webkitgtk-2.4.9webkitgtk-2.4.9

1 files changed, 763 insertions, 1190 deletions

diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
index 394974eaa..eec5b7076 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2010, 2012-2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009, 2010, 2012, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -11,7 +11,7 @@
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
- * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
@@ -30,42 +30,35 @@
 #include "config.h"
 #include "CodeBlock.h"
 
-#include "BasicBlockLocation.h"
 #include "BytecodeGenerator.h"
 #include "BytecodeUseDef.h"
 #include "CallLinkStatus.h"
 #include "DFGCapabilities.h"
 #include "DFGCommon.h"
 #include "DFGDriver.h"
-#include "DFGJITCode.h"
+#include "DFGNode.h"
 #include "DFGWorklist.h"
 #include "Debugger.h"
-#include "FunctionExecutableDump.h"
 #include "Interpreter.h"
 #include "JIT.h"
 #include "JITStubs.h"
+#include "JSActivation.h"
 #include "JSCJSValue.h"
 #include "JSFunction.h"
-#include "JSLexicalEnvironment.h"
+#include "JSNameScope.h"
 #include "LLIntEntrypoint.h"
 #include "LowLevelInterpreter.h"
-#include "JSCInlines.h"
-#include "PolymorphicGetByIdList.h"
+#include "Operations.h"
 #include "PolymorphicPutByIdList.h"
-#include "ProfilerDatabase.h"
 #include "ReduceWhitespace.h"
 #include "Repatch.h"
 #include "RepatchBuffer.h"
 #include "SlotVisitorInlines.h"
-#include "StackVisitor.h"
-#include "TypeLocationCache.h"
-#include "TypeProfiler.h"
 #include "UnlinkedInstructionStream.h"
 #include <wtf/BagToHashMap.h>
 #include <wtf/CommaPrinter.h>
 #include <wtf/StringExtras.h>
 #include <wtf/StringPrintStream.h>
-#include <wtf/text/UniquedStringImpl.h>
 
 #if ENABLE(DFG_JIT)
 #include "DFGOperations.h"
@@ -134,36 +127,22 @@ CString CodeBlock::sourceCodeOnOneLine() const
     return reduceWhitespace(sourceCodeForTools());
 }
 
-CString CodeBlock::hashAsStringIfPossible() const
-{
-    if (hasHash() || isSafeToComputeHash())
-        return toCString(hash());
-    return "<no-hash>";
-}
-
 void CodeBlock::dumpAssumingJITType(PrintStream& out, JITCode::JITType jitType) const
 {
-    out.print(inferredName(), "#", hashAsStringIfPossible());
-    out.print(":[", RawPointer(this), "->");
-    if (!!m_alternative)
-        out.print(RawPointer(m_alternative.get()), "->");
-    out.print(RawPointer(ownerExecutable()), ", ", jitType, codeType());
+    if (hasHash() || isSafeToComputeHash())
+        out.print(inferredName(), "#", hash(), ":[", RawPointer(this), "->", RawPointer(ownerExecutable()), ", ", jitType, codeType());
+    else
+        out.print(inferredName(), "#<no-hash>:[", RawPointer(this), "->", RawPointer(ownerExecutable()), ", ", jitType, codeType());
 
     if (codeType() == FunctionCode)
         out.print(specializationKind());
     out.print(", ", instructionCount());
     if (this->jitType() == JITCode::BaselineJIT && m_shouldAlwaysBeInlined)
-        out.print(" (ShouldAlwaysBeInlined)");
+        out.print(" (SABI)");
     if (ownerExecutable()->neverInline())
         out.print(" (NeverInline)");
-    if (ownerExecutable()->didTryToEnterInLoop())
-        out.print(" (DidTryToEnterInLoop)");
     if (ownerExecutable()->isStrictMode())
         out.print(" (StrictMode)");
-    if (this->jitType() == JITCode::BaselineJIT && m_didFailFTLCompilation)
-        out.print(" (FTLFail)");
-    if (this->jitType() == JITCode::BaselineJIT && m_hasBeenCompiledWithFTL)
-        out.print(" (HadFTLReplacement)");
     out.print("]");
 }
 
@@ -172,6 +151,11 @@ void CodeBlock::dump(PrintStream& out) const
     dumpAssumingJITType(out, jitType());
 }
 
+static CString constantName(int k, JSValue value)
+{
+    return toCString(value, "(@k", k - FirstConstantRegisterIndex, ")");
+}
+
 static CString idName(int id0, const Identifier& ident)
 {
     return toCString(ident.impl(), "(@id", id0, ")");
@@ -179,16 +163,19 @@ static CString idName(int id0, const Identifier& ident)
 
 CString CodeBlock::registerName(int r) const
 {
+    if (r == missingThisObjectMarker())
+        return "<null>";
+
     if (isConstantRegisterIndex(r))
-        return constantName(r);
+        return constantName(r, getConstant(r));
 
-    return toCString(VirtualRegister(r));
-}
+    if (operandIsArgument(r)) {
+        if (!VirtualRegister(r).toArgument())
+            return "this";
+        return toCString("arg", VirtualRegister(r).toArgument());
+    }
 
-CString CodeBlock::constantName(int index) const
-{
-    JSValue value = getConstant(index);
-    return toCString(value, "(", VirtualRegister(index), ")");
+    return toCString("loc", VirtualRegister(r).toLocal());
 }
 
 static CString regexpToSourceString(RegExp* regExp)
@@ -267,14 +254,45 @@ void CodeBlock::printGetByIdOp(PrintStream& out, ExecState* exec, int location,
     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();
-#if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
         op = 0;
-#endif
     }
     int r0 = (++it)->u.operand;
     int r1 = (++it)->u.operand;
@@ -284,19 +302,22 @@ void CodeBlock::printGetByIdOp(PrintStream& out, ExecState* exec, int location,
     it += 4; // Increment up to the value profiler.
 }
 
-static void dumpStructure(PrintStream& out, const char* name, Structure* structure, const Identifier& ident)
+#if ENABLE(JIT) || ENABLE(LLINT) // unused in some configurations
+static void dumpStructure(PrintStream& out, const char* name, ExecState* exec, Structure* structure, const Identifier& ident)
 {
     if (!structure)
         return;
     
     out.printf("%s = %p", name, structure);
     
-    PropertyOffset offset = structure->getConcurrently(ident.impl());
+    PropertyOffset offset = structure->getConcurrently(exec->vm(), ident.impl());
     if (offset != invalidOffset)
         out.printf(" (offset = %d)", offset);
 }
+#endif
 
-static void dumpChain(PrintStream& out, StructureChain* chain, const Identifier& ident)
+#if ENABLE(JIT) // unused when not ENABLE(JIT), leading to silly warnings
+static void dumpChain(PrintStream& out, ExecState* exec, StructureChain* chain, const Identifier& ident)
 {
     out.printf("chain = %p: [", chain);
     bool first = true;
@@ -307,10 +328,11 @@ static void dumpChain(PrintStream& out, StructureChain* chain, const Identifier&
             first = false;
         else
             out.printf(", ");
-        dumpStructure(out, "struct", currentStructure->get(), ident);
+        dumpStructure(out, "struct", exec, currentStructure->get(), ident);
     }
     out.printf("]");
 }
+#endif
 
 void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
 {
@@ -320,39 +342,65 @@ void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int l
     
     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", structure, ident);
+        dumpStructure(out, "struct", exec, structure, ident);
         out.printf(")");
     }
+#endif
 
 #if ENABLE(JIT)
     if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
         StructureStubInfo& stubInfo = *stubPtr;
-        if (stubInfo.resetByGC)
-            out.print(" (Reset By GC)");
-        
         if (stubInfo.seen) {
             out.printf(" jit(");
             
             Structure* baseStructure = 0;
             Structure* prototypeStructure = 0;
-            PolymorphicGetByIdList* list = 0;
+            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_list:
-                out.printf("list");
-                list = stubInfo.u.getByIdList.list;
+            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;
@@ -360,24 +408,36 @@ void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int l
             
             if (baseStructure) {
                 out.printf(", ");
-                dumpStructure(out, "struct", baseStructure, ident);
+                dumpStructure(out, "struct", exec, baseStructure, ident);
             }
             
             if (prototypeStructure) {
                 out.printf(", ");
-                dumpStructure(out, "prototypeStruct", baseStructure, ident);
+                dumpStructure(out, "prototypeStruct", exec, baseStructure, ident);
             }
             
-            if (list) {
-                out.printf(", list = %p: [", list);
-                for (unsigned i = 0; i < list->size(); ++i) {
+            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", list->at(i).structure(), ident);
-                    if (!list->at(i).conditionSet().isEmpty()) {
-                        out.printf(", ");
-                        out.print(list->at(i).conditionSet());
+                    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(")");
                 }
@@ -391,115 +451,7 @@ void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int l
 #endif
 }
 
-void CodeBlock::printPutByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
-{
-    Instruction* instruction = instructions().begin() + location;
-
-    const Identifier& ident = identifier(instruction[2].u.operand);
-    
-    UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
-    
-    if (Structure* structure = instruction[4].u.structure.get()) {
-        switch (exec->interpreter()->getOpcodeID(instruction[0].u.opcode)) {
-        case op_put_by_id:
-        case op_put_by_id_out_of_line:
-            out.print(" llint(");
-            dumpStructure(out, "struct", structure, ident);
-            out.print(")");
-            break;
-            
-        case op_put_by_id_transition_direct:
-        case op_put_by_id_transition_normal:
-        case op_put_by_id_transition_direct_out_of_line:
-        case op_put_by_id_transition_normal_out_of_line:
-            out.print(" llint(");
-            dumpStructure(out, "prev", structure, ident);
-            out.print(", ");
-            dumpStructure(out, "next", instruction[6].u.structure.get(), ident);
-            if (StructureChain* chain = instruction[7].u.structureChain.get()) {
-                out.print(", ");
-                dumpChain(out, chain, ident);
-            }
-            out.print(")");
-            break;
-            
-        default:
-            out.print(" llint(unknown)");
-            break;
-        }
-    }
-
-#if ENABLE(JIT)
-    if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
-        StructureStubInfo& stubInfo = *stubPtr;
-        if (stubInfo.resetByGC)
-            out.print(" (Reset By GC)");
-        
-        if (stubInfo.seen) {
-            out.printf(" jit(");
-            
-            switch (stubInfo.accessType) {
-            case access_put_by_id_replace:
-                out.print("replace, ");
-                dumpStructure(out, "struct", stubInfo.u.putByIdReplace.baseObjectStructure.get(), ident);
-                break;
-            case access_put_by_id_transition_normal:
-            case access_put_by_id_transition_direct:
-                out.print("transition, ");
-                dumpStructure(out, "prev", stubInfo.u.putByIdTransition.previousStructure.get(), ident);
-                out.print(", ");
-                dumpStructure(out, "next", stubInfo.u.putByIdTransition.structure.get(), ident);
-                if (stubInfo.u.putByIdTransition.rawConditionSet)
-                    out.print(", ", ObjectPropertyConditionSet::fromRawPointer(stubInfo.u.putByIdTransition.rawConditionSet));
-                break;
-            case access_put_by_id_list: {
-                out.printf("list = [");
-                PolymorphicPutByIdList* list = stubInfo.u.putByIdList.list;
-                CommaPrinter comma;
-                for (unsigned i = 0; i < list->size(); ++i) {
-                    out.print(comma, "(");
-                    const PutByIdAccess& access = list->at(i);
-                    
-                    if (access.isReplace()) {
-                        out.print("replace, ");
-                        dumpStructure(out, "struct", access.oldStructure(), ident);
-                    } else if (access.isSetter()) {
-                        out.print("setter, ");
-                        dumpStructure(out, "struct", access.oldStructure(), ident);
-                    } else if (access.isCustom()) {
-                        out.print("custom, ");
-                        dumpStructure(out, "struct", access.oldStructure(), ident);
-                    } else if (access.isTransition()) {
-                        out.print("transition, ");
-                        dumpStructure(out, "prev", access.oldStructure(), ident);
-                        out.print(", ");
-                        dumpStructure(out, "next", access.newStructure(), ident);
-                        if (!access.conditionSet().isEmpty())
-                            out.print(", ", access.conditionSet());
-                    } else
-                        out.print("unknown");
-                    
-                    out.print(")");
-                }
-                out.print("]");
-                break;
-            }
-            case access_unset:
-                out.printf("unset");
-                break;
-            default:
-                RELEASE_ASSERT_NOT_REACHED();
-                break;
-            }
-            out.printf(")");
-        }
-    }
-#else
-    UNUSED_PARAM(map);
-#endif
-}
-
-void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, CacheDumpMode cacheDumpMode, bool& hasPrintedProfiling, const CallLinkInfoMap& map)
+void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, CacheDumpMode cacheDumpMode, bool& hasPrintedProfiling)
 {
     int dst = (++it)->u.operand;
     int func = (++it)->u.operand;
@@ -508,6 +460,7 @@ void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, con
     printLocationAndOp(out, exec, location, it, op);
     out.printf("%s, %s, %d, %d", registerName(dst).data(), registerName(func).data(), argCount, registerOffset);
     if (cacheDumpMode == DumpCaches) {
+#if ENABLE(LLINT)
         LLIntCallLinkInfo* callLinkInfo = it[1].u.callLinkInfo;
         if (callLinkInfo->lastSeenCallee) {
             out.printf(
@@ -515,21 +468,17 @@ void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, con
                 callLinkInfo->lastSeenCallee.get(),
                 callLinkInfo->lastSeenCallee->executable());
         }
+#endif
 #if ENABLE(JIT)
-        if (CallLinkInfo* info = map.get(CodeOrigin(location))) {
-            JSFunction* target = info->lastSeenCallee();
+        if (numberOfCallLinkInfos()) {
+            JSFunction* target = getCallLinkInfo(location).lastSeenCallee.get();
             if (target)
                 out.printf(" jit(%p, exec %p)", target, target->executable());
         }
-        
-        if (jitType() != JITCode::FTLJIT)
-            out.print(" status(", CallLinkStatus::computeFor(this, location, map), ")");
-#else
-        UNUSED_PARAM(map);
 #endif
+        out.print(" status(", CallLinkStatus::computeFor(this, location), ")");
     }
     ++it;
-    ++it;
     dumpArrayProfiling(out, it, hasPrintedProfiling);
     dumpValueProfiling(out, it, hasPrintedProfiling);
 }
@@ -544,31 +493,6 @@ void CodeBlock::printPutByIdOp(PrintStream& out, ExecState* exec, int location,
     it += 5;
 }
 
