bytecode/CodeBlock.h

   1 /*
   2  * Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
   3  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1.  Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  * 2.  Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  15  *     its contributors may be used to endorse or promote products derived
  16  *     from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #ifndef CodeBlock_h
  31 #define CodeBlock_h
  32
  33 #include "ArrayProfile.h"
  34 #include "ByValInfo.h"
  35 #include "BytecodeConventions.h"
  36 #include "CallLinkInfo.h"
  37 #include "CallReturnOffsetToBytecodeOffset.h"
  38 #include "CodeBlockHash.h"
  39 #include "CodeOrigin.h"
  40 #include "CodeType.h"
  41 #include "CompactJITCodeMap.h"
  42 #include "DFGCodeBlocks.h"
  43 #include "DFGCommon.h"
  44 #include "DFGExitProfile.h"
  45 #include "DFGMinifiedGraph.h"
  46 #include "DFGOSREntry.h"
  47 #include "DFGOSRExit.h"
  48 #include "DFGVariableEventStream.h"
  49 #include "EvalCodeCache.h"
  50 #include "ExecutionCounter.h"
  51 #include "ExpressionRangeInfo.h"
  52 #include "HandlerInfo.h"
  53 #include "ObjectAllocationProfile.h"
  54 #include "Options.h"
  55 #include "Instruction.h"
  56 #include "JITCode.h"
  57 #include "JITWriteBarrier.h"
  58 #include "JSGlobalObject.h"
  59 #include "JumpReplacementWatchpoint.h"
  60 #include "JumpTable.h"
  61 #include "LLIntCallLinkInfo.h"
  62 #include "LazyOperandValueProfile.h"
  63 #include "LineInfo.h"
  64 #include "ProfilerCompilation.h"
  65 #include "RegExpObject.h"
  66 #include "ResolveOperation.h"
  67 #include "StructureStubInfo.h"
  68 #include "UnconditionalFinalizer.h"
  69 #include "ValueProfile.h"
  70 #include "Watchpoint.h"
  71 #include <wtf/RefCountedArray.h>
  72 #include <wtf/FastAllocBase.h>
  73 #include <wtf/PassOwnPtr.h>
  74 #include <wtf/Platform.h>
  75 #include <wtf/RefPtr.h>
  76 #include <wtf/SegmentedVector.h>
  77 #include <wtf/Vector.h>
  78 #include <wtf/text/WTFString.h>
  79
  80 namespace JSC {
  81
  82 class DFGCodeBlocks;
  83 class ExecState;
  84 class LLIntOffsetsExtractor;
  85 class RepatchBuffer;
  86
  87 inline int unmodifiedArgumentsRegister(int argumentsRegister) { return argumentsRegister - 1; }
  88
  89 static ALWAYS_INLINE int missingThisObjectMarker() { return std::numeric_limits<int>::max(); }
  90
  91 class CodeBlock : public UnconditionalFinalizer, public WeakReferenceHarvester {
  92     WTF_MAKE_FAST_ALLOCATED;
  93     friend class JIT;
  94     friend class LLIntOffsetsExtractor;
  95 public:
  96     enum CopyParsedBlockTag { CopyParsedBlock };
  97 protected:
  98     CodeBlock(CopyParsedBlockTag, CodeBlock& other);
  99
 100     CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSGlobalObject*, unsigned baseScopeDepth, PassRefPtr<SourceProvider>, unsigned sourceOffset, unsigned firstLineColumnOffset, PassOwnPtr<CodeBlock> alternative);
 101
 102     WriteBarrier<JSGlobalObject> m_globalObject;
 103     Heap* m_heap;
 104
 105 public:
 106     JS_EXPORT_PRIVATE virtual ~CodeBlock();
 107
 108     UnlinkedCodeBlock* unlinkedCodeBlock() const { return m_unlinkedCode.get(); }
 109
 110     String inferredName() const;
 111     CodeBlockHash hash() const;
 112     String sourceCodeForTools() const; // Not quite the actual source we parsed; this will do things like prefix the source for a function with a reified signature.
 113     String sourceCodeOnOneLine() const; // As sourceCodeForTools(), but replaces all whitespace runs with a single space.
 114     void dumpAssumingJITType(PrintStream&, JITCode::JITType) const;
 115     void dump(PrintStream&) const;
 116
 117     int numParameters() const { return m_numParameters; }
 118     void setNumParameters(int newValue);
 119
 120     int* addressOfNumParameters() { return &m_numParameters; }
 121     static ptrdiff_t offsetOfNumParameters() { return OBJECT_OFFSETOF(CodeBlock, m_numParameters); }
 122
 123     CodeBlock* alternative() { return m_alternative.get(); }
 124     PassOwnPtr<CodeBlock> releaseAlternative() { return m_alternative.release(); }
 125     void setAlternative(PassOwnPtr<CodeBlock> alternative) { m_alternative = alternative; }
 126
 127     CodeSpecializationKind specializationKind() const
 128     {
 129         return specializationFromIsConstruct(m_isConstructor);
 130     }
 131
 132 #if ENABLE(JIT)
 133     CodeBlock* baselineVersion()
 134     {
 135         CodeBlock* result = replacement();
 136         if (!result)
 137             return 0; // This can happen if we're in the process of creating the baseline version.
 138         while (result->alternative())
 139             result = result->alternative();
 140         ASSERT(result);
 141         ASSERT(JITCode::isBaselineCode(result->getJITType()));
 142         return result;
 143     }
 144 #else
 145     CodeBlock* baselineVersion()
 146     {
 147         return this;
 148     }
 149 #endif
 150
 151     void visitAggregate(SlotVisitor&);
 152
 153     static void dumpStatistics();
 154
 155     void dumpBytecode(PrintStream& = WTF::dataFile());
 156     void dumpBytecode(PrintStream&, unsigned bytecodeOffset);
 157     void printStructures(PrintStream&, const Instruction*);
 158     void printStructure(PrintStream&, const char* name, const Instruction*, int operand);
 159
 160     bool isStrictMode() const { return m_isStrictMode; }
 161
 162     inline bool isKnownNotImmediate(int index)
 163     {
 164         if (index == m_thisRegister && !m_isStrictMode)
 165             return true;
 166
 167         if (isConstantRegisterIndex(index))
 168             return getConstant(index).isCell();
 169
 170         return false;
 171     }
 172
 173     ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
 174     {
 175         return index >= m_numVars;
 176     }
 177
 178     HandlerInfo* handlerForBytecodeOffset(unsigned bytecodeOffset);
 179     unsigned lineNumberForBytecodeOffset(unsigned bytecodeOffset);
 180     unsigned columnNumberForBytecodeOffset(unsigned bytecodeOffset);
 181     void expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot,
 182         int& startOffset, int& endOffset, unsigned& line, unsigned& column);
 183
 184 #if ENABLE(JIT)
 185
 186     StructureStubInfo& getStubInfo(ReturnAddressPtr returnAddress)
 187     {
 188         return *(binarySearch<StructureStubInfo, void*>(m_structureStubInfos, m_structureStubInfos.size(), returnAddress.value(), getStructureStubInfoReturnLocation));
 189     }
 190
 191     StructureStubInfo& getStubInfo(unsigned bytecodeIndex)
 192     {
