]> git.saurik.com Git - apple/javascriptcore.git/blobdiff - bytecode/CodeBlock.cpp
JavaScriptCore-1218.tar.gz
[apple/javascriptcore.git] / bytecode / CodeBlock.cpp
index 1f64992ea14580d403e0de8e333352cdc36b1f3c..bd76ef3635d19af198a3eccba4dc2d56c9f1e225 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
  *
  * Redistribution and use in source and binary forms, with or without
 #include "config.h"
 #include "CodeBlock.h"
 
-#include "JIT.h"
-#include "JSValue.h"
-#include "Interpreter.h"
-#include "Debugger.h"
 #include "BytecodeGenerator.h"
+#include "CallLinkStatus.h"
+#include "DFGCapabilities.h"
+#include "DFGCommon.h"
+#include "DFGNode.h"
+#include "DFGRepatch.h"
+#include "Debugger.h"
+#include "Interpreter.h"
+#include "JIT.h"
+#include "JITStubs.h"
+#include "JSActivation.h"
+#include "JSCJSValue.h"
+#include "JSFunction.h"
+#include "JSNameScope.h"
+#include "LowLevelInterpreter.h"
+#include "Operations.h"
+#include "ReduceWhitespace.h"
+#include "RepatchBuffer.h"
+#include "SlotVisitorInlines.h"
 #include <stdio.h>
+#include <wtf/CommaPrinter.h>
 #include <wtf/StringExtras.h>
+#include <wtf/StringPrintStream.h>
+
+#if ENABLE(DFG_JIT)
+#include "DFGOperations.h"
+#endif
 
 #define DUMP_CODE_BLOCK_STATISTICS 0
 
 namespace JSC {
 
-#if !defined(NDEBUG) || ENABLE(OPCODE_SAMPLING)
+#if ENABLE(DFG_JIT)
+using namespace DFG;
+#endif
 
-static UString escapeQuotes(const UString& str)
+String CodeBlock::inferredName() const
 {
-    UString result = str;
-    int pos = 0;
-    while ((pos = result.find('\"', pos)) >= 0) {
-        result = result.substr(0, pos) + "\"\\\"\"" + result.substr(pos + 1);
-        pos += 4;
+    switch (codeType()) {
+    case GlobalCode:
+        return "<global>";
+    case EvalCode:
+        return "<eval>";
+    case FunctionCode:
+        return jsCast<FunctionExecutable*>(ownerExecutable())->inferredName().string();
+    default:
+        CRASH();
+        return String();
     }
-    return result;
 }
 
-static UString valueToSourceString(ExecState* exec, JSValue val)
+CodeBlockHash CodeBlock::hash() const
 {
-    if (!val)
-        return "0";
+    return CodeBlockHash(ownerExecutable()->source(), specializationKind());
+}
 
-    if (val.isString()) {
-        UString result("\"");
-        result += escapeQuotes(val.toString(exec)) + "\"";
-        return result;
-    } 
+String CodeBlock::sourceCodeForTools() const
+{
+    if (codeType() != FunctionCode)
+        return ownerExecutable()->source().toString();
+    
+    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;
+    StringBuilder builder;
+    builder.append("function ");
+    builder.append(provider->getRange(
+        delta + unlinked->functionStartOffset(),
+        delta + unlinked->startOffset() + unlinked->sourceLength()));
+    return builder.toString();
+}
 
-    return val.toString(exec);
+String CodeBlock::sourceCodeOnOneLine() const
+{
+    return reduceWhitespace(sourceCodeForTools());
 }
 
-static CString registerName(int r)
+void CodeBlock::dumpAssumingJITType(PrintStream& out, JITCode::JITType jitType) const
 {
-    if (r == missingThisObjectMarker())
-        return "<null>";
+    out.print(inferredName(), "#", hash(), ":[", RawPointer(this), "->", RawPointer(ownerExecutable()), ", ", jitType, codeType());
+    if (codeType() == FunctionCode)
+        out.print(specializationKind());
+    out.print("]");
+}
+
+void CodeBlock::dump(PrintStream& out) const
+{
+    dumpAssumingJITType(out, getJITType());
+}
+
+static String escapeQuotes(const String& str)
+{
+    String result = str;
+    size_t pos = 0;
+    while ((pos = result.find('\"', pos)) != notFound) {
+        result = makeString(result.substringSharingImpl(0, pos), "\"\\\"\"", result.substringSharingImpl(pos + 1));
+        pos += 4;
+    }
+    return result;
+}
+
+static String valueToSourceString(ExecState* exec, JSValue val)
+{
+    if (!val)
+        return ASCIILiteral("0");
 
-    return (UString("r") + UString::from(r)).UTF8String();
+    if (val.isString())
+        return makeString("\"", escapeQuotes(val.toString(exec)->value(exec)), "\"");
+
+    return toString(val);
 }
 
 static CString constantName(ExecState* exec, int k, JSValue value)
 {
-    return (valueToSourceString(exec, value) + "(@k" + UString::from(k) + ")").UTF8String();
+    return makeString(valueToSourceString(exec, value), "(@k", String::number(k - FirstConstantRegisterIndex), ")").utf8();
 }
 
 static CString idName(int id0, const Identifier& ident)
 {
-    return (ident.ustring() + "(@id" + UString::from(id0) +")").UTF8String();
+    return makeString(ident.string(), "(@id", String::number(id0), ")").utf8();
+}
+
+CString CodeBlock::registerName(ExecState* exec, int r) const
+{
+    if (r == missingThisObjectMarker())
+        return "<null>";
+
+    if (isConstantRegisterIndex(r))
+        return constantName(exec, r, getConstant(r));
+
+    return makeString("r", String::number(r)).utf8();
 }
 
-static UString regexpToSourceString(RegExp* regExp)
+static String regexpToSourceString(RegExp* regExp)
 {
-    UString pattern = UString("/") + regExp->pattern() + "/";
+    char postfix[5] = { '/', 0, 0, 0, 0 };
+    int index = 1;
     if (regExp->global())
-        pattern += "g";
+        postfix[index++] = 'g';
     if (regExp->ignoreCase())
-        pattern += "i";
+        postfix[index++] = 'i';
     if (regExp->multiline())
-        pattern += "m";
+        postfix[index] = 'm';
 
-    return pattern;
+    return makeString("/", regExp->pattern(), postfix);
 }
 
 static CString regexpName(int re, RegExp* regexp)
 {
-    return (regexpToSourceString(regexp) + "(@re" + UString::from(re) + ")").UTF8String();
+    return makeString(regexpToSourceString(regexp), "(@re", String::number(re), ")").utf8();
 }
 
-static UString pointerToSourceString(void* p)
+static String pointerToSourceString(void* p)
 {
     char buffer[2 + 2 * sizeof(void*) + 1]; // 0x [two characters per byte] \0
     snprintf(buffer, sizeof(buffer), "%p", p);
@@ -129,194 +209,311 @@ NEVER_INLINE static const char* debugHookName(int debugHookID)
             return "didReachBreakpoint";
     }
 
-    ASSERT_NOT_REACHED();
+    RELEASE_ASSERT_NOT_REACHED();
     return "";
 }
 
-static int locationForOffset(const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator& it, int offset)
-{
-    return it - begin + offset;
-}
-
-static void printUnaryOp(int location, Vector<Instruction>::const_iterator& it, const char* op)
+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;
 
-    printf("[%4d] %s\t\t %s, %s\n", location, op, registerName(r0).c_str(), registerName(r1).c_str());
+    out.printf("[%4d] %s\t\t %s, %s", location, op, registerName(exec, r0).data(), registerName(exec, r1).data());
 }
 
-static void printBinaryOp(int location, Vector<Instruction>::const_iterator& it, const char* op)
+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;
-    printf("[%4d] %s\t\t %s, %s, %s\n", location, op, registerName(r0).c_str(), registerName(r1).c_str(), registerName(r2).c_str());
+    out.printf("[%4d] %s\t\t %s, %s, %s", location, op, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
 }
 
-static void printConditionalJump(const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator& it, int location, const char* op)
+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;
-    printf("[%4d] %s\t\t %s, %d(->%d)\n", location, op, registerName(r0).c_str(), offset, locationForOffset(begin, it, offset));
+    out.printf("[%4d] %s\t\t %s, %d(->%d)", location, op, registerName(exec, r0).data(), offset, location + offset);
 }
 
-static void printGetByIdOp(int location, Vector<Instruction>::const_iterator& it, const Vector<Identifier>& m_identifiers, const char* op)
+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_by_id_self:
+        op = "get_by_id_self";
+        break;
+    case op_get_by_id_proto:
+        op = "get_by_id_proto";
+        break;
+    case op_get_by_id_chain:
+        op = "get_by_id_chain";
+        break;
+    case op_get_by_id_getter_self:
+        op = "get_by_id_getter_self";
+        break;
+    case op_get_by_id_getter_proto:
+        op = "get_by_id_getter_proto";
+        break;
+    case op_get_by_id_getter_chain:
+        op = "get_by_id_getter_chain";
+        break;
+    case op_get_by_id_custom_self:
+        op = "get_by_id_custom_self";
+        break;
+    case op_get_by_id_custom_proto:
+        op = "get_by_id_custom_proto";
+        break;
+    case op_get_by_id_custom_chain:
+        op = "get_by_id_custom_chain";
+        break;
+    case op_get_by_id_generic:
+        op = "get_by_id_generic";
+        break;
+    case op_get_array_length:
+        op = "array_length";
+        break;
+    case op_get_string_length:
+        op = "string_length";
+        break;
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        op = 0;
+    }
     int r0 = (++it)->u.operand;
     int r1 = (++it)->u.operand;
     int id0 = (++it)->u.operand;
-    printf("[%4d] %s\t %s, %s, %s\n", location, op, registerName(r0).c_str(), registerName(r1).c_str(), idName(id0, m_identifiers[id0]).c_str());
-    it += 4;
+    out.printf("[%4d] %s\t %s, %s, %s", location, op, registerName(exec, r0).data(), registerName(exec, r1).data(), idName(id0, m_identifiers[id0]).data());
+    it += 4; // Increment up to the value profiler.
 }
 
-static void printPutByIdOp(int location, Vector<Instruction>::const_iterator& it, const Vector<Identifier>& m_identifiers, const char* op)
+#if ENABLE(JIT) || ENABLE(LLINT) // unused in some configurations
+static void dumpStructure(PrintStream& out, const char* name, ExecState* exec, Structure* structure, Identifier& ident)
 {
-    int r0 = (++it)->u.operand;
-    int id0 = (++it)->u.operand;
-    int r1 = (++it)->u.operand;
-    printf("[%4d] %s\t %s, %s, %s\n", location, op, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
-    it += 4;
+    if (!structure)
+        return;
+    
+    out.printf("%s = %p", name, structure);
+    
+    PropertyOffset offset = structure->get(exec->vm(), ident);
+    if (offset != invalidOffset)
+        out.printf(" (offset = %d)", offset);
 }
+#endif
 
-#if ENABLE(JIT)
-static bool isGlobalResolve(OpcodeID opcodeID)
+#if ENABLE(JIT) // unused when not ENABLE(JIT), leading to silly warnings
+static void dumpChain(PrintStream& out, ExecState* exec, StructureChain* chain, Identifier& ident)
 {
-    return opcodeID == op_resolve_global;
+    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", exec, currentStructure->get(), ident);
+    }
+    out.printf("]");
 }
+#endif
 
-static bool isPropertyAccess(OpcodeID opcodeID)
+void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int location)
 {
-    switch (opcodeID) {
-        case op_get_by_id_self:
-        case op_get_by_id_proto:
-        case op_get_by_id_chain:
-        case op_get_by_id_self_list:
-        case op_get_by_id_proto_list:
-        case op_put_by_id_transition:
-        case op_put_by_id_replace:
-        case op_get_by_id:
-        case op_put_by_id:
-        case op_get_by_id_generic:
-        case op_put_by_id_generic:
-        case op_get_array_length:
-        case op_get_string_length:
-            return true;
-        default:
-            return false;
+    Instruction* instruction = instructions().begin() + location;
+
+    Identifier& ident = identifier(instruction[3].u.operand);
+    
+    UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
+    
+#if ENABLE(LLINT)
+    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", exec, structure, ident);
+        out.printf(")");
     }
-}
+#endif
 
-static unsigned instructionOffsetForNth(ExecState* exec, const Vector<Instruction>& instructions, int nth, bool (*predicate)(OpcodeID))
-{
-    size_t i = 0;
-    while (i < instructions.size()) {
-        OpcodeID currentOpcode = exec->interpreter()->getOpcodeID(instructions[i].u.opcode);
-        if (predicate(currentOpcode)) {
-            if (!--nth)
-                return i;
+#if ENABLE(JIT)
+    if (numberOfStructureStubInfos()) {
+        StructureStubInfo& stubInfo = getStubInfo(location);
+        if (stubInfo.seen) {
+            out.printf(" jit(");
+            
+            Structure* baseStructure = 0;
+            Structure* prototypeStructure = 0;
+            StructureChain* chain = 0;
+            PolymorphicAccessStructureList* structureList = 0;
+            int listSize = 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_proto:
+                out.printf("proto");
+                baseStructure = stubInfo.u.getByIdProto.baseObjectStructure.get();
+                prototypeStructure = stubInfo.u.getByIdProto.prototypeStructure.get();
+                break;
+            case access_get_by_id_chain:
+                out.printf("chain");
+                baseStructure = stubInfo.u.getByIdChain.baseObjectStructure.get();
+                chain = stubInfo.u.getByIdChain.chain.get();
+                break;
+            case access_get_by_id_self_list:
+                out.printf("self_list");
+                structureList = stubInfo.u.getByIdSelfList.structureList;
+                listSize = stubInfo.u.getByIdSelfList.listSize;
+                break;
+            case access_get_by_id_proto_list:
+                out.printf("proto_list");
+                structureList = stubInfo.u.getByIdProtoList.structureList;
+                listSize = stubInfo.u.getByIdProtoList.listSize;
+                break;
+            case access_unset:
+                out.printf("unset");
+                break;
+            case access_get_by_id_generic:
+                out.printf("generic");
+                break;
+            case access_get_array_length:
+                out.printf("array_length");
+                break;
+            case access_get_string_length:
+                out.printf("string_length");
+                break;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            
+            if (baseStructure) {
+                out.printf(", ");
+                dumpStructure(out, "struct", exec, baseStructure, ident);
+            }
+            
+            if (prototypeStructure) {
+                out.printf(", ");
+                dumpStructure(out, "prototypeStruct", exec, baseStructure, ident);
+            }
+            
+            if (chain) {
+                out.printf(", ");
+                dumpChain(out, exec, chain, ident);
+            }
+            
+            if (structureList) {
+                out.printf(", list = %p: [", structureList);
+                for (int i = 0; i < listSize; ++i) {
+                    if (i)
+                        out.printf(", ");
+                    out.printf("(");
+                    dumpStructure(out, "base", exec, structureList->list[i].base.get(), ident);
+                    if (structureList->list[i].isChain) {
+                        if (structureList->list[i].u.chain.get()) {
+                            out.printf(", ");
+                            dumpChain(out, exec, structureList->list[i].u.chain.get(), ident);
+                        }
+                    } else {
+                        if (structureList->list[i].u.proto.get()) {
+                            out.printf(", ");
+                            dumpStructure(out, "proto", exec, structureList->list[i].u.proto.get(), ident);
+                        }
+                    }
+                    out.printf(")");
+                }
+                out.printf("]");
+            }
+            out.printf(")");
         }
-        i += opcodeLengths[currentOpcode];
     }
-
-    ASSERT_NOT_REACHED();
-    return 0;
+#endif
 }
 
-static void printGlobalResolveInfo(const GlobalResolveInfo& resolveInfo, unsigned instructionOffset)
+void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, CacheDumpMode cacheDumpMode)
 {
-    printf("  [%4d] %s: %s\n", instructionOffset, "resolve_global", pointerToSourceString(resolveInfo.structure).UTF8String().c_str());
+    int func = (++it)->u.operand;
+    int argCount = (++it)->u.operand;
+    int registerOffset = (++it)->u.operand;
+    out.printf("[%4d] %s\t %s, %d, %d", location, op, registerName(exec, func).data(), argCount, registerOffset);
+    if (cacheDumpMode == DumpCaches) {
+#if ENABLE(LLINT)
+        LLIntCallLinkInfo* callLinkInfo = it[1].u.callLinkInfo;
+        if (callLinkInfo->lastSeenCallee) {
+            out.printf(
+                " llint(%p, exec %p)",
+                callLinkInfo->lastSeenCallee.get(),
+                callLinkInfo->lastSeenCallee->executable());
+        }
+#endif
+#if ENABLE(JIT)
+        if (numberOfCallLinkInfos()) {
+            JSFunction* target = getCallLinkInfo(location).lastSeenCallee.get();
+            if (target)
+                out.printf(" jit(%p, exec %p)", target, target->executable());
+        }
+#endif
+        out.print(" status(", CallLinkStatus::computeFor(this, location), ")");
+    }
+    it += 2;
 }
 
-static void printStructureStubInfo(const StructureStubInfo& stubInfo, unsigned instructionOffset)
+void CodeBlock::printPutByIdOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
 {
-    switch (stubInfo.opcodeID) {
-    case op_get_by_id_self:
-        printf("  [%4d] %s: %s\n", instructionOffset, "get_by_id_self", pointerToSourceString(stubInfo.u.getByIdSelf.baseObjectStructure).UTF8String().c_str());
-        return;
-    case op_get_by_id_proto:
-        printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_proto", pointerToSourceString(stubInfo.u.getByIdProto.baseObjectStructure).UTF8String().c_str(), pointerToSourceString(stubInfo.u.getByIdProto.prototypeStructure).UTF8String().c_str());
-        return;
-    case op_get_by_id_chain:
-        printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_chain", pointerToSourceString(stubInfo.u.getByIdChain.baseObjectStructure).UTF8String().c_str(), pointerToSourceString(stubInfo.u.getByIdChain.chain).UTF8String().c_str());
-        return;
-    case op_get_by_id_self_list:
-        printf("  [%4d] %s: %s (%d)\n", instructionOffset, "op_get_by_id_self_list", pointerToSourceString(stubInfo.u.getByIdSelfList.structureList).UTF8String().c_str(), stubInfo.u.getByIdSelfList.listSize);
-        return;
-    case op_get_by_id_proto_list:
-        printf("  [%4d] %s: %s (%d)\n", instructionOffset, "op_get_by_id_proto_list", pointerToSourceString(stubInfo.u.getByIdProtoList.structureList).UTF8String().c_str(), stubInfo.u.getByIdProtoList.listSize);
-        return;
-    case op_put_by_id_transition:
-        printf("  [%4d] %s: %s, %s, %s\n", instructionOffset, "put_by_id_transition", pointerToSourceString(stubInfo.u.putByIdTransition.previousStructure).UTF8String().c_str(), pointerToSourceString(stubInfo.u.putByIdTransition.structure).UTF8String().c_str(), pointerToSourceString(stubInfo.u.putByIdTransition.chain).UTF8String().c_str());
-        return;
-    case op_put_by_id_replace:
-        printf("  [%4d] %s: %s\n", instructionOffset, "put_by_id_replace", pointerToSourceString(stubInfo.u.putByIdReplace.baseObjectStructure).UTF8String().c_str());
-        return;
-    case op_get_by_id:
-        printf("  [%4d] %s\n", instructionOffset, "get_by_id");
-        return;
-    case op_put_by_id:
-        printf("  [%4d] %s\n", instructionOffset, "put_by_id");
-        return;
-    case op_get_by_id_generic:
-        printf("  [%4d] %s\n", instructionOffset, "op_get_by_id_generic");
-        return;
-    case op_put_by_id_generic:
-        printf("  [%4d] %s\n", instructionOffset, "op_put_by_id_generic");
-        return;
-    case op_get_array_length:
-        printf("  [%4d] %s\n", instructionOffset, "op_get_array_length");
-        return;
-    case op_get_string_length:
-        printf("  [%4d] %s\n", instructionOffset, "op_get_string_length");
-        return;
-    default:
-        ASSERT_NOT_REACHED();
-    }
+    int r0 = (++it)->u.operand;
+    int id0 = (++it)->u.operand;
+    int r1 = (++it)->u.operand;
+    out.printf("[%4d] %s\t %s, %s, %s", location, op, registerName(exec, r0).data(), idName(id0, m_identifiers[id0]).data(), registerName(exec, r1).data());
+    it += 5;
 }
-#endif
 
