo->codeOrigin == codeOrigin)
+            return stubInfo;
+    }
+    return nullptr;
+}
+
+ByValInfo* CodeBlock::addByValInfo()
+{
+    ConcurrentJITLocker locker(m_lock);
+    return m_byValInfos.add();
+}
+
+CallLinkInfo* CodeBlock::addCallLinkInfo()
+{
+    ConcurrentJITLocker locker(m_lock);
+    return m_callLinkInfos.add();
+}
+
+void CodeBlock::resetStub(StructureStubInfo& stubInfo)
+{
+    if (stubInfo.accessType == access_unset)
+        return;
+    
+    ConcurrentJITLocker locker(m_lock);
+    
+    RepatchBuffer repatchBuffer(this);
+    resetStubInternal(repatchBuffer, stubInfo);
+}
+
+void CodeBlock::resetStubInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
+{
+    AccessType accessType = static_cast<AccessType>(stubInfo.accessType);
+    
+    if (Options::verboseOSR()) {
+        // This can be called from GC destructor calls, so we don't try to do a full dump
+        // of the CodeBlock.
+        dataLog("Clearing structure cache (kind ", static_cast<int>(stubInfo.accessType), ") in ", RawPointer(this), ".\n");
+    }
+    
+    RELEASE_ASSERT(JITCode::isJIT(jitType()));
+    
+    if (isGetByIdAccess(accessType))
+        resetGetByID(repatchBuffer, stubInfo);
+    else if (isPutByIdAccess(accessType))
+        resetPutByID(repatchBuffer, stubInfo);
+    else {
+        RELEASE_ASSERT(isInAccess(accessType));
+        resetIn(repatchBuffer, stubInfo);
+    }
+    
+    stubInfo.reset();
+}
+
+void CodeBlock::resetStubDuringGCInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
+{
+    resetStubInternal(repatchBuffer, stubInfo);
+    stubInfo.resetByGC = true;
+}
+
+CallLinkInfo* CodeBlock::getCallLinkInfoForBytecodeIndex(unsigned index)
+{
+    for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
+        if ((*iter)->codeOrigin() == CodeOrigin(index))
+            return *iter;
+    }
+    return nullptr;
+}
+#endif
+
+void CodeBlock::stronglyVisitStrongReferences(SlotVisitor& visitor)
+{
+    visitor.append(&m_globalObject);
+    visitor.append(&m_ownerExecutable);
+    visitor.append(&m_unlinkedCode);
+    if (m_rareData)
+        m_rareData->m_evalCodeCache.visitAggregate(visitor);
+    visitor.appendValues(m_constantRegisters.data(), m_constantRegisters.size());
+    for (size_t i = 0; i < m_functionExprs.size(); ++i)
+        visitor.append(&m_functionExprs[i]);
+    for (size_t i = 0; i < m_functionDecls.size(); ++i)
+        visitor.append(&m_functionDecls[i]);
+    for (unsigned i = 0; i < m_objectAllocationProfiles.size(); ++i)
+        m_objectAllocationProfiles[i].visitAggregate(visitor);
+
+#if ENABLE(DFG_JIT)
+    if (JITCode::isOptimizingJIT(jitType())) {
+        // FIXME: This is an antipattern for two reasons. References introduced by the DFG
+        // that aren't in the original CodeBlock being compiled should be weakly referenced.
+        // Inline call frames aren't in the original CodeBlock, so they qualify as weak. Also,
+        // those weak references should already be tracked in the DFG as weak FrozenValues. So,
+        // there is probably no need for this. We already have assertions that this should be
+        // unnecessary.
+        // https://bugs.webkit.org/show_bug.cgi?id=146613
+        DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
+        if (dfgCommon->inlineCallFrames.get())
+            dfgCommon->inlineCallFrames->visitAggregate(visitor);
+    }
+#endif
+
+    updateAllPredictions();
+}
+
+void CodeBlock::stronglyVisitWeakReferences(SlotVisitor& visitor)
+{
+    UNUSED_PARAM(visitor);
+
+#if ENABLE(DFG_JIT)
+    if (!JITCode::isOptimizingJIT(jitType()))
+        return;
+    
+    DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
+
+    for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
+        if (!!dfgCommon->transitions[i].m_codeOrigin)
+            visitor.append(&dfgCommon->transitions[i].m_codeOrigin); // Almost certainly not necessary, since the code origin should also be a weak reference. Better to be safe, though.
+        visitor.append(&dfgCommon->transitions[i].m_from);
+        visitor.append(&dfgCommon->transitions[i].m_to);
+    }
+    
+    for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i)
+        visitor.append(&dfgCommon->weakReferences[i]);
+
+    for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i)
+        visitor.append(&dfgCommon->weakStructureReferences[i]);
+#endif    
+}
+
+CodeBlock* CodeBlock::baselineAlternative()
+{
+#if ENABLE(JIT)
+    CodeBlock* result = this;
+    while (result->alternative())
+        result = result->alternative();
+    RELEASE_ASSERT(result);
+    RELEASE_ASSERT(JITCode::isBaselineCode(result->jitType()) || result->jitType() == JITCode::None);
+    return result;
+#else
+    return this;
+#endif
+}
+
+CodeBlock* CodeBlock::baselineVersion()
+{
+#if ENABLE(JIT)
+    if (JITCode::isBaselineCode(jitType()))
+        return this;
+    CodeBlock* result = replacement();
+    if (!result) {
+        // This can happen if we're creating the original CodeBlock for an executable.
+        // Assume that we're the baseline CodeBlock.
+        RELEASE_ASSERT(jitType() == JITCode::None);
+        return this;
+    }
+    result = result->baselineAlternative();
+    return result;
+#else
+    return this;
+#endif
+}
+
+#if ENABLE(JIT)
+bool CodeBlock::hasOptimizedReplacement(JITCode::JITType typeToReplace)
+{
+    return JITCode::isHigherTier(replacement()->jitType(), typeToReplace);
+}
+
+bool CodeBlock::hasOptimizedReplacement()
+{
+    return hasOptimizedReplacement(jitType());
+}
+#endif
+
+HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler requiredHandler)
+{
+    RELEASE_ASSERT(bytecodeOffset < instructions().size());
+
+    if (!m_rareData)
+        return 0;
+    
+    Vector<HandlerInfo>& exceptionHandlers = m_rareData->m_exceptionHandlers;
+    for (size_t i = 0; i < exceptionHandlers.size(); ++i) {
+        HandlerInfo& handler = exceptionHandlers[i];
+        if ((requiredHandler == RequiredHandler::CatchHandler) && !handler.isCatchHandler())
+            continue;
+
+        // Handlers are ordered innermost first, so the first handler we encounter
+        // that contains the source address is the correct handler to use.