-void CodeBlock::dumpSource()
-{
-    dumpSource(WTF::dataFile());
-}
-
-void CodeBlock::dumpSource(PrintStream& out)
-{
-    ScriptExecutable* executable = ownerExecutable();
-    if (executable->isFunctionExecutable()) {
-        FunctionExecutable* functionExecutable = reinterpret_cast<FunctionExecutable*>(executable);
-        String source = functionExecutable->source().provider()->getRange(
-            functionExecutable->parametersStartOffset(),
-            functionExecutable->typeProfilingEndOffset() + 1); // Type profiling end offset is the character before the '}'.
-        
-        out.print("function ", inferredName(), source);
-        return;
-    }
-    out.print(executable->source().toString());
-}
-
-void CodeBlock::dumpBytecode()
-{
-    dumpBytecode(WTF::dataFile());
-}
-
 void CodeBlock::dumpBytecode(PrintStream& out)
 {
     // We only use the ExecState* for things that don't actually lead to JS execution,
@@ -586,19 +510,33 @@ void CodeBlock::dumpBytecode(PrintStream& out)
         static_cast<unsigned long>(instructions().size()),
         static_cast<unsigned long>(instructions().size() * sizeof(Instruction)),
         m_numParameters, m_numCalleeRegisters, m_numVars);
-    if (needsActivation() && codeType() == FunctionCode)
-        out.printf("; lexical environment in r%d", activationRegister().offset());
+    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().offset(),
+            unmodifiedArgumentsRegister(argumentsRegister()).offset());
+    }
+    if (needsFullScopeChain() && codeType() == FunctionCode)
+        out.printf("; activation in r%d", activationRegister().offset());
     out.printf("\n");
     
     StubInfoMap stubInfos;
-    CallLinkInfoMap callLinkInfos;
-    getStubInfoMap(stubInfos);
-    getCallLinkInfoMap(callLinkInfos);
+#if ENABLE(JIT)
+    {
+        ConcurrentJITLocker locker(m_lock);
+        getStubInfoMap(locker, stubInfos);
+    }
+#endif
     
     const Instruction* begin = instructions().begin();
     const Instruction* end = instructions().end();
     for (const Instruction* it = begin; it != end; ++it)
-        dumpBytecode(out, exec, begin, it, stubInfos, callLinkInfos);
+        dumpBytecode(out, exec, begin, it, stubInfos);
     
     if (numberOfIdentifiers()) {
         out.printf("\nIdentifiers:\n");
@@ -613,19 +551,7 @@ void CodeBlock::dumpBytecode(PrintStream& out)
         out.printf("\nConstants:\n");
         size_t i = 0;
         do {
-            const char* sourceCodeRepresentationDescription = nullptr;
-            switch (m_constantsSourceCodeRepresentation[i]) {
-            case SourceCodeRepresentation::Double:
-                sourceCodeRepresentationDescription = ": in source as double";
-                break;
-            case SourceCodeRepresentation::Integer:
-                sourceCodeRepresentationDescription = ": in source as integer";
-                break;
-            case SourceCodeRepresentation::Other:
-                sourceCodeRepresentationDescription = "";
-                break;
-            }
-            out.printf("   k%u = %s%s\n", static_cast<unsigned>(i), toCString(m_constantRegisters[i].get()).data(), sourceCodeRepresentationDescription);
+            out.printf("   k%u = %s\n", static_cast<unsigned>(i), toCString(m_constantRegisters[i].get()).data());
             ++i;
         } while (i < m_constantRegisters.size());
     }
@@ -643,9 +569,7 @@ void CodeBlock::dumpBytecode(PrintStream& out)
         out.printf("\nException Handlers:\n");
         unsigned i = 0;
         do {
-            HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
-            out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] } %s\n",
-                i + 1, handler.start, handler.end, handler.target, handler.typeName());
+            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());
     }
@@ -674,7 +598,7 @@ void CodeBlock::dumpBytecode(PrintStream& out)
             out.printf("  %1d = {\n", i);
             StringJumpTable::StringOffsetTable::const_iterator end = m_rareData->m_stringSwitchJumpTables[i].offsetTable.end();
             for (StringJumpTable::StringOffsetTable::const_iterator iter = m_rareData->m_stringSwitchJumpTables[i].offsetTable.begin(); iter != end; ++iter)
-                out.printf("\t\t\"%s\" => %04d\n", iter->key->utf8().data(), iter->value.branchOffset);
+                out.printf("\t\t\"%s\" => %04d\n", String(iter->key).utf8().data(), iter->value.branchOffset);
             out.printf("      }\n");
             ++i;
         } while (i < m_rareData->m_stringSwitchJumpTables.size());
@@ -729,74 +653,52 @@ void CodeBlock::dumpRareCaseProfile(PrintStream& out, const char* name, RareCase
     out.print(name, profile->m_counter);
 }
 