-void CodeBlock::printStructure(const char* name, const Instruction* vPC, int operand) const
+void CodeBlock::printStructure(PrintStream& out, const char* name, const Instruction* vPC, int operand)
 {
-    unsigned instructionOffset = vPC - m_instructions.begin();
-    printf("  [%4d] %s: %s\n", instructionOffset, name, pointerToSourceString(vPC[operand].u.structure).UTF8String().c_str());
+    unsigned instructionOffset = vPC - instructions().begin();
+    out.printf("  [%4d] %s: %s\n", instructionOffset, name, pointerToSourceString(vPC[operand].u.structure).utf8().data());
 }
 
-void CodeBlock::printStructures(const Instruction* vPC) const
+void CodeBlock::printStructures(PrintStream& out, const Instruction* vPC)
 {
-    Interpreter* interpreter = m_globalData->interpreter;
-    unsigned instructionOffset = vPC - m_instructions.begin();
+    Interpreter* interpreter = m_vm->interpreter;
+    unsigned instructionOffset = vPC - instructions().begin();
 
     if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id)) {
-        printStructure("get_by_id", vPC, 4);
+        printStructure(out, "get_by_id", vPC, 4);
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self)) {
-        printStructure("get_by_id_self", vPC, 4);
+        printStructure(out, "get_by_id_self", vPC, 4);
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto)) {
-        printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_proto", pointerToSourceString(vPC[4].u.structure).UTF8String().c_str(), pointerToSourceString(vPC[5].u.structure).UTF8String().c_str());
+        out.printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_proto", pointerToSourceString(vPC[4].u.structure).utf8().data(), pointerToSourceString(vPC[5].u.structure).utf8().data());
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_transition)) {
-        printf("  [%4d] %s: %s, %s, %s\n", instructionOffset, "put_by_id_transition", pointerToSourceString(vPC[4].u.structure).UTF8String().c_str(), pointerToSourceString(vPC[5].u.structure).UTF8String().c_str(), pointerToSourceString(vPC[6].u.structureChain).UTF8String().c_str());
+        out.printf("  [%4d] %s: %s, %s, %s\n", instructionOffset, "put_by_id_transition", pointerToSourceString(vPC[4].u.structure).utf8().data(), pointerToSourceString(vPC[5].u.structure).utf8().data(), pointerToSourceString(vPC[6].u.structureChain).utf8().data());
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain)) {
-        printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_chain", pointerToSourceString(vPC[4].u.structure).UTF8String().c_str(), pointerToSourceString(vPC[5].u.structureChain).UTF8String().c_str());
+        out.printf("  [%4d] %s: %s, %s\n", instructionOffset, "get_by_id_chain", pointerToSourceString(vPC[4].u.structure).utf8().data(), pointerToSourceString(vPC[5].u.structureChain).utf8().data());
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id)) {
-        printStructure("put_by_id", vPC, 4);
+        printStructure(out, "put_by_id", vPC, 4);
         return;
     }
     if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_replace)) {
-        printStructure("put_by_id_replace", vPC, 4);
-        return;
-    }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global)) {
-        printStructure("resolve_global", vPC, 4);
+        printStructure(out, "put_by_id_replace", vPC, 4);
         return;
     }
 
@@ -324,126 +521,106 @@ void CodeBlock::printStructures(const Instruction* vPC) const
     ASSERT(vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_call) || vPC[0].u.opcode == interpreter->getOpcode(op_call_eval) || vPC[0].u.opcode == interpreter->getOpcode(op_construct));
 }
 
-void CodeBlock::dump(ExecState* exec) const
+void CodeBlock::dumpBytecode(PrintStream& out)
 {
-    if (m_instructions.isEmpty()) {
-        printf("No instructions available.\n");
-        return;
-    }
-
+    // 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 < m_instructions.size(); i += opcodeLengths[exec->interpreter()->getOpcodeID(m_instructions[i].u.opcode)])
+    for (size_t i = 0; i < instructions().size(); i += opcodeLengths[exec->interpreter()->getOpcodeID(instructions()[i].u.opcode)])
         ++instructionCount;
 
-    printf("%lu m_instructions; %lu bytes at %p; %d parameter(s); %d callee register(s)\n\n",
-        static_cast<unsigned long>(instructionCount),
-        static_cast<unsigned long>(m_instructions.size() * sizeof(Instruction)),
-        this, m_numParameters, m_numCalleeRegisters);
+    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 (symbolTable() && symbolTable()->captureCount()) {
+        out.printf(
+            "; %d captured var(s) (from r%d to r%d, inclusive)",
+            symbolTable()->captureCount(), symbolTable()->captureStart(), symbolTable()->captureEnd() - 1);
+    }
+    if (usesArguments()) {
+        out.printf(
+            "; uses arguments, in r%d, r%d",
+            argumentsRegister(),
+            unmodifiedArgumentsRegister(argumentsRegister()));
+    }
+    if (needsFullScopeChain() && codeType() == FunctionCode)
+        out.printf("; activation in r%d", activationRegister());
+    out.print("\n\nSource: ", sourceCodeOnOneLine(), "\n\n");
 
-    Vector<Instruction>::const_iterator begin = m_instructions.begin();
-    Vector<Instruction>::const_iterator end = m_instructions.end();
-    for (Vector<Instruction>::const_iterator it = begin; it != end; ++it)
-        dump(exec, begin, it);
+    const Instruction* begin = instructions().begin();
+    const Instruction* end = instructions().end();
+    for (const Instruction* it = begin; it != end; ++it)
+        dumpBytecode(out, exec, begin, it);
 
     if (!m_identifiers.isEmpty()) {
-        printf("\nIdentifiers:\n");
+        out.printf("\nIdentifiers:\n");
         size_t i = 0;
         do {
-            printf("  id%u = %s\n", static_cast<unsigned>(i), m_identifiers[i].ascii());
+            out.printf("  id%u = %s\n", static_cast<unsigned>(i), m_identifiers[i].string().utf8().data());
             ++i;
         } while (i != m_identifiers.size());
     }
 
     if (!m_constantRegisters.isEmpty()) {
-        printf("\nConstants:\n");
-        unsigned registerIndex = m_numVars;
+        out.printf("\nConstants:\n");
         size_t i = 0;
         do {
-            printf("   r%u = %s\n", registerIndex, valueToSourceString(exec, m_constantRegisters[i].jsValue()).ascii());
+            out.printf("   k%u = %s\n", static_cast<unsigned>(i), valueToSourceString(exec, m_constantRegisters[i].get()).utf8().data());
             ++i;
-            ++registerIndex;
         } while (i < m_constantRegisters.size());
     }
 
-    if (m_rareData && !m_rareData->m_regexps.isEmpty()) {
-        printf("\nm_regexps:\n");
+    if (size_t count = m_unlinkedCode->numberOfRegExps()) {
+        out.printf("\nm_regexps:\n");
         size_t i = 0;
         do {
-            printf("  re%u = %s\n", static_cast<unsigned>(i), regexpToSourceString(m_rareData->m_regexps[i].get()).ascii());
+            out.printf("  re%u = %s\n", static_cast<unsigned>(i), regexpToSourceString(m_unlinkedCode->regexp(i)).utf8().data());
             ++i;
-        } while (i < m_rareData->m_regexps.size());
+        } while (i < count);
     }
 
 #if ENABLE(JIT)
-    if (!m_globalResolveInfos.isEmpty() || !m_structureStubInfos.isEmpty())
-        printf("\nStructures:\n");
-
-    if (!m_globalResolveInfos.isEmpty()) {
-        size_t i = 0;
-        do {
-             printGlobalResolveInfo(m_globalResolveInfos[i], instructionOffsetForNth(exec, m_instructions, i + 1, isGlobalResolve));
-             ++i;
-        } while (i < m_globalResolveInfos.size());
-    }
-    if (!m_structureStubInfos.isEmpty()) {
-        size_t i = 0;
-        do {
-            printStructureStubInfo(m_structureStubInfos[i], instructionOffsetForNth(exec, m_instructions, i + 1, isPropertyAccess));
-             ++i;
-        } while (i < m_structureStubInfos.size());
-    }
-#else
-    if (!m_globalResolveInstructions.isEmpty() || !m_propertyAccessInstructions.isEmpty())
-        printf("\nStructures:\n");
-
-    if (!m_globalResolveInstructions.isEmpty()) {
-        size_t i = 0;
-        do {
-             printStructures(&m_instructions[m_globalResolveInstructions[i]]);
-             ++i;
-        } while (i < m_globalResolveInstructions.size());
-    }
-    if (!m_propertyAccessInstructions.isEmpty()) {
-        size_t i = 0;
-        do {
-            printStructures(&m_instructions[m_propertyAccessInstructions[i]]);
-             ++i;
-        } while (i < m_propertyAccessInstructions.size());
-    }
+    if (!m_structureStubInfos.isEmpty())
+        out.printf("\nStructures:\n");
 #endif
 
     if (m_rareData && !m_rareData->m_exceptionHandlers.isEmpty()) {
-        printf("\nException Handlers:\n");
+        out.printf("\nException Handlers:\n");
         unsigned i = 0;
         do {
-            printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] }\n", i + 1, m_rareData->m_exceptionHandlers[i].start, m_rareData->m_exceptionHandlers[i].end, m_rareData->m_exceptionHandlers[i].target);
+            out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] depth: [%4d] }\n", i + 1, m_rareData->m_exceptionHandlers[i].start, m_rareData->m_exceptionHandlers[i].end, m_rareData->m_exceptionHandlers[i].target, m_rareData->m_exceptionHandlers[i].scopeDepth);
             ++i;
         } while (i < m_rareData->m_exceptionHandlers.size());
     }
     
     if (m_rareData && !m_rareData->m_immediateSwitchJumpTables.isEmpty()) {
-        printf("Immediate Switch Jump Tables:\n");
+        out.printf("Immediate Switch Jump Tables:\n");
         unsigned i = 0;
         do {
-            printf("  %1d = {\n", i);
+            out.printf("  %1d = {\n", i);
             int entry = 0;
             Vector<int32_t>::const_iterator end = m_rareData->m_immediateSwitchJumpTables[i].branchOffsets.end();
             for (Vector<int32_t>::const_iterator iter = m_rareData->m_immediateSwitchJumpTables[i].branchOffsets.begin(); iter != end; ++iter, ++entry) {
                 if (!*iter)
                     continue;
-                printf("\t\t%4d => %04d\n", entry + m_rareData->m_immediateSwitchJumpTables[i].min, *iter);
+                out.printf("\t\t%4d => %04d\n", entry + m_rareData->m_immediateSwitchJumpTables[i].min, *iter);
             }
-            printf("      }\n");
+            out.printf("      }\n");
             ++i;
         } while (i < m_rareData->m_immediateSwitchJumpTables.size());
     }
     
     if (m_rareData && !m_rareData->m_characterSwitchJumpTables.isEmpty()) {
-        printf("\nCharacter Switch Jump Tables:\n");
+        out.printf("\nCharacter Switch Jump Tables:\n");
         unsigned i = 0;
         do {
-            printf("  %1d = {\n", i);
+            out.printf("  %1d = {\n", i);
             int entry = 0;
             Vector<int32_t>::const_iterator end = m_rareData->m_characterSwitchJumpTables[i].branchOffsets.end();
             for (Vector<int32_t>::const_iterator iter = m_rareData->m_characterSwitchJumpTables[i].branchOffsets.begin(); iter != end; ++iter, ++entry) {
@@ -451,661 +628,839 @@ void CodeBlock::dump(ExecState* exec) const
                     continue;
                 ASSERT(!((i + m_rareData->m_characterSwitchJumpTables[i].min) & ~0xFFFF));
                 UChar ch = static_cast<UChar>(entry + m_rareData->m_characterSwitchJumpTables[i].min);
-                printf("\t\t\"%s\" => %04d\n", UString(&ch, 1).ascii(), *iter);
-        }
-            printf("      }\n");
+                out.printf("\t\t\"%s\" => %04d\n", String(&ch, 1).utf8().data(), *iter);
+            }
+            out.printf("      }\n");
             ++i;
         } while (i < m_rareData->m_characterSwitchJumpTables.size());
     }
     
     if (m_rareData && !m_rareData->m_stringSwitchJumpTables.isEmpty()) {
-        printf("\nString Switch Jump Tables:\n");
+        out.printf("\nString Switch Jump Tables:\n");
         unsigned i = 0;
         do {
-            printf("  %1d = {\n", i);
+            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)
-                printf("\t\t\"%s\" => %04d\n", UString(iter->first).ascii(), iter->second.branchOffset);
-            printf("      }\n");
+                out.printf("\t\t\"%s\" => %04d\n", String(iter->key).utf8().data(), iter->value.branchOffset);
+            out.printf("      }\n");
             ++i;
         } while (i < m_rareData->m_stringSwitchJumpTables.size());
     }
 
-    printf("\n");
+    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)
+{
+    ++it;
+#if ENABLE(VALUE_PROFILER)
+    CString description = it->u.profile->briefDescription();
+    if (!description.length())
+        return;
+    beginDumpProfiling(out, hasPrintedProfiling);
+    out.print(description);
+#else
+    UNUSED_PARAM(out);
+    UNUSED_PARAM(hasPrintedProfiling);
+#endif
+}
+
+void CodeBlock::dumpArrayProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
+{
+    ++it;
+#if ENABLE(VALUE_PROFILER)
+    CString description = it->u.arrayProfile->briefDescription(this);
+    if (!description.length())
+        return;
+    beginDumpProfiling(out, hasPrintedProfiling);
+    out.print(description);
+#else
+    UNUSED_PARAM(out);
+    UNUSED_PARAM(hasPrintedProfiling);
+#endif
+}
+
+#if ENABLE(VALUE_PROFILER)
+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);
 }
+#endif
 
