Timestamp: Apr 18, 2020 2:45:34 PM (9 months ago) Author: [email protected] Message:

Redesign how we do for-of iteration for JSArrays
​https://bugs.webkit.org/show_bug.cgi?id=175454

JSTests:

Reviewed by Filip Pizlo.

• microbenchmarks/for-of-iterate-array-entries.js:

(foo):

• stress/custom-iterators.js:

(catch):
(iter.return):
(iteratorInterfaceErrorTest):
(iteratorInterfaceErrorTestReturn):
(iteratorInterfaceBreakTestReturn):

• stress/for-of-array-different-globals.js: Added.

(foo):
(array.Symbol.iterator.proto.next):

• stress/for-of-array-mixed-values.js: Added.

(test):

• stress/for-of-no-direct-loop-back-edge-osr.js: Added.

(osrIfFinalTier):
(test):

• stress/generator-containing-for-of-on-map.js: Added.

(find):
(i.let.v.of.find):

• stress/generator-containing-for-of-on-set.js: Added.

(find):
(set add):

• stress/osr-from-for-of-done-getter.js: Added.

(i.let.iterable.next.return.get done):
(i.let.iterable.next):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):

• stress/osr-from-for-of-value-getter.js: Added.

(i.let.iterable.next.return.get value):
(i.let.iterable.next):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):

• stress/throw-for-of-next-returns-non-object.js: Added.

(i.let.iterable.next):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):
(i.catch):

• stress/throw-from-done-getter-in-for-of-header.js: Added.

(i.let.iterable.next):
(i.let.iterable.get done):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):
(i.catch):

• stress/throw-from-next-in-for-of-header.js: Added.

(i.let.iterable.next):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):
(i.catch):

• stress/throw-from-value-getter-in-for-of-header.js: Added.

(i.let.iterable.next):
(i.let.iterable.get value):
(i.let.iterable.Symbol.iterator):
(i.let.iterable.return):
(i.catch):

• stress/webidl-tokenizer-for-of.js: Added.

(tokenise.attemptTokenMatch):
(tokenise):
(Tokeniser):
(Tokeniser.prototype.probe):
(Tokeniser.prototype.consume):
(Tokeniser.prototype.unconsume):

Source/JavaScriptCore:

Reviewed by Filip Pizlo and Saam Barati.

This patch intrinsics for-of iteration for JSArrays when they are
being iterated with the built-in Symbol.iterator. We do this by
adding two new bytecodes op_iterator_open and
op_iterator_next. These bytecodes are essentially a fused set of
existing bytecodes with a special case for our intrinsiced JSArray
case. This patch only adds support for these instructions on
64-bit.

The op_iterator_open bytecode is semantically the same as:
iterator = symbolIterator.@call(iterable);
next = iterator.next;

where iterable is the rhs of the for-of and symbolIterator is the
result of running iterable.symbolIterator;

The op_iterator_next bytecode is semantically the same as:
nextResult = next.@call(iterator);
done = nextResult.done;
value = done ? (undefined / bottom) : nextResult.value;

where nextResult is a temporary (the value VirtualRegister in the
LLInt/Baseline and a tmp in the DFG).

In order to make sure these bytecodes have the same perfomance as
the existing bytecode sequence, we need to make sure we have the
same profiling data and inline caching. Most of the existing
get_by_id code assumed a particular bytecode member name was the
same in each flavor get_by_id access. This patch adds template
specialized functions that vend the correct
Profile/VirtualRegister for the current bytecode/checkpoint. This
means we can have meaningful names for our Bytecode structs and
still use the generic functions.

In the LLInt most of the logic for calls/get_by_id had to be
factored into helper macros, so we could have bytecodes that are
some combination of those.

The trickiest part of this patch was getting the hand rolled DFG
IR to work correctly. This is because we don't have a great way to
express large chucks of DFG graph that doesn't involve manually
tracking all the DFG's invariants. Such as:

1) Flushing/Phantoming values at the end of each block.
2) Rolling forwards and backwards the BytecodeIndex when switching

blocks.

3) Remembering to GetLocal each variable at the top of every block.
4) Ensuring that the JSValue stored to the op_iterator_next.m_value

local does not cause us to OSR exit at the set local.