-void CodeBlock::printLocationAndOp(PrintStream& out, ExecState*, int location, const Instruction*&, const char* op)
-{
-    out.printf("[%4d] %-17s ", location, op);
-}
-
-void CodeBlock::printLocationOpAndRegisterOperand(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, int operand)
-{
-    printLocationAndOp(out, exec, location, it, op);
-    out.printf("%s", registerName(operand).data());
-}
-
-void CodeBlock::dumpBytecode(
-    PrintStream& out, ExecState* exec, const Instruction* begin, const Instruction*& it,
-    const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
+void CodeBlock::dumpBytecode(PrintStream& out, ExecState* exec, const Instruction* begin, const Instruction*& it, const StubInfoMap& map)
 {
     int location = it - begin;
     bool hasPrintedProfiling = false;
-    OpcodeID opcode = exec->interpreter()->getOpcodeID(it->u.opcode);
-    switch (opcode) {
+    switch (exec->interpreter()->getOpcodeID(it->u.opcode)) {
         case op_enter: {
             printLocationAndOp(out, exec, location, it, "enter");
             break;
         }
-        case op_get_scope: {
+        case op_touch_entry: {
+            printLocationAndOp(out, exec, location, it, "touch_entry");
+            break;
+        }
+        case op_create_activation: {
             int r0 = (++it)->u.operand;
-            printLocationOpAndRegisterOperand(out, exec, location, it, "get_scope", r0);
+            printLocationOpAndRegisterOperand(out, exec, location, it, "create_activation", r0);
             break;
         }
-        case op_create_direct_arguments: {
+        case op_create_arguments: {
             int r0 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "create_direct_arguments");
-            out.printf("%s", registerName(r0).data());
+            printLocationOpAndRegisterOperand(out, exec, location, it, "create_arguments", r0);
             break;
         }
-        case op_create_scoped_arguments: {
+        case op_init_lazy_reg: {
             int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "create_scoped_arguments");
-            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            printLocationOpAndRegisterOperand(out, exec, location, it, "init_lazy_reg", r0);
             break;
         }
-        case op_create_out_of_band_arguments: {
+        case op_get_callee: {
             int r0 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "create_out_of_band_arguments");
-            out.printf("%s", registerName(r0).data());
+            printLocationOpAndRegisterOperand(out, exec, location, it, "get_callee", r0);
+            ++it;
             break;
         }
         case op_create_this: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             unsigned inferredInlineCapacity = (++it)->u.operand;
-            unsigned cachedFunction = (++it)->u.operand;
             printLocationAndOp(out, exec, location, it, "create_this");
-            out.printf("%s, %s, %u, %u", registerName(r0).data(), registerName(r1).data(), inferredInlineCapacity, cachedFunction);
+            out.printf("%s, %s, %u", registerName(r0).data(), registerName(r1).data(), inferredInlineCapacity);
             break;
         }
         case op_to_this: {
             int r0 = (++it)->u.operand;
             printLocationOpAndRegisterOperand(out, exec, location, it, "to_this", r0);
-            Structure* structure = (++it)->u.structure.get();
-            if (structure)
-                out.print(", cache(struct = ", RawPointer(structure), ")");
-            out.print(", ", (++it)->u.toThisStatus);
-            break;
-        }
-        case op_check_tdz: {
-            int r0 = (++it)->u.operand;
-            printLocationOpAndRegisterOperand(out, exec, location, it, "op_check_tdz", r0);
+            ++it; // Skip value profile.
             break;
         }
         case op_new_object: {
@@ -851,20 +753,12 @@ void CodeBlock::dumpBytecode(
             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
             break;
         }
-        case op_profile_type: {
+        case op_captured_mov: {
             int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "captured_mov");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
             ++it;
-            ++it;
-            ++it;
-            ++it;
-            printLocationAndOp(out, exec, location, it, "op_profile_type");
-            out.printf("%s", registerName(r0).data());
-            break;
-        }
-        case op_profile_control_flow: {
-            BasicBlockLocation* basicBlockLocation = (++it)->u.basicBlockLocation;
-            printLocationAndOp(out, exec, location, it, "profile_control_flow");
-            out.printf("[%d, %d]", basicBlockLocation->startOffset(), basicBlockLocation->endOffset());
             break;
         }
         case op_not: {
@@ -925,10 +819,6 @@ void CodeBlock::dumpBytecode(
             printUnaryOp(out, exec, location, it, "to_number");
             break;
         }
-        case op_to_string: {
-            printUnaryOp(out, exec, location, it, "to_string");
-            break;
-        }
         case op_negate: {
             printUnaryOp(out, exec, location, it, "negate");
             break;
@@ -1029,10 +919,6 @@ void CodeBlock::dumpBytecode(
             printUnaryOp(out, exec, location, it, "is_object");
             break;
         }
-        case op_is_object_or_null: {
-            printUnaryOp(out, exec, location, it, "is_object_or_null");
-            break;
-        }
         case op_is_function: {
             printUnaryOp(out, exec, location, it, "is_function");
             break;
@@ -1041,58 +927,81 @@ void CodeBlock::dumpBytecode(
             printBinaryOp(out, exec, location, it, "in");
             break;
         }
+        case op_init_global_const_nop: {
+            printLocationAndOp(out, exec, location, it, "init_global_const_nop");
+            it++;
+            it++;
+            it++;
+            it++;
+            break;
+        }
+        case op_init_global_const: {
+            WriteBarrier<Unknown>* registerPointer = (++it)->u.registerPointer;
+            int r0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "init_global_const");
+            out.printf("g%d(%p), %s", m_globalObject->findRegisterIndex(registerPointer), registerPointer, registerName(r0).data());
+            it++;
+            it++;
+            break;
+        }
         case op_get_by_id:
         case op_get_by_id_out_of_line:
-        case op_get_array_length: {
+        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, stubInfos);
+            printGetByIdCacheStatus(out, exec, location, map);
             dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
+        case op_get_arguments_length: {
+            printUnaryOp(out, exec, location, it, "get_arguments_length");
+            it++;
+            break;
+        }
         case op_put_by_id: {
             printPutByIdOp(out, exec, location, it, "put_by_id");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
             break;
         }
         case op_put_by_id_out_of_line: {
             printPutByIdOp(out, exec, location, it, "put_by_id_out_of_line");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
+            break;
+        }
+        case op_put_by_id_replace: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_replace");
+            break;
+        }
+        case op_put_by_id_transition: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_transition");
             break;
         }
         case op_put_by_id_transition_direct: {
             printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
             break;
         }
         case op_put_by_id_transition_direct_out_of_line: {
             printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct_out_of_line");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
             break;
         }
         case op_put_by_id_transition_normal: {
             printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
             break;
         }
         case op_put_by_id_transition_normal_out_of_line: {
             printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal_out_of_line");
-            printPutByIdCacheStatus(out, exec, location, stubInfos);
             break;
         }
-        case op_put_getter_by_id: {
-            int r0 = (++it)->u.operand;
-            int id0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "put_getter_by_id");
-            out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
-            break;
-        }
-        case op_put_setter_by_id: {
-            int r0 = (++it)->u.operand;
-            int id0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "put_setter_by_id");
-            out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
+        case op_put_by_id_generic: {
+            printPutByIdOp(out, exec, location, it, "put_by_id_generic");
             break;
         }
         case op_put_getter_setter: {
@@ -1122,6 +1031,27 @@ void CodeBlock::dumpBytecode(
             dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
+        case op_get_argument_by_val: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "get_argument_by_val");
+            out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
+            ++it;
+            dumpValueProfiling(out, it, hasPrintedProfiling);
+            break;
+        }
+        case op_get_by_pname: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int r2 = (++it)->u.operand;
+            int r3 = (++it)->u.operand;
+            int r4 = (++it)->u.operand;
+            int r5 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "get_by_pname");
+            out.printf("%s, %s, %s, %s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data(), registerName(r3).data(), registerName(r4).data(), registerName(r5).data());
+            break;
+        }
         case op_put_by_val: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
@@ -1280,51 +1210,73 @@ void CodeBlock::dumpBytecode(
         }
         case op_new_func: {
             int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
             int f0 = (++it)->u.operand;
+            int shouldCheck = (++it)->u.operand;
             printLocationAndOp(out, exec, location, it, "new_func");
-            out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
+            out.printf("%s, f%d, %s", registerName(r0).data(), f0, shouldCheck ? "<Checked>" : "<Unchecked>");
+            break;
+        }
+        case op_new_captured_func: {
+            int r0 = (++it)->u.operand;
+            int f0 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "new_captured_func");
+            out.printf("%s, f%d", registerName(r0).data(), f0);
+            ++it;
             break;
         }
         case op_new_func_exp: {
             int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
             int f0 = (++it)->u.operand;
             printLocationAndOp(out, exec, location, it, "new_func_exp");
-            out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
+            out.printf("%s, f%d", registerName(r0).data(), f0);
             break;
         }
         case op_call: {
-            printCallOp(out, exec, location, it, "call", DumpCaches, hasPrintedProfiling, callLinkInfos);
+            printCallOp(out, exec, location, it, "call", DumpCaches, hasPrintedProfiling);
             break;
         }
         case op_call_eval: {
-            printCallOp(out, exec, location, it, "call_eval", DontDumpCaches, hasPrintedProfiling, callLinkInfos);
+            printCallOp(out, exec, location, it, "call_eval", DontDumpCaches, hasPrintedProfiling);
             break;
         }
-            
-        case op_construct_varargs:
         case op_call_varargs: {
             int result = (++it)->u.operand;
             int callee = (++it)->u.operand;
             int thisValue = (++it)->u.operand;
             int arguments = (++it)->u.operand;
             int firstFreeRegister = (++it)->u.operand;
-            int varArgOffset = (++it)->u.operand;
             ++it;
-            printLocationAndOp(out, exec, location, it, opcode == op_call_varargs ? "call_varargs" : "construct_varargs");
-            out.printf("%s, %s, %s, %s, %d, %d", registerName(result).data(), registerName(callee).data(), registerName(thisValue).data(), registerName(arguments).data(), firstFreeRegister, varArgOffset);
+            printLocationAndOp(out, exec, location, it, "call_varargs");
+            out.printf("%s, %s, %s, %s, %d", registerName(result).data(), registerName(callee).data(), registerName(thisValue).data(), registerName(arguments).data(), firstFreeRegister);
             dumpValueProfiling(out, it, hasPrintedProfiling);
             break;
         }
-
+        case op_tear_off_activation: {
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "tear_off_activation", r0);
+            break;
+        }
+        case op_tear_off_arguments: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "tear_off_arguments");
+            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
         case op_ret: {
             int r0 = (++it)->u.operand;
             printLocationOpAndRegisterOperand(out, exec, location, it, "ret", r0);
             break;
         }
+        case op_ret_object_or_this: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "constructor_ret");
+            out.printf("%s %s", registerName(r0).data(), registerName(r1).data());
+            break;
+        }
         case op_construct: {
-            printCallOp(out, exec, location, it, "construct", DumpCaches, hasPrintedProfiling, callLinkInfos);
+            printCallOp(out, exec, location, it, "construct", DumpCaches, hasPrintedProfiling);
             break;
         }
         case op_strcat: {
@@ -1342,120 +1294,49 @@ void CodeBlock::dumpBytecode(
             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
             break;
         }
-        case op_get_enumerable_length: {
-            int dst = it[1].u.operand;
-            int base = it[2].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_get_enumerable_length");
-            out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
-            it += OPCODE_LENGTH(op_get_enumerable_length) - 1;
+        case op_get_pnames: {
+            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;
+            printLocationAndOp(out, exec, location, it, "get_pnames");
+            out.printf("%s, %s, %s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), registerName(r2).data(), registerName(r3).data(), offset, location + offset);
+            it += OPCODE_LENGTH(op_get_pnames) - 1;
             break;
         }
-        case op_has_indexed_property: {
-            int dst = it[1].u.operand;
+        case op_next_pname: {
+            int dest = it[1].u.operand;
             int base = it[2].u.operand;
-            int propertyName = it[3].u.operand;
-            ArrayProfile* arrayProfile = it[4].u.arrayProfile;
-            printLocationAndOp(out, exec, location, it, "op_has_indexed_property");
-            out.printf("%s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), arrayProfile);
-            it += OPCODE_LENGTH(op_has_indexed_property) - 1;
-            break;
-        }
-        case op_has_structure_property: {
-            int dst = it[1].u.operand;
-            int base = it[2].u.operand;
-            int propertyName = it[3].u.operand;
-            int enumerator = it[4].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_has_structure_property");
-            out.printf("%s, %s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(enumerator).data());
-            it += OPCODE_LENGTH(op_has_structure_property) - 1;
-            break;
-        }
-        case op_has_generic_property: {
-            int dst = it[1].u.operand;
-            int base = it[2].u.operand;
-            int propertyName = it[3].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_has_generic_property");
-            out.printf("%s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data());
-            it += OPCODE_LENGTH(op_has_generic_property) - 1;
-            break;
-        }
-        case op_get_direct_pname: {
-            int dst = it[1].u.operand;
-            int base = it[2].u.operand;
-            int propertyName = it[3].u.operand;
-            int index = it[4].u.operand;
-            int enumerator = it[5].u.operand;
-            ValueProfile* profile = it[6].u.profile;
-            printLocationAndOp(out, exec, location, it, "op_get_direct_pname");
-            out.printf("%s, %s, %s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(index).data(), registerName(enumerator).data(), profile);
-            it += OPCODE_LENGTH(op_get_direct_pname) - 1;
-            break;
-
-        }
-        case op_get_property_enumerator: {
-            int dst = it[1].u.operand;
-            int base = it[2].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_get_property_enumerator");
-            out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
-            it += OPCODE_LENGTH(op_get_property_enumerator) - 1;
-            break;
-        }
-        case op_enumerator_structure_pname: {
-            int dst = it[1].u.operand;
-            int enumerator = it[2].u.operand;
-            int index = it[3].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_enumerator_structure_pname");
-            out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
-            it += OPCODE_LENGTH(op_enumerator_structure_pname) - 1;
-            break;
-        }
-        case op_enumerator_generic_pname: {
-            int dst = it[1].u.operand;
-            int enumerator = it[2].u.operand;
-            int index = it[3].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_enumerator_generic_pname");
-            out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
-            it += OPCODE_LENGTH(op_enumerator_generic_pname) - 1;
-            break;
-        }
-        case op_to_index_string: {
-            int dst = it[1].u.operand;
-            int index = it[2].u.operand;
-            printLocationAndOp(out, exec, location, it, "op_to_index_string");
-            out.printf("%s, %s", registerName(dst).data(), registerName(index).data());
-            it += OPCODE_LENGTH(op_to_index_string) - 1;
+            int i = it[3].u.operand;
+            int size = it[4].u.operand;
+            int iter = it[5].u.operand;
+            int offset = it[6].u.operand;
+            printLocationAndOp(out, exec, location, it, "next_pname");
+            out.printf("%s, %s, %s, %s, %s, %d(->%d)", registerName(dest).data(), registerName(base).data(), registerName(i).data(), registerName(size).data(), registerName(iter).data(), offset, location + offset);
+            it += OPCODE_LENGTH(op_next_pname) - 1;
             break;
         }
         case op_push_with_scope: {
-            int dst = (++it)->u.operand;
-            int newScope = (++it)->u.operand;
-            int currentScope = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "push_with_scope");
-            out.printf("%s, %s, %s", registerName(dst).data(), registerName(newScope).data(), registerName(currentScope).data());
+            int r0 = (++it)->u.operand;
+            printLocationOpAndRegisterOperand(out, exec, location, it, "push_with_scope", r0);
             break;
         }
-        case op_get_parent_scope: {
-            int dst = (++it)->u.operand;
-            int parentScope = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "get_parent_scope");
-            out.printf("%s, %s", registerName(dst).data(), registerName(parentScope).data());
+        case op_pop_scope: {
+            printLocationAndOp(out, exec, location, it, "pop_scope");
             break;
         }
-        case op_create_lexical_environment: {
-            int dst = (++it)->u.operand;
-            int scope = (++it)->u.operand;
-            int symbolTable = (++it)->u.operand;
-            int initialValue = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "create_lexical_environment");
-            out.printf("%s, %s, %s, %s", 
-                registerName(dst).data(), registerName(scope).data(), registerName(symbolTable).data(), registerName(initialValue).data());
+        case op_push_name_scope: {
+            int id0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            unsigned attributes = (++it)->u.operand;
+            printLocationAndOp(out, exec, location, it, "push_name_scope");
+            out.printf("%s, %s, %u", idName(id0, identifier(id0)).data(), registerName(r1).data(), attributes);
             break;
         }
         case op_catch: {
             int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "catch");
-            out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
+            printLocationOpAndRegisterOperand(out, exec, location, it, "catch", r0);
             break;
         }
         case op_throw: {
@@ -1467,7 +1348,7 @@ void CodeBlock::dumpBytecode(
             int k0 = (++it)->u.operand;
             int k1 = (++it)->u.operand;
             printLocationAndOp(out, exec, location, it, "throw_static_error");
-            out.printf("%s, %s", constantName(k0).data(), k1 ? "true" : "false");
+            out.printf("%s, %s", constantName(k0, getConstant(k0)).data(), k1 ? "true" : "false");
             break;
         }
         case op_debug: {
@@ -1494,14 +1375,11 @@ void CodeBlock::dumpBytecode(
         }
         case op_resolve_scope: {
             int r0 = (++it)->u.operand;
-            int scope = (++it)->u.operand;
             int id0 = (++it)->u.operand;
-            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
-            int depth = (++it)->u.operand;
+            int resolveModeAndType = (++it)->u.operand;
+            ++it; // depth
             printLocationAndOp(out, exec, location, it, "resolve_scope");
-            out.printf("%s, %s, %s, %u<%s|%s>, %d", registerName(r0).data(), registerName(scope).data(), idName(id0, identifier(id0)).data(),
-                modeAndType.operand(), resolveModeName(modeAndType.mode()), resolveTypeName(modeAndType.type()),
-                depth);
+            out.printf("%s, %s, %d", registerName(r0).data(), idName(id0, identifier(id0)).data(), resolveModeAndType);
             ++it;
             break;
         }
@@ -1509,54 +1387,29 @@ void CodeBlock::dumpBytecode(
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
             int id0 = (++it)->u.operand;
-            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
+            int resolveModeAndType = (++it)->u.operand;
             ++it; // Structure
-            int operand = (++it)->u.operand; // Operand
+            ++it; // Operand
+            ++it; // Skip value profile.
             printLocationAndOp(out, exec, location, it, "get_from_scope");
-            out.print(registerName(r0), ", ", registerName(r1));
-            if (static_cast<unsigned>(id0) == UINT_MAX)
-                out.print(", anonymous");
-            else
-                out.print(", ", idName(id0, identifier(id0)));
-            out.print(", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, ", operand);
-            dumpValueProfiling(out, it, hasPrintedProfiling);
+            out.printf("%s, %s, %s, %d", registerName(r0).data(), registerName(r1).data(), idName(id0, identifier(id0)).data(), resolveModeAndType);
             break;
         }
         case op_put_to_scope: {
             int r0 = (++it)->u.operand;
             int id0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
-            ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
+            int resolveModeAndType = (++it)->u.operand;
             ++it; // Structure
-            int operand = (++it)->u.operand; // Operand
+            ++it; // Operand
             printLocationAndOp(out, exec, location, it, "put_to_scope");
-            out.print(registerName(r0));
-            if (static_cast<unsigned>(id0) == UINT_MAX)
-                out.print(", anonymous");
-            else
-                out.print(", ", idName(id0, identifier(id0)));
-            out.print(", ", registerName(r1), ", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, <structure>, ", operand);
-            break;
-        }
-        case op_get_from_arguments: {
-            int r0 = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            int offset = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "get_from_arguments");
-            out.printf("%s, %s, %d", registerName(r0).data(), registerName(r1).data(), offset);
-            dumpValueProfiling(out, it, hasPrintedProfiling);
-            break;
-        }
-        case op_put_to_arguments: {
-            int r0 = (++it)->u.operand;
-            int offset = (++it)->u.operand;
-            int r1 = (++it)->u.operand;
-            printLocationAndOp(out, exec, location, it, "put_to_arguments");
-            out.printf("%s, %d, %s", registerName(r0).data(), offset, registerName(r1).data());
+            out.printf("%s, %s, %s, %d", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data(), resolveModeAndType);
             break;
         }
+#if ENABLE(LLINT_C_LOOP)
         default:
             RELEASE_ASSERT_NOT_REACHED();
+#endif
     }
 
     dumpRareCaseProfile(out, "rare case: ", rareCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
@@ -1568,7 +1421,7 @@ void CodeBlock::dumpBytecode(
         out.print(" !! frequent exits: ");
         CommaPrinter comma;
         for (unsigned i = 0; i < exitSites.size(); ++i)
-            out.print(comma, exitSites[i].kind(), " ", exitSites[i].jitType());
+            out.print(comma, exitSites[i].kind());
     }
 #else // ENABLE(DFG_JIT)
     UNUSED_PARAM(location);
@@ -1576,13 +1429,11 @@ void CodeBlock::dumpBytecode(
     out.print("\n");
 }
 
-void CodeBlock::dumpBytecode(
-    PrintStream& out, unsigned bytecodeOffset,
-    const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
+void CodeBlock::dumpBytecode(PrintStream& out, unsigned bytecodeOffset)
 {
     ExecState* exec = m_globalObject->globalExec();
     const Instruction* it = instructions().begin() + bytecodeOffset;
-    dumpBytecode(out, exec, instructions().begin(), it, stubInfos, callLinkInfos);
+    dumpBytecode(out, exec, instructions().begin(), it);
 }
 
 #define FOR_EACH_MEMBER_VECTOR(macro) \
@@ -1610,28 +1461,6 @@ static size_t sizeInBytes(const Vector<T>& vector)
     return vector.capacity() * sizeof(T);
 }
 
-namespace {
-
-class PutToScopeFireDetail : public FireDetail {
-public:
-    PutToScopeFireDetail(CodeBlock* codeBlock, const Identifier& ident)
-        : m_codeBlock(codeBlock)
-        , m_ident(ident)
-    {
-    }
-    
-    virtual void dump(PrintStream& out) const override
-    {
-        out.print("Linking put_to_scope in ", FunctionExecutableDump(jsCast<FunctionExecutable*>(m_codeBlock->ownerExecutable())), " for ", m_ident);
-    }
-    
-private:
-    CodeBlock* m_codeBlock;
-    const Identifier& m_ident;
-};
-
-} // anonymous namespace
-
 CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
     : m_globalObject(other.m_globalObject)
     , m_heap(other.m_heap)
@@ -1640,26 +1469,22 @@ CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
     , m_isConstructor(other.m_isConstructor)
     , m_shouldAlwaysBeInlined(true)
     , m_didFailFTLCompilation(false)
-    , m_hasBeenCompiledWithFTL(false)
     , m_unlinkedCode(*other.m_vm, other.m_ownerExecutable.get(), other.m_unlinkedCode.get())
-    , m_hasDebuggerStatement(false)
     , m_steppingMode(SteppingModeDisabled)
     , m_numBreakpoints(0)
     , m_ownerExecutable(*other.m_vm, other.m_ownerExecutable.get(), other.m_ownerExecutable.get())
     , m_vm(other.m_vm)
     , m_instructions(other.m_instructions)
     , m_thisRegister(other.m_thisRegister)
-    , m_scopeRegister(other.m_scopeRegister)
-    , m_lexicalEnvironmentRegister(other.m_lexicalEnvironmentRegister)
+    , m_argumentsRegister(other.m_argumentsRegister)
+    , m_activationRegister(other.m_activationRegister)
     , m_isStrictMode(other.m_isStrictMode)
     , m_needsActivation(other.m_needsActivation)
-    , m_mayBeExecuting(false)
     , m_source(other.m_source)
     , m_sourceOffset(other.m_sourceOffset)
     , m_firstLineColumnOffset(other.m_firstLineColumnOffset)
     , m_codeType(other.m_codeType)
     , m_constantRegisters(other.m_constantRegisters)
-    , m_constantsSourceCodeRepresentation(other.m_constantsSourceCodeRepresentation)
     , m_functionDecls(other.m_functionDecls)
     , m_functionExprs(other.m_functionExprs)
     , m_osrExitCounter(0)
@@ -1670,11 +1495,11 @@ CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
     , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
 #endif
 {
-    m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
-
     ASSERT(m_heap->isDeferred());
-    ASSERT(m_scopeRegister.isLocal());
-
+    
+    if (SymbolTable* symbolTable = other.symbolTable())
+        m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable);
+    
     setNumParameters(other.numParameters());
     optimizeAfterWarmUp();
     jitAfterWarmUp();
@@ -1689,7 +1514,7 @@ CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
     }
     
     m_heap->m_codeBlocks.add(this);
-    m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock));
+    m_heap->reportExtraMemoryCost(sizeof(CodeBlock));
 }
 
 CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
@@ -1700,19 +1525,16 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
     , m_isConstructor(unlinkedCodeBlock->isConstructor())
     , m_shouldAlwaysBeInlined(true)
     , m_didFailFTLCompilation(false)
-    , m_hasBeenCompiledWithFTL(false)
     , m_unlinkedCode(m_globalObject->vm(), ownerExecutable, unlinkedCodeBlock)
-    , m_hasDebuggerStatement(false)
     , m_steppingMode(SteppingModeDisabled)
     , m_numBreakpoints(0)
     , m_ownerExecutable(m_globalObject->vm(), ownerExecutable, ownerExecutable)
     , m_vm(unlinkedCodeBlock->vm())
     , m_thisRegister(unlinkedCodeBlock->thisRegister())
-    , m_scopeRegister(unlinkedCodeBlock->scopeRegister())
-    , m_lexicalEnvironmentRegister(unlinkedCodeBlock->activationRegister())
+    , m_argumentsRegister(unlinkedCodeBlock->argumentsRegister())
+    , m_activationRegister(unlinkedCodeBlock->activationRegister())
     , m_isStrictMode(unlinkedCodeBlock->isStrictMode())
-    , m_needsActivation(unlinkedCodeBlock->hasActivationRegister() && unlinkedCodeBlock->codeType() == FunctionCode)
-    , m_mayBeExecuting(false)
+    , m_needsActivation(unlinkedCodeBlock->needsFullScopeChain() && unlinkedCodeBlock->codeType() == FunctionCode)
     , m_source(sourceProvider)
     , m_sourceOffset(sourceOffset)
     , m_firstLineColumnOffset(firstLineColumnOffset)
@@ -1724,59 +1546,54 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
     , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
 #endif
 {
-    m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
-
     ASSERT(m_heap->isDeferred());
-    ASSERT(m_scopeRegister.isLocal());
 
+    bool didCloneSymbolTable = false;
+    
+    if (SymbolTable* symbolTable = unlinkedCodeBlock->symbolTable()) {
+        if (codeType() == FunctionCode && symbolTable->captureCount()) {
+            m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable->clone(*m_vm));
+            didCloneSymbolTable = true;
+        } else
+            m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable);
+    }
+    
     ASSERT(m_source);
     setNumParameters(unlinkedCodeBlock->numParameters());
 
-    if (vm()->typeProfiler() || vm()->controlFlowProfiler())
-        vm()->functionHasExecutedCache()->removeUnexecutedRange(m_ownerExecutable->sourceID(), m_ownerExecutable->typeProfilingStartOffset(), m_ownerExecutable->typeProfilingEndOffset());
-
-    setConstantRegisters(unlinkedCodeBlock->constantRegisters(), unlinkedCodeBlock->constantsSourceCodeRepresentation());
+    setConstantRegisters(unlinkedCodeBlock->constantRegisters());
     if (unlinkedCodeBlock->usesGlobalObject())
-        m_constantRegisters[unlinkedCodeBlock->globalObjectRegister().toConstantIndex()].set(*m_vm, ownerExecutable, m_globalObject.get());
-
-    for (unsigned i = 0; i < LinkTimeConstantCount; i++) {
-        LinkTimeConstant type = static_cast<LinkTimeConstant>(i);
-        if (unsigned registerIndex = unlinkedCodeBlock->registerIndexForLinkTimeConstant(type))
-            m_constantRegisters[registerIndex].set(*m_vm, ownerExecutable, m_globalObject->jsCellForLinkTimeConstant(type));
-    }
-
-    HashSet<int, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>> clonedConstantSymbolTables;
-    {
-        HashSet<SymbolTable*> clonedSymbolTables;
-        for (unsigned i = 0; i < m_constantRegisters.size(); i++) {
-            if (m_constantRegisters[i].get().isEmpty())
-                continue;
-            if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(m_constantRegisters[i].get())) {
-                RELEASE_ASSERT(clonedSymbolTables.add(symbolTable).isNewEntry);
-                if (m_vm->typeProfiler()) {
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
-                    symbolTable->prepareForTypeProfiling(locker);
-                }
-                m_constantRegisters[i].set(*m_vm, ownerExecutable, symbolTable->cloneScopePart(*m_vm));
-                clonedConstantSymbolTables.add(i + FirstConstantRegisterIndex);
-            }
-        }
-    }
-
+        m_constantRegisters[unlinkedCodeBlock->globalObjectRegister().offset()].set(*m_vm, ownerExecutable, m_globalObject.get());
     m_functionDecls.resizeToFit(unlinkedCodeBlock->numberOfFunctionDecls());
     for (size_t count = unlinkedCodeBlock->numberOfFunctionDecls(), i = 0; i < count; ++i) {
         UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionDecl(i);
-        if (vm()->typeProfiler() || vm()->controlFlowProfiler())
-            vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
-        m_functionDecls[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
+        unsigned lineCount = unlinkedExecutable->lineCount();
+        unsigned firstLine = ownerExecutable->lineNo() + unlinkedExecutable->firstLineOffset();
+        bool startColumnIsOnOwnerStartLine = !unlinkedExecutable->firstLineOffset();
+        unsigned startColumn = unlinkedExecutable->unlinkedBodyStartColumn() + (startColumnIsOnOwnerStartLine ? ownerExecutable->startColumn() : 1);
+        bool endColumnIsOnStartLine = !lineCount;
+        unsigned endColumn = unlinkedExecutable->unlinkedBodyEndColumn() + (endColumnIsOnStartLine ? startColumn : 1);
+        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, endColumn);
+        m_functionDecls[i].set(*m_vm, ownerExecutable, executable);
     }
 
     m_functionExprs.resizeToFit(unlinkedCodeBlock->numberOfFunctionExprs());
     for (size_t count = unlinkedCodeBlock->numberOfFunctionExprs(), i = 0; i < count; ++i) {
         UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionExpr(i);
-        if (vm()->typeProfiler() || vm()->controlFlowProfiler())
-            vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
-        m_functionExprs[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
+        unsigned lineCount = unlinkedExecutable->lineCount();
+        unsigned firstLine = ownerExecutable->lineNo() + unlinkedExecutable->firstLineOffset();
+        bool startColumnIsOnOwnerStartLine = !unlinkedExecutable->firstLineOffset();
+        unsigned startColumn = unlinkedExecutable->unlinkedBodyStartColumn() + (startColumnIsOnOwnerStartLine ? ownerExecutable->startColumn() : 1);
+        bool endColumnIsOnStartLine = !lineCount;
+        unsigned endColumn = unlinkedExecutable->unlinkedBodyEndColumn() + (endColumnIsOnStartLine ? startColumn : 1);
+        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, endColumn);
+        m_functionExprs[i].set(*m_vm, ownerExecutable, executable);
     }
 
     if (unlinkedCodeBlock->hasRareData()) {
@@ -1790,13 +1607,15 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
         }
         if (size_t count = unlinkedCodeBlock->numberOfExceptionHandlers()) {
             m_rareData->m_exceptionHandlers.resizeToFit(count);
+            size_t nonLocalScopeDepth = scope->depth();
             for (size_t i = 0; i < count; i++) {
-                const UnlinkedHandlerInfo& unlinkedHandler = unlinkedCodeBlock->exceptionHandler(i);
-                HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
-#if ENABLE(JIT)
-                handler.initialize(unlinkedHandler, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(LLInt::getCodePtr(op_catch))));
-#else
-                handler.initialize(unlinkedHandler);
+                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 = nonLocalScopeDepth + handler.scopeDepth;
+#if ENABLE(JIT) && ENABLE(LLINT)
+                m_rareData->m_exceptionHandlers[i].nativeCode = CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(LLInt::getCodePtr(llint_op_catch)));
 #endif
             }
         }
@@ -1826,8 +1645,10 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
     }
 
     // Allocate metadata buffers for the bytecode
+#if ENABLE(LLINT)
     if (size_t size = unlinkedCodeBlock->numberOfLLintCallLinkInfos())
         m_llintCallLinkInfos.resizeToFit(size);
+#endif
     if (size_t size = unlinkedCodeBlock->numberOfArrayProfiles())
         m_arrayProfiles.grow(size);
     if (size_t size = unlinkedCodeBlock->numberOfArrayAllocationProfiles())
@@ -1841,8 +1662,7 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
     unsigned instructionCount = unlinkedCodeBlock->instructions().count();
     UnlinkedInstructionStream::Reader instructionReader(unlinkedCodeBlock->instructions());
 
-    RefCountedArray<Instruction> instructions(instructionCount);
-
+    Vector<Instruction, 0, UnsafeVectorOverflow> instructions(instructionCount);
     for (unsigned i = 0; !instructionReader.atEnd(); ) {
         const UnlinkedInstruction* pc = instructionReader.next();
 
@@ -1855,25 +1675,16 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
             instructions[i + j].u.operand = pc[j].u.operand;
         }
         switch (pc[0].u.opcode) {
-        case op_has_indexed_property: {
-            int arrayProfileIndex = pc[opLength - 1].u.operand;
-            m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
-
-            instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
-            break;
-        }
         case op_call_varargs:
-        case op_construct_varargs:
-        case op_get_by_val: {
+        case op_get_by_val:
+        case op_get_argument_by_val: {
             int arrayProfileIndex = pc[opLength - 2].u.operand;
             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
 
             instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
             FALLTHROUGH;
         }
-        case op_get_direct_pname:
-        case op_get_by_id:
-        case op_get_from_arguments: {
+        case op_get_by_id: {
             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
             ASSERT(profile->m_bytecodeOffset == -1);
             profile->m_bytecodeOffset = i;
@@ -1920,11 +1731,15 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
             int arrayProfileIndex = pc[opLength - 2].u.operand;
             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
             instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
+#if ENABLE(LLINT)
             instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
+#endif
             break;
         }
         case op_construct: {
+#if ENABLE(LLINT)
             instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
+#endif
             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
             ASSERT(profile->m_bytecodeOffset == -1);
             profile->m_bytecodeOffset = i;
@@ -1932,28 +1747,41 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
             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_create_lexical_environment: {
-            int symbolTableIndex = pc[3].u.operand;
-            RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
+        case op_init_global_const_nop: {
+            ASSERT(codeType() == GlobalCode);
+            Identifier ident = identifier(pc[4].u.operand);
+            SymbolTableEntry entry = m_globalObject->symbolTable()->get(ident.impl());
+            if (entry.isNull())
+                break;
+
+            instructions[i + 0] = vm()->interpreter->getOpcode(op_init_global_const);
+            instructions[i + 1] = &m_globalObject->registerAt(entry.getIndex());
             break;
         }
 
         case op_resolve_scope: {
-            const Identifier& ident = identifier(pc[3].u.operand);
-            ResolveType type = static_cast<ResolveType>(pc[4].u.operand);
-            RELEASE_ASSERT(type != LocalClosureVar);
-            int localScopeDepth = pc[5].u.operand;
-
-            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type);
-            instructions[i + 4].u.operand = op.type;
-            instructions[i + 5].u.operand = op.depth;
-            if (op.lexicalEnvironment)
-                instructions[i + 6].u.symbolTable.set(*vm(), ownerExecutable, op.lexicalEnvironment->symbolTable());
-            else
-                instructions[i + 6].u.pointer = nullptr;
+            const Identifier& ident = identifier(pc[2].u.operand);
+            ResolveType type = static_cast<ResolveType>(pc[3].u.operand);
+
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), scope, ident, Get, type);
+            instructions[i + 3].u.operand = op.type;
+            instructions[i + 4].u.operand = op.depth;
+            if (op.activation)
+                instructions[i + 5].u.activation.set(*vm(), ownerExecutable, op.activation);
             break;
         }
 
@@ -1964,18 +1792,9 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
             instructions[i + opLength - 1] = profile;
 