-void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator& it) const
+void CodeBlock::dumpBytecode(PrintStream& out, ExecState* exec, const Instruction* begin, const Instruction*& it)
 {
     int location = it - begin;
+    bool hasPrintedProfiling = false;
     switch (exec->interpreter()->getOpcodeID(it->u.opcode)) {
         case op_enter: {
-            printf("[%4d] enter\n", location);
+            out.printf("[%4d] enter", location);
             break;
         }
-        case op_enter_with_activation: {
+        case op_create_activation: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] enter_with_activation %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] create_activation %s", location, registerName(exec, r0).data());
             break;
         }
         case op_create_arguments: {
-            printf("[%4d] create_arguments\n", location);
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] create_arguments\t %s", location, registerName(exec, r0).data());
+            break;
+        }
+        case op_init_lazy_reg: {
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] init_lazy_reg\t %s", location, registerName(exec, r0).data());
+            break;
+        }
+        case op_get_callee: {
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] op_get_callee %s\n", location, registerName(exec, r0).data());
+            ++it;
             break;
         }
-        case op_init_arguments: {
-            printf("[%4d] init_arguments\n", location);
+        case op_create_this: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            unsigned inferredInlineCapacity = (++it)->u.operand;
+            out.printf("[%4d] create_this %s, %s, %u", location, registerName(exec, r0).data(), registerName(exec, r1).data(), inferredInlineCapacity);
             break;
         }
         case op_convert_this: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] convert_this %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] convert_this\t %s", location, registerName(exec, r0).data());
+            ++it; // Skip value profile.
             break;
         }
         case op_new_object: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] new_object\t %s\n", location, registerName(r0).c_str());
+            unsigned inferredInlineCapacity = (++it)->u.operand;
+            out.printf("[%4d] new_object\t %s, %u", location, registerName(exec, 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;
-            printf("[%4d] new_array\t %s, %s, %d\n", location, registerName(dst).c_str(), registerName(argv).c_str(), argc);
+            out.printf("[%4d] new_array\t %s, %s, %d", location, registerName(exec, dst).data(), registerName(exec, 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;
+            out.printf("[%4d] new_array_with_size\t %s, %s", location, registerName(exec, dst).data(), registerName(exec, 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;
+            out.printf("[%4d] new_array_buffer\t %s, %d, %d", location, registerName(exec, dst).data(), argv, argc);
+            ++it; // Skip array allocation profile.
             break;
         }
         case op_new_regexp: {
             int r0 = (++it)->u.operand;
             int re0 = (++it)->u.operand;
-            printf("[%4d] new_regexp\t %s, %s\n", location, registerName(r0).c_str(), regexpName(re0, regexp(re0)).c_str());
+            out.printf("[%4d] new_regexp\t %s, ", location, registerName(exec, 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;
-            printf("[%4d] mov\t\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
+            out.printf("[%4d] mov\t\t %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data());
             break;
         }
         case op_not: {
-            printUnaryOp(location, it, "not");
+            printUnaryOp(out, exec, location, it, "not");
             break;
         }
         case op_eq: {
-            printBinaryOp(location, it, "eq");
+            printBinaryOp(out, exec, location, it, "eq");
             break;
         }
         case op_eq_null: {
-            printUnaryOp(location, it, "eq_null");
+            printUnaryOp(out, exec, location, it, "eq_null");
             break;
         }
         case op_neq: {
-            printBinaryOp(location, it, "neq");
+            printBinaryOp(out, exec, location, it, "neq");
             break;
         }
         case op_neq_null: {
-            printUnaryOp(location, it, "neq_null");
+            printUnaryOp(out, exec, location, it, "neq_null");
             break;
         }
         case op_stricteq: {
-            printBinaryOp(location, it, "stricteq");
+            printBinaryOp(out, exec, location, it, "stricteq");
             break;
         }
         case op_nstricteq: {
-            printBinaryOp(location, it, "nstricteq");
+            printBinaryOp(out, exec, location, it, "nstricteq");
             break;
         }
         case op_less: {
-            printBinaryOp(location, it, "less");
+            printBinaryOp(out, exec, location, it, "less");
             break;
         }
         case op_lesseq: {
-            printBinaryOp(location, it, "lesseq");
+            printBinaryOp(out, exec, location, it, "lesseq");
             break;
         }
-        case op_pre_inc: {
-            int r0 = (++it)->u.operand;
-            printf("[%4d] pre_inc\t\t %s\n", location, registerName(r0).c_str());
+        case op_greater: {
+            printBinaryOp(out, exec, location, it, "greater");
             break;
         }
-        case op_pre_dec: {
-            int r0 = (++it)->u.operand;
-            printf("[%4d] pre_dec\t\t %s\n", location, registerName(r0).c_str());
+        case op_greatereq: {
+            printBinaryOp(out, exec, location, it, "greatereq");
             break;
         }
-        case op_post_inc: {
-            printUnaryOp(location, it, "post_inc");
+        case op_inc: {
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] pre_inc\t\t %s", location, registerName(exec, r0).data());
             break;
         }
-        case op_post_dec: {
-            printUnaryOp(location, it, "post_dec");
+        case op_dec: {
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] pre_dec\t\t %s", location, registerName(exec, r0).data());
             break;
         }
-        case op_to_jsnumber: {
-            printUnaryOp(location, it, "to_jsnumber");
+        case op_to_number: {
+            printUnaryOp(out, exec, location, it, "to_number");
             break;
         }
         case op_negate: {
-            printUnaryOp(location, it, "negate");
+            printUnaryOp(out, exec, location, it, "negate");
             break;
         }
         case op_add: {
-            printBinaryOp(location, it, "add");
+            printBinaryOp(out, exec, location, it, "add");
             ++it;
             break;
         }
         case op_mul: {
-            printBinaryOp(location, it, "mul");
+            printBinaryOp(out, exec, location, it, "mul");
             ++it;
             break;
         }
         case op_div: {
-            printBinaryOp(location, it, "div");
+            printBinaryOp(out, exec, location, it, "div");
             ++it;
             break;
         }
         case op_mod: {
-            printBinaryOp(location, it, "mod");
+            printBinaryOp(out, exec, location, it, "mod");
             break;
         }
         case op_sub: {
-            printBinaryOp(location, it, "sub");
+            printBinaryOp(out, exec, location, it, "sub");
             ++it;
             break;
         }
         case op_lshift: {
-            printBinaryOp(location, it, "lshift");
+            printBinaryOp(out, exec, location, it, "lshift");
             break;            
         }
         case op_rshift: {
-            printBinaryOp(location, it, "rshift");
+            printBinaryOp(out, exec, location, it, "rshift");
             break;
         }
         case op_urshift: {
-            printBinaryOp(location, it, "urshift");
+            printBinaryOp(out, exec, location, it, "urshift");
             break;
         }
         case op_bitand: {
-            printBinaryOp(location, it, "bitand");
+            printBinaryOp(out, exec, location, it, "bitand");
             ++it;
             break;
         }
         case op_bitxor: {
-            printBinaryOp(location, it, "bitxor");
+            printBinaryOp(out, exec, location, it, "bitxor");
             ++it;
             break;
         }
         case op_bitor: {
-            printBinaryOp(location, it, "bitor");
+            printBinaryOp(out, exec, location, it, "bitor");
             ++it;
             break;
         }
-        case op_bitnot: {
-            printUnaryOp(location, it, "bitnot");
+        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;
+            out.printf("[%4d] check_has_instance\t\t %s, %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data(), offset, location + offset);
             break;
         }
         case op_instanceof: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int r2 = (++it)->u.operand;
-            int r3 = (++it)->u.operand;
-            printf("[%4d] instanceof\t\t %s, %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), registerName(r2).c_str(), registerName(r3).c_str());
+            out.printf("[%4d] instanceof\t\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
             break;
         }
         case op_typeof: {
-            printUnaryOp(location, it, "typeof");
+            printUnaryOp(out, exec, location, it, "typeof");
             break;
         }
         case op_is_undefined: {
-            printUnaryOp(location, it, "is_undefined");
+            printUnaryOp(out, exec, location, it, "is_undefined");
             break;
         }
         case op_is_boolean: {
-            printUnaryOp(location, it, "is_boolean");
+            printUnaryOp(out, exec, location, it, "is_boolean");
             break;
         }
         case op_is_number: {
-            printUnaryOp(location, it, "is_number");
+            printUnaryOp(out, exec, location, it, "is_number");
             break;
         }
         case op_is_string: {
-            printUnaryOp(location, it, "is_string");
+            printUnaryOp(out, exec, location, it, "is_string");
             break;
         }
         case op_is_object: {
-            printUnaryOp(location, it, "is_object");
+            printUnaryOp(out, exec, location, it, "is_object");
             break;
         }
         case op_is_function: {
-            printUnaryOp(location, it, "is_function");
+            printUnaryOp(out, exec, location, it, "is_function");
             break;
         }
         case op_in: {
-            printBinaryOp(location, it, "in");
+            printBinaryOp(out, exec, location, it, "in");
             break;
         }
-        case op_resolve: {
-            int r0 = (++it)->u.operand;
-            int id0 = (++it)->u.operand;
-            printf("[%4d] resolve\t\t %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str());
-            break;
-        }
-        case op_resolve_skip: {
-            int r0 = (++it)->u.operand;
+        case op_put_to_base_variable:
+        case op_put_to_base: {
+            int base = (++it)->u.operand;
             int id0 = (++it)->u.operand;
-            int skipLevels = (++it)->u.operand;
-            printf("[%4d] resolve_skip\t %s, %s, %d\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), skipLevels);
+            int value = (++it)->u.operand;
+            int resolveInfo = (++it)->u.operand;
+            out.printf("[%4d] put_to_base\t %s, %s, %s, %d", location, registerName(exec, base).data(), idName(id0, m_identifiers[id0]).data(), registerName(exec, value).data(), resolveInfo);
             break;
         }
-        case op_resolve_global: {
+        case op_resolve:
+        case op_resolve_global_property:
+        case op_resolve_global_var:
+        case op_resolve_scoped_var:
+        case op_resolve_scoped_var_on_top_scope:
+        case op_resolve_scoped_var_with_top_scope_check: {
             int r0 = (++it)->u.operand;
-            JSValue scope = JSValue((++it)->u.jsCell);
             int id0 = (++it)->u.operand;
-            printf("[%4d] resolve_global\t %s, %s, %s\n", location, registerName(r0).c_str(), valueToSourceString(exec, scope).ascii(), idName(id0, m_identifiers[id0]).c_str());
-            it += 2;
+            int resolveInfo = (++it)->u.operand;
+            out.printf("[%4d] resolve\t\t %s, %s, %d", location, registerName(exec, r0).data(), idName(id0, m_identifiers[id0]).data(), resolveInfo);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
         case op_get_scoped_var: {
             int r0 = (++it)->u.operand;
             int index = (++it)->u.operand;
             int skipLevels = (++it)->u.operand;
-            printf("[%4d] get_scoped_var\t %s, %d, %d\n", location, registerName(r0).c_str(), index, skipLevels);
+            out.printf("[%4d] get_scoped_var\t %s, %d, %d", location, registerName(exec, r0).data(), index, skipLevels);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
         case op_put_scoped_var: {
             int index = (++it)->u.operand;
             int skipLevels = (++it)->u.operand;
             int r0 = (++it)->u.operand;
-            printf("[%4d] put_scoped_var\t %d, %d, %s\n", location, index, skipLevels, registerName(r0).c_str());
+            out.printf("[%4d] put_scoped_var\t %d, %d, %s", location, index, skipLevels, registerName(exec, r0).data());
+            break;
+        }
+        case op_init_global_const_nop: {
+            out.printf("[%4d] init_global_const_nop\t", location);
+            it++;
+            it++;
+            it++;
+            it++;
             break;
         }
-        case op_get_global_var: {
+        case op_init_global_const: {
+            WriteBarrier<Unknown>* registerPointer = (++it)->u.registerPointer;
             int r0 = (++it)->u.operand;
-            JSValue scope = JSValue((++it)->u.jsCell);
-            int index = (++it)->u.operand;
-            printf("[%4d] get_global_var\t %s, %s, %d\n", location, registerName(r0).c_str(), valueToSourceString(exec, scope).ascii(), index);
+            out.printf("[%4d] init_global_const\t g%d(%p), %s", location, m_globalObject->findRegisterIndex(registerPointer), registerPointer, registerName(exec, r0).data());
+            it++;
+            it++;
             break;
         }
-        case op_put_global_var: {
-            JSValue scope = JSValue((++it)->u.jsCell);
-            int index = (++it)->u.operand;
+        case op_init_global_const_check: {
+            WriteBarrier<Unknown>* registerPointer = (++it)->u.registerPointer;
             int r0 = (++it)->u.operand;
-            printf("[%4d] put_global_var\t %s, %d, %s\n", location, valueToSourceString(exec, scope).ascii(), index, registerName(r0).c_str());
+            out.printf("[%4d] init_global_const_check\t g%d(%p), %s", location, m_globalObject->findRegisterIndex(registerPointer), registerPointer, registerName(exec, r0).data());
+            it++;
+            it++;
             break;
         }
+        case op_resolve_base_to_global:
+        case op_resolve_base_to_global_dynamic:
+        case op_resolve_base_to_scope:
+        case op_resolve_base_to_scope_with_top_scope_check:
         case op_resolve_base: {
             int r0 = (++it)->u.operand;
             int id0 = (++it)->u.operand;
-            printf("[%4d] resolve_base\t %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str());
+            int isStrict = (++it)->u.operand;
+            int resolveInfo = (++it)->u.operand;
+            int putToBaseInfo = (++it)->u.operand;
+            out.printf("[%4d] resolve_base%s\t %s, %s, %d, %d", location, isStrict ? "_strict" : "", registerName(exec, r0).data(), idName(id0, m_identifiers[id0]).data(), resolveInfo, putToBaseInfo);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
         case op_resolve_with_base: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int id0 = (++it)->u.operand;
-            printf("[%4d] resolve_with_base %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), idName(id0, m_identifiers[id0]).c_str());
-            break;
-        }
-        case op_get_by_id: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id");
+            int resolveInfo = (++it)->u.operand;
+            int putToBaseInfo = (++it)->u.operand;
+            out.printf("[%4d] resolve_with_base %s, %s, %s, %d, %d", location, registerName(exec, r0).data(), registerName(exec, r1).data(), idName(id0, m_identifiers[id0]).data(), resolveInfo, putToBaseInfo);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_get_by_id_self: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id_self");
+        case op_resolve_with_this: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int id0 = (++it)->u.operand;
+            int resolveInfo = (++it)->u.operand;
+            out.printf("[%4d] resolve_with_this %s, %s, %s, %d", location, registerName(exec, r0).data(), registerName(exec, r1).data(), idName(id0, m_identifiers[id0]).data(), resolveInfo);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_get_by_id_self_list: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id_self_list");
+        case op_get_by_id:
+        case op_get_by_id_out_of_line:
+        case op_get_by_id_self:
+        case op_get_by_id_proto:
+        case op_get_by_id_chain:
+        case op_get_by_id_getter_self:
+        case op_get_by_id_getter_proto:
+        case op_get_by_id_getter_chain:
+        case op_get_by_id_custom_self:
+        case op_get_by_id_custom_proto:
+        case op_get_by_id_custom_chain:
+        case op_get_by_id_generic:
+        case op_get_array_length:
+        case op_get_string_length: {
+            printGetByIdOp(out, exec, location, it);
+            printGetByIdCacheStatus(out, exec, location);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_get_by_id_proto: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id_proto");
+        case op_get_arguments_length: {
+            printUnaryOp(out, exec, location, it, "get_arguments_length");
+            it++;
             break;
         }
-        case op_get_by_id_proto_list: {
-            printGetByIdOp(location, it, m_identifiers, "op_get_by_id_proto_list");
+        case op_put_by_id: {
+            printPutByIdOp(out, exec, location, it, "put_by_id");
             break;
         }
-        case op_get_by_id_chain: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id_chain");
+        case op_put_by_id_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_out_of_line");
             break;
         }
-        case op_get_by_id_generic: {
-            printGetByIdOp(location, it, m_identifiers, "get_by_id_generic");
+        case op_put_by_id_replace: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_replace");
             break;
         }
-        case op_get_array_length: {
-            printGetByIdOp(location, it, m_identifiers, "get_array_length");
+        case op_put_by_id_transition: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition");
             break;
         }
-        case op_get_string_length: {
-            printGetByIdOp(location, it, m_identifiers, "get_string_length");
+        case op_put_by_id_transition_direct: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct");
             break;
         }
-        case op_put_by_id: {
-            printPutByIdOp(location, it, m_identifiers, "put_by_id");
+        case op_put_by_id_transition_direct_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct_out_of_line");
             break;
         }
-        case op_put_by_id_replace: {
-            printPutByIdOp(location, it, m_identifiers, "put_by_id_replace");
+        case op_put_by_id_transition_normal: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal");
             break;
         }
-        case op_put_by_id_transition: {
-            printPutByIdOp(location, it, m_identifiers, "put_by_id_transition");
+        case op_put_by_id_transition_normal_out_of_line: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal_out_of_line");
             break;
         }
         case op_put_by_id_generic: {
-            printPutByIdOp(location, it, m_identifiers, "put_by_id_generic");
+            printPutByIdOp(out, exec, location, it, "put_by_id_generic");
             break;
         }
-        case op_put_getter: {
+        case op_put_getter_setter: {
             int r0 = (++it)->u.operand;
             int id0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] put_getter\t %s, %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
+            int r2 = (++it)->u.operand;
+            out.printf("[%4d] put_getter_setter\t %s, %s, %s, %s", location, registerName(exec, r0).data(), idName(id0, m_identifiers[id0]).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
             break;
         }
-        case op_put_setter: {
+        case op_del_by_id: {
             int r0 = (++it)->u.operand;
-            int id0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] put_setter\t %s, %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
+            int id0 = (++it)->u.operand;
+            out.printf("[%4d] del_by_id\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), idName(id0, m_identifiers[id0]).data());
             break;
         }
-        case op_method_check: {
-            printf("[%4d] op_method_check\n", location);
+        case op_get_by_val: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            out.printf("[%4d] get_by_val\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
+            dumpArrayProfiling(out, it, hasPrintedProfiling);
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_del_by_id: {
+        case op_get_argument_by_val: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            int id0 = (++it)->u.operand;
-            printf("[%4d] del_by_id\t %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), idName(id0, m_identifiers[id0]).c_str());
+            int r2 = (++it)->u.operand;
+            out.printf("[%4d] get_argument_by_val\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
+            ++it;
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_get_by_val: {
+        case op_get_by_pname: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int r2 = (++it)->u.operand;
-            printf("[%4d] get_by_val\t %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), registerName(r2).c_str());
+            int r3 = (++it)->u.operand;
+            int r4 = (++it)->u.operand;
+            int r5 = (++it)->u.operand;
+            out.printf("[%4d] get_by_pname\t %s, %s, %s, %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data(), registerName(exec, r3).data(), registerName(exec, r4).data(), registerName(exec, r5).data());
             break;
         }
         case op_put_by_val: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int r2 = (++it)->u.operand;
-            printf("[%4d] put_by_val\t %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), registerName(r2).c_str());
+            out.printf("[%4d] put_by_val\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, 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;
-            printf("[%4d] del_by_val\t %s, %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str(), registerName(r2).c_str());
+            out.printf("[%4d] del_by_val\t %s, %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data());
             break;
         }
         case op_put_by_index: {
             int r0 = (++it)->u.operand;
             unsigned n0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] put_by_index\t %s, %u, %s\n", location, registerName(r0).c_str(), n0, registerName(r1).c_str());
+            out.printf("[%4d] put_by_index\t %s, %u, %s", location, registerName(exec, r0).data(), n0, registerName(exec, r1).data());
             break;
         }
         case op_jmp: {
             int offset = (++it)->u.operand;
-            printf("[%4d] jmp\t\t %d(->%d)\n", location, offset, locationForOffset(begin, it, offset));
-            break;
-        }
-        case op_loop: {
-            int offset = (++it)->u.operand;
-            printf("[%4d] loop\t\t %d(->%d)\n", location, offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jmp\t\t %d(->%d)", location, offset, location + offset);
             break;
         }
         case op_jtrue: {
-            printConditionalJump(begin, it, location, "jtrue");
+            printConditionalJump(out, exec, begin, it, location, "jtrue");
             break;
         }
-        case op_loop_if_true: {
-            printConditionalJump(begin, it, location, "loop_if_true");
-            break;
-        }
-        case op_jfalse: {
-            printConditionalJump(begin, it, location, "jfalse");
+        case op_jfalse: {
+            printConditionalJump(out, exec, begin, it, location, "jfalse");
             break;
         }
         case op_jeq_null: {
-            printConditionalJump(begin, it, location, "jeq_null");
+            printConditionalJump(out, exec, begin, it, location, "jeq_null");
             break;
         }
         case op_jneq_null: {
-            printConditionalJump(begin, it, location, "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;
+            out.printf("[%4d] jneq_ptr\t\t %s, %d (%p), %d(->%d)", location, registerName(exec, 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;
+            out.printf("[%4d] jless\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jlesseq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            out.printf("[%4d] jlesseq\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jgreater: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            out.printf("[%4d] jgreater\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
+            break;
+        }
+        case op_jgreatereq: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int offset = (++it)->u.operand;
-            printf("[%4d] jneq_ptr\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jgreatereq\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
             break;
         }
         case op_jnless: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int offset = (++it)->u.operand;
-            printf("[%4d] jnless\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jnless\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
             break;
         }
         case op_jnlesseq: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int offset = (++it)->u.operand;
-            printf("[%4d] jnlesseq\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jnlesseq\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
             break;
         }
-        case op_loop_if_less: {
+        case op_jngreater: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int offset = (++it)->u.operand;
-            printf("[%4d] loop_if_less\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jngreater\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
             break;
         }
-        case op_loop_if_lesseq: {
+        case op_jngreatereq: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int offset = (++it)->u.operand;
-            printf("[%4d] loop_if_lesseq\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            out.printf("[%4d] jngreatereq\t\t %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), offset, location + offset);
+            break;
+        }
+        case op_loop_hint: {
+            out.printf("[%4d] loop_hint", location);
             break;
         }
         case op_switch_imm: {
             int tableIndex = (++it)->u.operand;
             int defaultTarget = (++it)->u.operand;
             int scrutineeRegister = (++it)->u.operand;
-            printf("[%4d] switch_imm\t %d, %d(->%d), %s\n", location, tableIndex, defaultTarget, locationForOffset(begin, it, defaultTarget), registerName(scrutineeRegister).c_str());
+            out.printf("[%4d] switch_imm\t %d, %d(->%d), %s", location, tableIndex, defaultTarget, location + defaultTarget, registerName(exec, scrutineeRegister).data());
             break;
         }
         case op_switch_char: {
             int tableIndex = (++it)->u.operand;
             int defaultTarget = (++it)->u.operand;
             int scrutineeRegister = (++it)->u.operand;
-            printf("[%4d] switch_char\t %d, %d(->%d), %s\n", location, tableIndex, defaultTarget, locationForOffset(begin, it, defaultTarget), registerName(scrutineeRegister).c_str());
+            out.printf("[%4d] switch_char\t %d, %d(->%d), %s", location, tableIndex, defaultTarget, location + defaultTarget, registerName(exec, scrutineeRegister).data());
             break;
         }
         case op_switch_string: {
             int tableIndex = (++it)->u.operand;
             int defaultTarget = (++it)->u.operand;
             int scrutineeRegister = (++it)->u.operand;
-            printf("[%4d] switch_string\t %d, %d(->%d), %s\n", location, tableIndex, defaultTarget, locationForOffset(begin, it, defaultTarget), registerName(scrutineeRegister).c_str());
+            out.printf("[%4d] switch_string\t %d, %d(->%d), %s", location, tableIndex, defaultTarget, location + defaultTarget, registerName(exec, scrutineeRegister).data());
             break;
         }
         case op_new_func: {
             int r0 = (++it)->u.operand;
             int f0 = (++it)->u.operand;
-            printf("[%4d] new_func\t\t %s, f%d\n", location, registerName(r0).c_str(), f0);
+            int shouldCheck = (++it)->u.operand;
+            out.printf("[%4d] new_func\t\t %s, f%d, %s", location, registerName(exec, r0).data(), f0, shouldCheck ? "<Checked>" : "<Unchecked>");
             break;
         }
         case op_new_func_exp: {
             int r0 = (++it)->u.operand;
             int f0 = (++it)->u.operand;
-            printf("[%4d] new_func_exp\t %s, f%d\n", location, registerName(r0).c_str(), f0);
+            out.printf("[%4d] new_func_exp\t %s, f%d", location, registerName(exec, r0).data(), f0);
             break;
         }
         case op_call: {
-            int dst = (++it)->u.operand;
-            int func = (++it)->u.operand;
-            int argCount = (++it)->u.operand;
-            int registerOffset = (++it)->u.operand;
-            printf("[%4d] call\t\t %s, %s, %d, %d\n", location, registerName(dst).c_str(), registerName(func).c_str(), argCount, registerOffset);
+            printCallOp(out, exec, location, it, "call", DumpCaches);
             break;
         }
         case op_call_eval: {
-            int dst = (++it)->u.operand;
-            int func = (++it)->u.operand;
-            int argCount = (++it)->u.operand;
-            int registerOffset = (++it)->u.operand;
-            printf("[%4d] call_eval\t %s, %s, %d, %d\n", location, registerName(dst).c_str(), registerName(func).c_str(), argCount, registerOffset);
+            printCallOp(out, exec, location, it, "call_eval", DontDumpCaches);
             break;
         }
         case op_call_varargs: {
-            int dst = (++it)->u.operand;
-            int func = (++it)->u.operand;
-            int argCount = (++it)->u.operand;
-            int registerOffset = (++it)->u.operand;
-            printf("[%4d] call_varargs\t %s, %s, %s, %d\n", location, registerName(dst).c_str(), registerName(func).c_str(), registerName(argCount).c_str(), registerOffset);
-            break;
-        }
-        case op_load_varargs: {
-            printUnaryOp(location, it, "load_varargs");
+            int callee = (++it)->u.operand;
+            int thisValue = (++it)->u.operand;
+            int arguments = (++it)->u.operand;
+            int firstFreeRegister = (++it)->u.operand;
+            out.printf("[%4d] call_varargs\t %s, %s, %s, %d", location, registerName(exec, callee).data(), registerName(exec, thisValue).data(), registerName(exec, arguments).data(), firstFreeRegister);
             break;
         }
         case op_tear_off_activation: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] tear_off_activation\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] tear_off_activation\t %s", location, registerName(exec, r0).data());
             break;
         }
         case op_tear_off_arguments: {
-            printf("[%4d] tear_off_arguments\n", location);
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            out.printf("[%4d] tear_off_arguments %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data());
             break;
         }
         case op_ret: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] ret\t\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] ret\t\t %s", location, registerName(exec, r0).data());
             break;
         }
-        case op_construct: {
-            int dst = (++it)->u.operand;
-            int func = (++it)->u.operand;
-            int argCount = (++it)->u.operand;
-            int registerOffset = (++it)->u.operand;
-            int proto = (++it)->u.operand;
-            int thisRegister = (++it)->u.operand;
-            printf("[%4d] construct\t %s, %s, %d, %d, %s, %s\n", location, registerName(dst).c_str(), registerName(func).c_str(), argCount, registerOffset, registerName(proto).c_str(), registerName(thisRegister).c_str());
+        case op_call_put_result: {
+            int r0 = (++it)->u.operand;
+            out.printf("[%4d] call_put_result\t\t %s", location, registerName(exec, r0).data());
+            dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-        case op_construct_verify: {
+        case op_ret_object_or_this: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] construct_verify\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
+            out.printf("[%4d] constructor_ret\t\t %s %s", location, registerName(exec, r0).data(), registerName(exec, r1).data());
+            break;
+        }
+        case op_construct: {
+            printCallOp(out, exec, location, it, "construct", DumpCaches);
             break;
         }
         case op_strcat: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int count = (++it)->u.operand;
-            printf("[%4d] op_strcat\t %s, %s, %d\n", location, registerName(r0).c_str(), registerName(r1).c_str(), count);
+            out.printf("[%4d] strcat\t\t %s, %s, %d", location, registerName(exec, r0).data(), registerName(exec, r1).data(), count);
             break;
         }
         case op_to_primitive: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] op_to_primitive\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
+            out.printf("[%4d] to_primitive\t %s, %s", location, registerName(exec, r0).data(), registerName(exec, r1).data());
             break;
         }
         case op_get_pnames: {
-            int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printf("[%4d] get_pnames\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
+            int r0 = it[1].u.operand;
+            int r1 = it[2].u.operand;
+            int r2 = it[3].u.operand;
+            int r3 = it[4].u.operand;
+            int offset = it[5].u.operand;
+            out.printf("[%4d] get_pnames\t %s, %s, %s, %s, %d(->%d)", location, registerName(exec, r0).data(), registerName(exec, r1).data(), registerName(exec, r2).data(), registerName(exec, r3).data(), offset, location + offset);
+            it += OPCODE_LENGTH(op_get_pnames) - 1;
             break;
         }
         case op_next_pname: {
-            int dest = (++it)->u.operand;
-            int iter = (++it)->u.operand;
-            int offset = (++it)->u.operand;
-            printf("[%4d] next_pname\t %s, %s, %d(->%d)\n", location, registerName(dest).c_str(), registerName(iter).c_str(), offset, locationForOffset(begin, it, offset));
+            int dest = it[1].u.operand;
+            int base = it[2].u.operand;
+            int i = it[3].u.operand;
+            int size = it[4].u.operand;
+            int iter = it[5].u.operand;
+            int offset = it[6].u.operand;
+            out.printf("[%4d] next_pname\t %s, %s, %s, %s, %s, %d(->%d)", location, registerName(exec, dest).data(), registerName(exec, base).data(), registerName(exec, i).data(), registerName(exec, size).data(), registerName(exec, iter).data(), offset, location + offset);
+            it += OPCODE_LENGTH(op_next_pname) - 1;
             break;
         }
-        case op_push_scope: {
+        case op_push_with_scope: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] push_scope\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] push_with_scope\t %s", location, registerName(exec, r0).data());
             break;
         }
         case op_pop_scope: {
-            printf("[%4d] pop_scope\n", location);
+            out.printf("[%4d] pop_scope", location);
             break;
         }
-        case op_push_new_scope: {
-            int r0 = (++it)->u.operand;
+        case op_push_name_scope: {
             int id0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            printf("[%4d] push_new_scope \t%s, %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
-            break;
-        }
-        case op_jmp_scopes: {
-            int scopeDelta = (++it)->u.operand;
-            int offset = (++it)->u.operand;
-            printf("[%4d] jmp_scopes\t^%d, %d(->%d)\n", location, scopeDelta, offset, locationForOffset(begin, it, offset));
+            unsigned attributes = (++it)->u.operand;
+            out.printf("[%4d] push_name_scope \t%s, %s, %u", location, idName(id0, m_identifiers[id0]).data(), registerName(exec, r1).data(), attributes);
             break;
         }
         case op_catch: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] catch\t\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] catch\t\t %s", location, registerName(exec, r0).data());
             break;
         }
         case op_throw: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] throw\t\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] throw\t\t %s", location, registerName(exec, r0).data());
             break;
         }
-        case op_new_error: {
-            int r0 = (++it)->u.operand;
-            int errorType = (++it)->u.operand;
+        case op_throw_static_error: {
             int k0 = (++it)->u.operand;
-            printf("[%4d] new_error\t %s, %d, %s\n", location, registerName(r0).c_str(), errorType, constantName(exec, k0, getConstant(k0)).c_str());
-            break;
-        }
-        case op_jsr: {
-            int retAddrDst = (++it)->u.operand;
-            int offset = (++it)->u.operand;
-            printf("[%4d] jsr\t\t %s, %d(->%d)\n", location, registerName(retAddrDst).c_str(), offset, locationForOffset(begin, it, offset));
-            break;
-        }
-        case op_sret: {
-            int retAddrSrc = (++it)->u.operand;
-            printf("[%4d] sret\t\t %s\n", location, registerName(retAddrSrc).c_str());
+            int k1 = (++it)->u.operand;
+            out.printf("[%4d] throw_static_error\t %s, %s", location, constantName(exec, k0, getConstant(k0)).data(), k1 ? "true" : "false");
             break;
         }
         case op_debug: {
             int debugHookID = (++it)->u.operand;
             int firstLine = (++it)->u.operand;
             int lastLine = (++it)->u.operand;
-            printf("[%4d] debug\t\t %s, %d, %d\n", location, debugHookName(debugHookID), firstLine, lastLine);
+            int column = (++it)->u.operand;
+            out.printf("[%4d] debug\t\t %s, %d, %d, %d", location, debugHookName(debugHookID), firstLine, lastLine, column);
             break;
         }
         case op_profile_will_call: {
             int function = (++it)->u.operand;
-            printf("[%4d] profile_will_call %s\n", location, registerName(function).c_str());
+            out.printf("[%4d] profile_will_call %s", location, registerName(exec, function).data());
             break;
         }
         case op_profile_did_call: {
             int function = (++it)->u.operand;
-            printf("[%4d] profile_did_call\t %s\n", location, registerName(function).c_str());
+            out.printf("[%4d] profile_did_call\t %s", location, registerName(exec, function).data());
             break;
         }
         case op_end: {
             int r0 = (++it)->u.operand;
-            printf("[%4d] end\t\t %s\n", location, registerName(r0).c_str());
+            out.printf("[%4d] end\t\t %s", location, registerName(exec, r0).data());
             break;
         }
+#if ENABLE(LLINT_C_LOOP)
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+#endif
+    }
+
+#if ENABLE(VALUE_PROFILER)
+    dumpRareCaseProfile(out, "rare case: ", rareCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
+    dumpRareCaseProfile(out, "special fast case: ", specialFastCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
+#endif
+    
+#if ENABLE(DFG_JIT)
+    Vector<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());
     }
+#else // ENABLE(DFG_JIT)
+    UNUSED_PARAM(location);
+#endif // ENABLE(DFG_JIT)
+    out.print("\n");
 }
 