+        if (handler.start <= bytecodeOffset && handler.end > bytecodeOffset)
+            return &handler;
+    }
+
+    return 0;
+}
+
+unsigned CodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
+{
+    RELEASE_ASSERT(bytecodeOffset < instructions().size());
+    return m_ownerExecutable->firstLine() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
+}
+
+unsigned CodeBlock::columnNumberForBytecodeOffset(unsigned bytecodeOffset)
+{
+    int divot;
+    int startOffset;
+    int endOffset;
+    unsigned line;
+    unsigned column;
+    expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
+    return column;
+}
+
+void CodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset, unsigned& line, unsigned& column)
+{
+    m_unlinkedCode->expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
+    divot += m_sourceOffset;
+    column += line ? 1 : firstLineColumnOffset();
+    line += m_ownerExecutable->firstLine();
+}
+
+bool CodeBlock::hasOpDebugForLineAndColumn(unsigned line, unsigned column)
+{
+    Interpreter* interpreter = vm()->interpreter;
+    const Instruction* begin = instructions().begin();
+    const Instruction* end = instructions().end();
+    for (const Instruction* it = begin; it != end;) {
+        OpcodeID opcodeID = interpreter->getOpcodeID(it->u.opcode);
+        if (opcodeID == op_debug) {
+            unsigned bytecodeOffset = it - begin;
+            int unused;
+            unsigned opDebugLine;
+            unsigned opDebugColumn;
+            expressionRangeForBytecodeOffset(bytecodeOffset, unused, unused, unused, opDebugLine, opDebugColumn);
+            if (line == opDebugLine && (column == Breakpoint::unspecifiedColumn || column == opDebugColumn))
+                return true;
+        }
+        it += opcodeLengths[opcodeID];
+    }
+    return false;
+}
+
+void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
+{
+    m_rareCaseProfiles.shrinkToFit();
+    m_specialFastCaseProfiles.shrinkToFit();
+    
+    if (shrinkMode == EarlyShrink) {
+        m_constantRegisters.shrinkToFit();
+        m_constantsSourceCodeRepresentation.shrinkToFit();
+        
+        if (m_rareData) {
+            m_rareData->m_switchJumpTables.shrinkToFit();
+            m_rareData->m_stringSwitchJumpTables.shrinkToFit();
+        }
+    } // else don't shrink these, because we would have already pointed pointers into these tables.
+}
+
+#if ENABLE(JIT)
+void CodeBlock::unlinkCalls()
+{
+    if (!!m_alternative)
+        m_alternative->unlinkCalls();
+    for (size_t i = 0; i < m_llintCallLinkInfos.size(); ++i) {
+        if (m_llintCallLinkInfos[i].isLinked())
+            m_llintCallLinkInfos[i].unlink();
+    }
+    if (m_callLinkInfos.isEmpty())
+        return;
+    if (!m_vm->canUseJIT())
+        return;
+    RepatchBuffer repatchBuffer(this);
+    for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
+        CallLinkInfo& info = **iter;
+        if (!info.isLinked())
+            continue;
+        info.unlink(repatchBuffer);
+    }
+}
+
+void CodeBlock::linkIncomingCall(ExecState* callerFrame, CallLinkInfo* incoming)
+{
+    noticeIncomingCall(callerFrame);
+    m_incomingCalls.push(incoming);
+}
+
+void CodeBlock::linkIncomingPolymorphicCall(ExecState* callerFrame, PolymorphicCallNode* incoming)
+{
+    noticeIncomingCall(callerFrame);
+    m_incomingPolymorphicCalls.push(incoming);
+}
+#endif // ENABLE(JIT)
+
+void CodeBlock::unlinkIncomingCalls()
+{
+    while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
+        m_incomingLLIntCalls.begin()->unlink();
+#if ENABLE(JIT)
+    if (m_incomingCalls.isEmpty() && m_incomingPolymorphicCalls.isEmpty())
+        return;
+    RepatchBuffer repatchBuffer(this);
+    while (m_incomingCalls.begin() != m_incomingCalls.end())
+        m_incomingCalls.begin()->unlink(repatchBuffer);
+    while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
+        m_incomingPolymorphicCalls.begin()->unlink(repatchBuffer);
+#endif // ENABLE(JIT)
+}
+
+void CodeBlock::linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo* incoming)
+{
+    noticeIncomingCall(callerFrame);
+    m_incomingLLIntCalls.push(incoming);
+}
+
+void CodeBlock::install()
+{
+    ownerExecutable()->installCode(this);
+}
+
+PassRefPtr<CodeBlock> CodeBlock::newReplacement()
+{
+    return ownerExecutable()->newReplacementCodeBlockFor(specializationKind());
+}
+
+#if ENABLE(JIT)
+CodeBlock* ProgramCodeBlock::replacement()
+{
+    return jsCast<ProgramExecutable*>(ownerExecutable())->codeBlock();
+}
+
+CodeBlock* EvalCodeBlock::replacement()
+{
+    return jsCast<EvalExecutable*>(ownerExecutable())->codeBlock();
+}
+
+CodeBlock* FunctionCodeBlock::replacement()
+{
+    return jsCast<FunctionExecutable*>(ownerExecutable())->codeBlockFor(m_isConstructor ? CodeForConstruct : CodeForCall);
+}
+
+DFG::CapabilityLevel ProgramCodeBlock::capabilityLevelInternal()
+{
+    return DFG::programCapabilityLevel(this);
+}
+
+DFG::CapabilityLevel EvalCodeBlock::capabilityLevelInternal()
+{
+    return DFG::evalCapabilityLevel(this);
+}
+
+DFG::CapabilityLevel FunctionCodeBlock::capabilityLevelInternal()
+{
+    if (m_isConstructor)
+        return DFG::functionForConstructCapabilityLevel(this);
+    return DFG::functionForCallCapabilityLevel(this);
+}
+#endif
+
+void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mode, const FireDetail* detail)
+{
+    RELEASE_ASSERT(reason != Profiler::NotJettisoned);
+    
+#if ENABLE(DFG_JIT)
+    if (DFG::shouldShowDisassembly()) {
+        dataLog("Jettisoning ", *this);
+        if (mode == CountReoptimization)
+            dataLog(" and counting reoptimization");
+        dataLog(" due to ", reason);
+        if (detail)
+            dataLog(", ", *detail);
+        dataLog(".\n");
+    }
+    
+    DeferGCForAWhile deferGC(*m_heap);
+    RELEASE_ASSERT(JITCode::isOptimizingJIT(jitType()));
+    
+    if (Profiler::Compilation* compilation = jitCode()->dfgCommon()->compilation.get())
+        compilation->setJettisonReason(reason, detail);
+    
+    // We want to accomplish two things here:
+    // 1) Make sure that if this CodeBlock is on the stack right now, then if we return to it
+    //    we should OSR exit at the top of the next bytecode instruction after the return.