             // get_from_scope dst, scope, id, ResolveModeAndType, Structure, Operand
-
-            int localScopeDepth = pc[5].u.operand;
-            instructions[i + 5].u.pointer = nullptr;
-
-            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
-            if (modeAndType.type() == LocalClosureVar) {
-                instructions[i + 4] = ResolveModeAndType(modeAndType.mode(), ClosureVar).operand();
-                break;
-            }
-
             const Identifier& ident = identifier(pc[3].u.operand);
-            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, modeAndType.type());
+            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), scope, ident, Get, modeAndType.type());
 
             instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
             if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
@@ -1988,131 +1807,35 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
 
         case op_put_to_scope: {
             // put_to_scope scope, id, value, ResolveModeAndType, Structure, Operand
-            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
-            if (modeAndType.type() == LocalClosureVar) {
-                // Only do watching if the property we're putting to is not anonymous.
-                if (static_cast<unsigned>(pc[2].u.operand) != UINT_MAX) {
-                    int symbolTableIndex = pc[5].u.operand;
-                    RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
-                    SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
-                    const Identifier& ident = identifier(pc[2].u.operand);
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
-                    auto iter = symbolTable->find(locker, ident.impl());
-                    RELEASE_ASSERT(iter != symbolTable->end(locker));
-                    iter->value.prepareToWatch();
-                    instructions[i + 5].u.watchpointSet = iter->value.watchpointSet();
-                } else
-                    instructions[i + 5].u.watchpointSet = nullptr;
-                break;
-            }
-
             const Identifier& ident = identifier(pc[2].u.operand);
-            int localScopeDepth = pc[5].u.operand;
-            instructions[i + 5].u.pointer = nullptr;
-            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Put, modeAndType.type());
+            ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), scope, ident, Put, modeAndType.type());
 
             instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
             if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
                 instructions[i + 5].u.watchpointSet = op.watchpointSet;
             else if (op.type == ClosureVar || op.type == ClosureVarWithVarInjectionChecks) {
                 if (op.watchpointSet)
-                    op.watchpointSet->invalidate(PutToScopeFireDetail(this, ident));
+                    op.watchpointSet->invalidate();
             } else if (op.structure)
                 instructions[i + 5].u.structure.set(*vm(), ownerExecutable, op.structure);
             instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
-
             break;
         }
-
-        case op_profile_type: {
-            RELEASE_ASSERT(vm()->typeProfiler());
-            // The format of this instruction is: op_profile_type regToProfile, TypeLocation*, flag, identifier?, resolveType?
-            size_t instructionOffset = i + opLength - 1;
-            unsigned divotStart, divotEnd;
-            GlobalVariableID globalVariableID = 0;
-            RefPtr<TypeSet> globalTypeSet;
-            bool shouldAnalyze = m_unlinkedCode->typeProfilerExpressionInfoForBytecodeOffset(instructionOffset, divotStart, divotEnd);
-            VirtualRegister profileRegister(pc[1].u.operand);
-            ProfileTypeBytecodeFlag flag = static_cast<ProfileTypeBytecodeFlag>(pc[3].u.operand);
-            SymbolTable* symbolTable = nullptr;
-
-            switch (flag) {
-            case ProfileTypeBytecodeClosureVar: {
-                const Identifier& ident = identifier(pc[4].u.operand);
-                int localScopeDepth = pc[2].u.operand;
-                ResolveType type = static_cast<ResolveType>(pc[5].u.operand);
-                // Even though type profiling may be profiling either a Get or a Put, we can always claim a Get because
-                // we're abstractly "read"ing from a JSScope.
-                ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type);
-
-                if (op.type == ClosureVar)
-                    symbolTable = op.lexicalEnvironment->symbolTable();
-                else if (op.type == GlobalVar)
-                    symbolTable = m_globalObject.get()->symbolTable();
-                
-                if (symbolTable) {
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
-                    // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
-                    symbolTable->prepareForTypeProfiling(locker);
-                    globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
-                    globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
-                } else
-                    globalVariableID = TypeProfilerNoGlobalIDExists;
-
-                break;
-            }
-            case ProfileTypeBytecodeLocallyResolved: {
-                int symbolTableIndex = pc[2].u.operand;
-                RELEASE_ASSERT(clonedConstantSymbolTables.contains(symbolTableIndex));
-                SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
-                const Identifier& ident = identifier(pc[4].u.operand);
-                ConcurrentJITLocker locker(symbolTable->m_lock);
-                // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
-                globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
-                globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
-
-                break;
-            }
-            case ProfileTypeBytecodeDoesNotHaveGlobalID: 
-            case ProfileTypeBytecodeFunctionArgument: {
-                globalVariableID = TypeProfilerNoGlobalIDExists;
-                break;
-            }
-            case ProfileTypeBytecodeFunctionReturnStatement: {
-                RELEASE_ASSERT(ownerExecutable->isFunctionExecutable());
-                globalTypeSet = jsCast<FunctionExecutable*>(ownerExecutable)->returnStatementTypeSet();
-                globalVariableID = TypeProfilerReturnStatement;
-                if (!shouldAnalyze) {
-                    // Because a return statement can be added implicitly to return undefined at the end of a function,
-                    // and these nodes don't emit expression ranges because they aren't in the actual source text of
-                    // the user's program, give the type profiler some range to identify these return statements.
-                    // Currently, the text offset that is used as identification is on the open brace of the function 
-                    // and is stored on TypeLocation's m_divotForFunctionOffsetIfReturnStatement member variable.
-                    divotStart = divotEnd = m_sourceOffset;
-                    shouldAnalyze = true;
-                }
+            
+        case op_captured_mov:
+        case op_new_captured_func: {
+            if (pc[3].u.index == UINT_MAX) {
+                instructions[i + 3].u.watchpointSet = 0;
                 break;
             }
-            }
-
-            std::pair<TypeLocation*, bool> locationPair = vm()->typeProfiler()->typeLocationCache()->getTypeLocation(globalVariableID,
-                m_ownerExecutable->sourceID(), divotStart, divotEnd, globalTypeSet, vm());
-            TypeLocation* location = locationPair.first;
-            bool isNewLocation = locationPair.second;
-
-            if (flag == ProfileTypeBytecodeFunctionReturnStatement)
-                location->m_divotForFunctionOffsetIfReturnStatement = m_sourceOffset;
-
-            if (shouldAnalyze && isNewLocation)
-                vm()->typeProfiler()->insertNewLocation(location);
-
-            instructions[i + 2].u.location = location;
-            break;
-        }
-
-        case op_debug: {
-            if (pc[1].u.index == DidReachBreakpoint)
-                m_hasDebuggerStatement = true;
+            StringImpl* uid = identifier(pc[3].u.index).impl();
+            RELEASE_ASSERT(didCloneSymbolTable);
+            ConcurrentJITLocker locker(m_symbolTable->m_lock);
+            SymbolTable::Map::iterator iter = m_symbolTable->find(locker, uid);
+            ASSERT(iter != m_symbolTable->end(locker));
+            iter->value.prepareToWatch();
+            instructions[i + 3].u.watchpointSet = iter->value.watchpointSet();
             break;
         }
 
@@ -2121,11 +1844,7 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
         }
         i += opLength;
     }
-
-    if (vm()->controlFlowProfiler())
-        insertBasicBlockBoundariesForControlFlowProfiler(instructions);
-
-    m_instructions = WTF::move(instructions);
+    m_instructions = WTF::RefCountedArray<Instruction>(instructions);
 
     // Set optimization thresholds only after m_instructions is initialized, since these
     // rely on the instruction count (and are in theory permitted to also inspect the
@@ -2135,14 +1854,25 @@ CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlin
 
     // If the concurrent thread will want the code block's hash, then compute it here
     // synchronously.
-    if (Options::alwaysComputeHash())
+    if (Options::showDisassembly()
+        || Options::showDFGDisassembly()
+        || Options::dumpBytecodeAtDFGTime()
+        || Options::dumpGraphAtEachPhase()
+        || Options::verboseCompilation()
+        || Options::logCompilationChanges()
+        || Options::validateGraph()
+        || Options::validateGraphAtEachPhase()
+        || Options::verboseOSR()
+        || Options::verboseCompilationQueue()
+        || Options::reportCompileTimes()
+        || Options::verboseCFA())
         hash();
 
     if (Options::dumpGeneratedBytecodes())
         dumpBytecode();
-    
+
     m_heap->m_codeBlocks.add(this);
-    m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock) + m_instructions.size() * sizeof(Instruction));
+    m_heap->reportExtraMemoryCost(sizeof(CodeBlock) + m_instructions.size() * sizeof(Instruction));
 }
 
 CodeBlock::~CodeBlock()
@@ -2153,8 +1883,11 @@ CodeBlock::~CodeBlock()
 #if ENABLE(VERBOSE_VALUE_PROFILE)
     dumpValueProfiles();
 #endif
+
+#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
@@ -2164,8 +1897,6 @@ CodeBlock::~CodeBlock()
     // destructor will try to remove nodes from our (no longer valid) linked list.
     while (m_incomingCalls.begin() != m_incomingCalls.end())
         m_incomingCalls.begin()->remove();
-    while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
-        m_incomingPolymorphicCalls.begin()->remove();
     
     // Note that our outgoing calls will be removed from other CodeBlocks'
     // m_incomingCalls linked lists through the execution of the ~CallLinkInfo
@@ -2206,11 +1937,26 @@ void CodeBlock::visitAggregate(SlotVisitor& visitor)
 {
 #if ENABLE(PARALLEL_GC)
     // I may be asked to scan myself more than once, and it may even happen concurrently.
-    // To this end, use an atomic operation to check (and set) if I've been called already.
-    // Only one thread may proceed past this point - whichever one wins the atomic set race.
-    bool setByMe = m_visitAggregateHasBeenCalled.compareExchangeStrong(false, true);
-    if (!setByMe)
-        return;
+    // 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_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_visitAggregateHasBeenCalled, 0, 1));
 #endif // ENABLE(PARALLEL_GC)
     
     if (!!m_alternative)
@@ -2219,15 +1965,15 @@ void CodeBlock::visitAggregate(SlotVisitor& visitor)
     if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
         otherBlock->visitAggregate(visitor);
 
-    visitor.reportExtraMemoryVisited(ownerExecutable(), sizeof(CodeBlock));
+    visitor.reportExtraMemoryUsage(ownerExecutable(), sizeof(CodeBlock));
     if (m_jitCode)
-        visitor.reportExtraMemoryVisited(ownerExecutable(), m_jitCode->size());
+        visitor.reportExtraMemoryUsage(ownerExecutable(), m_jitCode->size());
     if (m_instructions.size()) {
         // Divide by refCount() because m_instructions points to something that is shared
         // by multiple CodeBlocks, and we only want to count it towards the heap size once.
         // Having each CodeBlock report only its proportional share of the size is one way
         // of accomplishing this.
-        visitor.reportExtraMemoryVisited(ownerExecutable(), m_instructions.size() * sizeof(Instruction) / m_instructions.refCount());
+        visitor.reportExtraMemoryUsage(ownerExecutable(), m_instructions.size() * sizeof(Instruction) / m_instructions.refCount());
     }
 
     visitor.append(&m_unlinkedCode);
@@ -2238,6 +1984,10 @@ void CodeBlock::visitAggregate(SlotVisitor& visitor)
     // and when it runs, it figures out whether it has any work to do.
     visitor.addUnconditionalFinalizer(this);
     
+    // There are two things that we use weak reference harvesters for: DFG fixpoint for
+    // jettisoning, and trying to find structures that would be live based on some
+    // inline cache. So it makes sense to register them regardless.
+    visitor.addWeakReferenceHarvester(this);
     m_allTransitionsHaveBeenMarked = false;
     
     if (shouldImmediatelyAssumeLivenessDuringScan()) {
@@ -2248,11 +1998,6 @@ void CodeBlock::visitAggregate(SlotVisitor& visitor)
         return;
     }
     
-    // There are two things that we use weak reference harvesters for: DFG fixpoint for
-    // jettisoning, and trying to find structures that would be live based on some
-    // inline cache. So it makes sense to register them regardless.
-    visitor.addWeakReferenceHarvester(this);
-
 #if ENABLE(DFG_JIT)
     // We get here if we're live in the sense that our owner executable is live,
     // but we're not yet live for sure in another sense: we may yet decide that this
@@ -2272,62 +2017,6 @@ void CodeBlock::visitAggregate(SlotVisitor& visitor)
 #endif // ENABLE(DFG_JIT)
 }
 
-bool CodeBlock::shouldImmediatelyAssumeLivenessDuringScan()
-{
-#if ENABLE(DFG_JIT)
-    // Interpreter and Baseline JIT CodeBlocks don't need to be jettisoned when
-    // their weak references go stale. So if a basline JIT CodeBlock gets
-    // scanned, we can assume that this means that it's live.
-    if (!JITCode::isOptimizingJIT(jitType()))
-        return true;
-
-    // For simplicity, we don't attempt to jettison code blocks during GC if
-    // they are executing. Instead we strongly mark their weak references to
-    // allow them to continue to execute soundly.
-    if (m_mayBeExecuting)
-        return true;
-
-    if (Options::forceDFGCodeBlockLiveness())
-        return true;
-
-    return false;
-#else
-    return true;
-#endif
-}
-
-bool CodeBlock::isKnownToBeLiveDuringGC()
-{
-#if ENABLE(DFG_JIT)
-    // This should return true for:
-    // - Code blocks that behave like normal objects - i.e. if they are referenced then they
-    //   are live.
-    // - Code blocks that were running on the stack.
-    // - Code blocks that survived the last GC if the current GC is an Eden GC. This is
-    //   because either livenessHasBeenProved would have survived as true or m_mayBeExecuting
-    //   would survive as true.
-    // - Code blocks that don't have any dead weak references.
-    
-    return shouldImmediatelyAssumeLivenessDuringScan()
-        || m_jitCode->dfgCommon()->livenessHasBeenProved;
-#else
-    return true;
-#endif
-}
-
-#if ENABLE(DFG_JIT)
-static bool shouldMarkTransition(DFG::WeakReferenceTransition& transition)
-{
-    if (transition.m_codeOrigin && !Heap::isMarked(transition.m_codeOrigin.get()))
-        return false;
-    
-    if (!Heap::isMarked(transition.m_from.get()))
-        return false;
-    
-    return true;
-}
-#endif // ENABLE(DFG_JIT)
-
 void CodeBlock::propagateTransitions(SlotVisitor& visitor)
 {
     UNUSED_PARAM(visitor);
@@ -2337,6 +2026,7 @@ void CodeBlock::propagateTransitions(SlotVisitor& visitor)
 
     bool allAreMarkedSoFar = true;
         
+#if ENABLE(LLINT)
     Interpreter* interpreter = m_vm->interpreter;
     if (jitType() == JITCode::InterpreterThunk) {
         const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
@@ -2358,6 +2048,7 @@ void CodeBlock::propagateTransitions(SlotVisitor& visitor)
             }
         }
     }
+#endif // ENABLE(LLINT)
 
 #if ENABLE(JIT)
     if (JITCode::isJIT(jitType())) {
@@ -2404,28 +2095,21 @@ void CodeBlock::propagateTransitions(SlotVisitor& visitor)
 #if ENABLE(DFG_JIT)
     if (JITCode::isOptimizingJIT(jitType())) {
         DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
-        
         for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
-            if (shouldMarkTransition(dfgCommon->transitions[i])) {
+            if ((!dfgCommon->transitions[i].m_codeOrigin
+                 || Heap::isMarked(dfgCommon->transitions[i].m_codeOrigin.get()))
+                && Heap::isMarked(dfgCommon->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.
-                //
-                // We also short-circuit the liveness if the structure is harmless
-                // to mark (i.e. its global object and prototype are both already
-                // live).
-                
                 visitor.append(&dfgCommon->transitions[i].m_to);
             } else
                 allAreMarkedSoFar = false;
@@ -2460,14 +2144,6 @@ void CodeBlock::determineLiveness(SlotVisitor& visitor)
             break;
         }
     }
-    if (allAreLiveSoFar) {
-        for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i) {
-            if (!Heap::isMarked(dfgCommon->weakStructureReferences[i].get())) {
-                allAreLiveSoFar = false;
-                break;
-            }
-        }
-    }
     