 193         return *(binarySearch<StructureStubInfo, unsigned>(m_structureStubInfos, m_structureStubInfos.size(), bytecodeIndex, getStructureStubInfoBytecodeIndex));
 194     }
 195
 196     void resetStub(StructureStubInfo&);
 197
 198     ByValInfo& getByValInfo(unsigned bytecodeIndex)
 199     {
 200         return *(binarySearch<ByValInfo, unsigned>(m_byValInfos, m_byValInfos.size(), bytecodeIndex, getByValInfoBytecodeIndex));
 201     }
 202
 203     CallLinkInfo& getCallLinkInfo(ReturnAddressPtr returnAddress)
 204     {
 205         return *(binarySearch<CallLinkInfo, void*>(m_callLinkInfos, m_callLinkInfos.size(), returnAddress.value(), getCallLinkInfoReturnLocation));
 206     }
 207
 208     CallLinkInfo& getCallLinkInfo(unsigned bytecodeIndex)
 209     {
 210         ASSERT(JITCode::isBaselineCode(getJITType()));
 211         return *(binarySearch<CallLinkInfo, unsigned>(m_callLinkInfos, m_callLinkInfos.size(), bytecodeIndex, getCallLinkInfoBytecodeIndex));
 212     }
 213 #endif // ENABLE(JIT)
 214
 215 #if ENABLE(LLINT)
 216     Instruction* adjustPCIfAtCallSite(Instruction*);
 217 #endif
 218     unsigned bytecodeOffset(ExecState*, ReturnAddressPtr);
 219
 220 #if ENABLE(JIT)
 221     unsigned bytecodeOffsetForCallAtIndex(unsigned index)
 222     {
 223         if (!m_rareData)
 224             return 1;
 225         Vector<CallReturnOffsetToBytecodeOffset, 0, UnsafeVectorOverflow>& callIndices = m_rareData->m_callReturnIndexVector;
 226         if (!callIndices.size())
 227             return 1;
 228         // FIXME: Fix places in DFG that call out to C that don't set the CodeOrigin. https://bugs.webkit.org/show_bug.cgi?id=118315
 229         ASSERT(index < m_rareData->m_callReturnIndexVector.size());
 230         if (index >= m_rareData->m_callReturnIndexVector.size())
 231             return 1;
 232         return m_rareData->m_callReturnIndexVector[index].bytecodeOffset;
 233     }
 234
 235     void unlinkCalls();
 236
 237     bool hasIncomingCalls() { return m_incomingCalls.begin() != m_incomingCalls.end(); }
 238
 239     void linkIncomingCall(CallLinkInfo* incoming)
 240     {
 241         m_incomingCalls.push(incoming);
 242     }
 243
 244     bool isIncomingCallAlreadyLinked(CallLinkInfo* incoming)
 245     {
 246         return m_incomingCalls.isOnList(incoming);
 247     }
 248 #endif // ENABLE(JIT)
 249
 250 #if ENABLE(LLINT)
 251     void linkIncomingCall(LLIntCallLinkInfo* incoming)
 252     {
 253         m_incomingLLIntCalls.push(incoming);
 254     }
 255 #endif // ENABLE(LLINT)
 256
 257     void unlinkIncomingCalls();
 258
 259 #if ENABLE(DFG_JIT) || ENABLE(LLINT)
 260     void setJITCodeMap(PassOwnPtr<CompactJITCodeMap> jitCodeMap)
 261     {
 262         m_jitCodeMap = jitCodeMap;
 263     }
 264     CompactJITCodeMap* jitCodeMap()
 265     {
 266         return m_jitCodeMap.get();
 267     }
 268 #endif
 269
 270 #if ENABLE(DFG_JIT)
 271     void createDFGDataIfNecessary()
 272     {
 273         if (!!m_dfgData)
 274             return;
 275
 276         m_dfgData = adoptPtr(new DFGData);
 277     }
 278
 279     void saveCompilation(PassRefPtr<Profiler::Compilation> compilation)
 280     {
 281         createDFGDataIfNecessary();
 282         m_dfgData->compilation = compilation;
 283     }
 284
 285     Profiler::Compilation* compilation()
 286     {
 287         if (!m_dfgData)
 288             return 0;
 289         return m_dfgData->compilation.get();
 290     }
 291
 292     DFG::OSREntryData* appendDFGOSREntryData(unsigned bytecodeIndex, unsigned machineCodeOffset)
 293     {
 294         createDFGDataIfNecessary();
 295         DFG::OSREntryData entry;
 296         entry.m_bytecodeIndex = bytecodeIndex;
 297         entry.m_machineCodeOffset = machineCodeOffset;
 298         m_dfgData->osrEntry.append(entry);
 299         return &m_dfgData->osrEntry.last();
 300     }
 301     unsigned numberOfDFGOSREntries() const
 302     {
 303         if (!m_dfgData)
 304             return 0;
 305         return m_dfgData->osrEntry.size();
 306     }
 307     DFG::OSREntryData* dfgOSREntryData(unsigned i) { return &m_dfgData->osrEntry[i]; }
 308     DFG::OSREntryData* dfgOSREntryDataForBytecodeIndex(unsigned bytecodeIndex)
 309     {
 310         if (!m_dfgData)
 311             return 0;
 312         return tryBinarySearch<DFG::OSREntryData, unsigned>(
 313             m_dfgData->osrEntry, m_dfgData->osrEntry.size(), bytecodeIndex,
 314             DFG::getOSREntryDataBytecodeIndex);
 315     }
 316
 317     unsigned appendOSRExit(const DFG::OSRExit& osrExit)
 318     {
 319         createDFGDataIfNecessary();
 320         unsigned result = m_dfgData->osrExit.size();
 321         m_dfgData->osrExit.append(osrExit);
 322         return result;
 323     }
 324
 325     DFG::OSRExit& lastOSRExit()
 326     {
 327         return m_dfgData->osrExit.last();
 328     }
 329
 330     unsigned appendSpeculationRecovery(const DFG::SpeculationRecovery& recovery)
 331     {
 332         createDFGDataIfNecessary();
 333         unsigned result = m_dfgData->speculationRecovery.size();
 334         m_dfgData->speculationRecovery.append(recovery);
 335         return result;
 336     }
 337
 338     unsigned appendWatchpoint(const JumpReplacementWatchpoint& watchpoint)
 339     {
 340         createDFGDataIfNecessary();
 341         unsigned result = m_dfgData->watchpoints.size();
 342         m_dfgData->watchpoints.append(watchpoint);
 343         return result;
 344     }
 345
 346     unsigned numberOfOSRExits()
 347     {
 348         if (!m_dfgData)
 349             return 0;
 350         return m_dfgData->osrExit.size();
 351     }
 352
 353     unsigned numberOfSpeculationRecoveries()
 354     {
 355         if (!m_dfgData)
 356             return 0;
 357         return m_dfgData->speculationRecovery.size();
 358     }
 359
 360     unsigned numberOfWatchpoints()
 361     {
 362         if (!m_dfgData)
 363             return 0;
 364         return m_dfgData->watchpoints.size();
 365     }
 366
 367     DFG::OSRExit& osrExit(unsigned index)
 368     {
 369         return m_dfgData->osrExit[index];
 370     }
 371
 372     DFG::SpeculationRecovery& speculationRecovery(unsigned index)
 373     {
 374         return m_dfgData->speculationRecovery[index];
 375     }
 376
 377     JumpReplacementWatchpoint& watchpoint(unsigned index)
 378     {
 379         return m_dfgData->watchpoints[index];
 380     }
 381
 382     void appendWeakReference(JSCell* target)
 383     {
 384         createDFGDataIfNecessary();
 385         m_dfgData->weakReferences.append(WriteBarrier<JSCell>(*vm(), ownerExecutable(), target));