+    // 2) Make sure that if we call the owner executable, then we shouldn't call this CodeBlock.
+    
+    // This accomplishes the OSR-exit-on-return part, and does its own book-keeping about
+    // whether the invalidation has already happened.
+    if (!jitCode()->dfgCommon()->invalidate()) {
+        // Nothing to do since we've already been invalidated. That means that we cannot be
+        // the optimized replacement.
+        RELEASE_ASSERT(this != replacement());
+        return;
+    }
+    
+    if (DFG::shouldShowDisassembly())
+        dataLog("    Did invalidate ", *this, "\n");
+    
+    // Count the reoptimization if that's what the user wanted.
+    if (mode == CountReoptimization) {
+        // FIXME: Maybe this should call alternative().
+        // https://bugs.webkit.org/show_bug.cgi?id=123677
+        baselineAlternative()->countReoptimization();
+        if (DFG::shouldShowDisassembly())
+            dataLog("    Did count reoptimization for ", *this, "\n");
+    }
+    
+    // Now take care of the entrypoint.
+    if (this != replacement()) {
+        // This means that we were never the entrypoint. This can happen for OSR entry code
+        // blocks.
+        return;
+    }
+    alternative()->optimizeAfterWarmUp();
+    tallyFrequentExitSites();
+    alternative()->install();
+    if (DFG::shouldShowDisassembly())
+        dataLog("    Did install baseline version of ", *this, "\n");
+#else // ENABLE(DFG_JIT)
+    UNUSED_PARAM(mode);
+    UNUSED_PARAM(detail);
+    UNREACHABLE_FOR_PLATFORM();
+#endif // ENABLE(DFG_JIT)
+}
+
+JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
+{
+    if (!codeOrigin.inlineCallFrame)
+        return globalObject();
+    return jsCast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())->eitherCodeBlock()->globalObject();
+}
+
+class RecursionCheckFunctor {
+public:
+    RecursionCheckFunctor(CallFrame* startCallFrame, CodeBlock* codeBlock, unsigned depthToCheck)
+        : m_startCallFrame(startCallFrame)
+        , m_codeBlock(codeBlock)
+        , m_depthToCheck(depthToCheck)
+        , m_foundStartCallFrame(false)
+        , m_didRecurse(false)
+    { }
+
+    StackVisitor::Status operator()(StackVisitor& visitor)
+    {
+        CallFrame* currentCallFrame = visitor->callFrame();
+
+        if (currentCallFrame == m_startCallFrame)
+            m_foundStartCallFrame = true;
+
+        if (m_foundStartCallFrame) {
+            if (visitor->callFrame()->codeBlock() == m_codeBlock) {
+                m_didRecurse = true;
+                return StackVisitor::Done;
+            }
+
+            if (!m_depthToCheck--)
+                return StackVisitor::Done;
+        }
+
+        return StackVisitor::Continue;
+    }
+
+    bool didRecurse() const { return m_didRecurse; }
+
+private:
+    CallFrame* m_startCallFrame;
+    CodeBlock* m_codeBlock;
+    unsigned m_depthToCheck;
+    bool m_foundStartCallFrame;
+    bool m_didRecurse;
+};
+
+void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
+{
+    CodeBlock* callerCodeBlock = callerFrame->codeBlock();
+    
+    if (Options::verboseCallLink())
+        dataLog("Noticing call link from ", pointerDump(callerCodeBlock), " to ", *this, "\n");
+    
+#if ENABLE(DFG_JIT)
+    if (!m_shouldAlwaysBeInlined)
+        return;
+    
+    if (!callerCodeBlock) {
+        m_shouldAlwaysBeInlined = false;
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI because caller is native.\n");
+        return;
+    }
+
+    if (!hasBaselineJITProfiling())
+        return;
+
+    if (!DFG::mightInlineFunction(this))
+        return;
+
+    if (!canInline(m_capabilityLevelState))
+        return;
+    
+    if (!DFG::isSmallEnoughToInlineCodeInto(callerCodeBlock)) {
+        m_shouldAlwaysBeInlined = false;
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI because caller is too large.\n");
+        return;
+    }
+
+    if (callerCodeBlock->jitType() == JITCode::InterpreterThunk) {
+        // If the caller is still in the interpreter, then we can't expect inlining to
+        // happen anytime soon. Assume it's profitable to optimize it separately. This
+        // ensures that a function is SABI only if it is called no more frequently than
+        // any of its callers.
+        m_shouldAlwaysBeInlined = false;
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI because caller is in LLInt.\n");
+        return;
+    }
+    
+    if (JITCode::isOptimizingJIT(callerCodeBlock->jitType())) {
+        m_shouldAlwaysBeInlined = false;
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI bcause caller was already optimized.\n");
+        return;
+    }
+    
+    if (callerCodeBlock->codeType() != FunctionCode) {
+        // If the caller is either eval or global code, assume that that won't be
+        // optimized anytime soon. For eval code this is particularly true since we
+        // delay eval optimization by a *lot*.
+        m_shouldAlwaysBeInlined = false;
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI because caller is not a function.\n");
+        return;
+    }
+
+    // Recursive calls won't be inlined.