     // If some weak references are dead, then this fixpoint iteration was
     // unsuccessful.
@@ -2533,38 +2209,28 @@ void CodeBlock::finalizeUnconditionally()
                 if (Options::verboseOSR())
                     dataLogF("Clearing LLInt to_this with structure %p.\n", curInstruction[2].u.structure.get());
                 curInstruction[2].u.structure.clear();
-                curInstruction[3].u.toThisStatus = merge(
-                    curInstruction[3].u.toThisStatus, ToThisClearedByGC);
                 break;
-            case op_create_this: {
-                auto& cacheWriteBarrier = curInstruction[4].u.jsCell;
-                if (!cacheWriteBarrier || cacheWriteBarrier.unvalidatedGet() == JSCell::seenMultipleCalleeObjects())
-                    break;
-                JSCell* cachedFunction = cacheWriteBarrier.get();
-                if (Heap::isMarked(cachedFunction))
+            case op_get_callee:
+                if (!curInstruction[2].u.jsCell || Heap::isMarked(curInstruction[2].u.jsCell.get()))
                     break;
                 if (Options::verboseOSR())
-                    dataLogF("Clearing LLInt create_this with cached callee %p.\n", cachedFunction);
-                cacheWriteBarrier.clear();
+                    dataLogF("Clearing LLInt get callee with function %p.\n", curInstruction[2].u.jsCell.get());
+                curInstruction[2].u.jsCell.clear();
                 break;
-            }
             case op_resolve_scope: {
-                // Right now this isn't strictly necessary. Any symbol tables that this will refer to
-                // are for outer functions, and we refer to those functions strongly, and they refer
-                // to the symbol table strongly. But it's nice to be on the safe side.
-                WriteBarrierBase<SymbolTable>& symbolTable = curInstruction[6].u.symbolTable;
-                if (!symbolTable || Heap::isMarked(symbolTable.get()))
+                WriteBarrierBase<JSActivation>& activation = curInstruction[5].u.activation;
+                if (!activation || Heap::isMarked(activation.get()))
                     break;
                 if (Options::verboseOSR())
-                    dataLogF("Clearing dead symbolTable %p.\n", symbolTable.get());
-                symbolTable.clear();
+                    dataLogF("Clearing dead activation %p.\n", activation.get());
+                activation.clear();
                 break;
             }
             case op_get_from_scope:
             case op_put_to_scope: {
                 ResolveModeAndType modeAndType =
                     ResolveModeAndType(curInstruction[4].u.operand);
-                if (modeAndType.type() == GlobalVar || modeAndType.type() == GlobalVarWithVarInjectionChecks || modeAndType.type() == LocalClosureVar)
+                if (modeAndType.type() == GlobalVar || modeAndType.type() == GlobalVarWithVarInjectionChecks)
                     continue;
                 WriteBarrierBase<Structure>& structure = curInstruction[5].u.structure;
                 if (!structure || Heap::isMarked(structure.get()))
@@ -2575,11 +2241,11 @@ void CodeBlock::finalizeUnconditionally()
                 break;
             }
             default:
-                OpcodeID opcodeID = interpreter->getOpcodeID(curInstruction[0].u.opcode);
-                ASSERT_WITH_MESSAGE_UNUSED(opcodeID, false, "Unhandled opcode in CodeBlock::finalizeUnconditionally, %s(%d) at bc %u", opcodeNames[opcodeID], opcodeID, propertyAccessInstructions[i]);
+                RELEASE_ASSERT_NOT_REACHED();
             }
         }
 
+#if ENABLE(LLINT)
         for (unsigned i = 0; i < m_llintCallLinkInfos.size(); ++i) {
             if (m_llintCallLinkInfos[i].isLinked() && !Heap::isMarked(m_llintCallLinkInfos[i].callee.get())) {
                 if (Options::verboseOSR())
@@ -2589,11 +2255,12 @@ void CodeBlock::finalizeUnconditionally()
             if (!!m_llintCallLinkInfos[i].lastSeenCallee && !Heap::isMarked(m_llintCallLinkInfos[i].lastSeenCallee.get()))
                 m_llintCallLinkInfos[i].lastSeenCallee.clear();
         }
+#endif // ENABLE(LLINT)
     }
 
 #if ENABLE(DFG_JIT)
     // Check if we're not live. If we are, then jettison.
-    if (!isKnownToBeLiveDuringGC()) {
+    if (!(shouldImmediatelyAssumeLivenessDuringScan() || m_jitCode->dfgCommon()->livenessHasBeenProved)) {
         if (Options::verboseOSR())
             dataLog(*this, " has dead weak references, jettisoning during GC.\n");
 
@@ -2617,7 +2284,7 @@ void CodeBlock::finalizeUnconditionally()
             }
         }
         
-        jettison(Profiler::JettisonDueToWeakReference);
+        jettison();
         return;
     }
 #endif // ENABLE(DFG_JIT)
@@ -2626,14 +2293,39 @@ void CodeBlock::finalizeUnconditionally()
     // Handle inline caches.
     if (!!jitCode()) {
         RepatchBuffer repatchBuffer(this);
-        
-        for (auto iter = callLinkInfosBegin(); !!iter; ++iter)
-            (*iter)->visitWeak(repatchBuffer);
-
+        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 (Options::verboseOSR()) {
+                            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 (Options::verboseOSR()) {
+                        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 (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter) {
             StructureStubInfo& stubInfo = **iter;
             
-            if (stubInfo.visitWeakReferences(repatchBuffer))
+            if (stubInfo.visitWeakReferences())
                 continue;
             
             resetStubDuringGCInternal(repatchBuffer, stubInfo);
@@ -2642,52 +2334,6 @@ void CodeBlock::finalizeUnconditionally()
 #endif
 }
 
-void CodeBlock::getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result)
-{
-#if ENABLE(JIT)
-    toHashMap(m_stubInfos, getStructureStubInfoCodeOrigin, result);
-#else
-    UNUSED_PARAM(result);
-#endif
-}
-
-void CodeBlock::getStubInfoMap(StubInfoMap& result)
-{
-    ConcurrentJITLocker locker(m_lock);
-    getStubInfoMap(locker, result);
-}
-
-void CodeBlock::getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result)
-{
-#if ENABLE(JIT)
-    toHashMap(m_callLinkInfos, getCallLinkInfoCodeOrigin, result);
-#else
-    UNUSED_PARAM(result);
-#endif
-}
-
-void CodeBlock::getCallLinkInfoMap(CallLinkInfoMap& result)
-{
-    ConcurrentJITLocker locker(m_lock);
-    getCallLinkInfoMap(locker, result);
-}
-
-void CodeBlock::getByValInfoMap(const ConcurrentJITLocker&, ByValInfoMap& result)
-{
-#if ENABLE(JIT)
-    for (auto* byValInfo : m_byValInfos)
-        result.add(CodeOrigin(byValInfo->bytecodeIndex), byValInfo);
-#else
-    UNUSED_PARAM(result);
-#endif
-}
-
-void CodeBlock::getByValInfoMap(ByValInfoMap& result)
-{
-    ConcurrentJITLocker locker(m_lock);
-    getByValInfoMap(locker, result);
-}
-
 #if ENABLE(JIT)
 StructureStubInfo* CodeBlock::addStubInfo()
 {
@@ -2695,25 +2341,9 @@ StructureStubInfo* CodeBlock::addStubInfo()
     return m_stubInfos.add();
 }
 
-StructureStubInfo* CodeBlock::findStubInfo(CodeOrigin codeOrigin)
-{
-    for (StructureStubInfo* stubInfo : m_stubInfos) {
-        if (stubInfo->codeOrigin == codeOrigin)
-            return stubInfo;
-    }
-    return nullptr;
-}
-
-ByValInfo* CodeBlock::addByValInfo()
-{
-    ConcurrentJITLocker locker(m_lock);
-    return m_byValInfos.add();
-}
-
-CallLinkInfo* CodeBlock::addCallLinkInfo()
+void CodeBlock::getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result)
 {
-    ConcurrentJITLocker locker(m_lock);
-    return m_callLinkInfos.add();
+    toHashMap(m_stubInfos, getStructureStubInfoCodeOrigin, result);
 }
 
 void CodeBlock::resetStub(StructureStubInfo& stubInfo)
@@ -2756,21 +2386,13 @@ void CodeBlock::resetStubDuringGCInternal(RepatchBuffer& repatchBuffer, Structur
     resetStubInternal(repatchBuffer, stubInfo);
     stubInfo.resetByGC = true;
 }
-
-CallLinkInfo* CodeBlock::getCallLinkInfoForBytecodeIndex(unsigned index)
-{
-    for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
-        if ((*iter)->codeOrigin() == CodeOrigin(index))
-            return *iter;
-    }
-    return nullptr;
-}
 #endif
 
 void CodeBlock::stronglyVisitStrongReferences(SlotVisitor& visitor)
 {
     visitor.append(&m_globalObject);
     visitor.append(&m_ownerExecutable);
+    visitor.append(&m_symbolTable);
     visitor.append(&m_unlinkedCode);
     if (m_rareData)
         m_rareData->m_evalCodeCache.visitAggregate(visitor);
@@ -2782,21 +2404,6 @@ void CodeBlock::stronglyVisitStrongReferences(SlotVisitor& visitor)
     for (unsigned i = 0; i < m_objectAllocationProfiles.size(); ++i)
         m_objectAllocationProfiles[i].visitAggregate(visitor);
 
-#if ENABLE(DFG_JIT)
-    if (JITCode::isOptimizingJIT(jitType())) {
-        // FIXME: This is an antipattern for two reasons. References introduced by the DFG
-        // that aren't in the original CodeBlock being compiled should be weakly referenced.
-        // Inline call frames aren't in the original CodeBlock, so they qualify as weak. Also,
-        // those weak references should already be tracked in the DFG as weak FrozenValues. So,
-        // there is probably no need for this. We already have assertions that this should be
-        // unnecessary.
-        // https://bugs.webkit.org/show_bug.cgi?id=146613
-        DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
-        if (dfgCommon->inlineCallFrames.get())
-            dfgCommon->inlineCallFrames->visitAggregate(visitor);
-    }
-#endif
-
     updateAllPredictions();
 }
 
@@ -2819,9 +2426,6 @@ void CodeBlock::stronglyVisitWeakReferences(SlotVisitor& visitor)
     
     for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i)
         visitor.append(&dfgCommon->weakReferences[i]);
-
-    for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i)
-        visitor.append(&dfgCommon->weakStructureReferences[i]);
 #endif    
 }
 
@@ -2870,7 +2474,66 @@ bool CodeBlock::hasOptimizedReplacement()
 }
 #endif
 
-HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler requiredHandler)
+bool CodeBlock::isCaptured(VirtualRegister operand, InlineCallFrame* inlineCallFrame) const
+{
+    if (operand.isArgument())
+        return operand.toArgument() && usesArguments();
+
+    if (inlineCallFrame)
+        return inlineCallFrame->capturedVars.get(operand.toLocal());
+
+    // The activation object isn't in the captured region, but it's "captured"
+    // in the sense that stores to its location can be observed indirectly.
+    if (needsActivation() && operand == activationRegister())
+        return true;
+
+    // Ditto for the arguments object.
+    if (usesArguments() && operand == argumentsRegister())
+        return true;
+
+    // Ditto for the arguments object.
+    if (usesArguments() && operand == unmodifiedArgumentsRegister(argumentsRegister()))
+        return true;
+
+    // We're in global code so there are no locals to capture
+    if (!symbolTable())
+        return false;
+
+    return symbolTable()->isCaptured(operand.offset());
+}
+
+int CodeBlock::framePointerOffsetToGetActivationRegisters(int machineCaptureStart)
+{
+    // We'll be adding this to the stack pointer to get a registers pointer that looks
+    // like it would have looked in the baseline engine. For example, if bytecode would
+    // have put the first captured variable at offset -5 but we put it at offset -1, then
+    // we'll have an offset of 4.
+    int32_t offset = 0;
+    
+    // Compute where we put the captured variables. This offset will point the registers
+    // pointer directly at the first captured var.
+    offset += machineCaptureStart;
+    
+    // Now compute the offset needed to make the runtime see the captured variables at the
+    // same offset that the bytecode would have used.
+    offset -= symbolTable()->captureStart();
+    
+    return offset;
+}
+
+int CodeBlock::framePointerOffsetToGetActivationRegisters()
+{
+    if (!JITCode::isOptimizingJIT(jitType()))
+        return 0;
+#if ENABLE(DFG_JIT)
+    return framePointerOffsetToGetActivationRegisters(jitCode()->dfgCommon()->machineCaptureStart);
+#else
+    RELEASE_ASSERT_NOT_REACHED();
+    return 0;
+#endif
+}
+
+HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset)
 {
     RELEASE_ASSERT(bytecodeOffset < instructions().size());
 
@@ -2879,14 +2542,10 @@ HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, Requir
     
     Vector<HandlerInfo>& exceptionHandlers = m_rareData->m_exceptionHandlers;
     for (size_t i = 0; i < exceptionHandlers.size(); ++i) {
-        HandlerInfo& handler = exceptionHandlers[i];
-        if ((requiredHandler == RequiredHandler::CatchHandler) && !handler.isCatchHandler())
-            continue;
-
         // Handlers are ordered innermost first, so the first handler we encounter
         // that contains the source address is the correct handler to use.
-        if (handler.start <= bytecodeOffset && handler.end > bytecodeOffset)
-            return &handler;
+        if (exceptionHandlers[i].start <= bytecodeOffset && exceptionHandlers[i].end > bytecodeOffset)
+            return &exceptionHandlers[i];
     }
 
     return 0;
@@ -2895,7 +2554,7 @@ HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, Requir
 unsigned CodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
 {
     RELEASE_ASSERT(bytecodeOffset < instructions().size());
-    return m_ownerExecutable->firstLine() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
+    return m_ownerExecutable->lineNo() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
 }
 
 unsigned CodeBlock::columnNumberForBytecodeOffset(unsigned bytecodeOffset)
@@ -2914,7 +2573,7 @@ void CodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& d
     m_unlinkedCode->expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
     divot += m_sourceOffset;
     column += line ? 1 : firstLineColumnOffset();
-    line += m_ownerExecutable->firstLine();
+    line += m_ownerExecutable->lineNo();
 }
 
 bool CodeBlock::hasOpDebugForLineAndColumn(unsigned line, unsigned column)
@@ -2945,7 +2604,6 @@ void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
     
     if (shrinkMode == EarlyShrink) {
         m_constantRegisters.shrinkToFit();
-        m_constantsSourceCodeRepresentation.shrinkToFit();
         
         if (m_rareData) {
             m_rareData->m_switchJumpTables.shrinkToFit();
@@ -2954,25 +2612,47 @@ void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
     } // else don't shrink these, because we would have already pointed pointers into these tables.
 }
 