 386     }
 387
 388     void appendWeakReferenceTransition(JSCell* codeOrigin, JSCell* from, JSCell* to)
 389     {
 390         createDFGDataIfNecessary();
 391         m_dfgData->transitions.append(
 392             WeakReferenceTransition(*vm(), ownerExecutable(), codeOrigin, from, to));
 393     }
 394
 395     DFG::MinifiedGraph& minifiedDFG()
 396     {
 397         createDFGDataIfNecessary();
 398         return m_dfgData->minifiedDFG;
 399     }
 400
 401     DFG::VariableEventStream& variableEventStream()
 402     {
 403         createDFGDataIfNecessary();
 404         return m_dfgData->variableEventStream;
 405     }
 406 #endif
 407
 408     unsigned bytecodeOffset(Instruction* returnAddress)
 409     {
 410         RELEASE_ASSERT(returnAddress >= instructions().begin() && returnAddress < instructions().end());
 411         return static_cast<Instruction*>(returnAddress) - instructions().begin();
 412     }
 413
 414     bool isNumericCompareFunction() { return m_unlinkedCode->isNumericCompareFunction(); }
 415
 416     unsigned numberOfInstructions() const { return m_instructions.size(); }
 417     RefCountedArray<Instruction>& instructions() { return m_instructions; }
 418     const RefCountedArray<Instruction>& instructions() const { return m_instructions; }
 419
 420     size_t predictedMachineCodeSize();
 421
 422     bool usesOpcode(OpcodeID);
 423
 424     unsigned instructionCount() { return m_instructions.size(); }
 425
 426     int argumentIndexAfterCapture(size_t argument);
 427
 428 #if ENABLE(JIT)
 429     void setJITCode(const JITCode& code, MacroAssemblerCodePtr codeWithArityCheck)
 430     {
 431         m_jitCode = code;
 432         m_jitCodeWithArityCheck = codeWithArityCheck;
 433 #if ENABLE(DFG_JIT)
 434         if (m_jitCode.jitType() == JITCode::DFGJIT) {
 435             createDFGDataIfNecessary();
 436             m_vm->heap.m_dfgCodeBlocks.m_set.add(this);
 437         }
 438 #endif
 439     }
 440     JITCode& getJITCode() { return m_jitCode; }
 441     MacroAssemblerCodePtr getJITCodeWithArityCheck() { return m_jitCodeWithArityCheck; }
 442     JITCode::JITType getJITType() const { return m_jitCode.jitType(); }
 443     ExecutableMemoryHandle* executableMemory() { return getJITCode().getExecutableMemory(); }
 444     virtual JSObject* compileOptimized(ExecState*, JSScope*, unsigned bytecodeIndex) = 0;
 445     void jettison();
 446     enum JITCompilationResult { AlreadyCompiled, CouldNotCompile, CompiledSuccessfully };
 447     JITCompilationResult jitCompile(ExecState* exec)
 448     {
 449         if (getJITType() != JITCode::InterpreterThunk) {
 450             ASSERT(getJITType() == JITCode::BaselineJIT);
 451             return AlreadyCompiled;
 452         }
 453 #if ENABLE(JIT)
 454         if (jitCompileImpl(exec))
 455             return CompiledSuccessfully;
 456         return CouldNotCompile;
 457 #else
 458         UNUSED_PARAM(exec);
 459         return CouldNotCompile;
 460 #endif
 461     }
 462     virtual CodeBlock* replacement() = 0;
 463
 464     virtual DFG::CapabilityLevel canCompileWithDFGInternal() = 0;
 465     DFG::CapabilityLevel canCompileWithDFG()
 466     {
 467         DFG::CapabilityLevel result = canCompileWithDFGInternal();
 468         m_canCompileWithDFGState = result;
 469         return result;
 470     }
 471     DFG::CapabilityLevel canCompileWithDFGState() { return m_canCompileWithDFGState; }
 472
 473     bool hasOptimizedReplacement()
 474     {
 475         ASSERT(JITCode::isBaselineCode(getJITType()));
 476         bool result = replacement()->getJITType() > getJITType();
 477 #if !ASSERT_DISABLED
 478         if (result)
 479             ASSERT(replacement()->getJITType() == JITCode::DFGJIT);
 480         else {
 481             ASSERT(JITCode::isBaselineCode(replacement()->getJITType()));
 482             ASSERT(replacement() == this);
 483         }
 484 #endif
 485         return result;
 486     }
 487 #else
 488     JITCode::JITType getJITType() const { return JITCode::BaselineJIT; }
 489 #endif
 490
 491     ScriptExecutable* ownerExecutable() const { return m_ownerExecutable.get(); }
 492
 493     void setVM(VM* vm) { m_vm = vm; }
 494     VM* vm() { return m_vm; }
 495
 496     void setThisRegister(int thisRegister) { m_thisRegister = thisRegister; }
 497     int thisRegister() const { return m_thisRegister; }
 498
 499     bool needsFullScopeChain() const { return m_unlinkedCode->needsFullScopeChain(); }
 500     bool usesEval() const { return m_unlinkedCode->usesEval(); }
 501
 502     void setArgumentsRegister(int argumentsRegister)
 503     {
 504         ASSERT(argumentsRegister != -1);
 505         m_argumentsRegister = argumentsRegister;
 506         ASSERT(usesArguments());
 507     }
 508     int argumentsRegister() const
 509     {
 510         ASSERT(usesArguments());
 511         return m_argumentsRegister;
 512     }
 513     int uncheckedArgumentsRegister()
 514     {
 515         if (!usesArguments())
 516             return InvalidVirtualRegister;
 517         return argumentsRegister();
 518     }
 519     void setActivationRegister(int activationRegister)
 520     {
 521         m_activationRegister = activationRegister;
 522     }
 523     int activationRegister() const
 524     {
 525         ASSERT(needsFullScopeChain());
 526         return m_activationRegister;
 527     }
 528     int uncheckedActivationRegister()
 529     {
 530         if (!needsFullScopeChain())
 531             return InvalidVirtualRegister;
 532         return activationRegister();
 533     }
 534     bool usesArguments() const { return m_argumentsRegister != -1; }
 535
 536     bool needsActivation() const
 537     {
 538         return needsFullScopeChain() && codeType() != GlobalCode;
 539     }
 540
 541     bool isCaptured(int operand, InlineCallFrame* inlineCallFrame = 0) const
 542     {
 543         if (operandIsArgument(operand))
 544             return operandToArgument(operand) && usesArguments();
 545
 546         if (inlineCallFrame)
 547             return inlineCallFrame->capturedVars.get(operand);
 548
 549         // The activation object isn't in the captured region, but it's "captured"
 550         // in the sense that stores to its location can be observed indirectly.
 551         if (needsActivation() && operand == activationRegister())
 552             return true;
 553
 554         // Ditto for the arguments object.
 555         if (usesArguments() && operand == argumentsRegister())
 556             return true;
 557
 558         // Ditto for the arguments object.