-#endif // !defined(NDEBUG) || ENABLE(OPCODE_SAMPLING)
+void CodeBlock::dumpBytecode(PrintStream& out, unsigned bytecodeOffset)
+{
+    ExecState* exec = m_globalObject->globalExec();
+    const Instruction* it = instructions().begin() + bytecodeOffset;
+    dumpBytecode(out, exec, instructions().begin(), it);
+}
 
 #if DUMP_CODE_BLOCK_STATISTICS
 static HashSet<CodeBlock*> liveCodeBlockSet;
@@ -1128,13 +1483,10 @@ static HashSet<CodeBlock*> liveCodeBlockSet;
     macro(immediateSwitchJumpTables) \
     macro(characterSwitchJumpTables) \
     macro(stringSwitchJumpTables) \
-    macro(functionRegisterInfos)
-
-#define FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(macro) \
+    macro(evalCodeCache) \
     macro(expressionInfo) \
     macro(lineInfo) \
-    macro(getByIdExceptionInfo) \
-    macro(pcVector)
+    macro(callReturnIndexVector)
 
 template<typename T>
 static size_t sizeInBytes(const Vector<T>& vector)
@@ -1148,7 +1500,6 @@ void CodeBlock::dumpStatistics()
     #define DEFINE_VARS(name) size_t name##IsNotEmpty = 0; size_t name##TotalSize = 0;
         FOR_EACH_MEMBER_VECTOR(DEFINE_VARS)
         FOR_EACH_MEMBER_VECTOR_RARE_DATA(DEFINE_VARS)
-        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(DEFINE_VARS)
     #undef DEFINE_VARS
 
     // Non-vector data members
@@ -1157,7 +1508,6 @@ void CodeBlock::dumpStatistics()
     size_t symbolTableIsNotEmpty = 0;
     size_t symbolTableTotalSize = 0;
 
-    size_t hasExceptionInfo = 0;
     size_t hasRareData = 0;
 
     size_t isFunctionCode = 0;
@@ -1172,16 +1522,9 @@ void CodeBlock::dumpStatistics()
             FOR_EACH_MEMBER_VECTOR(GET_STATS)
         #undef GET_STATS
 
-        if (!codeBlock->m_symbolTable.isEmpty()) {
+        if (codeBlock->symbolTable() && !codeBlock->symbolTable()->isEmpty()) {
             symbolTableIsNotEmpty++;
-            symbolTableTotalSize += (codeBlock->m_symbolTable.capacity() * (sizeof(SymbolTable::KeyType) + sizeof(SymbolTable::MappedType)));
-        }
-
-        if (codeBlock->m_exceptionInfo) {
-            hasExceptionInfo++;
-            #define GET_STATS(name) if (!codeBlock->m_exceptionInfo->m_##name.isEmpty()) { name##IsNotEmpty++; name##TotalSize += sizeInBytes(codeBlock->m_exceptionInfo->m_##name); }
-                FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(GET_STATS)
-            #undef GET_STATS
+            symbolTableTotalSize += (codeBlock->symbolTable()->capacity() * (sizeof(SymbolTable::KeyType) + sizeof(SymbolTable::MappedType)));
         }
 
         if (codeBlock->m_rareData) {
@@ -1212,181 +1555,510 @@ void CodeBlock::dumpStatistics()
     #define GET_TOTAL_SIZE(name) totalSize += name##TotalSize;
         FOR_EACH_MEMBER_VECTOR(GET_TOTAL_SIZE)
         FOR_EACH_MEMBER_VECTOR_RARE_DATA(GET_TOTAL_SIZE)
-        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(GET_TOTAL_SIZE)
     #undef GET_TOTAL_SIZE
 
     totalSize += symbolTableTotalSize;
     totalSize += (liveCodeBlockSet.size() * sizeof(CodeBlock));
 
-    printf("Number of live CodeBlocks: %d\n", liveCodeBlockSet.size());
-    printf("Size of a single CodeBlock [sizeof(CodeBlock)]: %zu\n", sizeof(CodeBlock));
-    printf("Size of all CodeBlocks: %zu\n", totalSize);
-    printf("Average size of a CodeBlock: %zu\n", totalSize / liveCodeBlockSet.size());
+    dataLogF("Number of live CodeBlocks: %d\n", liveCodeBlockSet.size());
+    dataLogF("Size of a single CodeBlock [sizeof(CodeBlock)]: %zu\n", sizeof(CodeBlock));
+    dataLogF("Size of all CodeBlocks: %zu\n", totalSize);
+    dataLogF("Average size of a CodeBlock: %zu\n", totalSize / liveCodeBlockSet.size());
 
-    printf("Number of FunctionCode CodeBlocks: %zu (%.3f%%)\n", isFunctionCode, static_cast<double>(isFunctionCode) * 100.0 / liveCodeBlockSet.size());
-    printf("Number of GlobalCode CodeBlocks: %zu (%.3f%%)\n", isGlobalCode, static_cast<double>(isGlobalCode) * 100.0 / liveCodeBlockSet.size());
-    printf("Number of EvalCode CodeBlocks: %zu (%.3f%%)\n", isEvalCode, static_cast<double>(isEvalCode) * 100.0 / liveCodeBlockSet.size());
+    dataLogF("Number of FunctionCode CodeBlocks: %zu (%.3f%%)\n", isFunctionCode, static_cast<double>(isFunctionCode) * 100.0 / liveCodeBlockSet.size());
+    dataLogF("Number of GlobalCode CodeBlocks: %zu (%.3f%%)\n", isGlobalCode, static_cast<double>(isGlobalCode) * 100.0 / liveCodeBlockSet.size());
+    dataLogF("Number of EvalCode CodeBlocks: %zu (%.3f%%)\n", isEvalCode, static_cast<double>(isEvalCode) * 100.0 / liveCodeBlockSet.size());
 
-    printf("Number of CodeBlocks with exception info: %zu (%.3f%%)\n", hasExceptionInfo, static_cast<double>(hasExceptionInfo) * 100.0 / liveCodeBlockSet.size());
-    printf("Number of CodeBlocks with rare data: %zu (%.3f%%)\n", hasRareData, static_cast<double>(hasRareData) * 100.0 / liveCodeBlockSet.size());
+    dataLogF("Number of CodeBlocks with rare data: %zu (%.3f%%)\n", hasRareData, static_cast<double>(hasRareData) * 100.0 / liveCodeBlockSet.size());
 
-    #define PRINT_STATS(name) printf("Number of CodeBlocks with " #name ": %zu\n", name##IsNotEmpty); printf("Size of all " #name ": %zu\n", name##TotalSize); 
+    #define PRINT_STATS(name) dataLogF("Number of CodeBlocks with " #name ": %zu\n", name##IsNotEmpty); dataLogF("Size of all " #name ": %zu\n", name##TotalSize); 
         FOR_EACH_MEMBER_VECTOR(PRINT_STATS)
         FOR_EACH_MEMBER_VECTOR_RARE_DATA(PRINT_STATS)
-        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(PRINT_STATS)
     #undef PRINT_STATS
 