+    RecursionCheckFunctor functor(callerFrame, this, Options::maximumInliningDepth());
+    vm()->topCallFrame->iterate(functor);
+
+    if (functor.didRecurse()) {
+        if (Options::verboseCallLink())
+            dataLog("    Clearing SABI because recursion was detected.\n");
+        m_shouldAlwaysBeInlined = false;
+        return;
+    }
+    
+    if (callerCodeBlock->m_capabilityLevelState == DFG::CapabilityLevelNotSet) {
+        dataLog("In call from ", *callerCodeBlock, " ", callerFrame->codeOrigin(), " to ", *this, ": caller's DFG capability level is not set.\n");
+        CRASH();
+    }
+    
+    if (canCompile(callerCodeBlock->m_capabilityLevelState))
+        return;
+    
+    if (Options::verboseCallLink())
+        dataLog("    Clearing SABI because the caller is not a DFG candidate.\n");
+    
+    m_shouldAlwaysBeInlined = false;
+#endif
+}
+
+unsigned CodeBlock::reoptimizationRetryCounter() const
+{
+#if ENABLE(JIT)
+    ASSERT(m_reoptimizationRetryCounter <= Options::reoptimizationRetryCounterMax());
+    return m_reoptimizationRetryCounter;
+#else
+    return 0;
+#endif // ENABLE(JIT)
+}
+
+#if ENABLE(JIT)
+void CodeBlock::countReoptimization()
+{
+    m_reoptimizationRetryCounter++;
+    if (m_reoptimizationRetryCounter > Options::reoptimizationRetryCounterMax())
+        m_reoptimizationRetryCounter = Options::reoptimizationRetryCounterMax();
+}
+
+unsigned CodeBlock::numberOfDFGCompiles()
+{
+    ASSERT(JITCode::isBaselineCode(jitType()));
+    if (Options::testTheFTL()) {
+        if (m_didFailFTLCompilation)
+            return 1000000;
+        return (m_hasBeenCompiledWithFTL ? 1 : 0) + m_reoptimizationRetryCounter;
+    }
+    return (JITCode::isOptimizingJIT(replacement()->jitType()) ? 1 : 0) + m_reoptimizationRetryCounter;
+}
+
+int32_t CodeBlock::codeTypeThresholdMultiplier() const
+{
+    if (codeType() == EvalCode)
+        return Options::evalThresholdMultiplier();
+    
+    return 1;
+}
+
+double CodeBlock::optimizationThresholdScalingFactor()
+{
+    // This expression arises from doing a least-squares fit of
+    //
+    // F[x_] =: a * Sqrt[x + b] + Abs[c * x] + d
+    //
+    // against the data points:
+    //
+    //    x       F[x_]
+    //    10       0.9          (smallest reasonable code block)
+    //   200       1.0          (typical small-ish code block)
+    //   320       1.2          (something I saw in 3d-cube that I wanted to optimize)
+    //  1268       5.0          (something I saw in 3d-cube that I didn't want to optimize)
+    //  4000       5.5          (random large size, used to cause the function to converge to a shallow curve of some sort)
+    // 10000       6.0          (similar to above)
+    //
+    // I achieve the minimization using the following Mathematica code:
+    //
+    // MyFunctionTemplate[x_, a_, b_, c_, d_] := a*Sqrt[x + b] + Abs[c*x] + d
+    //
+    // samples = {{10, 0.9}, {200, 1}, {320, 1.2}, {1268, 5}, {4000, 5.5}, {10000, 6}}
+    //
+    // solution = 
+    //     Minimize[Plus @@ ((MyFunctionTemplate[#[[1]], a, b, c, d] - #[[2]])^2 & /@ samples),
+    //         {a, b, c, d}][[2]]
+    //
+    // And the code below (to initialize a, b, c, d) is generated by:
+    //
+    // Print["const double " <> ToString[#[[1]]] <> " = " <>
+    //     If[#[[2]] < 0.00001, "0.0", ToString[#[[2]]]] <> ";"] & /@ solution
+    //
+    // We've long known the following to be true:
+    // - Small code blocks are cheap to optimize and so we should do it sooner rather
+    //   than later.
+    // - Large code blocks are expensive to optimize and so we should postpone doing so,
+    //   and sometimes have a large enough threshold that we never optimize them.
+    // - The difference in cost is not totally linear because (a) just invoking the
+    //   DFG incurs some base cost and (b) for large code blocks there is enough slop
+    //   in the correlation between instruction count and the actual compilation cost
+    //   that for those large blocks, the instruction count should not have a strong
+    //   influence on our threshold.
+    //
+    // I knew the goals but I didn't know how to achieve them; so I picked an interesting
+    // example where the heuristics were right (code block in 3d-cube with instruction
+    // count 320, which got compiled early as it should have been) and one where they were
+    // totally wrong (code block in 3d-cube with instruction count 1268, which was expensive
+    // to compile and didn't run often enough to warrant compilation in my opinion), and
+    // then threw in additional data points that represented my own guess of what our
+    // heuristics should do for some round-numbered examples.
+    //
+    // The expression to which I decided to fit the data arose because I started with an
+    // affine function, and then did two things: put the linear part in an Abs to ensure
+    // that the fit didn't end up choosing a negative value of c (which would result in
+    // the function turning over and going negative for large x) and I threw in a Sqrt
+    // term because Sqrt represents my intution that the function should be more sensitive
+    // to small changes in small values of x, but less sensitive when x gets large.
+    
+    // Note that the current fit essentially eliminates the linear portion of the
+    // expression (c == 0.0).
+    const double a = 0.061504;
+    const double b = 1.02406;
+    const double c = 0.0;
+    const double d = 0.825914;
+    
+    double instructionCount = this->instructionCount();
+    
+    ASSERT(instructionCount); // Make sure this is called only after we have an instruction stream; otherwise it'll just return the value of d, which makes no sense.