 559         if (usesArguments() && operand == unmodifiedArgumentsRegister(argumentsRegister()))
 560             return true;
 561
 562         // We're in global code so there are no locals to capture
 563         if (!symbolTable())
 564             return false;
 565
 566         return operand >= symbolTable()->captureStart()
 567             && operand < symbolTable()->captureEnd();
 568     }
 569
 570     CodeType codeType() const { return m_unlinkedCode->codeType(); }
 571
 572     SourceProvider* source() const { return m_source.get(); }
 573     unsigned sourceOffset() const { return m_sourceOffset; }
 574     unsigned firstLineColumnOffset() const { return m_firstLineColumnOffset; }
 575
 576     size_t numberOfJumpTargets() const { return m_unlinkedCode->numberOfJumpTargets(); }
 577     unsigned jumpTarget(int index) const { return m_unlinkedCode->jumpTarget(index); }
 578
 579     void createActivation(CallFrame*);
 580
 581     void clearEvalCache();
 582
 583     String nameForRegister(int registerNumber);
 584
 585 #if ENABLE(JIT)
 586     void setNumberOfStructureStubInfos(size_t size) { m_structureStubInfos.grow(size); }
 587     size_t numberOfStructureStubInfos() const { return m_structureStubInfos.size(); }
 588     StructureStubInfo& structureStubInfo(int index) { return m_structureStubInfos[index]; }
 589
 590     void setNumberOfByValInfos(size_t size) { m_byValInfos.grow(size); }
 591     size_t numberOfByValInfos() const { return m_byValInfos.size(); }
 592     ByValInfo& byValInfo(size_t index) { return m_byValInfos[index]; }
 593
 594     void setNumberOfCallLinkInfos(size_t size) { m_callLinkInfos.grow(size); }
 595     size_t numberOfCallLinkInfos() const { return m_callLinkInfos.size(); }
 596     CallLinkInfo& callLinkInfo(int index) { return m_callLinkInfos[index]; }
 597 #endif
 598
 599 #if ENABLE(VALUE_PROFILER)
 600     unsigned numberOfArgumentValueProfiles()
 601     {
 602         ASSERT(m_numParameters >= 0);
 603         ASSERT(m_argumentValueProfiles.size() == static_cast<unsigned>(m_numParameters));
 604         return m_argumentValueProfiles.size();
 605     }
 606     ValueProfile* valueProfileForArgument(unsigned argumentIndex)
 607     {
 608         ValueProfile* result = &m_argumentValueProfiles[argumentIndex];
 609         ASSERT(result->m_bytecodeOffset == -1);
 610         return result;
 611     }
 612
 613     unsigned numberOfValueProfiles() { return m_valueProfiles.size(); }
 614     ValueProfile* valueProfile(int index) { return &m_valueProfiles[index]; }
 615     ValueProfile* valueProfileForBytecodeOffset(int bytecodeOffset)
 616     {
 617         ValueProfile* result = binarySearch<ValueProfile, int>(
 618             m_valueProfiles, m_valueProfiles.size(), bytecodeOffset,
 619             getValueProfileBytecodeOffset<ValueProfile>);
 620         ASSERT(result->m_bytecodeOffset != -1);
 621         ASSERT(instructions()[bytecodeOffset + opcodeLength(
 622             m_vm->interpreter->getOpcodeID(
 623                 instructions()[
 624                     bytecodeOffset].u.opcode)) - 1].u.profile == result);
 625         return result;
 626     }
 627     SpeculatedType valueProfilePredictionForBytecodeOffset(int bytecodeOffset)
 628     {
 629         return valueProfileForBytecodeOffset(bytecodeOffset)->computeUpdatedPrediction();
 630     }
 631
 632     unsigned totalNumberOfValueProfiles()
 633     {
 634         return numberOfArgumentValueProfiles() + numberOfValueProfiles();
 635     }
 636     ValueProfile* getFromAllValueProfiles(unsigned index)
 637     {
 638         if (index < numberOfArgumentValueProfiles())
 639             return valueProfileForArgument(index);
 640         return valueProfile(index - numberOfArgumentValueProfiles());
 641     }
 642
 643     RareCaseProfile* addRareCaseProfile(int bytecodeOffset)
 644     {
 645         m_rareCaseProfiles.append(RareCaseProfile(bytecodeOffset));
 646         return &m_rareCaseProfiles.last();
 647     }
 648     unsigned numberOfRareCaseProfiles() { return m_rareCaseProfiles.size(); }
 649     RareCaseProfile* rareCaseProfile(int index) { return &m_rareCaseProfiles[index]; }
 650     RareCaseProfile* rareCaseProfileForBytecodeOffset(int bytecodeOffset)
 651     {
 652         return tryBinarySearch<RareCaseProfile, int>(
 653             m_rareCaseProfiles, m_rareCaseProfiles.size(), bytecodeOffset,
 654             getRareCaseProfileBytecodeOffset);
 655     }
 656
 657     bool likelyToTakeSlowCase(int bytecodeOffset)
 658     {
 659         if (!numberOfRareCaseProfiles())
 660             return false;
 661         unsigned value = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 662         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 663     }
 664
 665     bool couldTakeSlowCase(int bytecodeOffset)
 666     {
 667         if (!numberOfRareCaseProfiles())
 668             return false;
 669         unsigned value = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 670         return value >= Options::couldTakeSlowCaseMinimumCount();
 671     }
 672
 673     RareCaseProfile* addSpecialFastCaseProfile(int bytecodeOffset)
 674     {
 675         m_specialFastCaseProfiles.append(RareCaseProfile(bytecodeOffset));
 676         return &m_specialFastCaseProfiles.last();
 677     }
 678     unsigned numberOfSpecialFastCaseProfiles() { return m_specialFastCaseProfiles.size(); }
 679     RareCaseProfile* specialFastCaseProfile(int index) { return &m_specialFastCaseProfiles[index]; }
 680     RareCaseProfile* specialFastCaseProfileForBytecodeOffset(int bytecodeOffset)
 681     {
 682         return tryBinarySearch<RareCaseProfile, int>(
 683             m_specialFastCaseProfiles, m_specialFastCaseProfiles.size(), bytecodeOffset,
 684             getRareCaseProfileBytecodeOffset);
 685     }
 686
 687     bool likelyToTakeSpecialFastCase(int bytecodeOffset)
 688     {
 689         if (!numberOfRareCaseProfiles())
 690             return false;
 691         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 692         return specialFastCaseCount >= Options::likelyToTakeSlowCaseMinimumCount();
 693     }
 694
 695     bool couldTakeSpecialFastCase(int bytecodeOffset)
 696     {
 697         if (!numberOfRareCaseProfiles())
 698             return false;
 699         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 700         return specialFastCaseCount >= Options::couldTakeSlowCaseMinimumCount();
 701     }
 702
 703     bool likelyToTakeDeepestSlowCase(int bytecodeOffset)
 704     {
 705         if (!numberOfRareCaseProfiles())
 706             return false;
 707         unsigned slowCaseCount = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 708         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 709         unsigned value = slowCaseCount - specialFastCaseCount;
 710         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 711     }
 712
 713     bool likelyToTakeAnySlowCase(int bytecodeOffset)
 714     {
 715         if (!numberOfRareCaseProfiles())
 716             return false;
 717         unsigned slowCaseCount = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 718         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 719         unsigned value = slowCaseCount + specialFastCaseCount;
 720         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 721     }
 722
 723     unsigned numberOfArrayProfiles() const { return m_arrayProfiles.size(); }
 724     const ArrayProfileVector& arrayProfiles() { return m_arrayProfiles; }
 725     ArrayProfile* addArrayProfile(unsigned bytecodeOffset)
 726     {
 727         m_arrayProfiles.append(ArrayProfile(bytecodeOffset));
 728         return &m_arrayProfiles.last();
 729     }
 730     ArrayProfile* getArrayProfile(unsigned bytecodeOffset);
 731     ArrayProfile* getOrAddArrayProfile(unsigned bytecodeOffset);
 732 #endif
 733
 734     // Exception handling support
 735
 736     size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
 737     void allocateHandlers(const Vector<UnlinkedHandlerInfo>& unlinkedHandlers)
 738     {
 739         size_t count = unlinkedHandlers.size();
 740         if (!count)
 741             return;
 742         createRareDataIfNecessary();
 743         m_rareData->m_exceptionHandlers.resize(count);
 744         for (size_t i = 0; i < count; ++i) {
 745             m_rareData->m_exceptionHandlers[i].start = unlinkedHandlers[i].start;
 746             m_rareData->m_exceptionHandlers[i].end = unlinkedHandlers[i].end;
 747             m_rareData->m_exceptionHandlers[i].target = unlinkedHandlers[i].target;
 748             m_rareData->m_exceptionHandlers[i].scopeDepth = unlinkedHandlers[i].scopeDepth;
 749         }
 750
 751     }
 752     HandlerInfo& exceptionHandler(int index) { RELEASE_ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
 753
 754     bool hasExpressionInfo() { return m_unlinkedCode->hasExpressionInfo(); }
 755
 756 #if ENABLE(JIT)
 757     Vector<CallReturnOffsetToBytecodeOffset, 0, UnsafeVectorOverflow>& callReturnIndexVector()
 758     {
 759         createRareDataIfNecessary();
 760         return m_rareData->m_callReturnIndexVector;
 761     }
 762 #endif
 763
 764 #if ENABLE(DFG_JIT)
 765     SegmentedVector<InlineCallFrame, 4>& inlineCallFrames()
 766     {
 767         createRareDataIfNecessary();
 768         return m_rareData->m_inlineCallFrames;
 769     }
 770
 771     Vector<CodeOriginAtCallReturnOffset, 0, UnsafeVectorOverflow>& codeOrigins()
 772     {
 773         createRareDataIfNecessary();
 774         return m_rareData->m_codeOrigins;
 775     }
 776
 777     // Having code origins implies that there has been some inlining.