-    printf("Number of CodeBlocks with evalCodeCache: %zu\n", evalCodeCacheIsNotEmpty);
-    printf("Number of CodeBlocks with symbolTable: %zu\n", symbolTableIsNotEmpty);
+    dataLogF("Number of CodeBlocks with evalCodeCache: %zu\n", evalCodeCacheIsNotEmpty);
+    dataLogF("Number of CodeBlocks with symbolTable: %zu\n", symbolTableIsNotEmpty);
 
-    printf("Size of all symbolTables: %zu\n", symbolTableTotalSize);
+    dataLogF("Size of all symbolTables: %zu\n", symbolTableTotalSize);
 
 #else
-    printf("Dumping CodeBlock statistics is not enabled.\n");
+    dataLogF("Dumping CodeBlock statistics is not enabled.\n");
 #endif
 }
 
-CodeBlock::CodeBlock(ScopeNode* ownerNode)
-    : m_numCalleeRegisters(0)
-    , m_numVars(0)
-    , m_numParameters(0)
-    , m_ownerNode(ownerNode)
-    , m_globalData(0)
-#ifndef NDEBUG
-    , m_instructionCount(0)
+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_unlinkedCode(*other.m_vm, other.m_ownerExecutable.get(), other.m_unlinkedCode.get())
+    , 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_argumentsRegister(other.m_argumentsRegister)
+    , m_activationRegister(other.m_activationRegister)
+    , m_isStrictMode(other.m_isStrictMode)
+    , m_needsActivation(other.m_needsActivation)
+    , m_source(other.m_source)
+    , m_sourceOffset(other.m_sourceOffset)
+    , m_firstLineColumnOffset(other.m_firstLineColumnOffset)
+    , m_codeType(other.m_codeType)
+    , m_identifiers(other.m_identifiers)
+    , m_constantRegisters(other.m_constantRegisters)
+    , m_functionDecls(other.m_functionDecls)
+    , m_functionExprs(other.m_functionExprs)
+    , m_osrExitCounter(0)
+    , m_optimizationDelayCounter(0)
+    , m_reoptimizationRetryCounter(0)
+    , m_resolveOperations(other.m_resolveOperations)
+    , m_putToBaseOperations(other.m_putToBaseOperations)
+#if ENABLE(JIT)
+    , m_canCompileWithDFGState(DFG::CapabilityLevelNotSet)
 #endif
-    , m_needsFullScopeChain(false)
-    , m_usesEval(false)
-    , m_isNumericCompareFunction(false)
-    , m_codeType(NativeCode)
-    , m_source(0)
-    , m_sourceOffset(0)
-    , m_exceptionInfo(0)
 {
-#if DUMP_CODE_BLOCK_STATISTICS
-    liveCodeBlockSet.add(this);
-#endif
+    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_immediateSwitchJumpTables = other.m_rareData->m_immediateSwitchJumpTables;
+        m_rareData->m_characterSwitchJumpTables = other.m_rareData->m_characterSwitchJumpTables;
+        m_rareData->m_stringSwitchJumpTables = other.m_rareData->m_stringSwitchJumpTables;
+    }
 }
 
-CodeBlock::CodeBlock(ScopeNode* ownerNode, CodeType codeType, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset)
-    : m_numCalleeRegisters(0)
-    , m_numVars(0)
-    , m_numParameters(0)
-    , m_ownerNode(ownerNode)
-    , m_globalData(0)
-#ifndef NDEBUG
-    , m_instructionCount(0)
-#endif
-    , m_needsFullScopeChain(ownerNode->needsActivation())
-    , m_usesEval(ownerNode->usesEval())
-    , m_isNumericCompareFunction(false)
-    , m_codeType(codeType)
+CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSGlobalObject* globalObject, unsigned baseScopeDepth, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset, PassOwnPtr<CodeBlock> alternative)
+    : m_globalObject(globalObject->vm(), ownerExecutable, globalObject)
+    , m_heap(&m_globalObject->vm().heap)
+    , m_numCalleeRegisters(unlinkedCodeBlock->m_numCalleeRegisters)
+    , m_numVars(unlinkedCodeBlock->m_numVars)
+    , m_isConstructor(unlinkedCodeBlock->isConstructor())
+    , m_unlinkedCode(globalObject->vm(), ownerExecutable, unlinkedCodeBlock)
+    , m_ownerExecutable(globalObject->vm(), ownerExecutable, ownerExecutable)
+    , m_vm(unlinkedCodeBlock->vm())
+    , m_thisRegister(unlinkedCodeBlock->thisRegister())
+    , m_argumentsRegister(unlinkedCodeBlock->argumentsRegister())
+    , m_activationRegister(unlinkedCodeBlock->activationRegister())
+    , m_isStrictMode(unlinkedCodeBlock->isStrictMode())
+    , m_needsActivation(unlinkedCodeBlock->needsFullScopeChain())
     , m_source(sourceProvider)
     , m_sourceOffset(sourceOffset)
-    , m_exceptionInfo(new ExceptionInfo)
+    , m_firstLineColumnOffset(firstLineColumnOffset)
+    , m_codeType(unlinkedCodeBlock->codeType())
+    , m_alternative(alternative)
+    , m_osrExitCounter(0)
+    , m_optimizationDelayCounter(0)
+    , m_reoptimizationRetryCounter(0)
 {
+    m_vm->startedCompiling(this);
+
     ASSERT(m_source);
+    setNumParameters(unlinkedCodeBlock->numParameters());
 
 #if DUMP_CODE_BLOCK_STATISTICS
     liveCodeBlockSet.add(this);
 #endif
-}
-
-CodeBlock::~CodeBlock()
-{
-#if !ENABLE(JIT)
-    for (size_t size = m_globalResolveInstructions.size(), i = 0; i < size; ++i)
-        derefStructures(&m_instructions[m_globalResolveInstructions[i]]);
+    setIdentifiers(unlinkedCodeBlock->identifiers());
+    setConstantRegisters(unlinkedCodeBlock->constantRegisters());
+    if (unlinkedCodeBlock->usesGlobalObject())
+        m_constantRegisters[unlinkedCodeBlock->globalObjectRegister()].set(*m_vm, ownerExecutable, globalObject);
+    m_functionDecls.grow(unlinkedCodeBlock->numberOfFunctionDecls());
+    for (size_t count = unlinkedCodeBlock->numberOfFunctionDecls(), i = 0; i < count; ++i) {
+        UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionDecl(i);
+        unsigned lineCount = unlinkedExecutable->lineCount();
+        unsigned firstLine = ownerExecutable->lineNo() + unlinkedExecutable->firstLineOffset();
+        unsigned startColumn = unlinkedExecutable->functionStartColumn();
+        startColumn += (unlinkedExecutable->firstLineOffset() ? 1 : ownerExecutable->startColumn());
+        unsigned startOffset = sourceOffset + unlinkedExecutable->startOffset();
+        unsigned sourceLength = unlinkedExecutable->sourceLength();
+        SourceCode code(m_source, startOffset, startOffset + sourceLength, firstLine, startColumn);
+        FunctionExecutable* executable = FunctionExecutable::create(*m_vm, code, unlinkedExecutable, firstLine, firstLine + lineCount, startColumn);
+        m_functionDecls[i].set(*m_vm, ownerExecutable, executable);
+    }
 
-    for (size_t size = m_propertyAccessInstructions.size(), i = 0; i < size; ++i)
-        derefStructures(&m_instructions[m_propertyAccessInstructions[i]]);
-#else
-    for (size_t size = m_globalResolveInfos.size(), i = 0; i < size; ++i) {
-        if (m_globalResolveInfos[i].structure)
-            m_globalResolveInfos[i].structure->deref();
+    m_functionExprs.grow(unlinkedCodeBlock->numberOfFunctionExprs());
+    for (size_t count = unlinkedCodeBlock->numberOfFunctionExprs(), i = 0; i < count; ++i) {
+        UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionExpr(i);
+        unsigned lineCount = unlinkedExecutable->lineCount();
+        unsigned firstLine = ownerExecutable->lineNo() + unlinkedExecutable->firstLineOffset();
+        unsigned startColumn = unlinkedExecutable->functionStartColumn();
+        startColumn += (unlinkedExecutable->firstLineOffset() ? 1 : ownerExecutable->startColumn());
+        unsigned startOffset = sourceOffset + unlinkedExecutable->startOffset();
+        unsigned sourceLength = unlinkedExecutable->sourceLength();
+        SourceCode code(m_source, startOffset, startOffset + sourceLength, firstLine, startColumn);
+        FunctionExecutable* executable = FunctionExecutable::create(*m_vm, code, unlinkedExecutable, firstLine, firstLine + lineCount, startColumn);
+        m_functionExprs[i].set(*m_vm, ownerExecutable, executable);
     }
 
-    for (size_t size = m_structureStubInfos.size(), i = 0; i < size; ++i)
-        m_structureStubInfos[i].deref();
+    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.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                const UnlinkedHandlerInfo& handler = unlinkedCodeBlock->exceptionHandler(i);
+                m_rareData->m_exceptionHandlers[i].start = handler.start;
+                m_rareData->m_exceptionHandlers[i].end = handler.end;
+                m_rareData->m_exceptionHandlers[i].target = handler.target;
+                m_rareData->m_exceptionHandlers[i].scopeDepth = handler.scopeDepth + baseScopeDepth;
+#if ENABLE(JIT) && ENABLE(LLINT)
+                m_rareData->m_exceptionHandlers[i].nativeCode = CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(LLInt::getCodePtr(llint_op_catch)));
+#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->numberOfImmediateSwitchJumpTables()) {
+            m_rareData->m_immediateSwitchJumpTables.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                UnlinkedSimpleJumpTable& sourceTable = unlinkedCodeBlock->immediateSwitchJumpTable(i);
+                SimpleJumpTable& destTable = m_rareData->m_immediateSwitchJumpTables[i];
+                destTable.branchOffsets = sourceTable.branchOffsets;
+                destTable.min = sourceTable.min;
+            }
+        }
+
+        if (size_t count = unlinkedCodeBlock->numberOfCharacterSwitchJumpTables()) {
+            m_rareData->m_characterSwitchJumpTables.grow(count);
+            for (size_t i = 0; i < count; i++) {
+                UnlinkedSimpleJumpTable& sourceTable = unlinkedCodeBlock->characterSwitchJumpTable(i);
+                SimpleJumpTable& destTable = m_rareData->m_characterSwitchJumpTables[i];
+                destTable.branchOffsets = sourceTable.branchOffsets;
+                destTable.min = sourceTable.min;
+            }
+        }
+    }
 
-    for (size_t size = m_callLinkInfos.size(), i = 0; i < size; ++i) {
-        CallLinkInfo* callLinkInfo = &m_callLinkInfos[i];
-        if (callLinkInfo->isLinked())
-            callLinkInfo->callee->removeCaller(callLinkInfo);
+    // Allocate metadata buffers for the bytecode
+#if ENABLE(LLINT)
+    if (size_t size = unlinkedCodeBlock->numberOfLLintCallLinkInfos())
+        m_llintCallLinkInfos.grow(size);
+#endif
+#if ENABLE(DFG_JIT)
+    if (size_t size = unlinkedCodeBlock->numberOfArrayProfiles())
+        m_arrayProfiles.grow(size);
+    if (size_t size = unlinkedCodeBlock->numberOfArrayAllocationProfiles())
+        m_arrayAllocationProfiles.grow(size);
+    if (size_t size = unlinkedCodeBlock->numberOfValueProfiles())
+        m_valueProfiles.grow(size);
+#endif
+    if (size_t size = unlinkedCodeBlock->numberOfObjectAllocationProfiles())
+        m_objectAllocationProfiles.grow(size);
+    if (size_t size = unlinkedCodeBlock->numberOfResolveOperations())
+        m_resolveOperations.grow(size);
+    if (size_t putToBaseCount = unlinkedCodeBlock->numberOfPutToBaseOperations()) {
+        m_putToBaseOperations.reserveInitialCapacity(putToBaseCount);
+        for (size_t i = 0; i < putToBaseCount; ++i)
+            m_putToBaseOperations.uncheckedAppend(PutToBaseOperation(isStrictMode()));
     }
 
-    for (size_t size = m_methodCallLinkInfos.size(), i = 0; i < size; ++i) {
-        if (Structure* structure = m_methodCallLinkInfos[i].cachedStructure) {
-            structure->deref();
-            // Both members must be filled at the same time
-            ASSERT(m_methodCallLinkInfos[i].cachedPrototypeStructure);
-            m_methodCallLinkInfos[i].cachedPrototypeStructure->deref();
+    // Copy and translate the UnlinkedInstructions
+    size_t instructionCount = unlinkedCodeBlock->instructions().size();
+    UnlinkedInstruction* pc = unlinkedCodeBlock->instructions().data();
+    Vector<Instruction, 0, UnsafeVectorOverflow> instructions(instructionCount);
+    for (size_t i = 0; i < unlinkedCodeBlock->instructions().size(); ) {
+        unsigned opLength = opcodeLength(pc[i].u.opcode);
+        instructions[i] = vm()->interpreter->getOpcode(pc[i].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[i + j].u.operand;
+        }
+        switch (pc[i].u.opcode) {
+#if ENABLE(DFG_JIT)
+        case op_get_by_val:
+        case op_get_argument_by_val: {
+            int arrayProfileIndex = pc[i + opLength - 2].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+
+            instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
+            // fallthrough
+        }
+        case op_convert_this:
+        case op_get_by_id:
+        case op_call_put_result:
+        case op_get_callee: {
+            ValueProfile* profile = &m_valueProfiles[pc[i + 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[i + 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[i + opLength - 1].u.operand;
+            instructions[i + opLength - 1] = &m_arrayAllocationProfiles[arrayAllocationProfileIndex];
+            break;
+        }
+#endif
+        case op_resolve_base:
+        case op_resolve_base_to_global:
+        case op_resolve_base_to_global_dynamic:
+        case op_resolve_base_to_scope:
+        case op_resolve_base_to_scope_with_top_scope_check: {
+            instructions[i + 4].u.resolveOperations = &m_resolveOperations[pc[i + 4].u.operand];
+            instructions[i + 5].u.putToBaseOperation = &m_putToBaseOperations[pc[i + 5].u.operand];
+#if ENABLE(DFG_JIT)
+            ValueProfile* profile = &m_valueProfiles[pc[i + opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            ASSERT((opLength - 1) > 5);
+            instructions[i + opLength - 1] = profile;
+#endif
+            break;
+        }
+        case op_resolve_global_property:
+        case op_resolve_global_var:
+        case op_resolve_scoped_var:
+        case op_resolve_scoped_var_on_top_scope:
+        case op_resolve_scoped_var_with_top_scope_check: {
+            instructions[i + 3].u.resolveOperations = &m_resolveOperations[pc[i + 3].u.operand];
+            break;
+        }
+        case op_put_to_base:
+        case op_put_to_base_variable: {
+            instructions[i + 4].u.putToBaseOperation = &m_putToBaseOperations[pc[i + 4].u.operand];
+            break;
+        }
+        case op_resolve: {
+#if ENABLE(DFG_JIT)
+            ValueProfile* profile = &m_valueProfiles[pc[i + opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            ASSERT((opLength - 1) > 3);
+            instructions[i + opLength - 1] = profile;
+#endif
+            instructions[i + 3].u.resolveOperations = &m_resolveOperations[pc[i + 3].u.operand];
+            break;
+        }
+        case op_resolve_with_base:
+        case op_resolve_with_this: {
+            instructions[i + 4].u.resolveOperations = &m_resolveOperations[pc[i + 4].u.operand];
+            if (pc[i].u.opcode != op_resolve_with_this)
+                instructions[i + 5].u.putToBaseOperation = &m_putToBaseOperations[pc[i + 5].u.operand];
+#if ENABLE(DFG_JIT)
+            ValueProfile* profile = &m_valueProfiles[pc[i + opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+#endif
+            break;
+        }
+        case op_new_object: {
+            int objectAllocationProfileIndex = pc[i + opLength - 1].u.operand;
+            ObjectAllocationProfile* objectAllocationProfile = &m_objectAllocationProfiles[objectAllocationProfileIndex];
+            int inferredInlineCapacity = pc[i + opLength - 2].u.operand;
+
+            instructions[i + opLength - 1] = objectAllocationProfile;
+            objectAllocationProfile->initialize(*vm(),
+                m_ownerExecutable.get(), m_globalObject->objectPrototype(), inferredInlineCapacity);
+            break;
+        }
+
+        case op_get_scoped_var: {
+#if ENABLE(DFG_JIT)
+            ValueProfile* profile = &m_valueProfiles[pc[i + opLength - 1].u.operand];
+            ASSERT(profile->m_bytecodeOffset == -1);
+            profile->m_bytecodeOffset = i;
+            instructions[i + opLength - 1] = profile;
+#endif
+            break;
+        }
+
+        case op_call:
+        case op_call_eval: {
+#if ENABLE(DFG_JIT)
+            int arrayProfileIndex = pc[i + opLength - 1].u.operand;
+            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
+            instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
+#endif
+#if ENABLE(LLINT)
+            instructions[i + 4] = &m_llintCallLinkInfos[pc[i + 4].u.operand];
+#endif
+            break;
+        }
+        case op_construct:
+#if ENABLE(LLINT)
+            instructions[i + 4] = &m_llintCallLinkInfos[pc[i + 4].u.operand];
+#endif
+            break;
+        case op_get_by_id_out_of_line:
+        case op_get_by_id_self:
+        case op_get_by_id_proto:
+        case op_get_by_id_chain:
+        case op_get_by_id_getter_self:
+        case op_get_by_id_getter_proto:
+        case op_get_by_id_getter_chain:
+        case op_get_by_id_custom_self:
+        case op_get_by_id_custom_proto:
+        case op_get_by_id_custom_chain:
+        case op_get_by_id_generic:
+        case op_get_array_length:
+        case op_get_string_length:
+            CRASH();
+
+        case op_init_global_const_nop: {
+            ASSERT(codeType() == GlobalCode);
+            Identifier ident = identifier(pc[i + 4].u.operand);
+            SymbolTableEntry entry = globalObject->symbolTable()->get(ident.impl());
+            if (entry.isNull())
+                break;
+
+            if (entry.couldBeWatched()) {
+                instructions[i + 0] = vm()->interpreter->getOpcode(op_init_global_const_check);
+                instructions[i + 1] = &globalObject->registerAt(entry.getIndex());
+                instructions[i + 3] = entry.addressOfIsWatched();
+                break;
+            }
+
+            instructions[i + 0] = vm()->interpreter->getOpcode(op_init_global_const);
+            instructions[i + 1] = &globalObject->registerAt(entry.getIndex());
+            break;
+        }
+
+        case op_debug: {
+            instructions[i + 4] = columnNumberForBytecodeOffset(i);
+            break;
         }
+
+        default:
+            break;
+        }
+        i += opLength;
     }
+    m_instructions = WTF::RefCountedArray<Instruction>(instructions);
 