+unsigned CodeBlock::addOrFindConstant(JSValue v)
+{
+    unsigned result;
+    if (findConstant(v, result))
+        return result;
+    return addConstant(v);
+}
+
+bool CodeBlock::findConstant(JSValue v, unsigned& index)
+{
+    unsigned numberOfConstants = numberOfConstantRegisters();
+    for (unsigned i = 0; i < numberOfConstants; ++i) {
+        if (getConstant(FirstConstantRegisterIndex + i) == v) {
+            index = i;
+            return true;
+        }
+    }
+    index = numberOfConstants;
+    return false;
+}
+
 #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();
     }
-    if (m_callLinkInfos.isEmpty())
+#endif
+    if (!m_callLinkInfos.size())
         return;
     if (!m_vm->canUseJIT())
         return;
     RepatchBuffer repatchBuffer(this);
-    for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
-        CallLinkInfo& info = **iter;
-        if (!info.isLinked())
+    for (size_t i = 0; i < m_callLinkInfos.size(); i++) {
+        if (!m_callLinkInfos[i].isLinked())
             continue;
-        info.unlink(repatchBuffer);
+        m_callLinkInfos[i].unlink(*m_vm, repatchBuffer);
     }
 }
 
@@ -2981,34 +2661,41 @@ void CodeBlock::linkIncomingCall(ExecState* callerFrame, CallLinkInfo* incoming)
     noticeIncomingCall(callerFrame);
     m_incomingCalls.push(incoming);
 }
-
-void CodeBlock::linkIncomingPolymorphicCall(ExecState* callerFrame, PolymorphicCallNode* incoming)
-{
-    noticeIncomingCall(callerFrame);
-    m_incomingPolymorphicCalls.push(incoming);
-}
 #endif // ENABLE(JIT)
 
 void CodeBlock::unlinkIncomingCalls()
 {
+#if ENABLE(LLINT)
     while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
         m_incomingLLIntCalls.begin()->unlink();
+#endif // ENABLE(LLINT)
 #if ENABLE(JIT)
-    if (m_incomingCalls.isEmpty() && m_incomingPolymorphicCalls.isEmpty())
+    if (m_incomingCalls.isEmpty())
         return;
     RepatchBuffer repatchBuffer(this);
     while (m_incomingCalls.begin() != m_incomingCalls.end())
-        m_incomingCalls.begin()->unlink(repatchBuffer);
-    while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
-        m_incomingPolymorphicCalls.begin()->unlink(repatchBuffer);
+        m_incomingCalls.begin()->unlink(*m_vm, repatchBuffer);
 #endif // ENABLE(JIT)
 }
 
+#if ENABLE(LLINT)
 void CodeBlock::linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo* incoming)
 {
     noticeIncomingCall(callerFrame);
     m_incomingLLIntCalls.push(incoming);
 }
+#endif // ENABLE(LLINT)
+
+void CodeBlock::clearEvalCache()
+{
+    if (!!m_alternative)
+        m_alternative->clearEvalCache();
+    if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
+        otherBlock->clearEvalCache();
+    if (!m_rareData)
+        return;
+    m_rareData->m_evalCodeCache.clear();
+}
 
 void CodeBlock::install()
 {
@@ -3020,6 +2707,18 @@ PassRefPtr<CodeBlock> CodeBlock::newReplacement()
     return ownerExecutable()->newReplacementCodeBlockFor(specializationKind());
 }
 
+const SlowArgument* CodeBlock::machineSlowArguments()
+{
+    if (!JITCode::isOptimizingJIT(jitType()))
+        return symbolTable()->slowArguments();
+    
+#if ENABLE(DFG_JIT)
+    return jitCode()->dfgCommon()->slowArguments.get();
+#else // ENABLE(DFG_JIT)
+    return 0;
+#endif // ENABLE(DFG_JIT)
+}
+
 #if ENABLE(JIT)
 CodeBlock* ProgramCodeBlock::replacement()
 {
@@ -3054,27 +2753,19 @@ DFG::CapabilityLevel FunctionCodeBlock::capabilityLevelInternal()
 }
 #endif
 
-void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mode, const FireDetail* detail)
+void CodeBlock::jettison(ReoptimizationMode mode)
 {
-    RELEASE_ASSERT(reason != Profiler::NotJettisoned);
-    
 #if ENABLE(DFG_JIT)
     if (DFG::shouldShowDisassembly()) {
         dataLog("Jettisoning ", *this);
         if (mode == CountReoptimization)
             dataLog(" and counting reoptimization");
-        dataLog(" due to ", reason);
-        if (detail)
-            dataLog(", ", *detail);
         dataLog(".\n");
     }
     
     DeferGCForAWhile deferGC(*m_heap);
     RELEASE_ASSERT(JITCode::isOptimizingJIT(jitType()));
     
-    if (Profiler::Compilation* compilation = jitCode()->dfgCommon()->compilation.get())
-        compilation->setJettisonReason(reason, detail);
-    
     // We want to accomplish two things here:
     // 1) Make sure that if this CodeBlock is on the stack right now, then if we return to it
     //    we should OSR exit at the top of the next bytecode instruction after the return.
@@ -3114,7 +2805,6 @@ void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mod
         dataLog("    Did install baseline version of ", *this, "\n");
 #else // ENABLE(DFG_JIT)
     UNUSED_PARAM(mode);
-    UNUSED_PARAM(detail);
     UNREACHABLE_FOR_PLATFORM();
 #endif // ENABLE(DFG_JIT)
 }
@@ -3126,64 +2816,17 @@ JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
     return jsCast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())->eitherCodeBlock()->globalObject();
 }
 
-class RecursionCheckFunctor {
-public:
-    RecursionCheckFunctor(CallFrame* startCallFrame, CodeBlock* codeBlock, unsigned depthToCheck)
-        : m_startCallFrame(startCallFrame)
-        , m_codeBlock(codeBlock)
-        , m_depthToCheck(depthToCheck)
-        , m_foundStartCallFrame(false)
-        , m_didRecurse(false)
-    { }
-
-    StackVisitor::Status operator()(StackVisitor& visitor)
-    {
-        CallFrame* currentCallFrame = visitor->callFrame();
-
-        if (currentCallFrame == m_startCallFrame)
-            m_foundStartCallFrame = true;
-
-        if (m_foundStartCallFrame) {
-            if (visitor->callFrame()->codeBlock() == m_codeBlock) {
-                m_didRecurse = true;
-                return StackVisitor::Done;
-            }
-
-            if (!m_depthToCheck--)
-                return StackVisitor::Done;
-        }
-
-        return StackVisitor::Continue;
-    }
-
-    bool didRecurse() const { return m_didRecurse; }
-
-private:
-    CallFrame* m_startCallFrame;
-    CodeBlock* m_codeBlock;
-    unsigned m_depthToCheck;
-    bool m_foundStartCallFrame;
-    bool m_didRecurse;
-};
-
 void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
 {
     CodeBlock* callerCodeBlock = callerFrame->codeBlock();
     
     if (Options::verboseCallLink())
-        dataLog("Noticing call link from ", pointerDump(callerCodeBlock), " to ", *this, "\n");
+        dataLog("Noticing call link from ", *callerCodeBlock, " to ", *this, "\n");
     
-#if ENABLE(DFG_JIT)
     if (!m_shouldAlwaysBeInlined)
         return;
-    
-    if (!callerCodeBlock) {
-        m_shouldAlwaysBeInlined = false;
-        if (Options::verboseCallLink())
-            dataLog("    Clearing SABI because caller is native.\n");
-        return;
-    }
 
+#if ENABLE(DFG_JIT)
     if (!hasBaselineJITProfiling())
         return;
 
@@ -3192,13 +2835,6 @@ void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
 
     if (!canInline(m_capabilityLevelState))
         return;
-    
-    if (!DFG::isSmallEnoughToInlineCodeInto(callerCodeBlock)) {
-        m_shouldAlwaysBeInlined = false;
-        if (Options::verboseCallLink())
-            dataLog("    Clearing SABI because caller is too large.\n");
-        return;
-    }
 
     if (callerCodeBlock->jitType() == JITCode::InterpreterThunk) {
         // If the caller is still in the interpreter, then we can't expect inlining to
@@ -3207,14 +2843,7 @@ void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
         // any of its callers.
         m_shouldAlwaysBeInlined = false;
         if (Options::verboseCallLink())
-            dataLog("    Clearing SABI because caller is in LLInt.\n");
-        return;
-    }
-    
-    if (JITCode::isOptimizingJIT(callerCodeBlock->jitType())) {
-        m_shouldAlwaysBeInlined = false;
-        if (Options::verboseCallLink())
-            dataLog("    Clearing SABI bcause caller was already optimized.\n");
+            dataLog("    Marking SABI because caller is in LLInt.\n");
         return;
     }
     
@@ -3224,47 +2853,42 @@ void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
         // delay eval optimization by a *lot*.
         m_shouldAlwaysBeInlined = false;
         if (Options::verboseCallLink())
-            dataLog("    Clearing SABI because caller is not a function.\n");
-        return;
-    }
-
-    // Recursive calls won't be inlined.
-    RecursionCheckFunctor functor(callerFrame, this, Options::maximumInliningDepth());
-    vm()->topCallFrame->iterate(functor);
-
-    if (functor.didRecurse()) {
-        if (Options::verboseCallLink())
-            dataLog("    Clearing SABI because recursion was detected.\n");
-        m_shouldAlwaysBeInlined = false;
+            dataLog("    Marking SABI because caller is not a function.\n");
         return;
     }
     
-    if (callerCodeBlock->m_capabilityLevelState == DFG::CapabilityLevelNotSet) {
-        dataLog("In call from ", *callerCodeBlock, " ", callerFrame->codeOrigin(), " to ", *this, ": caller's DFG capability level is not set.\n");
-        CRASH();
+    ExecState* frame = callerFrame;
+    for (unsigned i = Options::maximumInliningDepth(); i--; frame = frame->callerFrame()) {
+        if (frame->isVMEntrySentinel())
+            break;
+        if (frame->codeBlock() == this) {
+            // Recursive calls won't be inlined.
+            if (Options::verboseCallLink())
+                dataLog("    Marking SABI because recursion was detected.\n");
+            m_shouldAlwaysBeInlined = false;
+            return;
+        }
     }
     
+    RELEASE_ASSERT(callerCodeBlock->m_capabilityLevelState != DFG::CapabilityLevelNotSet);
+    
     if (canCompile(callerCodeBlock->m_capabilityLevelState))
         return;
     
     if (Options::verboseCallLink())
-        dataLog("    Clearing SABI because the caller is not a DFG candidate.\n");
+        dataLog("    Marking SABI because the caller is not a DFG candidate.\n");
     
     m_shouldAlwaysBeInlined = false;
 #endif
 }
 
+#if ENABLE(JIT)
 unsigned CodeBlock::reoptimizationRetryCounter() const
 {
-#if ENABLE(JIT)
     ASSERT(m_reoptimizationRetryCounter <= Options::reoptimizationRetryCounterMax());
     return m_reoptimizationRetryCounter;
-#else
-    return 0;
-#endif // ENABLE(JIT)
 }
 
-#if ENABLE(JIT)
 void CodeBlock::countReoptimization()
 {
     m_reoptimizationRetryCounter++;
@@ -3275,11 +2899,6 @@ void CodeBlock::countReoptimization()
 unsigned CodeBlock::numberOfDFGCompiles()
 {
     ASSERT(JITCode::isBaselineCode(jitType()));
-    if (Options::testTheFTL()) {
-        if (m_didFailFTLCompilation)
-            return 1000000;
-        return (m_hasBeenCompiledWithFTL ? 1 : 0) + m_reoptimizationRetryCounter;
-    }
     return (JITCode::isOptimizingJIT(replacement()->jitType()) ? 1 : 0) + m_reoptimizationRetryCounter;
 }
 
@@ -3360,16 +2979,13 @@ double CodeBlock::optimizationThresholdScalingFactor()
     ASSERT(instructionCount); // Make sure this is called only after we have an instruction stream; otherwise it'll just return the value of d, which makes no sense.
     
     double result = d + a * sqrt(instructionCount + b) + c * instructionCount;
-    
-    result *= codeTypeThresholdMultiplier();
-    
     if (Options::verboseOSR()) {
         dataLog(
             *this, ": instruction count is ", instructionCount,
             ", scaling execution counter by ", result, " * ", codeTypeThresholdMultiplier(),
             "\n");
     }
-    return result;
+    return result * codeTypeThresholdMultiplier();
 }
 
 static int32_t clipThreshold(double threshold)
@@ -3394,7 +3010,7 @@ int32_t CodeBlock::adjustedCounterValue(int32_t desiredThreshold)
 bool CodeBlock::checkIfOptimizationThresholdReached()
 {
 #if ENABLE(DFG_JIT)
-    if (DFG::Worklist* worklist = DFG::existingGlobalDFGWorklistOrNull()) {
+    if (DFG::Worklist* worklist = m_vm->worklist.get()) {
         if (worklist->compilationState(DFG::CompilationKey(this, DFG::DFGMode))
             == DFG::Worklist::Compiled) {
             optimizeNextInvocation();
@@ -3460,22 +3076,8 @@ void CodeBlock::forceOptimizationSlowPathConcurrently()
 #if ENABLE(DFG_JIT)
 void CodeBlock::setOptimizationThresholdBasedOnCompilationResult(CompilationResult result)
 {
-    JITCode::JITType type = jitType();
-    if (type != JITCode::BaselineJIT) {
-        dataLog(*this, ": expected to have baseline code but have ", type, "\n");
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    CodeBlock* theReplacement = replacement();
-    if ((result == CompilationSuccessful) != (theReplacement != this)) {
-        dataLog(*this, ": we have result = ", result, " but ");
-        if (theReplacement == this)
-            dataLog("we are our own replacement.\n");
-        else
-            dataLog("our replacement is ", pointerDump(theReplacement), "\n");
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
+    RELEASE_ASSERT(jitType() == JITCode::BaselineJIT);
+    RELEASE_ASSERT((result == CompilationSuccessful) == (replacement() != this));
     switch (result) {
     case CompilationSuccessful:
         RELEASE_ASSERT(JITCode::isOptimizingJIT(replacement()->jitType()));
@@ -3498,8 +3100,6 @@ void CodeBlock::setOptimizationThresholdBasedOnCompilationResult(CompilationResu
         optimizeAfterWarmUp();
         return;
     }
-    
-    dataLog("Unrecognized result: ", static_cast<int>(result), "\n");
     RELEASE_ASSERT_NOT_REACHED();
 }
 