+    
+    double result = d + a * sqrt(instructionCount + b) + c * instructionCount;
+    
+    result *= codeTypeThresholdMultiplier();
+    
+    if (Options::verboseOSR()) {
+        dataLog(
+            *this, ": instruction count is ", instructionCount,
+            ", scaling execution counter by ", result, " * ", codeTypeThresholdMultiplier(),
+            "\n");
+    }
+    return result;
+}
+
+static int32_t clipThreshold(double threshold)
+{
+    if (threshold < 1.0)
+        return 1;
+    
+    if (threshold > static_cast<double>(std::numeric_limits<int32_t>::max()))
+        return std::numeric_limits<int32_t>::max();
+    
+    return static_cast<int32_t>(threshold);
+}
+
+int32_t CodeBlock::adjustedCounterValue(int32_t desiredThreshold)
+{
+    return clipThreshold(
+        static_cast<double>(desiredThreshold) *
+        optimizationThresholdScalingFactor() *
+        (1 << reoptimizationRetryCounter()));
+}
+
+bool CodeBlock::checkIfOptimizationThresholdReached()
+{
+#if ENABLE(DFG_JIT)
+    if (DFG::Worklist* worklist = DFG::existingGlobalDFGWorklistOrNull()) {
+        if (worklist->compilationState(DFG::CompilationKey(this, DFG::DFGMode))
+            == DFG::Worklist::Compiled) {
+            optimizeNextInvocation();
+            return true;
+        }
+    }
+#endif
+    
+    return m_jitExecuteCounter.checkIfThresholdCrossedAndSet(this);
+}
+
+void CodeBlock::optimizeNextInvocation()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Optimizing next invocation.\n");
+    m_jitExecuteCounter.setNewThreshold(0, this);
+}
+
+void CodeBlock::dontOptimizeAnytimeSoon()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Not optimizing anytime soon.\n");
+    m_jitExecuteCounter.deferIndefinitely();
+}
+
+void CodeBlock::optimizeAfterWarmUp()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Optimizing after warm-up.\n");
+#if ENABLE(DFG_JIT)
+    m_jitExecuteCounter.setNewThreshold(
+        adjustedCounterValue(Options::thresholdForOptimizeAfterWarmUp()), this);
+#endif
+}
+
+void CodeBlock::optimizeAfterLongWarmUp()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Optimizing after long warm-up.\n");
+#if ENABLE(DFG_JIT)
+    m_jitExecuteCounter.setNewThreshold(
+        adjustedCounterValue(Options::thresholdForOptimizeAfterLongWarmUp()), this);
+#endif
+}
+
+void CodeBlock::optimizeSoon()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Optimizing soon.\n");
+#if ENABLE(DFG_JIT)
+    m_jitExecuteCounter.setNewThreshold(
+        adjustedCounterValue(Options::thresholdForOptimizeSoon()), this);
+#endif
+}
+
+void CodeBlock::forceOptimizationSlowPathConcurrently()
+{
+    if (Options::verboseOSR())
+        dataLog(*this, ": Forcing slow path concurrently.\n");
+    m_jitExecuteCounter.forceSlowPathConcurrently();
+}
+
+#if ENABLE(DFG_JIT)
+void CodeBlock::setOptimizationThresholdBasedOnCompilationResult(CompilationResult result)
+{
+    JITCode::JITType type = jitType();
+    if (type != JITCode::BaselineJIT) {
+        dataLog(*this, ": expected to have baseline code but have ", type, "\n");
+        RELEASE_ASSERT_NOT_REACHED();
+    }
+    
+    CodeBlock* theReplacement = replacement();
+    if ((result == CompilationSuccessful) != (theReplacement != this)) {
+        dataLog(*this, ": we have result = ", result, " but ");
+        if (theReplacement == this)
+            dataLog("we are our own replacement.\n");
+        else
+            dataLog("our replacement is ", pointerDump(theReplacement), "\n");
+        RELEASE_ASSERT_NOT_REACHED();
+    }
+    
+    switch (result) {
+    case CompilationSuccessful:
+        RELEASE_ASSERT(JITCode::isOptimizingJIT(replacement()->jitType()));
+        optimizeNextInvocation();
+        return;
+    case CompilationFailed:
+        dontOptimizeAnytimeSoon();
+        return;
+    case CompilationDeferred:
+        // We'd like to do dontOptimizeAnytimeSoon() but we cannot because
+        // forceOptimizationSlowPathConcurrently() is inherently racy. It won't
+        // necessarily guarantee anything. So, we make sure that even if that
+        // function ends up being a no-op, we still eventually retry and realize
+        // that we have optimized code ready.
+        optimizeAfterWarmUp();
+        return;
+    case CompilationInvalidated:
+        // Retry with exponential backoff.
+        countReoptimization();
+        optimizeAfterWarmUp();
+        return;
+    }
+    
+    dataLog("Unrecognized result: ", static_cast<int>(result), "\n");
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+#endif
+    
+uint32_t CodeBlock::adjustedExitCountThreshold(uint32_t desiredThreshold)
+{
+    ASSERT(JITCode::isOptimizingJIT(jitType()));
+    // Compute this the lame way so we don't saturate. This is called infrequently
+    // enough that this loop won't hurt us.
+    unsigned result = desiredThreshold;
+    for (unsigned n = baselineVersion()->reoptimizationRetryCounter(); n--;) {
+        unsigned newResult = result << 1;
+        if (newResult < result)
+            return std::numeric_limits<uint32_t>::max();
+        result = newResult;
+    }
+    return result;
+}
+
+uint32_t CodeBlock::exitCountThresholdForReoptimization()
+{
+    return adjustedExitCountThreshold(Options::osrExitCountForReoptimization() * codeTypeThresholdMultiplier());
+}
+
+uint32_t CodeBlock::exitCountThresholdForReoptimizationFromLoop()
+{
+    return adjustedExitCountThreshold(Options::osrExitCountForReoptimizationFromLoop() * codeTypeThresholdMultiplier());
+}
+
+bool CodeBlock::shouldReoptimizeNow()
+{
+    return osrExitCounter() >= exitCountThresholdForReoptimization();
+}
+
+bool CodeBlock::shouldReoptimizeFromLoopNow()
+{
+    return osrExitCounter() >= exitCountThresholdForReoptimizationFromLoop();
+}
+#endif
+
+ArrayProfile* CodeBlock::getArrayProfile(unsigned bytecodeOffset)
+{
+    for (unsigned i = 0; i < m_arrayProfiles.size(); ++i) {
+        if (m_arrayProfiles[i].bytecodeOffset() == bytecodeOffset)
+            return &m_arrayProfiles[i];
+    }
+    return 0;
+}
+
+ArrayProfile* CodeBlock::getOrAddArrayProfile(unsigned bytecodeOffset)
+{
+    ArrayProfile* result = getArrayProfile(bytecodeOffset);
+    if (result)
+        return result;
+    return addArrayProfile(bytecodeOffset);
+}
+
+void CodeBlock::updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles)
+{
+    ConcurrentJITLocker locker(m_lock);
+    
+    numberOfLiveNonArgumentValueProfiles = 0;
+    numberOfSamplesInProfiles = 0; // If this divided by ValueProfile::numberOfBuckets equals numberOfValueProfiles() then value profiles are full.