 778     bool hasCodeOrigins()
 779     {
 780         return m_rareData && !!m_rareData->m_codeOrigins.size();
 781     }
 782
 783     bool codeOriginForReturn(ReturnAddressPtr, CodeOrigin&);
 784
 785     bool canGetCodeOrigin(unsigned index)
 786     {
 787         if (!m_rareData)
 788             return false;
 789         return m_rareData->m_codeOrigins.size() > index;
 790     }
 791
 792     CodeOrigin codeOrigin(unsigned index)
 793     {
 794         RELEASE_ASSERT(m_rareData);
 795         return m_rareData->m_codeOrigins[index].codeOrigin;
 796     }
 797
 798     bool addFrequentExitSite(const DFG::FrequentExitSite& site)
 799     {
 800         ASSERT(JITCode::isBaselineCode(getJITType()));
 801         return m_exitProfile.add(site);
 802     }
 803
 804     bool hasExitSite(const DFG::FrequentExitSite& site) const { return m_exitProfile.hasExitSite(site); }
 805
 806     DFG::ExitProfile& exitProfile() { return m_exitProfile; }
 807
 808     CompressedLazyOperandValueProfileHolder& lazyOperandValueProfiles()
 809     {
 810         return m_lazyOperandValueProfiles;
 811     }
 812 #endif
 813
 814     // Constant Pool
 815
 816     size_t numberOfIdentifiers() const { return m_identifiers.size(); }
 817     void addIdentifier(const Identifier& i) { return m_identifiers.append(i); }
 818     Identifier& identifier(int index) { return m_identifiers[index]; }
 819
 820     size_t numberOfConstantRegisters() const { return m_constantRegisters.size(); }
 821     unsigned addConstant(JSValue v)
 822     {
 823         unsigned result = m_constantRegisters.size();
 824         m_constantRegisters.append(WriteBarrier<Unknown>());
 825         m_constantRegisters.last().set(m_globalObject->vm(), m_ownerExecutable.get(), v);
 826         return result;
 827     }
 828
 829
 830     unsigned addOrFindConstant(JSValue);
 831     WriteBarrier<Unknown>& constantRegister(int index) { return m_constantRegisters[index - FirstConstantRegisterIndex]; }
 832     ALWAYS_INLINE bool isConstantRegisterIndex(int index) const { return index >= FirstConstantRegisterIndex; }
 833     ALWAYS_INLINE JSValue getConstant(int index) const { return m_constantRegisters[index - FirstConstantRegisterIndex].get(); }
 834
 835     FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
 836     int numberOfFunctionDecls() { return m_functionDecls.size(); }
 837     FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
 838
 839     RegExp* regexp(int index) const { return m_unlinkedCode->regexp(index); }
 840
 841     unsigned numberOfConstantBuffers() const
 842     {
 843         if (!m_rareData)
 844             return 0;
 845         return m_rareData->m_constantBuffers.size();
 846     }
 847     unsigned addConstantBuffer(const Vector<JSValue>& buffer)
 848     {
 849         createRareDataIfNecessary();
 850         unsigned size = m_rareData->m_constantBuffers.size();
 851         m_rareData->m_constantBuffers.append(buffer);
 852         return size;
 853     }
 854
 855     Vector<JSValue>& constantBufferAsVector(unsigned index)
 856     {
 857         ASSERT(m_rareData);
 858         return m_rareData->m_constantBuffers[index];
 859     }
 860     JSValue* constantBuffer(unsigned index)
 861     {
 862         return constantBufferAsVector(index).data();
 863     }
 864
 865     JSGlobalObject* globalObject() { return m_globalObject.get(); }
 866
 867     JSGlobalObject* globalObjectFor(CodeOrigin);
 868
 869     // Jump Tables
 870
 871     size_t numberOfImmediateSwitchJumpTables() const { return m_rareData ? m_rareData->m_immediateSwitchJumpTables.size() : 0; }
 872     SimpleJumpTable& addImmediateSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_immediateSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_immediateSwitchJumpTables.last(); }
 873     SimpleJumpTable& immediateSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_immediateSwitchJumpTables[tableIndex]; }
 874
 875     size_t numberOfCharacterSwitchJumpTables() const { return m_rareData ? m_rareData->m_characterSwitchJumpTables.size() : 0; }
 876     SimpleJumpTable& addCharacterSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_characterSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_characterSwitchJumpTables.last(); }
 877     SimpleJumpTable& characterSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_characterSwitchJumpTables[tableIndex]; }
 878
 879     size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
 880     StringJumpTable& addStringSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_stringSwitchJumpTables.append(StringJumpTable()); return m_rareData->m_stringSwitchJumpTables.last(); }
 881     StringJumpTable& stringSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
 882
 883
 884     SharedSymbolTable* symbolTable() const { return m_unlinkedCode->symbolTable(); }
 885
 886     EvalCodeCache& evalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_evalCodeCache; }
 887
 888     enum ShrinkMode {
 889         // Shrink prior to generating machine code that may point directly into vectors.
 890         EarlyShrink,
 891
 892         // Shrink after generating machine code, and after possibly creating new vectors
 893         // and appending to others. At this time it is not safe to shrink certain vectors
 894         // because we would have generated machine code that references them directly.
 895         LateShrink
 896     };
 897     void shrinkToFit(ShrinkMode);
 898
 899     void copyPostParseDataFrom(CodeBlock* alternative);
 900     void copyPostParseDataFromAlternative();
 901
 902     // Functions for controlling when JITting kicks in, in a mixed mode
 903     // execution world.
 904
 905     bool checkIfJITThresholdReached()
 906     {
 907         return m_llintExecuteCounter.checkIfThresholdCrossedAndSet(this);
 908     }
 909
 910     void dontJITAnytimeSoon()
 911     {
 912         m_llintExecuteCounter.deferIndefinitely();
 913     }
 914
 915     void jitAfterWarmUp()
 916     {
 917         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITAfterWarmUp(), this);
 918     }
 919
 920     void jitSoon()
 921     {
 922         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITSoon(), this);
 923     }
 924
 925     const ExecutionCounter& llintExecuteCounter() const
 926     {
 927         return m_llintExecuteCounter;
 928     }
 929
 930     // Functions for controlling when tiered compilation kicks in. This
 931     // controls both when the optimizing compiler is invoked and when OSR
 932     // entry happens. Two triggers exist: the loop trigger and the return
 933     // trigger. In either case, when an addition to m_jitExecuteCounter
 934     // causes it to become non-negative, the optimizing compiler is
 935     // invoked. This includes a fast check to see if this CodeBlock has
 936     // already been optimized (i.e. replacement() returns a CodeBlock
 937     // that was optimized with a higher tier JIT than this one). In the
 938     // case of the loop trigger, if the optimized compilation succeeds
 939     // (or has already succeeded in the past) then OSR is attempted to
 940     // redirect program flow into the optimized code.
 941
 942     // These functions are called from within the optimization triggers,
 943     // and are used as a single point at which we define the heuristics
 944     // for how much warm-up is mandated before the next optimization
 945     // trigger files. All CodeBlocks start out with optimizeAfterWarmUp(),
 946     // as this is called from the CodeBlock constructor.
 947
 948     // When we observe a lot of speculation failures, we trigger a
 949     // reoptimization. But each time, we increase the optimization trigger
 950     // to avoid thrashing.
 951     unsigned reoptimizationRetryCounter() const;
 952     void countReoptimization();
 953
 954     int32_t codeTypeThresholdMultiplier() const;
 955
 956     int32_t counterValueForOptimizeAfterWarmUp();
 957     int32_t counterValueForOptimizeAfterLongWarmUp();
 958     int32_t counterValueForOptimizeSoon();
 959
 960     int32_t* addressOfJITExecuteCounter()
 961     {
 962         return &m_jitExecuteCounter.m_counter;
 963     }
 964
 965     static ptrdiff_t offsetOfJITExecuteCounter() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(ExecutionCounter, m_counter); }
 966     static ptrdiff_t offsetOfJITExecutionActiveThreshold() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(ExecutionCounter, m_activeThreshold); }
 967     static ptrdiff_t offsetOfJITExecutionTotalCount() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(ExecutionCounter, m_totalCount); }
 968
 969     const ExecutionCounter& jitExecuteCounter() const { return m_jitExecuteCounter; }
 970
 971     unsigned optimizationDelayCounter() const { return m_optimizationDelayCounter; }
 972
 973     // Check if the optimization threshold has been reached, and if not,
 974     // adjust the heuristics accordingly. Returns true if the threshold has
 975     // been reached.