-#if ENABLE(JIT_OPTIMIZE_CALL)
-    unlinkCallers();
+    // 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 (Options::dumpGeneratedBytecodes())
+        dumpBytecode();
+    m_vm->finishedCompiling(this);
+}
+
+CodeBlock::~CodeBlock()
+{
+    if (m_vm->m_perBytecodeProfiler)
+        m_vm->m_perBytecodeProfiler->notifyDestruction(this);
+    
+#if ENABLE(DFG_JIT)
+    // Remove myself from the set of DFG code blocks. Note that I may not be in this set
+    // (because I'm not a DFG code block), in which case this is a no-op anyway.
+    m_vm->heap.m_dfgCodeBlocks.m_set.remove(this);
+#endif
+    
+#if ENABLE(VERBOSE_VALUE_PROFILE)
+    dumpValueProfiles();
 #endif
 
-#endif // !ENABLE(JIT)
+#if ENABLE(LLINT)    
+    while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
+        m_incomingLLIntCalls.begin()->remove();
+#endif // ENABLE(LLINT)
+#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();
+    
+    // Note that our outgoing calls will be removed from other CodeBlocks'
+    // m_incomingCalls linked lists through the execution of the ~CallLinkInfo
+    // destructors.
+
+    for (size_t size = m_structureStubInfos.size(), i = 0; i < size; ++i)
+        m_structureStubInfos[i].deref();
+#endif // ENABLE(JIT)
 
 #if DUMP_CODE_BLOCK_STATISTICS
     liveCodeBlockSet.remove(this);
 #endif
 }
 
-#if ENABLE(JIT_OPTIMIZE_CALL)
-void CodeBlock::unlinkCallers()
+void CodeBlock::setNumParameters(int newValue)
 {
-    size_t size = m_linkedCallerList.size();
-    for (size_t i = 0; i < size; ++i) {
-        CallLinkInfo* currentCaller = m_linkedCallerList[i];
-        JIT::unlinkCall(currentCaller);
-        currentCaller->setUnlinked();
-    }
-    m_linkedCallerList.clear();
-}
+    m_numParameters = newValue;
+
+#if ENABLE(VALUE_PROFILER)
+    m_argumentValueProfiles.resizeToFit(newValue);
 #endif
+}
 
-void CodeBlock::derefStructures(Instruction* vPC) const
+void CodeBlock::visitStructures(SlotVisitor& visitor, Instruction* vPC)
 {
-    ASSERT(m_codeType != NativeCode);
-    Interpreter* interpreter = m_globalData->interpreter;
+    Interpreter* interpreter = m_vm->interpreter;
 
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self)) {
-        vPC[4].u.structure->deref();
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id) && vPC[4].u.structure) {
+        visitor.append(&vPC[4].u.structure);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto)) {
-        vPC[4].u.structure->deref();
-        vPC[5].u.structure->deref();
+
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_getter_self) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_custom_self)) {
+        visitor.append(&vPC[4].u.structure);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain)) {
-        vPC[4].u.structure->deref();
-        vPC[5].u.structureChain->deref();
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_getter_proto) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_custom_proto)) {
+        visitor.append(&vPC[4].u.structure);
+        visitor.append(&vPC[5].u.structure);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_transition)) {
-        vPC[4].u.structure->deref();
-        vPC[5].u.structure->deref();
-        vPC[6].u.structureChain->deref();
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_getter_chain) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_custom_chain)) {
+        visitor.append(&vPC[4].u.structure);
+        if (vPC[5].u.structureChain)
+            visitor.append(&vPC[5].u.structureChain);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_replace)) {
-        vPC[4].u.structure->deref();
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_transition)) {
+        visitor.append(&vPC[4].u.structure);
+        visitor.append(&vPC[5].u.structure);
+        if (vPC[6].u.structureChain)
+            visitor.append(&vPC[6].u.structureChain);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global)) {
-        if(vPC[4].u.structure)
-            vPC[4].u.structure->deref();
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id) && vPC[4].u.structure) {
+        visitor.append(&vPC[4].u.structure);
         return;
     }
-    if ((vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto_list))
-        || (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self_list))) {
-        PolymorphicAccessStructureList* polymorphicStructures = vPC[4].u.polymorphicStructures;
-        polymorphicStructures->derefStructures(vPC[5].u.operand);
-        delete polymorphicStructures;
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_replace)) {
+        visitor.append(&vPC[4].u.structure);
         return;
     }
 
@@ -1394,132 +2066,391 @@ void CodeBlock::derefStructures(Instruction* vPC) const
     ASSERT(vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_get_array_length) || vPC[0].u.opcode == interpreter->getOpcode(op_get_string_length));
 }
 
-void CodeBlock::refStructures(Instruction* vPC) const
+void EvalCodeCache::visitAggregate(SlotVisitor& visitor)
 {
-    ASSERT(m_codeType != NativeCode);
-    Interpreter* interpreter = m_globalData->interpreter;
+    EvalCacheMap::iterator end = m_cacheMap.end();
+    for (EvalCacheMap::iterator ptr = m_cacheMap.begin(); ptr != end; ++ptr)
+        visitor.append(&ptr->value);
+}
 
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self)) {
-        vPC[4].u.structure->ref();
-        return;
+void CodeBlock::visitAggregate(SlotVisitor& visitor)
+{
+#if ENABLE(PARALLEL_GC) && ENABLE(DFG_JIT)
+    if (!!m_dfgData) {
+        // I may be asked to scan myself more than once, and it may even happen concurrently.
+        // To this end, use a CAS loop to check if I've been called already. Only one thread
+        // may proceed past this point - whichever one wins the CAS race.
+        unsigned oldValue;
+        do {
+            oldValue = m_dfgData->visitAggregateHasBeenCalled;
+            if (oldValue) {
+                // Looks like someone else won! Return immediately to ensure that we don't
+                // trace the same CodeBlock concurrently. Doing so is hazardous since we will
+                // be mutating the state of ValueProfiles, which contain JSValues, which can
+                // have word-tearing on 32-bit, leading to awesome timing-dependent crashes
+                // that are nearly impossible to track down.
+                
+                // Also note that it must be safe to return early as soon as we see the
+                // value true (well, (unsigned)1), since once a GC thread is in this method
+                // and has won the CAS race (i.e. was responsible for setting the value true)
+                // it will definitely complete the rest of this method before declaring
+                // termination.
+                return;
+            }
+        } while (!WTF::weakCompareAndSwap(&m_dfgData->visitAggregateHasBeenCalled, 0, 1));
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto)) {
-        vPC[4].u.structure->ref();
-        vPC[5].u.structure->ref();
+#endif // ENABLE(PARALLEL_GC) && ENABLE(DFG_JIT)
+    
+    if (!!m_alternative)
+        m_alternative->visitAggregate(visitor);
+
+    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);
+    
+    if (shouldImmediatelyAssumeLivenessDuringScan()) {
+        // This code block is live, so scan all references strongly and return.
+        stronglyVisitStrongReferences(visitor);
+        stronglyVisitWeakReferences(visitor);
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain)) {
-        vPC[4].u.structure->ref();
-        vPC[5].u.structureChain->ref();
-        return;
+    
+#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_dfgData->livenessHasBeenProved = false;
+    m_dfgData->allTransitionsHaveBeenMarked = false;
+    
+    performTracingFixpointIteration(visitor);
+
+    // GC doesn't have enough information yet for us to decide whether to keep our DFG
+    // data, so we need to register a handler to run again at the end of GC, when more
+    // information is available.
+    if (!(m_dfgData->livenessHasBeenProved && m_dfgData->allTransitionsHaveBeenMarked))
+        visitor.addWeakReferenceHarvester(this);
+    
+#else // ENABLE(DFG_JIT)
+    RELEASE_ASSERT_NOT_REACHED();
+#endif // ENABLE(DFG_JIT)
+}
+
+void CodeBlock::performTracingFixpointIteration(SlotVisitor& visitor)
+{
+    UNUSED_PARAM(visitor);
+    
+#if ENABLE(DFG_JIT)
+    // Evaluate our weak reference transitions, if there are still some to evaluate.
+    if (!m_dfgData->allTransitionsHaveBeenMarked) {
+        bool allAreMarkedSoFar = true;
+        for (unsigned i = 0; i < m_dfgData->transitions.size(); ++i) {
+            if ((!m_dfgData->transitions[i].m_codeOrigin
+                 || Heap::isMarked(m_dfgData->transitions[i].m_codeOrigin.get()))
+                && Heap::isMarked(m_dfgData->transitions[i].m_from.get())) {
+                // 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.
+                visitor.append(&m_dfgData->transitions[i].m_to);
+            } else
+                allAreMarkedSoFar = false;
+        }
+        
+        if (allAreMarkedSoFar)
+            m_dfgData->allTransitionsHaveBeenMarked = true;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_transition)) {
-        vPC[4].u.structure->ref();
-        vPC[5].u.structure->ref();
-        vPC[6].u.structureChain->ref();
+    
+    // Check if we have any remaining work to do.
+    if (m_dfgData->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 < m_dfgData->weakReferences.size(); ++i) {
+        if (!Heap::isMarked(m_dfgData->weakReferences[i].get())) {
+            allAreLiveSoFar = false;
+            break;
+        }
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_replace)) {
-        vPC[4].u.structure->ref();
+    
+    // If some weak references are dead, then this fixpoint iteration was
+    // unsuccessful.
+    if (!allAreLiveSoFar)
         return;
-    }
     
-    // These instructions don't ref their Structures.
-    ASSERT(vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_generic));
+    // All weak references are live. Record this information so we don't
+    // come back here again, and scan the strong references.
+    m_dfgData->livenessHasBeenProved = true;
+    stronglyVisitStrongReferences(visitor);
+#endif // ENABLE(DFG_JIT)
 }
 
-void CodeBlock::mark()
+void CodeBlock::visitWeakReferences(SlotVisitor& visitor)
 {
-    for (size_t i = 0; i < m_constantRegisters.size(); ++i)
-        if (!m_constantRegisters[i].marked())
-            m_constantRegisters[i].mark();
+    performTracingFixpointIteration(visitor);
+}
 
-    for (size_t i = 0; i < m_functionExpressions.size(); ++i)
-        m_functionExpressions[i]->body()->mark();
+#if ENABLE(JIT_VERBOSE_OSR)
+static const bool verboseUnlinking = true;
+#else
+static const bool verboseUnlinking = false;
+#endif
 
-    if (m_rareData) {
-        for (size_t i = 0; i < m_rareData->m_functions.size(); ++i)
-            m_rareData->m_functions[i]->body()->mark();
+void CodeBlock::finalizeUnconditionally()
+{
+#if ENABLE(LLINT)
+    Interpreter* interpreter = m_vm->interpreter;
+    if (!!numberOfInstructions()) {
+        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 (verboseUnlinking)
+                    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 (verboseUnlinking) {
+                    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;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+            }
+        }
 
-        m_rareData->m_evalCodeCache.mark();
+        for (unsigned i = 0; i < m_llintCallLinkInfos.size(); ++i) {
+            if (m_llintCallLinkInfos[i].isLinked() && !Heap::isMarked(m_llintCallLinkInfos[i].callee.get())) {
+                if (verboseUnlinking)
+                    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();
+        }
     }
-}
-
-void CodeBlock::reparseForExceptionInfoIfNecessary(CallFrame* callFrame)
-{
-    ASSERT(m_codeType != NativeCode);
-    if (m_exceptionInfo)
+#endif // ENABLE(LLINT)
+
+#if ENABLE(DFG_JIT)
+    // Check if we're not live. If we are, then jettison.
+    if (!(shouldImmediatelyAssumeLivenessDuringScan() || m_dfgData->livenessHasBeenProved)) {
+        if (verboseUnlinking)
+            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");
+            for (unsigned i = 0; i < m_dfgData->transitions.size(); ++i) {
+                WeakReferenceTransition& transition = m_dfgData->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 ", JSValue(origin), ", ", JSValue(from), " -> ", JSValue(to), ".\n");
+            }
+            for (unsigned i = 0; i < m_dfgData->weakReferences.size(); ++i) {
+                JSCell* weak = m_dfgData->weakReferences[i].get();
+                if (Heap::isMarked(weak))
+                    continue;
+                dataLog("    Weak reference ", JSValue(weak), ".\n");
+            }
+        }
+        
+        jettison();
         return;
-
-    ScopeChainNode* scopeChain = callFrame->scopeChain();
-    if (m_needsFullScopeChain) {
-        ScopeChain sc(scopeChain);
-        int scopeDelta = sc.localDepth();
-        if (m_codeType == EvalCode)
-            scopeDelta -= static_cast<EvalCodeBlock*>(this)->baseScopeDepth();
-        else if (m_codeType == FunctionCode)
-            scopeDelta++; // Compilation of function code assumes activation is not on the scope chain yet.
-        ASSERT(scopeDelta >= 0);
-        while (scopeDelta--)
-            scopeChain = scopeChain->next;
     }
+#endif // ENABLE(DFG_JIT)
 
-    switch (m_codeType) {
-        case FunctionCode: {
-            FunctionBodyNode* ownerFunctionBodyNode = static_cast<FunctionBodyNode*>(m_ownerNode);
-            RefPtr<FunctionBodyNode> newFunctionBody = m_globalData->parser->reparse<FunctionBodyNode>(m_globalData, ownerFunctionBodyNode);
-            ASSERT(newFunctionBody);
-            newFunctionBody->finishParsing(ownerFunctionBodyNode->copyParameters(), ownerFunctionBodyNode->parameterCount());
-
-            m_globalData->scopeNodeBeingReparsed = newFunctionBody.get();
-
-            CodeBlock& newCodeBlock = newFunctionBody->bytecodeForExceptionInfoReparse(scopeChain, this);
-            ASSERT(newCodeBlock.m_exceptionInfo);
-            ASSERT(newCodeBlock.m_instructionCount == m_instructionCount);
-
-#if ENABLE(JIT)
-            JIT::compile(m_globalData, &newCodeBlock);
-            ASSERT(newFunctionBody->generatedJITCode().size() == ownerNode()->generatedJITCode().size());
+    for (size_t size = m_putToBaseOperations.size(), i = 0; i < size; ++i) {
+        if (m_putToBaseOperations[i].m_structure && !Heap::isMarked(m_putToBaseOperations[i].m_structure.get())) {
+            if (verboseUnlinking)
+                dataLog("Clearing putToBase info in ", *this, "\n");
+            m_putToBaseOperations[i].m_structure.clear();
+        }
+    }
+    for (size_t size = m_resolveOperations.size(), i = 0; i < size; ++i) {
+        if (m_resolveOperations[i].isEmpty())
+            continue;
+#ifndef NDEBUG
+        for (size_t insnSize = m_resolveOperations[i].size() - 1, k = 0; k < insnSize; ++k)
+            ASSERT(!m_resolveOperations[i][k].m_structure);
 #endif
-
-            m_exceptionInfo.set(newCodeBlock.m_exceptionInfo.release());
-
-            m_globalData->scopeNodeBeingReparsed = 0;
-
-            break;
+        m_resolveOperations[i].last().m_structure.clear();
+        if (m_resolveOperations[i].last().m_structure && !Heap::isMarked(m_resolveOperations[i].last().m_structure.get())) {
+            if (verboseUnlinking)
+                dataLog("Clearing resolve info in ", *this, "\n");
+            m_resolveOperations[i].last().m_structure.clear();
         }
-        case EvalCode: {
-            EvalNode* ownerEvalNode = static_cast<EvalNode*>(m_ownerNode);
-            RefPtr<EvalNode> newEvalBody = m_globalData->parser->reparse<EvalNode>(m_globalData, ownerEvalNode);
-
-            m_globalData->scopeNodeBeingReparsed = newEvalBody.get();
-
-            EvalCodeBlock& newCodeBlock = newEvalBody->bytecodeForExceptionInfoReparse(scopeChain, this);
-            ASSERT(newCodeBlock.m_exceptionInfo);
-            ASSERT(newCodeBlock.m_instructionCount == m_instructionCount);
+    }
 
 #if ENABLE(JIT)
-            JIT::compile(m_globalData, &newCodeBlock);
-            ASSERT(newEvalBody->generatedJITCode().size() == ownerNode()->generatedJITCode().size());
-#endif
-
-            m_exceptionInfo.set(newCodeBlock.m_exceptionInfo.release());
-
-            m_globalData->scopeNodeBeingReparsed = 0;
-
-            break;
+    // Handle inline caches.
+    if (!!getJITCode()) {
+        RepatchBuffer repatchBuffer(this);
+        for (unsigned i = 0; i < numberOfCallLinkInfos(); ++i) {
+            if (callLinkInfo(i).isLinked()) {
+                if (ClosureCallStubRoutine* stub = callLinkInfo(i).stub.get()) {
+                    if (!Heap::isMarked(stub->structure())
+                        || !Heap::isMarked(stub->executable())) {
+                        if (verboseUnlinking) {
+                            dataLog(
+                                "Clearing closure call from ", *this, " to ",
+                                stub->executable()->hashFor(callLinkInfo(i).specializationKind()),
+                                ", stub routine ", RawPointer(stub), ".\n");
+                        }
+                        callLinkInfo(i).unlink(*m_vm, repatchBuffer);
+                    }
+                } else if (!Heap::isMarked(callLinkInfo(i).callee.get())) {
+                    if (verboseUnlinking) {
+                        dataLog(
+                            "Clearing call from ", *this, " to ",
+                            RawPointer(callLinkInfo(i).callee.get()), " (",
+                            callLinkInfo(i).callee.get()->executable()->hashFor(
+                                callLinkInfo(i).specializationKind()),
+                            ").\n");
+                    }
+                    callLinkInfo(i).unlink(*m_vm, repatchBuffer);
+                }
+            }
+            if (!!callLinkInfo(i).lastSeenCallee
+                && !Heap::isMarked(callLinkInfo(i).lastSeenCallee.get()))
+                callLinkInfo(i).lastSeenCallee.clear();
+        }
+        for (size_t size = m_structureStubInfos.size(), i = 0; i < size; ++i) {
+            StructureStubInfo& stubInfo = m_structureStubInfos[i];
+            
+            if (stubInfo.visitWeakReferences())
+                continue;
+            
+            resetStubDuringGCInternal(repatchBuffer, stubInfo);
         }
-        default:
-            // CodeBlocks for Global code blocks are transient and therefore to not gain from 
-            // from throwing out there exception information.
-            ASSERT_NOT_REACHED();
     }
+#endif
 }
 
-HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset)
+#if ENABLE(JIT)
+void CodeBlock::resetStub(StructureStubInfo& stubInfo)
+{
+    if (stubInfo.accessType == access_unset)
+        return;
+    
+    RepatchBuffer repatchBuffer(this);
+    resetStubInternal(repatchBuffer, stubInfo);
+}
+
+void CodeBlock::resetStubInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
+{
+    AccessType accessType = static_cast<AccessType>(stubInfo.accessType);
+    
+    if (verboseUnlinking)
+        dataLog("Clearing structure cache (kind ", static_cast<int>(stubInfo.accessType), ") in ", *this, ".\n");
+    
+    if (isGetByIdAccess(accessType)) {
+        if (getJITCode().jitType() == JITCode::DFGJIT)
+            DFG::dfgResetGetByID(repatchBuffer, stubInfo);
+        else
+            JIT::resetPatchGetById(repatchBuffer, &stubInfo);
+    } else {
+        ASSERT(isPutByIdAccess(accessType));
+        if (getJITCode().jitType() == JITCode::DFGJIT)
+            DFG::dfgResetPutByID(repatchBuffer, stubInfo);
+        else 
+            JIT::resetPatchPutById(repatchBuffer, &stubInfo);
+    }
+    
+    stubInfo.reset();
+}
+
+void CodeBlock::resetStubDuringGCInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
+{
+    resetStubInternal(repatchBuffer, stubInfo);
+    stubInfo.resetByGC = true;
+}
+#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);
+
+    updateAllPredictions(Collection);
+}
+
+void CodeBlock::stronglyVisitWeakReferences(SlotVisitor& visitor)
+{
+    UNUSED_PARAM(visitor);
+
+#if ENABLE(DFG_JIT)
+    if (!m_dfgData)
+        return;
+
+    for (unsigned i = 0; i < m_dfgData->transitions.size(); ++i) {
+        if (!!m_dfgData->transitions[i].m_codeOrigin)
+            visitor.append(&m_dfgData->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(&m_dfgData->transitions[i].m_from);
+        visitor.append(&m_dfgData->transitions[i].m_to);
+    }
+    
+    for (unsigned i = 0; i < m_dfgData->weakReferences.size(); ++i)
+        visitor.append(&m_dfgData->weakReferences[i]);
+#endif    
+}
+
+HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset)
 {
-    ASSERT(m_codeType != NativeCode);
-    ASSERT(bytecodeOffset < m_instructionCount);
+    RELEASE_ASSERT(bytecodeOffset < instructions().size());
 
     if (!m_rareData)
         return 0;
@@ -1528,225 +2459,908 @@ HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset)
     for (size_t i = 0; i < exceptionHandlers.size(); ++i) {
         // Handlers are ordered innermost first, so the first handler we encounter
         // that contains the source address is the correct handler to use.
-        if (exceptionHandlers[i].start <= bytecodeOffset && exceptionHandlers[i].end >= bytecodeOffset)
+        if (exceptionHandlers[i].start <= bytecodeOffset && exceptionHandlers[i].end > bytecodeOffset)
             return &exceptionHandlers[i];
     }
 
     return 0;
 }
 
-int CodeBlock::lineNumberForBytecodeOffset(CallFrame* callFrame, unsigned bytecodeOffset)
+unsigned CodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
 {
-    ASSERT(m_codeType != NativeCode);
-    ASSERT(bytecodeOffset < m_instructionCount);
+    RELEASE_ASSERT(bytecodeOffset < instructions().size());
+    return m_ownerExecutable->lineNo() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
+}
 
-    reparseForExceptionInfoIfNecessary(callFrame);
-    ASSERT(m_exceptionInfo);
+unsigned CodeBlock::columnNumberForBytecodeOffset(unsigned bytecodeOffset)
+{
+    int divot;
+    int startOffset;
+    int endOffset;
+    unsigned line;
+    unsigned column;
+    expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
+    return column;
+}
 
-    if (!m_exceptionInfo->m_lineInfo.size())
-        return m_ownerNode->source().firstLine(); // Empty function
+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->lineNo();
+}
 
-    int low = 0;
-    int high = m_exceptionInfo->m_lineInfo.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_exceptionInfo->m_lineInfo[mid].instructionOffset <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
+void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
+{
+#if ENABLE(LLINT)
+    m_llintCallLinkInfos.shrinkToFit();
+#endif
+#if ENABLE(JIT)
+    m_structureStubInfos.shrinkToFit();
+    m_callLinkInfos.shrinkToFit();
+#endif
+#if ENABLE(VALUE_PROFILER)
+    m_rareCaseProfiles.shrinkToFit();
+    m_specialFastCaseProfiles.shrinkToFit();
+#endif
+    
+    if (shrinkMode == EarlyShrink) {
+        m_identifiers.shrinkToFit();
+        m_functionDecls.shrinkToFit();
+        m_functionExprs.shrinkToFit();
+        m_constantRegisters.shrinkToFit();
+    } // else don't shrink these, because we would have already pointed pointers into these tables.
+
+    if (m_rareData) {
+        m_rareData->m_exceptionHandlers.shrinkToFit();
+        m_rareData->m_immediateSwitchJumpTables.shrinkToFit();
+        m_rareData->m_characterSwitchJumpTables.shrinkToFit();
+        m_rareData->m_stringSwitchJumpTables.shrinkToFit();
+#if ENABLE(JIT)
+        m_rareData->m_callReturnIndexVector.shrinkToFit();
+#endif
+#if ENABLE(DFG_JIT)
+        m_rareData->m_inlineCallFrames.shrinkToFit();
+        m_rareData->m_codeOrigins.shrinkToFit();
+#endif
     }
     
-    if (!low)
-        return m_ownerNode->source().firstLine();
-    return m_exceptionInfo->m_lineInfo[low - 1].lineNumber;
+#if ENABLE(DFG_JIT)
+    if (m_dfgData) {
+        m_dfgData->osrEntry.shrinkToFit();
+        m_dfgData->osrExit.shrinkToFit();
+        m_dfgData->speculationRecovery.shrinkToFit();
+        m_dfgData->weakReferences.shrinkToFit();
+        m_dfgData->transitions.shrinkToFit();
+        m_dfgData->minifiedDFG.prepareAndShrink();
+        m_dfgData->variableEventStream.shrinkToFit();
+    }
+#endif
 }
 
-int CodeBlock::expressionRangeForBytecodeOffset(CallFrame* callFrame, unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset)
+void CodeBlock::createActivation(CallFrame* callFrame)
 {
-    ASSERT(m_codeType != NativeCode);
-    ASSERT(bytecodeOffset < m_instructionCount);
-
-    reparseForExceptionInfoIfNecessary(callFrame);
-    ASSERT(m_exceptionInfo);
+    ASSERT(codeType() == FunctionCode);
+    ASSERT(needsFullScopeChain());
+    ASSERT(!callFrame->uncheckedR(activationRegister()).jsValue());
+    JSActivation* activation = JSActivation::create(callFrame->vm(), callFrame, this);
+    callFrame->uncheckedR(activationRegister()) = JSValue(activation);
+    callFrame->setScope(activation);
+}
 
-    if (!m_exceptionInfo->m_expressionInfo.size()) {
-        // We didn't think anything could throw.  Apparently we were wrong.
-        startOffset = 0;
-        endOffset = 0;
-        divot = 0;
-        return lineNumberForBytecodeOffset(callFrame, bytecodeOffset);
+unsigned CodeBlock::addOrFindConstant(JSValue v)
+{
+    unsigned numberOfConstants = numberOfConstantRegisters();
+    for (unsigned i = 0; i < numberOfConstants; ++i) {
+        if (getConstant(FirstConstantRegisterIndex + i) == v)
+            return i;
     }
+    return addConstant(v);
+}
 
-    int low = 0;
-    int high = m_exceptionInfo->m_expressionInfo.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_exceptionInfo->m_expressionInfo[mid].instructionOffset <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
+#if ENABLE(JIT)
+void CodeBlock::unlinkCalls()
+{
+    if (!!m_alternative)
+        m_alternative->unlinkCalls();
+#if ENABLE(LLINT)
+    for (size_t i = 0; i < m_llintCallLinkInfos.size(); ++i) {
+        if (m_llintCallLinkInfos[i].isLinked())
+            m_llintCallLinkInfos[i].unlink();
     }
-    
-    ASSERT(low);
-    if (!low) {
-        startOffset = 0;
-        endOffset = 0;
-        divot = 0;
-        return lineNumberForBytecodeOffset(callFrame, bytecodeOffset);
+#endif
+    if (!m_callLinkInfos.size())
+        return;
+    if (!m_vm->canUseJIT())
+        return;
+    RepatchBuffer repatchBuffer(this);
+    for (size_t i = 0; i < m_callLinkInfos.size(); i++) {
+        if (!m_callLinkInfos[i].isLinked())
+            continue;
+        m_callLinkInfos[i].unlink(*m_vm, repatchBuffer);
     }
+}
 
-    startOffset = m_exceptionInfo->m_expressionInfo[low - 1].startOffset;
-    endOffset = m_exceptionInfo->m_expressionInfo[low - 1].endOffset;
-    divot = m_exceptionInfo->m_expressionInfo[low - 1].divotPoint + m_sourceOffset;
-    return lineNumberForBytecodeOffset(callFrame, bytecodeOffset);
+void CodeBlock::unlinkIncomingCalls()
+{
+#if ENABLE(LLINT)
+    while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
+        m_incomingLLIntCalls.begin()->unlink();
+#endif
+    if (m_incomingCalls.isEmpty())
+        return;
+    RepatchBuffer repatchBuffer(this);
+    while (m_incomingCalls.begin() != m_incomingCalls.end())
+        m_incomingCalls.begin()->unlink(*m_vm, repatchBuffer);
 }
+#endif // ENABLE(JIT)
 
-bool CodeBlock::getByIdExceptionInfoForBytecodeOffset(CallFrame* callFrame, unsigned bytecodeOffset, OpcodeID& opcodeID)
+#if ENABLE(LLINT)
+Instruction* CodeBlock::adjustPCIfAtCallSite(Instruction* potentialReturnPC)
 {
-    ASSERT(m_codeType != NativeCode);
-    ASSERT(bytecodeOffset < m_instructionCount);
+    ASSERT(potentialReturnPC);
+
+    unsigned returnPCOffset = potentialReturnPC - instructions().begin();
+    Instruction* adjustedPC;
+    unsigned opcodeLength;
+
+    // If we are at a callsite, the LLInt stores the PC after the call
+    // instruction rather than the PC of the call instruction. This requires
+    // some correcting. If so, we can rely on the fact that the preceding
+    // instruction must be one of the call instructions, so either it's a
+    // call_varargs or it's a call, construct, or eval.
+    //
+    // If we are not at a call site, then we need to guard against the
+    // possibility of peeking past the start of the bytecode range for this
+    // codeBlock. Hence, we do a bounds check before we peek at the
+    // potential "preceding" instruction.
+    //     The bounds check is done by comparing the offset of the potential
+    // returnPC with the length of the opcode. If there is room for a call
+    // instruction before the returnPC, then the offset of the returnPC must
+    // be greater than the size of the call opcode we're looking for.
+
+    // The determination of the call instruction present (if we are at a
+    // callsite) depends on the following assumptions. So, assert that
+    // they are still true:
+    ASSERT(OPCODE_LENGTH(op_call_varargs) <= OPCODE_LENGTH(op_call));
+    ASSERT(OPCODE_LENGTH(op_call) == OPCODE_LENGTH(op_construct));
+    ASSERT(OPCODE_LENGTH(op_call) == OPCODE_LENGTH(op_call_eval));
+
+    // Check for the case of a preceeding op_call_varargs:
+    opcodeLength = OPCODE_LENGTH(op_call_varargs);
+    adjustedPC = potentialReturnPC - opcodeLength;
+    if ((returnPCOffset >= opcodeLength)
+        && (adjustedPC->u.pointer == LLInt::getCodePtr(llint_op_call_varargs))) {
+        return adjustedPC;
+    }
 
-    reparseForExceptionInfoIfNecessary(callFrame);
-    ASSERT(m_exceptionInfo);        
+    // Check for the case of the other 3 call instructions:
+    opcodeLength = OPCODE_LENGTH(op_call);
+    adjustedPC = potentialReturnPC - opcodeLength;
+    if ((returnPCOffset >= opcodeLength)
+        && (adjustedPC->u.pointer == LLInt::getCodePtr(llint_op_call)
+            || adjustedPC->u.pointer == LLInt::getCodePtr(llint_op_construct)
+            || adjustedPC->u.pointer == LLInt::getCodePtr(llint_op_call_eval))) {
+        return adjustedPC;
+    }
 
-    if (!m_exceptionInfo->m_getByIdExceptionInfo.size())
-        return false;
+    // Not a call site. No need to adjust PC. Just return the original.
+    return potentialReturnPC;
+}
+#endif // ENABLE(LLINT)
 
-    int low = 0;
-    int high = m_exceptionInfo->m_getByIdExceptionInfo.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_exceptionInfo->m_getByIdExceptionInfo[mid].bytecodeOffset <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
+#if ENABLE(JIT)
+ClosureCallStubRoutine* CodeBlock::findClosureCallForReturnPC(ReturnAddressPtr returnAddress)
+{
+    for (unsigned i = m_callLinkInfos.size(); i--;) {
+        CallLinkInfo& info = m_callLinkInfos[i];
+        if (!info.stub)
+            continue;
+        if (!info.stub->code().executableMemory()->contains(returnAddress.value()))
+            continue;
+
+        RELEASE_ASSERT(info.stub->codeOrigin().bytecodeIndex < CodeOrigin::maximumBytecodeIndex);
+        return info.stub.get();
+    }
+    
+    // The stub routine may have been jettisoned. This is rare, but we have to handle it.
+    const JITStubRoutineSet& set = m_vm->heap.jitStubRoutines();
+    for (unsigned i = set.size(); i--;) {
+        GCAwareJITStubRoutine* genericStub = set.at(i);
+        if (!genericStub->isClosureCall())
+            continue;
+        ClosureCallStubRoutine* stub = static_cast<ClosureCallStubRoutine*>(genericStub);
+        if (!stub->code().executableMemory()->contains(returnAddress.value()))
+            continue;
+        RELEASE_ASSERT(stub->codeOrigin().bytecodeIndex < CodeOrigin::maximumBytecodeIndex);
+        return stub;
     }
+    
+    return 0;
+}
+#endif
+
+unsigned CodeBlock::bytecodeOffset(ExecState* exec, ReturnAddressPtr returnAddress)
+{
+    UNUSED_PARAM(exec);
+    UNUSED_PARAM(returnAddress);
+#if ENABLE(LLINT)
+#if !ENABLE(LLINT_C_LOOP)
+    // When using the JIT, we could have addresses that are not bytecode
+    // addresses. We check if the return address is in the LLint glue and
+    // opcode handlers range here to ensure that we are looking at bytecode
+    // before attempting to convert the return address into a bytecode offset.
+    //
+    // In the case of the C Loop LLInt, the JIT is disabled, and the only
+    // valid return addresses should be bytecode PCs. So, we can and need to
+    // forego this check because when we do not ENABLE(COMPUTED_GOTO_OPCODES),
+    // then the bytecode "PC"s are actually the opcodeIDs and are not bounded
+    // by llint_begin and llint_end.
+    if (returnAddress.value() >= LLInt::getCodePtr(llint_begin)
+        && returnAddress.value() <= LLInt::getCodePtr(llint_end))
+#endif
+    {
+        RELEASE_ASSERT(exec->codeBlock());
+        RELEASE_ASSERT(exec->codeBlock() == this);
+        RELEASE_ASSERT(JITCode::isBaselineCode(getJITType()));
+        Instruction* instruction = exec->currentVPC();
+        RELEASE_ASSERT(instruction);
+
+        instruction = adjustPCIfAtCallSite(instruction);
+        return bytecodeOffset(instruction);
+    }
+#endif // !ENABLE(LLINT)
+
+#if ENABLE(JIT)
+    if (!m_rareData)
+        return 1;
+    Vector<CallReturnOffsetToBytecodeOffset, 0, UnsafeVectorOverflow>& callIndices = m_rareData->m_callReturnIndexVector;
+    if (!callIndices.size())
+        return 1;
+    
+    if (getJITCode().getExecutableMemory()->contains(returnAddress.value())) {
+        unsigned callReturnOffset = getJITCode().offsetOf(returnAddress.value());
+        CallReturnOffsetToBytecodeOffset* result =
+            binarySearch<CallReturnOffsetToBytecodeOffset, unsigned>(
+                callIndices, callIndices.size(), callReturnOffset, getCallReturnOffset);
+        RELEASE_ASSERT(result->callReturnOffset == callReturnOffset);
+        RELEASE_ASSERT(result->bytecodeOffset < instructionCount());
+        return result->bytecodeOffset;
+    }
+    ClosureCallStubRoutine* closureInfo = findClosureCallForReturnPC(returnAddress);
+    CodeOrigin origin = closureInfo->codeOrigin();
+    while (InlineCallFrame* inlineCallFrame = origin.inlineCallFrame) {
+        if (inlineCallFrame->baselineCodeBlock() == this)
+            break;
+        origin = inlineCallFrame->caller;
+        RELEASE_ASSERT(origin.bytecodeIndex < CodeOrigin::maximumBytecodeIndex);
+    }
+    RELEASE_ASSERT(origin.bytecodeIndex < CodeOrigin::maximumBytecodeIndex);
+    unsigned bytecodeIndex = origin.bytecodeIndex;
+    RELEASE_ASSERT(bytecodeIndex < instructionCount());
+    return bytecodeIndex;
+#endif // ENABLE(JIT)
+
+#if !ENABLE(LLINT) && !ENABLE(JIT)
+    return 1;
+#endif
+}
 
-    if (!low || m_exceptionInfo->m_getByIdExceptionInfo[low - 1].bytecodeOffset != bytecodeOffset)
+#if ENABLE(DFG_JIT)
+bool CodeBlock::codeOriginForReturn(ReturnAddressPtr returnAddress, CodeOrigin& codeOrigin)
+{
+    if (!hasCodeOrigins())
         return false;
 