+    for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
+        ValueProfile* profile = getFromAllValueProfiles(i);
+        unsigned numSamples = profile->totalNumberOfSamples();
+        if (numSamples > ValueProfile::numberOfBuckets)
+            numSamples = ValueProfile::numberOfBuckets; // We don't want profiles that are extremely hot to be given more weight.
+        numberOfSamplesInProfiles += numSamples;
+        if (profile->m_bytecodeOffset < 0) {
+            profile->computeUpdatedPrediction(locker);
+            continue;
+        }
+        if (profile->numberOfSamples() || profile->m_prediction != SpecNone)
+            numberOfLiveNonArgumentValueProfiles++;
+        profile->computeUpdatedPrediction(locker);
+    }
+    
+#if ENABLE(DFG_JIT)
+    m_lazyOperandValueProfiles.computeUpdatedPredictions(locker);
+#endif
+}
+
+void CodeBlock::updateAllValueProfilePredictions()
+{
+    unsigned ignoredValue1, ignoredValue2;
+    updateAllPredictionsAndCountLiveness(ignoredValue1, ignoredValue2);
+}
+
+void CodeBlock::updateAllArrayPredictions()
+{
+    ConcurrentJITLocker locker(m_lock);
+    
+    for (unsigned i = m_arrayProfiles.size(); i--;)
+        m_arrayProfiles[i].computeUpdatedPrediction(locker, this);
+    
+    // Don't count these either, for similar reasons.
+    for (unsigned i = m_arrayAllocationProfiles.size(); i--;)
+        m_arrayAllocationProfiles[i].updateIndexingType();
+}
+
+void CodeBlock::updateAllPredictions()
+{
+    updateAllValueProfilePredictions();
+    updateAllArrayPredictions();
+}
+
+bool CodeBlock::shouldOptimizeNow()
+{
+    if (Options::verboseOSR())
+        dataLog("Considering optimizing ", *this, "...\n");
+
+    if (m_optimizationDelayCounter >= Options::maximumOptimizationDelay())
+        return true;
+    
+    updateAllArrayPredictions();
+    
+    unsigned numberOfLiveNonArgumentValueProfiles;
+    unsigned numberOfSamplesInProfiles;
+    updateAllPredictionsAndCountLiveness(numberOfLiveNonArgumentValueProfiles, numberOfSamplesInProfiles);
+
+    if (Options::verboseOSR()) {
+        dataLogF(
+            "Profile hotness: %lf (%u / %u), %lf (%u / %u)\n",
+            (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles(),
+            numberOfLiveNonArgumentValueProfiles, numberOfValueProfiles(),
+            (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles(),
+            numberOfSamplesInProfiles, ValueProfile::numberOfBuckets * numberOfValueProfiles());
+    }
+
+    if ((!numberOfValueProfiles() || (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles() >= Options::desiredProfileLivenessRate())
+        && (!totalNumberOfValueProfiles() || (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / totalNumberOfValueProfiles() >= Options::desiredProfileFullnessRate())
+        && static_cast<unsigned>(m_optimizationDelayCounter) + 1 >= Options::minimumOptimizationDelay())
+        return true;
+    
+    ASSERT(m_optimizationDelayCounter < std::numeric_limits<uint8_t>::max());
+    m_optimizationDelayCounter++;
+    optimizeAfterWarmUp();
+    return false;
+}
+
+#if ENABLE(DFG_JIT)
+void CodeBlock::tallyFrequentExitSites()
+{
+    ASSERT(JITCode::isOptimizingJIT(jitType()));
+    ASSERT(alternative()->jitType() == JITCode::BaselineJIT);
+    
+    CodeBlock* profiledBlock = alternative();
+    
+    switch (jitType()) {
+    case JITCode::DFGJIT: {
+        DFG::JITCode* jitCode = m_jitCode->dfg();
+        for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
+            DFG::OSRExit& exit = jitCode->osrExit[i];
+            exit.considerAddingAsFrequentExitSite(profiledBlock);
+        }
+        break;
+    }
+
+#if ENABLE(FTL_JIT)
+    case JITCode::FTLJIT: {
+        // There is no easy way to avoid duplicating this code since the FTL::JITCode::osrExit
+        // vector contains a totally different type, that just so happens to behave like
+        // DFG::JITCode::osrExit.
+        FTL::JITCode* jitCode = m_jitCode->ftl();
+        for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
+            FTL::OSRExit& exit = jitCode->osrExit[i];
+            exit.considerAddingAsFrequentExitSite(profiledBlock);
+        }
+        break;
+    }
+#endif
+        
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        break;
+    }
+}
+#endif // ENABLE(DFG_JIT)
+
+#if ENABLE(VERBOSE_VALUE_PROFILE)
+void CodeBlock::dumpValueProfiles()
+{
+    dataLog("ValueProfile for ", *this, ":\n");
+    for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
+        ValueProfile* profile = getFromAllValueProfiles(i);
+        if (profile->m_bytecodeOffset < 0) {
+            ASSERT(profile->m_bytecodeOffset == -1);
+            dataLogF("   arg = %u: ", i);
+        } else
+            dataLogF("   bc = %d: ", profile->m_bytecodeOffset);
+        if (!profile->numberOfSamples() && profile->m_prediction == SpecNone) {
+            dataLogF("<empty>\n");
+            continue;
+        }
+        profile->dump(WTF::dataFile());
+        dataLogF("\n");
+    }
+    dataLog("RareCaseProfile for ", *this, ":\n");
+    for (unsigned i = 0; i < numberOfRareCaseProfiles(); ++i) {
+        RareCaseProfile* profile = rareCaseProfile(i);
+        dataLogF("   bc = %d: %u\n", profile->m_bytecodeOffset, profile->m_counter);
+    }
+    dataLog("SpecialFastCaseProfile for ", *this, ":\n");
+    for (unsigned i = 0; i < numberOfSpecialFastCaseProfiles(); ++i) {
+        RareCaseProfile* profile = specialFastCaseProfile(i);
+        dataLogF("   bc = %d: %u\n", profile->m_bytecodeOffset, profile->m_counter);
+    }
+}
+#endif // ENABLE(VERBOSE_VALUE_PROFILE)
+
+unsigned CodeBlock::frameRegisterCount()
+{
+    switch (jitType()) {
+    case JITCode::InterpreterThunk:
+        return LLInt::frameRegisterCountFor(this);
+
+#if ENABLE(JIT)
+    case JITCode::BaselineJIT:
+        return JIT::frameRegisterCountFor(this);
+#endif // ENABLE(JIT)
+
+#if ENABLE(DFG_JIT)
+    case JITCode::DFGJIT:
+    case JITCode::FTLJIT:
+        return jitCode()->dfgCommon()->frameRegisterCount;
+#endif // ENABLE(DFG_JIT)
+        
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        return 0;
+    }
+}
+
+int CodeBlock::stackPointerOffset()
+{
+    return virtualRegisterForLocal(frameRegisterCount() - 1).offset();
+}
+
+size_t CodeBlock::predictedMachineCodeSize()
+{
+    // This will be called from CodeBlock::CodeBlock before either m_vm or the
+    // instructions have been initialized. It's OK to return 0 because what will really
+    // matter is the recomputation of this value when the slow path is triggered.