(4) is handled by a new function, bottomValueMatchingSpeculation,
on DFGGraph that produces a FrozenValue that is roughly the bottom
for a given speculated type. In a future patch we should make this
more complete, probably by adding a VM::bottomCellForSetLocal that
prediction propagation and AI know how treat as a true bottom
value. See: ​https://bugs.webkit.org/show_bug.cgi?id=210694

Lastly, this patch changes the DFG NodeType, CheckCell to be
CheckIsConstant. CheckIsConstant is equivalent to the == operator
on JSValue where it just checks the register values are the
same. In order to keep the same perf that we had for CheckCell,
CheckIsConstant supports CellUse.

• CMakeLists.txt:
• JavaScriptCore.xcodeproj/project.pbxproj:
• assembler/MacroAssemblerARM64.h:

(JSC::MacroAssemblerARM64::or8):
(JSC::MacroAssemblerARM64::store8):

• assembler/MacroAssemblerX86_64.h:

(JSC::MacroAssemblerX86_64::or8):

• bytecode/ArrayProfile.h:

(JSC::ArrayProfile::observeStructureID):
(JSC::ArrayProfile::observeStructure):

• bytecode/BytecodeList.rb:
• bytecode/BytecodeLivenessAnalysis.cpp:

(JSC::tmpLivenessForCheckpoint):

• bytecode/BytecodeOperandsForCheckpoint.h: Added.

(JSC::arrayProfileForImpl):
(JSC::hasArrayProfileFor):
(JSC::arrayProfileFor):
(JSC::valueProfileForImpl):
(JSC::hasValueProfileFor):
(JSC::valueProfileFor):
(JSC::destinationFor):
(JSC::calleeFor):
(JSC::argumentCountIncludingThisFor):
(JSC::stackOffsetInRegistersForCall):
(JSC::callLinkInfoFor):

• bytecode/BytecodeUseDef.cpp:

(JSC::computeUsesForBytecodeIndexImpl):
(JSC::computeDefsForBytecodeIndexImpl):

• bytecode/CallLinkInfo.cpp:

(JSC::CallLinkInfo::callTypeFor):

• bytecode/CallLinkStatus.cpp:

(JSC::CallLinkStatus::computeFromLLInt):

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::finishCreation):
(JSC::CodeBlock::finalizeLLIntInlineCaches):
(JSC::CodeBlock::tryGetValueProfileForBytecodeIndex):

• bytecode/CodeBlock.h:

(JSC::CodeBlock::instructionAt const):

• bytecode/CodeBlockInlines.h:

(JSC::CodeBlock::forEachValueProfile):
(JSC::CodeBlock::forEachArrayProfile):

• bytecode/GetByStatus.cpp:

(JSC::GetByStatus::computeFromLLInt):

• bytecode/Instruction.h:

(JSC::BaseInstruction::width const):
(JSC::BaseInstruction::hasCheckpoints const):
(JSC::BaseInstruction::asKnownWidth const):
(JSC::BaseInstruction::wide16 const):
(JSC::BaseInstruction::wide32 const):

• bytecode/InstructionStream.h:
• bytecode/IterationModeMetadata.h: Copied from Source/JavaScriptCore/bytecode/SuperSampler.h.
• bytecode/LLIntPrototypeLoadAdaptiveStructureWatchpoint.cpp:

(JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint::fireInternal):
(JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint::clearLLIntGetByIdCache):

• bytecode/LLIntPrototypeLoadAdaptiveStructureWatchpoint.h:
• bytecode/Opcode.h:
• bytecode/SpeculatedType.h:

(JSC::isSubtypeSpeculation):
(JSC::speculationContains):

• bytecode/SuperSampler.h:

(JSC::SuperSamplerScope::release):

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::emitGenericEnumeration):
(JSC::BytecodeGenerator::emitEnumeration):
(JSC::BytecodeGenerator::emitIsEmpty):
(JSC::BytecodeGenerator::emitIteratorOpen):
(JSC::BytecodeGenerator::emitIteratorNext):
(JSC::BytecodeGenerator::emitGetGenericIterator):
(JSC::BytecodeGenerator::emitIteratorGenericNext):
(JSC::BytecodeGenerator::emitIteratorGenericNextWithValue):
(JSC::BytecodeGenerator::emitIteratorGenericClose):
(JSC::BytecodeGenerator::emitGetAsyncIterator):
(JSC::BytecodeGenerator::emitDelegateYield):
(JSC::BytecodeGenerator::emitIteratorNextWithValue): Deleted.
(JSC::BytecodeGenerator::emitIteratorClose): Deleted.
(JSC::BytecodeGenerator::emitGetIterator): Deleted.

