Ignore:
Timestamp:
Oct 9, 2012, 4:39:53 PM (13 years ago)
Author:
[email protected]
Message:

JSC should infer when indexed storage is contiguous, and optimize for it
​https://bugs.webkit.org/show_bug.cgi?id=97288

Reviewed by Mark Hahnenberg.

Source/JavaScriptCore:

This introduces a new kind of indexed property storage called Contiguous,
which has the following properties:

  • No header bits beyond IndexedHeader. This results in a 16 byte reduction in memory usage per array versus an ArrayStorage array. It also means that the total memory usage for an empty array is now just 3 * 8 on both 32-bit and 64-bit. Of that, only 8 bytes are array-specific; the rest is our standard object header overhead.


  • No need for hole checks on store. This results in a ~4% speed-up on Kraken and a ~1% speed-up on V8v7.


  • publicLength <= vectorLength. This means that doing new Array(blah) immediately allocates room for blah elements.


  • No sparse map or index bias.


If you ever do things to an array that would require publicLength >
vectorLength, a sparse map, or index bias, then we switch to ArrayStorage
mode. This seems to never happen in any benchmark we track, and is unlikely
to happen very frequently on any website.

  • CMakeLists.txt:
  • GNUmakefile.list.am:
  • JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.vcproj:
  • JavaScriptCore.xcodeproj/project.pbxproj:
  • Target.pri:
  • assembler/AbstractMacroAssembler.h:

(JSC::AbstractMacroAssembler::JumpList::append):

  • assembler/MacroAssembler.h:

(MacroAssembler):
(JSC::MacroAssembler::patchableBranchTest32):

  • bytecode/ByValInfo.h: Added.

(JSC):
(JSC::isOptimizableIndexingType):
(JSC::jitArrayModeForIndexingType):
(JSC::ByValInfo::ByValInfo):
(ByValInfo):
(JSC::getByValInfoBytecodeIndex):

  • bytecode/CodeBlock.h:

(CodeBlock):
(JSC::CodeBlock::getByValInfo):
(JSC::CodeBlock::setNumberOfByValInfos):
(JSC::CodeBlock::numberOfByValInfos):
(JSC::CodeBlock::byValInfo):

  • bytecode/SamplingTool.h:
  • dfg/DFGAbstractState.cpp:

(JSC::DFG::AbstractState::execute):

  • dfg/DFGArrayMode.cpp:

(JSC::DFG::fromObserved):
(JSC::DFG::modeAlreadyChecked):
(JSC::DFG::modeToString):

  • dfg/DFGArrayMode.h:

(DFG):
(JSC::DFG::modeUsesButterfly):
(JSC::DFG::modeIsJSArray):
(JSC::DFG::isInBoundsAccess):
(JSC::DFG::mayStoreToTail):
(JSC::DFG::mayStoreToHole):
(JSC::DFG::modeIsPolymorphic):
(JSC::DFG::polymorphicIncludesContiguous):
(JSC::DFG::polymorphicIncludesArrayStorage):
(JSC::DFG::canCSEStorage):
(JSC::DFG::modeSupportsLength):
(JSC::DFG::benefitsFromStructureCheck):
(JSC::DFG::isEffectful):

  • dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleIntrinsic):

  • dfg/DFGCSEPhase.cpp:

(JSC::DFG::CSEPhase::getArrayLengthElimination):
(JSC::DFG::CSEPhase::getByValLoadElimination):
(JSC::DFG::CSEPhase::performNodeCSE):

  • dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):
(JSC::DFG::FixupPhase::checkArray):
(JSC::DFG::FixupPhase::blessArrayOperation):

  • dfg/DFGGraph.h:

(JSC::DFG::Graph::byValIsPure):

  • dfg/DFGOperations.cpp:
  • dfg/DFGOperations.h:
  • dfg/DFGRepatch.cpp:

(JSC::DFG::tryCacheGetByID):

  • dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::checkArray):
(JSC::DFG::SpeculativeJIT::arrayify):
(JSC::DFG::SpeculativeJIT::compileGetArrayLength):
(JSC::DFG::SpeculativeJIT::temporaryRegisterForPutByVal):
(DFG):