+    if (!m_vm)
+        return 0;
+    
+    if (!m_vm->machineCodeBytesPerBytecodeWordForBaselineJIT)
+        return 0; // It's as good of a prediction as we'll get.
+    
+    // Be conservative: return a size that will be an overestimation 84% of the time.
+    double multiplier = m_vm->machineCodeBytesPerBytecodeWordForBaselineJIT.mean() +
+        m_vm->machineCodeBytesPerBytecodeWordForBaselineJIT.standardDeviation();
+    
+    // Be paranoid: silently reject bogus multipiers. Silently doing the "wrong" thing
+    // here is OK, since this whole method is just a heuristic.
+    if (multiplier < 0 || multiplier > 1000)
+        return 0;
+    
+    double doubleResult = multiplier * m_instructions.size();
+    
+    // Be even more paranoid: silently reject values that won't fit into a size_t. If
+    // the function is so huge that we can't even fit it into virtual memory then we
+    // should probably have some other guards in place to prevent us from even getting
+    // to this point.
+    if (doubleResult > std::numeric_limits<size_t>::max())
+        return 0;
+    
+    return static_cast<size_t>(doubleResult);
+}
+
+bool CodeBlock::usesOpcode(OpcodeID opcodeID)
+{
+    Interpreter* interpreter = vm()->interpreter;
+    Instruction* instructionsBegin = instructions().begin();
+    unsigned instructionCount = instructions().size();
+    
+    for (unsigned bytecodeOffset = 0; bytecodeOffset < instructionCount; ) {
+        switch (interpreter->getOpcodeID(instructionsBegin[bytecodeOffset].u.opcode)) {
+#define DEFINE_OP(curOpcode, length)        \
+        case curOpcode:                     \
+            if (curOpcode == opcodeID)      \
+                return true;                \
+            bytecodeOffset += length;       \
+            break;
+            FOR_EACH_OPCODE_ID(DEFINE_OP)
+#undef DEFINE_OP
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            break;
+        }
+    }
+    
+    return false;
+}
+
+String CodeBlock::nameForRegister(VirtualRegister virtualRegister)
+{
+    for (unsigned i = 0; i < m_constantRegisters.size(); i++) {
+        if (m_constantRegisters[i].get().isEmpty())
+            continue;
+        if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(m_constantRegisters[i].get())) {
+            ConcurrentJITLocker locker(symbolTable->m_lock);
+            auto end = symbolTable->end(locker);
+            for (auto ptr = symbolTable->begin(locker); ptr != end; ++ptr) {
+                if (ptr->value.varOffset() == VarOffset(virtualRegister)) {
+                    // FIXME: This won't work from the compilation thread.
+                    // https://bugs.webkit.org/show_bug.cgi?id=115300
+                    return ptr->key.get();
+                }
+            }
+        }
+    }
+    if (virtualRegister == thisRegister())
+        return ASCIILiteral("this");
+    if (virtualRegister.isArgument())
+        return String::format("arguments[%3d]", virtualRegister.toArgument());
+
+    return "";
+}
+
+ValueProfile* CodeBlock::valueProfileForBytecodeOffset(int bytecodeOffset)
+{
+    ValueProfile* result = binarySearch<ValueProfile, int>(
+        m_valueProfiles, m_valueProfiles.size(), bytecodeOffset,
+        getValueProfileBytecodeOffset<ValueProfile>);
+    ASSERT(result->m_bytecodeOffset != -1);
+    ASSERT(instructions()[bytecodeOffset + opcodeLength(
+        m_vm->interpreter->getOpcodeID(
+            instructions()[bytecodeOffset].u.opcode)) - 1].u.profile == result);
+    return result;
+}
+
+void CodeBlock::validate()
+{
+    BytecodeLivenessAnalysis liveness(this); // Compute directly from scratch so it doesn't effect CodeBlock footprint.