@@ -3655,7 +3255,9 @@ void CodeBlock::tallyFrequentExitSites()
         DFG::JITCode* jitCode = m_jitCode->dfg();
         for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
             DFG::OSRExit& exit = jitCode->osrExit[i];
-            exit.considerAddingAsFrequentExitSite(profiledBlock);
+            
+            if (!exit.considerAddingAsFrequentExitSite(profiledBlock))
+                continue;
         }
         break;
     }
@@ -3668,7 +3270,9 @@ void CodeBlock::tallyFrequentExitSites()
         FTL::JITCode* jitCode = m_jitCode->ftl();
         for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
             FTL::OSRExit& exit = jitCode->osrExit[i];
-            exit.considerAddingAsFrequentExitSite(profiledBlock);
+            
+            if (!exit.considerAddingAsFrequentExitSite(profiledBlock))
+                continue;
         }
         break;
     }
@@ -3715,8 +3319,10 @@ void CodeBlock::dumpValueProfiles()
 unsigned CodeBlock::frameRegisterCount()
 {
     switch (jitType()) {
+#if ENABLE(LLINT)
     case JITCode::InterpreterThunk:
         return LLInt::frameRegisterCountFor(this);
+#endif // ENABLE(LLINT)
 
 #if ENABLE(JIT)
     case JITCode::BaselineJIT:
@@ -3735,11 +3341,6 @@ unsigned CodeBlock::frameRegisterCount()
     }
 }
 
-int CodeBlock::stackPointerOffset()
-{
-    return virtualRegisterForLocal(frameRegisterCount() - 1).offset();
-}
-
 size_t CodeBlock::predictedMachineCodeSize()
 {
     // This will be called from CodeBlock::CodeBlock before either m_vm or the
@@ -3799,40 +3400,72 @@ bool CodeBlock::usesOpcode(OpcodeID opcodeID)
 
 String CodeBlock::nameForRegister(VirtualRegister virtualRegister)
 {
-    for (unsigned i = 0; i < m_constantRegisters.size(); i++) {
-        if (m_constantRegisters[i].get().isEmpty())
-            continue;
-        if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(m_constantRegisters[i].get())) {
-            ConcurrentJITLocker locker(symbolTable->m_lock);
-            auto end = symbolTable->end(locker);
-            for (auto ptr = symbolTable->begin(locker); ptr != end; ++ptr) {
-                if (ptr->value.varOffset() == VarOffset(virtualRegister)) {
-                    // FIXME: This won't work from the compilation thread.
-                    // https://bugs.webkit.org/show_bug.cgi?id=115300
-                    return ptr->key.get();
-                }
-            }
+    ConcurrentJITLocker locker(symbolTable()->m_lock);
+    SymbolTable::Map::iterator end = symbolTable()->end(locker);
+    for (SymbolTable::Map::iterator ptr = symbolTable()->begin(locker); ptr != end; ++ptr) {
+        if (ptr->value.getIndex() == virtualRegister.offset()) {
+            // FIXME: This won't work from the compilation thread.
+            // https://bugs.webkit.org/show_bug.cgi?id=115300
+            return String(ptr->key);
         }
     }
+    if (needsActivation() && virtualRegister == activationRegister())
+        return ASCIILiteral("activation");
     if (virtualRegister == thisRegister())
         return ASCIILiteral("this");
+    if (usesArguments()) {
+        if (virtualRegister == argumentsRegister())
+            return ASCIILiteral("arguments");
+        if (unmodifiedArgumentsRegister(argumentsRegister()) == virtualRegister)
+            return ASCIILiteral("real arguments");
+    }
     if (virtualRegister.isArgument())
-        return String::format("arguments[%3d]", virtualRegister.toArgument());
+        return String::format("arguments[%3d]", virtualRegister.toArgument()).impl();
 
     return "";
 }
 
-ValueProfile* CodeBlock::valueProfileForBytecodeOffset(int bytecodeOffset)
-{
-    ValueProfile* result = binarySearch<ValueProfile, int>(
-        m_valueProfiles, m_valueProfiles.size(), bytecodeOffset,
-        getValueProfileBytecodeOffset<ValueProfile>);
-    ASSERT(result->m_bytecodeOffset != -1);
-    ASSERT(instructions()[bytecodeOffset + opcodeLength(
-        m_vm->interpreter->getOpcodeID(
-            instructions()[bytecodeOffset].u.opcode)) - 1].u.profile == result);
-    return result;
-}
+namespace {
+
+struct VerifyCapturedDef {
+    void operator()(CodeBlock* codeBlock, Instruction* instruction, OpcodeID opcodeID, int operand)
+    {
+        unsigned bytecodeOffset = instruction - codeBlock->instructions().begin();
+        
+        if (codeBlock->isConstantRegisterIndex(operand)) {
+            codeBlock->beginValidationDidFail();
+            dataLog("    At bc#", bytecodeOffset, " encountered a definition of a constant.\n");
+            codeBlock->endValidationDidFail();
+            return;
+        }
+
+        switch (opcodeID) {
+        case op_enter:
+        case op_captured_mov:
+        case op_init_lazy_reg:
+        case op_create_arguments:
+        case op_new_captured_func:
+            return;
+        default:
+            break;
+        }
+        
+        VirtualRegister virtualReg(operand);
+        if (!virtualReg.isLocal())
+            return;
+        
+        if (codeBlock->captureCount() && codeBlock->symbolTable()->isCaptured(operand)) {
+            codeBlock->beginValidationDidFail();
+            dataLog("    At bc#", bytecodeOffset, " encountered invalid assignment to captured variable loc", virtualReg.toLocal(), ".\n");
+            codeBlock->endValidationDidFail();
+            return;
+        }
+        
+        return;
+    }
+};
+
+} // anonymous namespace
 
 void CodeBlock::validate()
 {
@@ -3849,15 +3482,38 @@ void CodeBlock::validate()
     }
     
     for (unsigned i = m_numCalleeRegisters; i--;) {
+        bool isCaptured = false;
         VirtualRegister reg = virtualRegisterForLocal(i);
         
-        if (liveAtHead.get(i)) {
-            beginValidationDidFail();
-            dataLog("    Variable ", reg, " is expected to be dead.\n");
-            dataLog("    Result: ", liveAtHead, "\n");
-            endValidationDidFail();
+        if (captureCount())
+            isCaptured = reg.offset() <= captureStart() && reg.offset() > captureEnd();
+        
+        if (isCaptured) {
+            if (!liveAtHead.get(i)) {
+                beginValidationDidFail();
+                dataLog("    Variable loc", i, " is expected to be live because it is captured, but it isn't live.\n");
+                dataLog("    Result: ", liveAtHead, "\n");
+                endValidationDidFail();
+            }
+        } else {
+            if (liveAtHead.get(i)) {
+                beginValidationDidFail();
+                dataLog("    Variable loc", i, " is expected to be dead.\n");
+                dataLog("    Result: ", liveAtHead, "\n");
+                endValidationDidFail();
+            }
         }
     }
+    
+    for (unsigned bytecodeOffset = 0; bytecodeOffset < instructions().size();) {
+        Instruction* currentInstruction = instructions().begin() + bytecodeOffset;
+        OpcodeID opcodeID = m_vm->interpreter->getOpcodeID(currentInstruction->u.opcode);
+        
+        VerifyCapturedDef verifyCapturedDef;
+        computeDefsForBytecodeOffset(this, bytecodeOffset, verifyCapturedDef);
+        
+        bytecodeOffset += opcodeLength(opcodeID);
+    }
 }
 
 void CodeBlock::beginValidationDidFail()
@@ -3879,98 +3535,15 @@ void CodeBlock::addBreakpoint(unsigned numBreakpoints)
 {
     m_numBreakpoints += numBreakpoints;
     ASSERT(m_numBreakpoints);
-    if (JITCode::isOptimizingJIT(jitType()))
-        jettison(Profiler::JettisonDueToDebuggerBreakpoint);
+    if (jitType() == JITCode::DFGJIT)
+        jettison();
 }
 
 void CodeBlock::setSteppingMode(CodeBlock::SteppingMode mode)
 {
     m_steppingMode = mode;
-    if (mode == SteppingModeEnabled && JITCode::isOptimizingJIT(jitType()))
-        jettison(Profiler::JettisonDueToDebuggerStepping);
-}
-
-RareCaseProfile* CodeBlock::rareCaseProfileForBytecodeOffset(int bytecodeOffset)
-{
-    return tryBinarySearch<RareCaseProfile, int>(
-        m_rareCaseProfiles, m_rareCaseProfiles.size(), bytecodeOffset,
-        getRareCaseProfileBytecodeOffset);
-}
-
-#if ENABLE(JIT)
-DFG::CapabilityLevel CodeBlock::capabilityLevel()
-{
-    DFG::CapabilityLevel result = capabilityLevelInternal();
-    m_capabilityLevelState = result;
-    return result;
-}
-#endif
-
-void CodeBlock::insertBasicBlockBoundariesForControlFlowProfiler(RefCountedArray<Instruction>& instructions)
-{
-    const Vector<size_t>& bytecodeOffsets = unlinkedCodeBlock()->opProfileControlFlowBytecodeOffsets();
-    for (size_t i = 0, offsetsLength = bytecodeOffsets.size(); i < offsetsLength; i++) {
-        // Because op_profile_control_flow is emitted at the beginning of every basic block, finding 
-        // the next op_profile_control_flow will give us the text range of a single basic block.
-        size_t startIdx = bytecodeOffsets[i];
-        RELEASE_ASSERT(vm()->interpreter->getOpcodeID(instructions[startIdx].u.opcode) == op_profile_control_flow);
-        int basicBlockStartOffset = instructions[startIdx + 1].u.operand;
-        int basicBlockEndOffset;
-        if (i + 1 < offsetsLength) {
-            size_t endIdx = bytecodeOffsets[i + 1];
-            RELEASE_ASSERT(vm()->interpreter->getOpcodeID(instructions[endIdx].u.opcode) == op_profile_control_flow);
-            basicBlockEndOffset = instructions[endIdx + 1].u.operand - 1;
-        } else {
-            basicBlockEndOffset = m_sourceOffset + m_ownerExecutable->source().length() - 1; // Offset before the closing brace.
-            basicBlockStartOffset = std::min(basicBlockStartOffset, basicBlockEndOffset); // Some start offsets may be at the closing brace, ensure it is the offset before.
-        }
-
-        // The following check allows for the same textual JavaScript basic block to have its bytecode emitted more
-        // than once and still play nice with the control flow profiler. When basicBlockStartOffset is larger than 
-        // basicBlockEndOffset, it indicates that the bytecode generator has emitted code for the same AST node 
-        // more than once (for example: ForInNode, Finally blocks in TryNode, etc). Though these are different 
-        // basic blocks at the bytecode level, they are generated from the same textual basic block in the JavaScript 
-        // program. The condition: 
-        // (basicBlockEndOffset < basicBlockStartOffset) 
-        // is encountered when op_profile_control_flow lies across the boundary of these duplicated bytecode basic 
-        // blocks and the textual offset goes from the end of the duplicated block back to the beginning. These 
-        // ranges are dummy ranges and are ignored. The duplicated bytecode basic blocks point to the same 
-        // internal data structure, so if any of them execute, it will record the same textual basic block in the 
-        // JavaScript program as executing.
-        // At the bytecode level, this situation looks like:
-        // j: op_profile_control_flow (from j->k, we have basicBlockEndOffset < basicBlockStartOffset)
-        // ...
-        // k: op_profile_control_flow (we want to skip over the j->k block and start fresh at offset k as the start of a new basic block k->m).
-        // ...
-        // m: op_profile_control_flow
-        if (basicBlockEndOffset < basicBlockStartOffset) {
-            RELEASE_ASSERT(i + 1 < offsetsLength); // We should never encounter dummy blocks at the end of a CodeBlock.
-            instructions[startIdx + 1].u.basicBlockLocation = vm()->controlFlowProfiler()->dummyBasicBlock();
-            continue;
-        }
-
-        BasicBlockLocation* basicBlockLocation = vm()->controlFlowProfiler()->getBasicBlockLocation(m_ownerExecutable->sourceID(), basicBlockStartOffset, basicBlockEndOffset);
-
-        // Find all functions that are enclosed within the range: [basicBlockStartOffset, basicBlockEndOffset]
-        // and insert these functions' start/end offsets as gaps in the current BasicBlockLocation.
-        // This is necessary because in the original source text of a JavaScript program, 
-        // function literals form new basic blocks boundaries, but they aren't represented 
-        // inside the CodeBlock's instruction stream.
-        auto insertFunctionGaps = [basicBlockLocation, basicBlockStartOffset, basicBlockEndOffset] (const WriteBarrier<FunctionExecutable>& functionExecutable) {
-            const UnlinkedFunctionExecutable* executable = functionExecutable->unlinkedExecutable();
-            int functionStart = executable->typeProfilingStartOffset();
-            int functionEnd = executable->typeProfilingEndOffset();
-            if (functionStart >= basicBlockStartOffset && functionEnd <= basicBlockEndOffset)
-                basicBlockLocation->insertGap(functionStart, functionEnd);
-        };
-
-        for (const WriteBarrier<FunctionExecutable>& executable : m_functionDecls)
-            insertFunctionGaps(executable);
-        for (const WriteBarrier<FunctionExecutable>& executable : m_functionExprs)
-            insertFunctionGaps(executable);
-
-        instructions[startIdx + 1].u.basicBlockLocation = basicBlockLocation;
-    }
+    if (mode == SteppingModeEnabled && jitType() == JITCode::DFGJIT)
+        jettison();
 }
 
 } // namespace JSC