  • dfg/DFGSpeculativeJIT.h:

(DFG):
(JSC::DFG::SpeculativeJIT::callOperation):
(SpeculativeJIT):
(JSC::DFG::SpeculativeJIT::putByValWillNeedExtraRegister):
(JSC::DFG::SpeculativeJIT::temporaryRegisterForPutByVal):

  • dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compileContiguousGetByVal):
(DFG):
(JSC::DFG::SpeculativeJIT::compileArrayStorageGetByVal):
(JSC::DFG::SpeculativeJIT::compileContiguousPutByVal):
(JSC::DFG::SpeculativeJIT::compileArrayStoragePutByVal):
(JSC::DFG::SpeculativeJIT::compile):

  • dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compileContiguousGetByVal):
(DFG):
(JSC::DFG::SpeculativeJIT::compileArrayStorageGetByVal):
(JSC::DFG::SpeculativeJIT::compileContiguousPutByVal):
(JSC::DFG::SpeculativeJIT::compileArrayStoragePutByVal):
(JSC::DFG::SpeculativeJIT::compile):

  • interpreter/Interpreter.cpp:

(SamplingScope):
(JSC::SamplingScope::SamplingScope):
(JSC::SamplingScope::~SamplingScope):
(JSC):
(JSC::Interpreter::execute):

  • jit/JIT.cpp:

(JSC::JIT::privateCompileSlowCases):
(JSC::JIT::privateCompile):

  • jit/JIT.h:

(JSC::ByValCompilationInfo::ByValCompilationInfo):
(ByValCompilationInfo):
(JSC):
(JIT):
(JSC::JIT::compileGetByVal):
(JSC::JIT::compilePutByVal):

  • jit/JITInlineMethods.h:

(JSC::JIT::emitAllocateJSArray):
(JSC::JIT::emitArrayProfileStoreToHoleSpecialCase):
(JSC):
(JSC::arrayProfileSaw):
(JSC::JIT::chooseArrayMode):

  • jit/JITOpcodes.cpp:

(JSC::JIT::emitSlow_op_get_argument_by_val):
(JSC::JIT::emit_op_new_array):
(JSC::JIT::emitSlow_op_new_array):

  • jit/JITOpcodes32_64.cpp:

(JSC::JIT::emitSlow_op_get_argument_by_val):

  • jit/JITPropertyAccess.cpp:

(JSC::JIT::emit_op_get_by_val):
(JSC):
(JSC::JIT::emitContiguousGetByVal):
(JSC::JIT::emitArrayStorageGetByVal):
(JSC::JIT::emitSlow_op_get_by_val):
(JSC::JIT::emit_op_put_by_val):
(JSC::JIT::emitContiguousPutByVal):
(JSC::JIT::emitArrayStoragePutByVal):
(JSC::JIT::emitSlow_op_put_by_val):
(JSC::JIT::privateCompilePatchGetArrayLength):
(JSC::JIT::privateCompileGetByVal):
(JSC::JIT::privateCompilePutByVal):

  • jit/JITPropertyAccess32_64.cpp:

(JSC::JIT::emit_op_get_by_val):
(JSC):
(JSC::JIT::emitContiguousGetByVal):
(JSC::JIT::emitArrayStorageGetByVal):
(JSC::JIT::emitSlow_op_get_by_val):
(JSC::JIT::emit_op_put_by_val):
(JSC::JIT::emitContiguousPutByVal):
(JSC::JIT::emitArrayStoragePutByVal):
(JSC::JIT::emitSlow_op_put_by_val):

  • jit/JITStubs.cpp:

(JSC::getByVal):
(JSC):
(JSC::DEFINE_STUB_FUNCTION):
(JSC::putByVal):

  • jit/JITStubs.h:
  • llint/LowLevelInterpreter.asm:
  • llint/LowLevelInterpreter32_64.asm:
  • llint/LowLevelInterpreter64.asm:
  • runtime/ArrayConventions.h:

(JSC::isDenseEnoughForVector):

  • runtime/ArrayPrototype.cpp:

(JSC):
(JSC::shift):
(JSC::unshift):
(JSC::arrayProtoFuncPush):
(JSC::arrayProtoFuncShift):
(JSC::arrayProtoFuncSplice):
(JSC::arrayProtoFuncUnShift):

  • runtime/Butterfly.h:

(Butterfly):
(JSC::Butterfly::fromPointer):
(JSC::Butterfly::pointer):
(JSC::Butterfly::publicLength):
(JSC::Butterfly::vectorLength):
(JSC::Butterfly::setPublicLength):
(JSC::Butterfly::setVectorLength):
(JSC::Butterfly::contiguous):
(JSC::Butterfly::fromContiguous):

  • runtime/ButterflyInlineMethods.h:

(JSC::Butterfly::unshift):
(JSC::Butterfly::shift):

  • runtime/IndexingHeaderInlineMethods.h:

(JSC::IndexingHeader::indexingPayloadSizeInBytes):

  • runtime/IndexingType.cpp: Added.

(JSC):
(JSC::indexingTypeToString):

  • runtime/IndexingType.h:

(JSC):
(JSC::hasContiguous):

  • runtime/JSArray.cpp:

(JSC::JSArray::setLengthWithArrayStorage):
(JSC::JSArray::setLength):
(JSC):
(JSC::JSArray::pop):
(JSC::JSArray::push):
(JSC::JSArray::shiftCountWithArrayStorage):
(JSC::JSArray::shiftCountWithAnyIndexingType):
(JSC::JSArray::unshiftCountWithArrayStorage):
(JSC::JSArray::unshiftCountWithAnyIndexingType):
(JSC::JSArray::sortNumericVector):
(JSC::JSArray::sortNumeric):
(JSC::JSArray::sortCompactedVector):
(JSC::JSArray::sort):
(JSC::JSArray::sortVector):
(JSC::JSArray::fillArgList):
(JSC::JSArray::copyToArguments):
(JSC::JSArray::compactForSorting):

  • runtime/JSArray.h:

(JSC::JSArray::shiftCountForShift):
(JSC::JSArray::shiftCountForSplice):
(JSArray):
(JSC::JSArray::shiftCount):
(JSC::JSArray::unshiftCountForShift):
(JSC::JSArray::unshiftCountForSplice):
(JSC::JSArray::unshiftCount):
(JSC::JSArray::isLengthWritable):
(JSC::createContiguousArrayButterfly):
(JSC):
(JSC::JSArray::create):
(JSC::JSArray::tryCreateUninitialized):

  • runtime/JSGlobalObject.cpp:

(JSC::JSGlobalObject::reset):
(JSC):
(JSC::JSGlobalObject::haveABadTime):
(JSC::JSGlobalObject::visitChildren):

  • runtime/JSGlobalObject.h:

(JSGlobalObject):
(JSC::JSGlobalObject::arrayStructureWithArrayStorage):
(JSC::JSGlobalObject::addressOfArrayStructureWithArrayStorage):
(JSC::constructEmptyArray):

  • runtime/JSObject.cpp:

(JSC::JSObject::visitButterfly):
(JSC::JSObject::getOwnPropertySlotByIndex):
(JSC::JSObject::putByIndex):
(JSC::JSObject::enterDictionaryIndexingMode):
(JSC::JSObject::createInitialContiguous):
(JSC):
(JSC::JSObject::createArrayStorage):
(JSC::JSObject::convertContiguousToArrayStorage):
(JSC::JSObject::ensureContiguousSlow):
(JSC::JSObject::ensureArrayStorageSlow):
(JSC::JSObject::ensureIndexedStorageSlow):
(JSC::JSObject::ensureArrayStorageExistsAndEnterDictionaryIndexingMode):
(JSC::JSObject::switchToSlowPutArrayStorage):
(JSC::JSObject::setPrototype):
(JSC::JSObject::deletePropertyByIndex):
(JSC::JSObject::getOwnPropertyNames):
(JSC::JSObject::defineOwnIndexedProperty):
(JSC::JSObject::putByIndexBeyondVectorLengthContiguousWithoutAttributes):
(JSC::JSObject::putByIndexBeyondVectorLength):
(JSC::JSObject::putDirectIndexBeyondVectorLengthWithArrayStorage):
(JSC::JSObject::putDirectIndexBeyondVectorLength):
(JSC::JSObject::getNewVectorLength):
(JSC::JSObject::countElementsInContiguous):
(JSC::JSObject::increaseVectorLength):
(JSC::JSObject::ensureContiguousLengthSlow):
(JSC::JSObject::getOwnPropertyDescriptor):

  • runtime/JSObject.h:

(JSC::JSObject::getArrayLength):
(JSC::JSObject::getVectorLength):
(JSC::JSObject::canGetIndexQuickly):
(JSC::JSObject::getIndexQuickly):
(JSC::JSObject::tryGetIndexQuickly):
(JSC::JSObject::canSetIndexQuickly):
(JSC::JSObject::canSetIndexQuicklyForPutDirect):
(JSC::JSObject::setIndexQuickly):
(JSC::JSObject::initializeIndex):
(JSC::JSObject::hasSparseMap):
(JSC::JSObject::inSparseIndexingMode):
(JSObject):
(JSC::JSObject::ensureContiguous):
(JSC::JSObject::ensureIndexedStorage):
(JSC::JSObject::ensureContiguousLength):
(JSC::JSObject::indexingData):
(JSC::JSObject::relevantLength):

  • runtime/JSValue.cpp:

(JSC::JSValue::description):

  • runtime/Options.cpp:

(JSC::Options::initialize):

  • runtime/Structure.cpp:

(JSC::Structure::needsSlowPutIndexing):
(JSC):
(JSC::Structure::suggestedArrayStorageTransition):

  • runtime/Structure.h:

(Structure):

  • runtime/StructureTransitionTable.h:

(JSC::newIndexingType):

Source/WTF:

Moved out this helpful math utility to MathExtras, since we now use it in
multiple places.

  • wtf/MathExtras.h:

(timesThreePlusOneDividedByTwo):

File:
1 edited

Legend:

Unmodified
Added
Removed

  • trunk/Source/JavaScriptCore/runtime/JSGlobalObject.cpp

    r130726 r130826  
    232232
    233233    m_arrayPrototype.set(exec->globalData(), this, ArrayPrototype::create(exec, this, ArrayPrototype::createStructure(exec->globalData(), this, m_objectPrototype.get())));
    234     m_arrayStructure.set(exec->globalData(), this, JSArray::createStructure(exec->globalData(), this, m_arrayPrototype.get(), ArrayWithArrayStorage));
     234    m_arrayStructure.set(exec->globalData(), this, JSArray::createStructure(exec->globalData(), this, m_arrayPrototype.get(), ArrayWithContiguous));
     235    m_arrayStructureWithArrayStorage.set(exec->globalData(), this, JSArray::createStructure(exec->globalData(), this, m_arrayPrototype.get(), ArrayWithArrayStorage));
    235236    m_arrayStructureForSlowPut.set(exec->globalData(), this, JSArray::createStructure(exec->globalData(), this, m_arrayPrototype.get(), ArrayWithSlowPutArrayStorage));
    236237    m_regExpMatchesArrayStructure.set(exec->globalData(), this, RegExpMatchesArray::createStructure(exec->globalData(), this, m_arrayPrototype.get()));
    … …  
    358359{
    359360    // This will change if we have more indexing types.
    360     return !!(object->structure()->indexingType() & HasArrayStorage);
     361    return !!(object->structure()->indexingType() & (HasArrayStorage | HasContiguous));
    361362}
    362363
    … …  
    411412    // this object now load a structure that uses SlowPut.
    412413    m_arrayStructure.set(globalData, this, m_arrayStructureForSlowPut.get());
     414    m_arrayStructureWithArrayStorage.set(globalData, this, m_arrayStructureForSlowPut.get());
    413415   
    414416    // Make sure that all objects that have indexed storage switch to the slow kind of
    … …  
    486488    visitor.append(&thisObject->m_argumentsStructure);
    487489    visitor.append(&thisObject->m_arrayStructure);
     490    visitor.append(&thisObject->m_arrayStructureWithArrayStorage);
    488491    visitor.append(&thisObject->m_arrayStructureForSlowPut);
    489492    visitor.append(&thisObject->m_booleanObjectStructure);
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