+    
+    FastBitVector liveAtHead = liveness.getLivenessInfoAtBytecodeOffset(0);
+    
+    if (liveAtHead.numBits() != static_cast<size_t>(m_numCalleeRegisters)) {
+        beginValidationDidFail();
+        dataLog("    Wrong number of bits in result!\n");
+        dataLog("    Result: ", liveAtHead, "\n");
+        dataLog("    Bit count: ", liveAtHead.numBits(), "\n");
+        endValidationDidFail();
+    }
+    
+    for (unsigned i = m_numCalleeRegisters; i--;) {
+        VirtualRegister reg = virtualRegisterForLocal(i);
+        
+        if (liveAtHead.get(i)) {
+            beginValidationDidFail();
+            dataLog("    Variable ", reg, " is expected to be dead.\n");
+            dataLog("    Result: ", liveAtHead, "\n");
+            endValidationDidFail();
+        }
+    }
+}
+
+void CodeBlock::beginValidationDidFail()
+{
+    dataLog("Validation failure in ", *this, ":\n");
+    dataLog("\n");
+}
+
+void CodeBlock::endValidationDidFail()
+{
+    dataLog("\n");
+    dumpBytecode();
+    dataLog("\n");
+    dataLog("Validation failure.\n");
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+void CodeBlock::addBreakpoint(unsigned numBreakpoints)
+{
+    m_numBreakpoints += numBreakpoints;
+    ASSERT(m_numBreakpoints);
+    if (JITCode::isOptimizingJIT(jitType()))
+        jettison(Profiler::JettisonDueToDebuggerBreakpoint);
+}
+
+void CodeBlock::setSteppingMode(CodeBlock::SteppingMode mode)
+{
+    m_steppingMode = mode;
+    if (mode == SteppingModeEnabled && JITCode::isOptimizingJIT(jitType()))
+        jettison(Profiler::JettisonDueToDebuggerStepping);
+}
+
+RareCaseProfile* CodeBlock::rareCaseProfileForBytecodeOffset(int bytecodeOffset)
+{
+    return tryBinarySearch<RareCaseProfile, int>(
+        m_rareCaseProfiles, m_rareCaseProfiles.size(), bytecodeOffset,
+        getRareCaseProfileBytecodeOffset);
+}
+
+#if ENABLE(JIT)
+DFG::CapabilityLevel CodeBlock::capabilityLevel()
+{
+    DFG::CapabilityLevel result = capabilityLevelInternal();
+    m_capabilityLevelState = result;
+    return result;
+}
+#endif
+
+void CodeBlock::insertBasicBlockBoundariesForControlFlowProfiler(RefCountedArray<Instruction>& instructions)
+{
+    const Vector<size_t>& bytecodeOffsets = unlinkedCodeBlock()->opProfileControlFlowBytecodeOffsets();
+    for (size_t i = 0, offsetsLength = bytecodeOffsets.size(); i < offsetsLength; i++) {
+        // Because op_profile_control_flow is emitted at the beginning of every basic block, finding 
+        // the next op_profile_control_flow will give us the text range of a single basic block.
+        size_t startIdx = bytecodeOffsets[i];
+        RELEASE_ASSERT(vm()->interpreter->getOpcodeID(instructions[startIdx].u.opcode) == op_profile_control_flow);
+        int basicBlockStartOffset = instructions[startIdx + 1].u.operand;
+        int basicBlockEndOffset;
+        if (i + 1 < offsetsLength) {
+            size_t endIdx = bytecodeOffsets[i + 1];
+            RELEASE_ASSERT(vm()->interpreter->getOpcodeID(instructions[endIdx].u.opcode) == op_profile_control_flow);
+            basicBlockEndOffset = instructions[endIdx + 1].u.operand - 1;
+        } else {
+            basicBlockEndOffset = m_sourceOffset + m_ownerExecutable->source().length() - 1; // Offset before the closing brace.
+            basicBlockStartOffset = std::min(basicBlockStartOffset, basicBlockEndOffset); // Some start offsets may be at the closing brace, ensure it is the offset before.
+        }
+
+        // The following check allows for the same textual JavaScript basic block to have its bytecode emitted more
+        // than once and still play nice with the control flow profiler. When basicBlockStartOffset is larger than 
+        // basicBlockEndOffset, it indicates that the bytecode generator has emitted code for the same AST node 
+        // more than once (for example: ForInNode, Finally blocks in TryNode, etc). Though these are different 
+        // basic blocks at the bytecode level, they are generated from the same textual basic block in the JavaScript 
+        // program. The condition: 
+        // (basicBlockEndOffset < basicBlockStartOffset) 
+        // is encountered when op_profile_control_flow lies across the boundary of these duplicated bytecode basic 
+        // blocks and the textual offset goes from the end of the duplicated block back to the beginning. These 
+        // ranges are dummy ranges and are ignored. The duplicated bytecode basic blocks point to the same 
+        // internal data structure, so if any of them execute, it will record the same textual basic block in the 
+        // JavaScript program as executing.
+        // At the bytecode level, this situation looks like:
+        // j: op_profile_control_flow (from j->k, we have basicBlockEndOffset < basicBlockStartOffset)
+        // ...
+        // k: op_profile_control_flow (we want to skip over the j->k block and start fresh at offset k as the start of a new basic block k->m).
+        // ...
+        // m: op_profile_control_flow
+        if (basicBlockEndOffset < basicBlockStartOffset) {
+            RELEASE_ASSERT(i + 1 < offsetsLength); // We should never encounter dummy blocks at the end of a CodeBlock.
+            instructions[startIdx + 1].u.basicBlockLocation = vm()->controlFlowProfiler()->dummyBasicBlock();
+            continue;
+        }
+
+        BasicBlockLocation* basicBlockLocation = vm()->controlFlowProfiler()->getBasicBlockLocation(m_ownerExecutable->sourceID(), basicBlockStartOffset, basicBlockEndOffset);
+
+        // Find all functions that are enclosed within the range: [basicBlockStartOffset, basicBlockEndOffset]
+        // and insert these functions' start/end offsets as gaps in the current BasicBlockLocation.
+        // This is necessary because in the original source text of a JavaScript program, 
+        // function literals form new basic blocks boundaries, but they aren't represented 
+        // inside the CodeBlock's instruction stream.
+        auto insertFunctionGaps = [basicBlockLocation, basicBlockStartOffset, basicBlockEndOffset] (const WriteBarrier<FunctionExecutable>& functionExecutable) {
+            const UnlinkedFunctionExecutable* executable = functionExecutable->unlinkedExecutable();
+            int functionStart = executable->typeProfilingStartOffset();
+            int functionEnd = executable->typeProfilingEndOffset();
+            if (functionStart >= basicBlockStartOffset && functionEnd <= basicBlockEndOffset)
+                basicBlockLocation->insertGap(functionStart, functionEnd);
+        };
+
+        for (const WriteBarrier<FunctionExecutable>& executable : m_functionDecls)
+            insertFunctionGaps(executable);
+        for (const WriteBarrier<FunctionExecutable>& executable : m_functionExprs)
+            insertFunctionGaps(executable);
+
+        instructions[startIdx + 1].u.basicBlockLocation = basicBlockLocation;
+    }
+}
+
+} // namespace JSC