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::ArrayPatternNode::bindValue const):

• dfg/DFGAbstractInterpreterInlines.h:

(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
(JSC::DFG::AbstractInterpreter<AbstractStateType>::forAllValues):

• dfg/DFGAtTailAbstractState.h:

(JSC::DFG::AtTailAbstractState::size const):
(JSC::DFG::AtTailAbstractState::numberOfTmps const):
(JSC::DFG::AtTailAbstractState::atIndex):
(JSC::DFG::AtTailAbstractState::tmp):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::progressToNextCheckpoint):
(JSC::DFG::ByteCodeParser::get):
(JSC::DFG::ByteCodeParser::set):
(JSC::DFG::ByteCodeParser::jsConstant):
(JSC::DFG::ByteCodeParser::weakJSConstant):
(JSC::DFG::ByteCodeParser::addCall):
(JSC::DFG::ByteCodeParser::allocateUntargetableBlock):
(JSC::DFG::ByteCodeParser::handleCall):
(JSC::DFG::ByteCodeParser::emitFunctionChecks):
(JSC::DFG::ByteCodeParser::inlineCall):
(JSC::DFG::ByteCodeParser::handleCallVariant):
(JSC::DFG::ByteCodeParser::handleVarargsInlining):
(JSC::DFG::ByteCodeParser::handleInlining):
(JSC::DFG::ByteCodeParser::handleMinMax):
(JSC::DFG::ByteCodeParser::handleIntrinsicCall):
(JSC::DFG::ByteCodeParser::handleDOMJITCall):
(JSC::DFG::ByteCodeParser::handleIntrinsicGetter):
(JSC::DFG::ByteCodeParser::handleDOMJITGetter):
(JSC::DFG::ByteCodeParser::handleModuleNamespaceLoad):
(JSC::DFG::ByteCodeParser::handleTypedArrayConstructor):
(JSC::DFG::ByteCodeParser::handleConstantInternalFunction):
(JSC::DFG::ByteCodeParser::handleGetById):
(JSC::DFG::ByteCodeParser::parseBlock):
(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
(JSC::DFG::ByteCodeParser::handlePutByVal):
(JSC::DFG::ByteCodeParser::handleCreateInternalFieldObject):
(JSC::DFG::ByteCodeParser::parse):

• dfg/DFGCFGSimplificationPhase.cpp:

(JSC::DFG::CFGSimplificationPhase::keepOperandAlive):
(JSC::DFG::CFGSimplificationPhase::jettisonBlock):
(JSC::DFG::CFGSimplificationPhase::mergeBlocks):

• dfg/DFGCapabilities.cpp:

(JSC::DFG::capabilityLevel):

• dfg/DFGClobberize.h:

(JSC::DFG::clobberize):

• dfg/DFGConstantFoldingPhase.cpp:

(JSC::DFG::ConstantFoldingPhase::foldConstants):

• dfg/DFGDoesGC.cpp:

(JSC::DFG::doesGC):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):
(JSC::DFG::FixupPhase::addStringReplacePrimordialChecks):

• dfg/DFGForAllKills.h:

(JSC::DFG::forAllKilledOperands):

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::bottomValueMatchingSpeculation):

• dfg/DFGGraph.h:
• dfg/DFGInPlaceAbstractState.cpp:

(JSC::DFG::InPlaceAbstractState::beginBasicBlock):
(JSC::DFG::InPlaceAbstractState::initialize):
(JSC::DFG::InPlaceAbstractState::endBasicBlock):
(JSC::DFG::InPlaceAbstractState::merge):

• dfg/DFGInPlaceAbstractState.h:

(JSC::DFG::InPlaceAbstractState::size const):
(JSC::DFG::InPlaceAbstractState::numberOfTmps const):
(JSC::DFG::InPlaceAbstractState::atIndex):
(JSC::DFG::InPlaceAbstractState::operand):
(JSC::DFG::InPlaceAbstractState::local):
(JSC::DFG::InPlaceAbstractState::argument):
(JSC::DFG::InPlaceAbstractState::variableAt): Deleted.