 976     bool checkIfOptimizationThresholdReached();
 977
 978     // Call this to force the next optimization trigger to fire. This is
 979     // rarely wise, since optimization triggers are typically more
 980     // expensive than executing baseline code.
 981     void optimizeNextInvocation();
 982
 983     // Call this to prevent optimization from happening again. Note that
 984     // optimization will still happen after roughly 2^29 invocations,
 985     // so this is really meant to delay that as much as possible. This
 986     // is called if optimization failed, and we expect it to fail in
 987     // the future as well.
 988     void dontOptimizeAnytimeSoon();
 989
 990     // Call this to reinitialize the counter to its starting state,
 991     // forcing a warm-up to happen before the next optimization trigger
 992     // fires. This is called in the CodeBlock constructor. It also
 993     // makes sense to call this if an OSR exit occurred. Note that
 994     // OSR exit code is code generated, so the value of the execute
 995     // counter that this corresponds to is also available directly.
 996     void optimizeAfterWarmUp();
 997
 998     // Call this to force an optimization trigger to fire only after
 999     // a lot of warm-up.
1000     void optimizeAfterLongWarmUp();
1001
1002     // Call this to cause an optimization trigger to fire soon, but
1003     // not necessarily the next one. This makes sense if optimization
1004     // succeeds. Successfuly optimization means that all calls are
1005     // relinked to the optimized code, so this only affects call
1006     // frames that are still executing this CodeBlock. The value here
1007     // is tuned to strike a balance between the cost of OSR entry
1008     // (which is too high to warrant making every loop back edge to
1009     // trigger OSR immediately) and the cost of executing baseline
1010     // code (which is high enough that we don't necessarily want to
1011     // have a full warm-up). The intuition for calling this instead of
1012     // optimizeNextInvocation() is for the case of recursive functions
1013     // with loops. Consider that there may be N call frames of some
1014     // recursive function, for a reasonably large value of N. The top
1015     // one triggers optimization, and then returns, and then all of
1016     // the others return. We don't want optimization to be triggered on
1017     // each return, as that would be superfluous. It only makes sense
1018     // to trigger optimization if one of those functions becomes hot
1019     // in the baseline code.
1020     void optimizeSoon();
1021
1022     uint32_t osrExitCounter() const { return m_osrExitCounter; }
1023
1024     void countOSRExit() { m_osrExitCounter++; }
1025
1026     uint32_t* addressOfOSRExitCounter() { return &m_osrExitCounter; }
1027
1028     static ptrdiff_t offsetOfOSRExitCounter() { return OBJECT_OFFSETOF(CodeBlock, m_osrExitCounter); }
1029
1030 #if ENABLE(JIT)
1031     uint32_t adjustedExitCountThreshold(uint32_t desiredThreshold);
1032     uint32_t exitCountThresholdForReoptimization();
1033     uint32_t exitCountThresholdForReoptimizationFromLoop();
1034     bool shouldReoptimizeNow();
1035     bool shouldReoptimizeFromLoopNow();
1036 #endif
1037
1038 #if ENABLE(VALUE_PROFILER)
1039     bool shouldOptimizeNow();
1040     void updateAllValueProfilePredictions(OperationInProgress = NoOperation);
1041     void updateAllArrayPredictions(OperationInProgress = NoOperation);
1042     void updateAllPredictions(OperationInProgress = NoOperation);
1043 #else
1044     bool shouldOptimizeNow() { return false; }
1045     void updateAllValueProfilePredictions(OperationInProgress = NoOperation) { }
1046     void updateAllArrayPredictions(OperationInProgress = NoOperation) { }
1047     void updateAllPredictions(OperationInProgress = NoOperation) { }
1048 #endif
1049
1050 #if ENABLE(JIT)
1051     void reoptimize();
1052 #endif
1053
1054 #if ENABLE(VERBOSE_VALUE_PROFILE)
1055     void dumpValueProfiles();
1056 #endif
1057
1058     // FIXME: Make these remaining members private.
1059
1060     int m_numCalleeRegisters;
1061     int m_numVars;
1062     bool m_isConstructor;
1063
1064 protected:
1065 #if ENABLE(JIT)
1066     virtual bool jitCompileImpl(ExecState*) = 0;
1067     virtual void jettisonImpl() = 0;
1068 #endif
1069     virtual void visitWeakReferences(SlotVisitor&);
1070     virtual void finalizeUnconditionally();
1071
1072 #if ENABLE(DFG_JIT)
1073     void tallyFrequentExitSites();
1074 #else
1075     void tallyFrequentExitSites() { }
1076 #endif
1077
1078 private:
1079     friend class DFGCodeBlocks;
1080
1081     double optimizationThresholdScalingFactor();
1082
1083 #if ENABLE(JIT)
1084     ClosureCallStubRoutine* findClosureCallForReturnPC(ReturnAddressPtr);
1085 #endif
1086
1087 #if ENABLE(VALUE_PROFILER)
1088     void updateAllPredictionsAndCountLiveness(OperationInProgress, unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles);
1089 #endif
1090
1091     void setIdentifiers(const Vector<Identifier>& identifiers)
1092     {
1093         RELEASE_ASSERT(m_identifiers.isEmpty());
1094         m_identifiers.appendVector(identifiers);
1095     }
1096
1097     void setConstantRegisters(const Vector<WriteBarrier<Unknown> >& constants)
1098     {
1099         size_t count = constants.size();
1100         m_constantRegisters.resize(count);
1101         for (size_t i = 0; i < count; i++)
1102             m_constantRegisters[i].set(*m_vm, ownerExecutable(), constants[i].get());
1103     }
1104
1105     void dumpBytecode(PrintStream&, ExecState*, const Instruction* begin, const Instruction*&);
1106
1107     CString registerName(ExecState*, int r) const;
1108     void printUnaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
1109     void printBinaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
1110     void printConditionalJump(PrintStream&, ExecState*, const Instruction*, const Instruction*&, int location, const char* op);
1111     void printGetByIdOp(PrintStream&, ExecState*, int location, const Instruction*&);
1112     void printGetByIdCacheStatus(PrintStream&, ExecState*, int location);
1113     enum CacheDumpMode { DumpCaches, DontDumpCaches };
1114     void printCallOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op, CacheDumpMode);
1115     void printPutByIdOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
1116     void beginDumpProfiling(PrintStream&, bool& hasPrintedProfiling);
1117     void dumpValueProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
1118     void dumpArrayProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
1119 #if ENABLE(VALUE_PROFILER)
1120     void dumpRareCaseProfile(PrintStream&, const char* name, RareCaseProfile*, bool& hasPrintedProfiling);
1121 #endif
1122
1123     void visitStructures(SlotVisitor&, Instruction* vPC);
1124
1125 #if ENABLE(DFG_JIT)
1126     bool shouldImmediatelyAssumeLivenessDuringScan()
1127     {
1128         // Null m_dfgData means that this is a baseline JIT CodeBlock. Baseline JIT
1129         // CodeBlocks don't need to be jettisoned when their weak references go
1130         // stale. So if a basline JIT CodeBlock gets scanned, we can assume that
1131         // this means that it's live.
1132         if (!m_dfgData)
1133             return true;
1134
1135         // For simplicity, we don't attempt to jettison code blocks during GC if
1136         // they are executing. Instead we strongly mark their weak references to
1137         // allow them to continue to execute soundly.
1138         if (m_dfgData->mayBeExecuting)
1139             return true;
1140
1141         if (Options::forceDFGCodeBlockLiveness())
1142             return true;
1143
1144         return false;
1145     }
1146 #else
1147     bool shouldImmediatelyAssumeLivenessDuringScan() { return true; }
1148 #endif
1149
1150     void performTracingFixpointIteration(SlotVisitor&);
1151
1152     void stronglyVisitStrongReferences(SlotVisitor&);
1153     void stronglyVisitWeakReferences(SlotVisitor&);
1154
1155     void createRareDataIfNecessary()
1156     {
1157         if (!m_rareData)
1158             m_rareData = adoptPtr(new RareData);
1159     }
1160
1161 #if ENABLE(JIT)
1162     void resetStubInternal(RepatchBuffer&, StructureStubInfo&);
1163     void resetStubDuringGCInternal(RepatchBuffer&, StructureStubInfo&);
1164 #endif
1165     WriteBarrier<UnlinkedCodeBlock> m_unlinkedCode;
1166     int m_numParameters;
1167     WriteBarrier<ScriptExecutable> m_ownerExecutable;
1168     VM* m_vm;
1169
1170     RefCountedArray<Instruction> m_instructions;
1171     int m_thisRegister;
1172     int m_argumentsRegister;
1173     int m_activationRegister;
1174
1175     bool m_isStrictMode;
1176     bool m_needsActivation;
1177
1178     RefPtr<SourceProvider> m_source;
1179     unsigned m_sourceOffset;
1180     unsigned m_firstLineColumnOffset;
1181     unsigned m_codeType;
1182
1183 #if ENABLE(LLINT)
1184     SegmentedVector<LLIntCallLinkInfo, 8> m_llintCallLinkInfos;
1185     SentinelLinkedList<LLIntCallLinkInfo, BasicRawSentinelNode<LLIntCallLinkInfo> > m_incomingLLIntCalls;
1186 #endif
1187 #if ENABLE(JIT)
1188     Vector<StructureStubInfo> m_structureStubInfos;
1189     Vector<ByValInfo> m_byValInfos;
1190     Vector<CallLinkInfo> m_callLinkInfos;
1191     JITCode m_jitCode;
1192     MacroAssemblerCodePtr m_jitCodeWithArityCheck;
1193     SentinelLinkedList<CallLinkInfo, BasicRawSentinelNode<CallLinkInfo> > m_incomingCalls;
1194 #endif
1195 #if ENABLE(DFG_JIT) || ENABLE(LLINT)
1196     OwnPtr<CompactJITCodeMap> m_jitCodeMap;
1197 #endif
1198 #if ENABLE(DFG_JIT)
1199     struct WeakReferenceTransition {
1200         WeakReferenceTransition() { }
1201
1202         WeakReferenceTransition(VM& vm, JSCell* owner, JSCell* codeOrigin, JSCell* from, JSCell* to)
1203             : m_from(vm, owner, from)
1204             , m_to(vm, owner, to)
1205         {
1206             if (!!codeOrigin)
1207                 m_codeOrigin.set(vm, owner, codeOrigin);
1208         }
1209
1210         WriteBarrier<JSCell> m_codeOrigin;
1211         WriteBarrier<JSCell> m_from;
1212         WriteBarrier<JSCell> m_to;
1213     };
1214
1215     struct DFGData {
1216         DFGData()
1217             : mayBeExecuting(false)
1218             , isJettisoned(false)
1219         {
1220         }
1221
1222         Vector<DFG::OSREntryData> osrEntry;
1223         SegmentedVector<DFG::OSRExit, 8> osrExit;
1224         Vector<DFG::SpeculationRecovery> speculationRecovery;
1225         SegmentedVector<JumpReplacementWatchpoint, 1, 0> watchpoints;
1226         Vector<WeakReferenceTransition> transitions;
1227         Vector<WriteBarrier<JSCell> > weakReferences;
1228         DFG::VariableEventStream variableEventStream;
1229         DFG::MinifiedGraph minifiedDFG;
1230         RefPtr<Profiler::Compilation> compilation;
1231         bool mayBeExecuting;
1232         bool isJettisoned;
1233         bool livenessHasBeenProved; // Initialized and used on every GC.
1234         bool allTransitionsHaveBeenMarked; // Initialized and used on every GC.
1235         unsigned visitAggregateHasBeenCalled; // Unsigned to make it work seamlessly with the broadest set of CAS implementations.
1236     };
1237
1238     OwnPtr<DFGData> m_dfgData;
1239
1240     // This is relevant to non-DFG code blocks that serve as the profiled code block
1241     // for DFG code blocks.
1242     DFG::ExitProfile m_exitProfile;
1243     CompressedLazyOperandValueProfileHolder m_lazyOperandValueProfiles;
1244 #endif
1245 #if ENABLE(VALUE_PROFILER)
1246     Vector<ValueProfile> m_argumentValueProfiles;
1247     SegmentedVector<ValueProfile, 8> m_valueProfiles;
1248     SegmentedVector<RareCaseProfile, 8> m_rareCaseProfiles;
1249     SegmentedVector<RareCaseProfile, 8> m_specialFastCaseProfiles;
1250     SegmentedVector<ArrayAllocationProfile, 8> m_arrayAllocationProfiles;
1251     ArrayProfileVector m_arrayProfiles;
1252 #endif
1253     SegmentedVector<ObjectAllocationProfile, 8> m_objectAllocationProfiles;
1254
1255     // Constant Pool
1256     Vector<Identifier> m_identifiers;
1257     COMPILE_ASSERT(sizeof(Register) == sizeof(WriteBarrier<Unknown>), Register_must_be_same_size_as_WriteBarrier_Unknown);
1258     // TODO: This could just be a pointer to m_unlinkedCodeBlock's data, but the DFG mutates
1259     // it, so we're stuck with it for now.
1260     Vector<WriteBarrier<Unknown> > m_constantRegisters;
1261     Vector<WriteBarrier<FunctionExecutable> > m_functionDecls;
1262     Vector<WriteBarrier<FunctionExecutable> > m_functionExprs;
1263
1264     OwnPtr<CodeBlock> m_alternative;
1265
1266     ExecutionCounter m_llintExecuteCounter;
1267
1268     ExecutionCounter m_jitExecuteCounter;
1269     int32_t m_totalJITExecutions;
1270     uint32_t m_osrExitCounter;
1271     uint16_t m_optimizationDelayCounter;
1272     uint16_t m_reoptimizationRetryCounter;
1273
1274     Vector<ResolveOperations> m_resolveOperations;
1275     Vector<PutToBaseOperation, 1> m_putToBaseOperations;
1276
1277     struct RareData {
1278         WTF_MAKE_FAST_ALLOCATED;
1279     public:
1280         Vector<HandlerInfo> m_exceptionHandlers;
1281
1282         // Buffers used for large array literals
1283         Vector<Vector<JSValue> > m_constantBuffers;
1284
1285         // Jump Tables
1286         Vector<SimpleJumpTable> m_immediateSwitchJumpTables;
1287         Vector<SimpleJumpTable> m_characterSwitchJumpTables;
1288         Vector<StringJumpTable> m_stringSwitchJumpTables;
1289
1290         EvalCodeCache m_evalCodeCache;
1291
1292 #if ENABLE(JIT)
1293         Vector<CallReturnOffsetToBytecodeOffset, 0, UnsafeVectorOverflow> m_callReturnIndexVector;
1294 #endif
1295 #if ENABLE(DFG_JIT)
1296         SegmentedVector<InlineCallFrame, 4> m_inlineCallFrames;
1297         Vector<CodeOriginAtCallReturnOffset, 0, UnsafeVectorOverflow> m_codeOrigins;
1298 #endif
1299     };
1300 #if COMPILER(MSVC)
1301     friend void WTF::deleteOwnedPtr<RareData>(RareData*);
1302 #endif
1303     OwnPtr<RareData> m_rareData;
1304 #if ENABLE(JIT)
1305     DFG::CapabilityLevel m_canCompileWithDFGState;
1306 #endif
1307 };
1308
1309 // Program code is not marked by any function, so we make the global object
1310 // responsible for marking it.
1311
1312 class GlobalCodeBlock : public CodeBlock {
1313 protected:
1314     GlobalCodeBlock(CopyParsedBlockTag, GlobalCodeBlock& other)
1315         : CodeBlock(CopyParsedBlock, other)
1316     {
1317     }
1318
1319     GlobalCodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSGlobalObject* globalObject, unsigned baseScopeDepth, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset, PassOwnPtr<CodeBlock> alternative)
1320         : CodeBlock(ownerExecutable, unlinkedCodeBlock, globalObject, baseScopeDepth, sourceProvider, sourceOffset, firstLineColumnOffset, alternative)
1321     {
1322     }
1323 };
1324
1325 class ProgramCodeBlock : public GlobalCodeBlock {
1326 public:
1327     ProgramCodeBlock(CopyParsedBlockTag, ProgramCodeBlock& other)
1328         : GlobalCodeBlock(CopyParsedBlock, other)
1329     {
1330     }
1331
1332     ProgramCodeBlock(ProgramExecutable* ownerExecutable, UnlinkedProgramCodeBlock* unlinkedCodeBlock, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset, PassOwnPtr<CodeBlock> alternative)
1333         : GlobalCodeBlock(ownerExecutable, unlinkedCodeBlock, globalObject, 0, sourceProvider, 0, firstLineColumnOffset, alternative)
1334     {
1335     }
1336
1337 #if ENABLE(JIT)
1338 protected:
1339     virtual JSObject* compileOptimized(ExecState*, JSScope*, unsigned bytecodeIndex);
1340     virtual void jettisonImpl();
1341     virtual bool jitCompileImpl(ExecState*);
1342     virtual CodeBlock* replacement();
1343     virtual DFG::CapabilityLevel canCompileWithDFGInternal();
1344 #endif
1345 };
1346
1347 class EvalCodeBlock : public GlobalCodeBlock {
1348 public:
1349     EvalCodeBlock(CopyParsedBlockTag, EvalCodeBlock& other)
1350         : GlobalCodeBlock(CopyParsedBlock, other)
1351     {
1352     }
1353
1354     EvalCodeBlock(EvalExecutable* ownerExecutable, UnlinkedEvalCodeBlock* unlinkedCodeBlock, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, int baseScopeDepth, PassOwnPtr<CodeBlock> alternative)
1355         : GlobalCodeBlock(ownerExecutable, unlinkedCodeBlock, globalObject, baseScopeDepth, sourceProvider, 0, 1, alternative)
1356     {
1357     }
1358
1359     const Identifier& variable(unsigned index) { return unlinkedEvalCodeBlock()->variable(index); }
1360     unsigned numVariables() { return unlinkedEvalCodeBlock()->numVariables(); }
1361
1362 #if ENABLE(JIT)
1363 protected:
1364     virtual JSObject* compileOptimized(ExecState*, JSScope*, unsigned bytecodeIndex);
1365     virtual void jettisonImpl();
1366     virtual bool jitCompileImpl(ExecState*);
1367     virtual CodeBlock* replacement();
1368     virtual DFG::CapabilityLevel canCompileWithDFGInternal();
1369 #endif
1370
1371 private:
1372     UnlinkedEvalCodeBlock* unlinkedEvalCodeBlock() const { return jsCast<UnlinkedEvalCodeBlock*>(unlinkedCodeBlock()); }
1373 };
1374
1375 class FunctionCodeBlock : public CodeBlock {
1376 public:
1377     FunctionCodeBlock(CopyParsedBlockTag, FunctionCodeBlock& other)
1378         : CodeBlock(CopyParsedBlock, other)
1379     {
1380     }
1381
1382     FunctionCodeBlock(FunctionExecutable* ownerExecutable, UnlinkedFunctionCodeBlock* unlinkedCodeBlock, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset, PassOwnPtr<CodeBlock> alternative = nullptr)
1383         : CodeBlock(ownerExecutable, unlinkedCodeBlock, globalObject, 0, sourceProvider, sourceOffset, firstLineColumnOffset, alternative)
1384     {
1385     }
1386
1387 #if ENABLE(JIT)
1388 protected:
1389     virtual JSObject* compileOptimized(ExecState*, JSScope*, unsigned bytecodeIndex);
1390     virtual void jettisonImpl();
1391     virtual bool jitCompileImpl(ExecState*);
1392     virtual CodeBlock* replacement();
1393     virtual DFG::CapabilityLevel canCompileWithDFGInternal();
1394 #endif
1395 };
1396
1397 inline CodeBlock* baselineCodeBlockForInlineCallFrame(InlineCallFrame* inlineCallFrame)
1398 {
1399     RELEASE_ASSERT(inlineCallFrame);
1400     ExecutableBase* executable = inlineCallFrame->executable.get();
1401     RELEASE_ASSERT(executable->structure()->classInfo() == &FunctionExecutable::s_info);
1402     return static_cast<FunctionExecutable*>(executable)->baselineCodeBlockFor(inlineCallFrame->isCall ? CodeForCall : CodeForConstruct);
1403 }
1404
1405 inline CodeBlock* baselineCodeBlockForOriginAndBaselineCodeBlock(const CodeOrigin& codeOrigin, CodeBlock* baselineCodeBlock)
1406 {
1407     if (codeOrigin.inlineCallFrame)
1408         return baselineCodeBlockForInlineCallFrame(codeOrigin.inlineCallFrame);
1409     return baselineCodeBlock;
1410 }
1411
1412 inline int CodeBlock::argumentIndexAfterCapture(size_t argument)
1413 {
1414     if (argument >= static_cast<size_t>(symbolTable()->parameterCount()))
1415         return CallFrame::argumentOffset(argument);
1416
1417     const SlowArgument* slowArguments = symbolTable()->slowArguments();
1418     if (!slowArguments || slowArguments[argument].status == SlowArgument::Normal)
1419         return CallFrame::argumentOffset(argument);
1420
1421     ASSERT(slowArguments[argument].status == SlowArgument::Captured);
1422     return slowArguments[argument].index;
1423 }
1424
1425 inline Register& ExecState::r(int index)
1426 {
1427     CodeBlock* codeBlock = this->codeBlock();
1428     if (codeBlock->isConstantRegisterIndex(index))
1429         return *reinterpret_cast<Register*>(&codeBlock->constantRegister(index));
1430     return this[index];
1431 }
1432
1433 inline Register& ExecState::uncheckedR(int index)
1434 {
1435     RELEASE_ASSERT(index < FirstConstantRegisterIndex);
1436     return this[index];
1437 }
1438
1439 #if ENABLE(DFG_JIT)
1440 inline bool ExecState::isInlineCallFrame()
1441 {
1442     if (LIKELY(!codeBlock() || codeBlock()->getJITType() != JITCode::DFGJIT))
1443         return false;
1444     return isInlineCallFrameSlow();
1445 }
1446 #endif
1447
1448 inline JSValue ExecState::argumentAfterCapture(size_t argument)
1449 {
1450     if (argument >= argumentCount())
1451         return jsUndefined();
1452
1453     if (!codeBlock())
1454         return this[argumentOffset(argument)].jsValue();
1455
1456     return this[codeBlock()->argumentIndexAfterCapture(argument)].jsValue();
1457 }
1458
1459 #if ENABLE(DFG_JIT)
1460 inline void DFGCodeBlocks::mark(void* candidateCodeBlock)
1461 {
1462     // We have to check for 0 and -1 because those are used by the HashMap as markers.
1463     uintptr_t value = reinterpret_cast<uintptr_t>(candidateCodeBlock);
1464
1465     // This checks for both of those nasty cases in one go.
1466     // 0 + 1 = 1
1467     // -1 + 1 = 0
1468     if (value + 1 <= 1)
1469         return;
1470
1471     HashSet<CodeBlock*>::iterator iter = m_set.find(static_cast<CodeBlock*>(candidateCodeBlock));
1472     if (iter == m_set.end())
1473         return;
1474
1475     (*iter)->m_dfgData->mayBeExecuting = true;
1476 }
1477 #endif
1478
1479 } // namespace JSC
1480
1481 #endif // CodeBlock_h