-    opcodeID = m_exceptionInfo->m_getByIdExceptionInfo[low - 1].isOpConstruct ? op_construct : op_instanceof;
+    if (!getJITCode().getExecutableMemory()->contains(returnAddress.value())) {
+        ClosureCallStubRoutine* stub = findClosureCallForReturnPC(returnAddress);
+        ASSERT(stub);
+        if (!stub)
+            return false;
+        codeOrigin = stub->codeOrigin();
+        return true;
+    }
+    
+    unsigned offset = getJITCode().offsetOf(returnAddress.value());
+    CodeOriginAtCallReturnOffset* entry =
+        tryBinarySearch<CodeOriginAtCallReturnOffset, unsigned>(
+            codeOrigins(), codeOrigins().size(), offset,
+            getCallReturnOffsetForCodeOrigin);
+    if (!entry)
+        return false;
+    codeOrigin = entry->codeOrigin;
     return true;
 }
+#endif // ENABLE(DFG_JIT)
+
+void CodeBlock::clearEvalCache()
+{
+    if (!!m_alternative)
+        m_alternative->clearEvalCache();
+    if (!m_rareData)
+        return;
+    m_rareData->m_evalCodeCache.clear();
+}
+
+template<typename T, size_t inlineCapacity, typename U, typename V>
+inline void replaceExistingEntries(Vector<T, inlineCapacity, U>& target, Vector<T, inlineCapacity, V>& source)
+{
+    ASSERT(target.size() <= source.size());
+    for (size_t i = 0; i < target.size(); ++i)
+        target[i] = source[i];
+}
+
+void CodeBlock::copyPostParseDataFrom(CodeBlock* alternative)
+{
+    if (!alternative)
+        return;
+    
+    replaceExistingEntries(m_constantRegisters, alternative->m_constantRegisters);
+    replaceExistingEntries(m_functionDecls, alternative->m_functionDecls);
+    replaceExistingEntries(m_functionExprs, alternative->m_functionExprs);
+    if (!!m_rareData && !!alternative->m_rareData)
+        replaceExistingEntries(m_rareData->m_constantBuffers, alternative->m_rareData->m_constantBuffers);
+}
+
+void CodeBlock::copyPostParseDataFromAlternative()
+{
+    copyPostParseDataFrom(m_alternative.get());
+}
 
 #if ENABLE(JIT)
-bool CodeBlock::functionRegisterForBytecodeOffset(unsigned bytecodeOffset, int& functionRegisterIndex)
+void CodeBlock::reoptimize()
 {
-    ASSERT(m_codeType != NativeCode);
-    ASSERT(bytecodeOffset < m_instructionCount);
+    ASSERT(replacement() != this);
+    ASSERT(replacement()->alternative() == this);
+    if (DFG::shouldShowDisassembly())
+        dataLog(*replacement(), " will be jettisoned due to reoptimization of ", *this, ".\n");
+    replacement()->jettison();
+    countReoptimization();
+}
 
-    if (!m_rareData || !m_rareData->m_functionRegisterInfos.size())
-        return false;
+CodeBlock* ProgramCodeBlock::replacement()
+{
+    return &static_cast<ProgramExecutable*>(ownerExecutable())->generatedBytecode();
+}
 
-    int low = 0;
-    int high = m_rareData->m_functionRegisterInfos.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_rareData->m_functionRegisterInfos[mid].bytecodeOffset <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
-    }
+CodeBlock* EvalCodeBlock::replacement()
+{
+    return &static_cast<EvalExecutable*>(ownerExecutable())->generatedBytecode();
+}
 
-    if (!low || m_rareData->m_functionRegisterInfos[low - 1].bytecodeOffset != bytecodeOffset)
-        return false;
+CodeBlock* FunctionCodeBlock::replacement()
+{
+    return &static_cast<FunctionExecutable*>(ownerExecutable())->generatedBytecodeFor(m_isConstructor ? CodeForConstruct : CodeForCall);
+}
 
-    functionRegisterIndex = m_rareData->m_functionRegisterInfos[low - 1].functionRegisterIndex;
-    return true;
+JSObject* ProgramCodeBlock::compileOptimized(ExecState* exec, JSScope* scope, unsigned bytecodeIndex)
+{
+    if (replacement()->getJITType() == JITCode::nextTierJIT(getJITType()))
+        return 0;
+    JSObject* error = static_cast<ProgramExecutable*>(ownerExecutable())->compileOptimized(exec, scope, bytecodeIndex);
+    return error;
+}
+
+JSObject* EvalCodeBlock::compileOptimized(ExecState* exec, JSScope* scope, unsigned bytecodeIndex)
+{
+    if (replacement()->getJITType() == JITCode::nextTierJIT(getJITType()))
+        return 0;
+    JSObject* error = static_cast<EvalExecutable*>(ownerExecutable())->compileOptimized(exec, scope, bytecodeIndex);
+    return error;
+}
+
+JSObject* FunctionCodeBlock::compileOptimized(ExecState* exec, JSScope* scope, unsigned bytecodeIndex)
+{
+    if (replacement()->getJITType() == JITCode::nextTierJIT(getJITType()))
+        return 0;
+    JSObject* error = static_cast<FunctionExecutable*>(ownerExecutable())->compileOptimizedFor(exec, scope, bytecodeIndex, m_isConstructor ? CodeForConstruct : CodeForCall);
+    return error;
+}
+
+DFG::CapabilityLevel ProgramCodeBlock::canCompileWithDFGInternal()
+{
+    return DFG::canCompileProgram(this);
+}
+
+DFG::CapabilityLevel EvalCodeBlock::canCompileWithDFGInternal()
+{
+    return DFG::canCompileEval(this);
+}
+
+DFG::CapabilityLevel FunctionCodeBlock::canCompileWithDFGInternal()
+{
+    if (m_isConstructor)
+        return DFG::canCompileFunctionForConstruct(this);
+    return DFG::canCompileFunctionForCall(this);
+}
+
+void CodeBlock::jettison()
+{
+    ASSERT(JITCode::isOptimizingJIT(getJITType()));
+    ASSERT(this == replacement());
+    alternative()->optimizeAfterWarmUp();
+    tallyFrequentExitSites();
+    if (DFG::shouldShowDisassembly())
+        dataLog("Jettisoning ", *this, ".\n");
+    jettisonImpl();
+}
+
+void ProgramCodeBlock::jettisonImpl()
+{
+    static_cast<ProgramExecutable*>(ownerExecutable())->jettisonOptimizedCode(*vm());
+}
+
+void EvalCodeBlock::jettisonImpl()
+{
+    static_cast<EvalExecutable*>(ownerExecutable())->jettisonOptimizedCode(*vm());
+}
+
+void FunctionCodeBlock::jettisonImpl()
+{
+    static_cast<FunctionExecutable*>(ownerExecutable())->jettisonOptimizedCodeFor(*vm(), m_isConstructor ? CodeForConstruct : CodeForCall);
+}
+
+bool ProgramCodeBlock::jitCompileImpl(ExecState* exec)
+{
+    ASSERT(getJITType() == JITCode::InterpreterThunk);
+    ASSERT(this == replacement());
+    return static_cast<ProgramExecutable*>(ownerExecutable())->jitCompile(exec);
+}
+
+bool EvalCodeBlock::jitCompileImpl(ExecState* exec)
+{
+    ASSERT(getJITType() == JITCode::InterpreterThunk);
+    ASSERT(this == replacement());
+    return static_cast<EvalExecutable*>(ownerExecutable())->jitCompile(exec);
+}
+
+bool FunctionCodeBlock::jitCompileImpl(ExecState* exec)
+{
+    ASSERT(getJITType() == JITCode::InterpreterThunk);
+    ASSERT(this == replacement());
+    return static_cast<FunctionExecutable*>(ownerExecutable())->jitCompileFor(exec, m_isConstructor ? CodeForConstruct : CodeForCall);
 }
 #endif
 
-#if !ENABLE(JIT)
-bool CodeBlock::hasGlobalResolveInstructionAtBytecodeOffset(unsigned bytecodeOffset)
+JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
 {
-    ASSERT(m_codeType != NativeCode);
-    if (m_globalResolveInstructions.isEmpty())
-        return false;
+    if (!codeOrigin.inlineCallFrame)
+        return globalObject();
+    return jsCast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())->generatedBytecode().globalObject();
+}
 
-    int low = 0;
-    int high = m_globalResolveInstructions.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_globalResolveInstructions[mid] <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
+unsigned CodeBlock::reoptimizationRetryCounter() const
+{
+    ASSERT(m_reoptimizationRetryCounter <= Options::reoptimizationRetryCounterMax());
+    return m_reoptimizationRetryCounter;
+}
+
+void CodeBlock::countReoptimization()
+{
+    m_reoptimizationRetryCounter++;
+    if (m_reoptimizationRetryCounter > Options::reoptimizationRetryCounterMax())
+        m_reoptimizationRetryCounter = Options::reoptimizationRetryCounterMax();
+}
+
+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;
+#if ENABLE(JIT_VERBOSE_OSR)
+    dataLog(*this, ": instruction count is ", instructionCount, ", scaling execution counter by ", result, " * ", codeTypeThresholdMultiplier(), "\n");
+#endif
+    return result * codeTypeThresholdMultiplier();
+}
+
+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::counterValueForOptimizeAfterWarmUp()
+{
+    return clipThreshold(
+        Options::thresholdForOptimizeAfterWarmUp() *
+        optimizationThresholdScalingFactor() *
+        (1 << reoptimizationRetryCounter()));
+}
+
+int32_t CodeBlock::counterValueForOptimizeAfterLongWarmUp()
+{
+    return clipThreshold(
+        Options::thresholdForOptimizeAfterLongWarmUp() *
+        optimizationThresholdScalingFactor() *
+        (1 << reoptimizationRetryCounter()));
+}
+
+int32_t CodeBlock::counterValueForOptimizeSoon()
+{
+    return clipThreshold(
+        Options::thresholdForOptimizeSoon() *
+        optimizationThresholdScalingFactor() *
+        (1 << reoptimizationRetryCounter()));
+}
+
+bool CodeBlock::checkIfOptimizationThresholdReached()
+{
+    return m_jitExecuteCounter.checkIfThresholdCrossedAndSet(this);
+}
+
+void CodeBlock::optimizeNextInvocation()
+{
+    m_jitExecuteCounter.setNewThreshold(0, this);
+}
+
+void CodeBlock::dontOptimizeAnytimeSoon()
+{
+    m_jitExecuteCounter.deferIndefinitely();
+}
+
+void CodeBlock::optimizeAfterWarmUp()
+{
+    m_jitExecuteCounter.setNewThreshold(counterValueForOptimizeAfterWarmUp(), this);
+}
+
+void CodeBlock::optimizeAfterLongWarmUp()
+{
+    m_jitExecuteCounter.setNewThreshold(counterValueForOptimizeAfterLongWarmUp(), this);
+}
+
+void CodeBlock::optimizeSoon()
+{
+    m_jitExecuteCounter.setNewThreshold(counterValueForOptimizeSoon(), this);
+}
+
+#if ENABLE(JIT)
+uint32_t CodeBlock::adjustedExitCountThreshold(uint32_t desiredThreshold)
+{
+    ASSERT(getJITType() == JITCode::DFGJIT);
+    // 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;
+}
 
-    if (!low || m_globalResolveInstructions[low - 1] != bytecodeOffset)
-        return false;
-    return true;
+uint32_t CodeBlock::exitCountThresholdForReoptimization()
+{
+    return adjustedExitCountThreshold(Options::osrExitCountForReoptimization() * codeTypeThresholdMultiplier());
 }
-#else
-bool CodeBlock::hasGlobalResolveInfoAtBytecodeOffset(unsigned bytecodeOffset)
+
+uint32_t CodeBlock::exitCountThresholdForReoptimizationFromLoop()
 {
-    ASSERT(m_codeType != NativeCode);
-    if (m_globalResolveInfos.isEmpty())
-        return false;
+    return adjustedExitCountThreshold(Options::osrExitCountForReoptimizationFromLoop() * codeTypeThresholdMultiplier());
+}
 
-    int low = 0;
-    int high = m_globalResolveInfos.size();
-    while (low < high) {
-        int mid = low + (high - low) / 2;
-        if (m_globalResolveInfos[mid].bytecodeOffset <= bytecodeOffset)
-            low = mid + 1;
-        else
-            high = mid;
+bool CodeBlock::shouldReoptimizeNow()
+{
+    return osrExitCounter() >= exitCountThresholdForReoptimization();
+}
+
+bool CodeBlock::shouldReoptimizeFromLoopNow()
+{
+    return osrExitCounter() >= exitCountThresholdForReoptimizationFromLoop();
+}
+#endif
+
+#if ENABLE(VALUE_PROFILER)
+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;
+}
 
-    if (!low || m_globalResolveInfos[low - 1].bytecodeOffset != bytecodeOffset)
-        return false;
-    return true;
+ArrayProfile* CodeBlock::getOrAddArrayProfile(unsigned bytecodeOffset)
+{
+    ArrayProfile* result = getArrayProfile(bytecodeOffset);
+    if (result)
+        return result;
+    return addArrayProfile(bytecodeOffset);
 }
+
+void CodeBlock::updateAllPredictionsAndCountLiveness(
+    OperationInProgress operation, unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles)
+{
+    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(operation);
+            continue;
+        }
+        if (profile->numberOfSamples() || profile->m_prediction != SpecNone)
+            numberOfLiveNonArgumentValueProfiles++;
+        profile->computeUpdatedPrediction(operation);
+    }
+    
+#if ENABLE(DFG_JIT)
+    m_lazyOperandValueProfiles.computeUpdatedPredictions(operation);
 #endif
+}
 
-#if ENABLE(JIT)
-void CodeBlock::setJITCode(JITCode jitCode)
+void CodeBlock::updateAllValueProfilePredictions(OperationInProgress operation)
+{
+    unsigned ignoredValue1, ignoredValue2;
+    updateAllPredictionsAndCountLiveness(operation, ignoredValue1, ignoredValue2);
+}
+
+void CodeBlock::updateAllArrayPredictions(OperationInProgress operation)
 {
-    ASSERT(m_codeType != NativeCode); 
-    ownerNode()->setJITCode(jitCode);
-#if !ENABLE(OPCODE_SAMPLING)
-    if (!BytecodeGenerator::dumpsGeneratedCode())
-        m_instructions.clear();
+    for (unsigned i = m_arrayProfiles.size(); i--;)
+        m_arrayProfiles[i].computeUpdatedPrediction(this, operation);
+    
+    // Don't count these either, for similar reasons.
+    for (unsigned i = m_arrayAllocationProfiles.size(); i--;)
+        m_arrayAllocationProfiles[i].updateIndexingType();
+}
+
+void CodeBlock::updateAllPredictions(OperationInProgress operation)
+{
+    updateAllValueProfilePredictions(operation);
+    updateAllArrayPredictions(operation);
+}
+
+bool CodeBlock::shouldOptimizeNow()
+{
+#if ENABLE(JIT_VERBOSE_OSR)
+    dataLog("Considering optimizing ", *this, "...\n");
+#endif
+
+#if ENABLE(VERBOSE_VALUE_PROFILE)
+    dumpValueProfiles();
+#endif
+
+    if (m_optimizationDelayCounter >= Options::maximumOptimizationDelay())
+        return true;
+    
+    updateAllArrayPredictions();
+    
+    unsigned numberOfLiveNonArgumentValueProfiles;
+    unsigned numberOfSamplesInProfiles;
+    updateAllPredictionsAndCountLiveness(NoOperation, numberOfLiveNonArgumentValueProfiles, numberOfSamplesInProfiles);
+
+#if ENABLE(JIT_VERBOSE_OSR)
+    dataLogF("Profile hotness: %lf (%u / %u), %lf (%u / %u)\n", (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles(), numberOfLiveNonArgumentValueProfiles, numberOfValueProfiles(), (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles(), numberOfSamplesInProfiles, ValueProfile::numberOfBuckets * numberOfValueProfiles());
 #endif
+
+    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;
 }
 #endif
 
-void CodeBlock::shrinkToFit()
+#if ENABLE(DFG_JIT)
+void CodeBlock::tallyFrequentExitSites()
 {
-    m_instructions.shrinkToFit();
-
-#if !ENABLE(JIT)
-    m_propertyAccessInstructions.shrinkToFit();
-    m_globalResolveInstructions.shrinkToFit();
-#else
-    m_structureStubInfos.shrinkToFit();
-    m_globalResolveInfos.shrinkToFit();
-    m_callLinkInfos.shrinkToFit();
-    m_linkedCallerList.shrinkToFit();
+    ASSERT(getJITType() == JITCode::DFGJIT);
+    ASSERT(alternative()->getJITType() == JITCode::BaselineJIT);
+    ASSERT(!!m_dfgData);
+    
+    CodeBlock* profiledBlock = alternative();
+    
+    for (unsigned i = 0; i < m_dfgData->osrExit.size(); ++i) {
+        DFG::OSRExit& exit = m_dfgData->osrExit[i];
+        
+        if (!exit.considerAddingAsFrequentExitSite(profiledBlock))
+            continue;
+        
+#if DFG_ENABLE(DEBUG_VERBOSE)
+        dataLog("OSR exit #", i, " (bc#", exit.m_codeOrigin.bytecodeIndex, ", ", exit.m_kind, ") for ", *this, " occurred frequently: counting as frequent exit site.\n");
 #endif
+    }
+}
+#endif // ENABLE(DFG_JIT)
 
-    m_identifiers.shrinkToFit();
-    m_functionExpressions.shrinkToFit();
-    m_constantRegisters.shrinkToFit();
+#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)
 
-    if (m_exceptionInfo) {
-        m_exceptionInfo->m_expressionInfo.shrinkToFit();
-        m_exceptionInfo->m_lineInfo.shrinkToFit();
-        m_exceptionInfo->m_getByIdExceptionInfo.shrinkToFit();
+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;
+}
 
-    if (m_rareData) {
-        m_rareData->m_exceptionHandlers.shrinkToFit();
-        m_rareData->m_functions.shrinkToFit();
-        m_rareData->m_regexps.shrinkToFit();
-        m_rareData->m_immediateSwitchJumpTables.shrinkToFit();
-        m_rareData->m_characterSwitchJumpTables.shrinkToFit();
-        m_rareData->m_stringSwitchJumpTables.shrinkToFit();
-#if ENABLE(JIT)
-        m_rareData->m_functionRegisterInfos.shrinkToFit();
-#endif
+String CodeBlock::nameForRegister(int registerNumber)
+{
+    SymbolTable::iterator end = symbolTable()->end();
+    for (SymbolTable::iterator ptr = symbolTable()->begin(); ptr != end; ++ptr) {
+        if (ptr->value.getIndex() == registerNumber)
+            return String(ptr->key);
+    }
+    if (needsActivation() && registerNumber == activationRegister())
+        return ASCIILiteral("activation");
+    if (registerNumber == thisRegister())
+        return ASCIILiteral("this");
+    if (usesArguments()) {
+        if (registerNumber == argumentsRegister())
+            return ASCIILiteral("arguments");
+        if (unmodifiedArgumentsRegister(argumentsRegister()) == registerNumber)
+            return ASCIILiteral("real arguments");
     }
+    if (registerNumber < 0) {
+        int argumentPosition = -registerNumber;
+        argumentPosition -= JSStack::CallFrameHeaderSize + 1;
+        return String::format("arguments[%3d]", argumentPosition - 1).impl();
+    }
+    return "";
 }
 
 } // namespace JSC