• dfg/DFGLazyJSValue.h:

(JSC::DFG::LazyJSValue::speculatedType const):

• dfg/DFGNode.h:

(JSC::DFG::Node::hasConstant):
(JSC::DFG::Node::hasCellOperand):

• dfg/DFGNodeType.h:
• dfg/DFGOSRExitCompilerCommon.cpp:

(JSC::DFG::callerReturnPC):

• dfg/DFGPredictionPropagationPhase.cpp:
• dfg/DFGSafeToExecute.h:

(JSC::DFG::safeToExecute):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileCheckIsConstant):
(JSC::DFG::SpeculativeJIT::compileCheckCell): Deleted.

• dfg/DFGSpeculativeJIT.h:
• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGValidate.cpp:
• ftl/FTLCapabilities.cpp:

(JSC::FTL::canCompile):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::compileNode):
(JSC::FTL::DFG::LowerDFGToB3::compileCheckIsConstant):
(JSC::FTL::DFG::LowerDFGToB3::compileCheckCell): Deleted.

• generator/DSL.rb:
• generator/Metadata.rb:
• generator/Section.rb:
• jit/JIT.cpp:

(JSC::JIT::privateCompileMainPass):
(JSC::JIT::privateCompileSlowCases):

• jit/JIT.h:
• jit/JITCall.cpp:

(JSC::JIT::emitPutCallResult):
(JSC::JIT::compileSetupFrame):
(JSC::JIT::compileOpCall):
(JSC::JIT::emit_op_iterator_open):
(JSC::JIT::emitSlow_op_iterator_open):
(JSC::JIT::emit_op_iterator_next):
(JSC::JIT::emitSlow_op_iterator_next):

• jit/JITCall32_64.cpp:

(JSC::JIT::emit_op_iterator_open):
(JSC::JIT::emitSlow_op_iterator_open):
(JSC::JIT::emit_op_iterator_next):
(JSC::JIT::emitSlow_op_iterator_next):

• jit/JITInlines.h:

(JSC::JIT::updateTopCallFrame):
(JSC::JIT::advanceToNextCheckpoint):
(JSC::JIT::emitJumpSlowToHotForCheckpoint):
(JSC::JIT::emitValueProfilingSite):

• jit/JITOperations.cpp:
• jit/JITOperations.h:
• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::setupGetByIdPrototypeCache):
(JSC::LLInt::performLLIntGetByID):
(JSC::LLInt::LLINT_SLOW_PATH_DECL):
(JSC::LLInt::genericCall):
(JSC::LLInt::handleIteratorOpenCheckpoint):
(JSC::LLInt::handleIteratorNextCheckpoint):
(JSC::LLInt::slow_path_checkpoint_osr_exit):
(JSC::LLInt::llint_dump_value):

• llint/LowLevelInterpreter.asm:
• llint/LowLevelInterpreter32_64.asm:
• llint/LowLevelInterpreter64.asm:
• offlineasm/transform.rb:
• runtime/CommonSlowPaths.cpp:

(JSC::iterator_open_try_fast):
(JSC::iterator_open_try_fast_narrow):
(JSC::iterator_open_try_fast_wide16):
(JSC::iterator_open_try_fast_wide32):
(JSC::iterator_next_try_fast):
(JSC::iterator_next_try_fast_narrow):
(JSC::iterator_next_try_fast_wide16):
(JSC::iterator_next_try_fast_wide32):

• runtime/CommonSlowPaths.h:
• runtime/Intrinsic.cpp:

(JSC::interationKindForIntrinsic):

• runtime/Intrinsic.h:
• runtime/JSArrayIterator.h:
• runtime/JSCJSValue.h:
• runtime/JSCJSValueInlines.h:

(JSC::JSValue::isCallable const):

• runtime/JSCast.h:
• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::arrayProtoValuesFunctionConcurrently const):

• runtime/OptionsList.h:
• runtime/Structure.cpp:

(JSC::Structure::dumpBrief const):

Source/WTF:

Reviewed by Filip Pizlo.

• wtf/EnumClassOperatorOverloads.h:

Location: trunk Files: