Polymorphic call inlining should be based on polymorphic call inline caching rather...
authorfpizlo@apple.com <fpizlo@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Thu, 29 Jan 2015 20:33:45 +0000 (20:33 +0000)
committerfpizlo@apple.com <fpizlo@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Thu, 29 Jan 2015 20:33:45 +0000 (20:33 +0000)
commit949029e83922ee8800d4bc75d87176af25a17ba5
tree84174bf2488ae088edd83a4bdcb3944301a10417
parent3192249dc663897fb2c38d28f6433edd0d63363d
Polymorphic call inlining should be based on polymorphic call inline caching rather than logging
https://bugs.webkit.org/show_bug.cgi?id=140660

Reviewed by Geoffrey Garen.

When we first implemented polymorphic call inlining, we did the profiling based on a call
edge log. The idea was to store each call edge (a tuple of call site and callee) into a
global log that was processed lazily. Processing the log would give precise counts of call
edges, and could be used to drive well-informed inlining decisions - polymorphic or not.
This was a speed-up on throughput tests but a slow-down for latency tests. It was a net win
nonetheless.

Experience with this code shows three things. First, the call edge profiler is buggy and
complex. It would take work to fix the bugs. Second, the call edge profiler incurs lots of
overhead for latency code that we care deeply about. Third, it's not at all clear that
having call edge counts for every possible callee is any better than just having call edge
counts for the limited number of callees that an inline cache would catch.

So, this patch removes the call edge profiler and replaces it with a polymorphic call inline
cache. If we miss the basic call inline cache, we inflate the cache to be a jump to an
out-of-line stub that cases on the previously known callees. If that misses again, then we
rewrite that stub to include the new callee. We do this up to some number of callees. If we
hit the limit then we switch to using a plain virtual call.

Substantial speed-up on V8Spider; undoes the slow-down that the original call edge profiler
caused. Might be a SunSpider speed-up (below 1%), depending on hardware.

* CMakeLists.txt:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CallEdge.h:
(JSC::CallEdge::count):
(JSC::CallEdge::CallEdge):
* bytecode/CallEdgeProfile.cpp: Removed.
* bytecode/CallEdgeProfile.h: Removed.
* bytecode/CallEdgeProfileInlines.h: Removed.
* bytecode/CallLinkInfo.cpp:
(JSC::CallLinkInfo::unlink):
(JSC::CallLinkInfo::visitWeak):
* bytecode/CallLinkInfo.h:
* bytecode/CallLinkStatus.cpp:
(JSC::CallLinkStatus::CallLinkStatus):
(JSC::CallLinkStatus::computeFor):
(JSC::CallLinkStatus::computeFromCallLinkInfo):
(JSC::CallLinkStatus::isClosureCall):
(JSC::CallLinkStatus::makeClosureCall):
(JSC::CallLinkStatus::dump):
(JSC::CallLinkStatus::computeFromCallEdgeProfile): Deleted.
* bytecode/CallLinkStatus.h:
(JSC::CallLinkStatus::CallLinkStatus):
(JSC::CallLinkStatus::isSet):
(JSC::CallLinkStatus::variants):
(JSC::CallLinkStatus::size):
(JSC::CallLinkStatus::at):
(JSC::CallLinkStatus::operator[]):
(JSC::CallLinkStatus::canOptimize):
(JSC::CallLinkStatus::edges): Deleted.
(JSC::CallLinkStatus::canTrustCounts): Deleted.
* bytecode/CallVariant.cpp:
(JSC::variantListWithVariant):
(JSC::despecifiedVariantList):
* bytecode/CallVariant.h:
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::~CodeBlock):
(JSC::CodeBlock::linkIncomingPolymorphicCall):
(JSC::CodeBlock::unlinkIncomingCalls):
(JSC::CodeBlock::noticeIncomingCall):
* bytecode/CodeBlock.h:
(JSC::CodeBlock::isIncomingCallAlreadyLinked): Deleted.
* dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::addCallWithoutSettingResult):
(JSC::DFG::ByteCodeParser::handleCall):
(JSC::DFG::ByteCodeParser::handleInlining):
* dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* dfg/DFGConstantFoldingPhase.cpp:
(JSC::DFG::ConstantFoldingPhase::foldConstants):
* dfg/DFGDoesGC.cpp:
(JSC::DFG::doesGC):
* dfg/DFGDriver.cpp:
(JSC::DFG::compileImpl):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* dfg/DFGNode.h:
(JSC::DFG::Node::hasHeapPrediction):
* dfg/DFGNodeType.h:
* dfg/DFGOperations.cpp:
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSafeToExecute.h:
(JSC::DFG::safeToExecute):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::emitCall):
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::emitCall):
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGTierUpCheckInjectionPhase.cpp:
(JSC::DFG::TierUpCheckInjectionPhase::run):
(JSC::DFG::TierUpCheckInjectionPhase::removeFTLProfiling): Deleted.
* ftl/FTLCapabilities.cpp:
(JSC::FTL::canCompile):
* heap/Heap.cpp:
(JSC::Heap::collect):
* jit/BinarySwitch.h:
* jit/ClosureCallStubRoutine.cpp: Removed.
* jit/ClosureCallStubRoutine.h: Removed.
* jit/JITCall.cpp:
(JSC::JIT::compileOpCall):
* jit/JITCall32_64.cpp:
(JSC::JIT::compileOpCall):
* jit/JITOperations.cpp:
* jit/JITOperations.h:
(JSC::operationLinkPolymorphicCallFor):
(JSC::operationLinkClosureCallFor): Deleted.
* jit/JITStubRoutine.h:
* jit/JITWriteBarrier.h:
* jit/PolymorphicCallStubRoutine.cpp: Added.
(JSC::PolymorphicCallNode::~PolymorphicCallNode):
(JSC::PolymorphicCallNode::unlink):
(JSC::PolymorphicCallCase::dump):
(JSC::PolymorphicCallStubRoutine::PolymorphicCallStubRoutine):
(JSC::PolymorphicCallStubRoutine::~PolymorphicCallStubRoutine):
(JSC::PolymorphicCallStubRoutine::variants):
(JSC::PolymorphicCallStubRoutine::edges):
(JSC::PolymorphicCallStubRoutine::visitWeak):
(JSC::PolymorphicCallStubRoutine::markRequiredObjectsInternal):
* jit/PolymorphicCallStubRoutine.h: Added.
(JSC::PolymorphicCallNode::PolymorphicCallNode):
(JSC::PolymorphicCallCase::PolymorphicCallCase):
(JSC::PolymorphicCallCase::variant):
(JSC::PolymorphicCallCase::codeBlock):
* jit/Repatch.cpp:
(JSC::linkSlowFor):
(JSC::linkFor):
(JSC::revertCall):
(JSC::unlinkFor):
(JSC::linkVirtualFor):
(JSC::linkPolymorphicCall):
(JSC::linkClosureCall): Deleted.
* jit/Repatch.h:
* jit/ThunkGenerators.cpp:
(JSC::linkPolymorphicCallForThunkGenerator):
(JSC::linkPolymorphicCallThunkGenerator):
(JSC::linkPolymorphicCallThatPreservesRegsThunkGenerator):
(JSC::linkClosureCallForThunkGenerator): Deleted.
(JSC::linkClosureCallThunkGenerator): Deleted.
(JSC::linkClosureCallThatPreservesRegsThunkGenerator): Deleted.
* jit/ThunkGenerators.h:
(JSC::linkPolymorphicCallThunkGeneratorFor):
(JSC::linkClosureCallThunkGeneratorFor): Deleted.
* llint/LLIntSlowPaths.cpp:
(JSC::LLInt::jitCompileAndSetHeuristics):
* runtime/Options.h:
* runtime/VM.cpp:
(JSC::VM::prepareToDiscardCode):
(JSC::VM::ensureCallEdgeLog): Deleted.
* runtime/VM.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@179357 268f45cc-cd09-0410-ab3c-d52691b4dbfc
52 files changed:
Source/JavaScriptCore/CMakeLists.txt
Source/JavaScriptCore/ChangeLog
Source/JavaScriptCore/JavaScriptCore.vcxproj/JavaScriptCore.vcxproj
Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
Source/JavaScriptCore/bytecode/CallEdge.h
Source/JavaScriptCore/bytecode/CallEdgeProfile.cpp [deleted file]
Source/JavaScriptCore/bytecode/CallEdgeProfile.h [deleted file]
Source/JavaScriptCore/bytecode/CallEdgeProfileInlines.h [deleted file]
Source/JavaScriptCore/bytecode/CallLinkInfo.cpp
Source/JavaScriptCore/bytecode/CallLinkInfo.h
Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
Source/JavaScriptCore/bytecode/CallLinkStatus.h
Source/JavaScriptCore/bytecode/CallVariant.cpp
Source/JavaScriptCore/bytecode/CallVariant.h
Source/JavaScriptCore/bytecode/CodeBlock.cpp
Source/JavaScriptCore/bytecode/CodeBlock.h
Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h
Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
Source/JavaScriptCore/dfg/DFGClobberize.h
Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp
Source/JavaScriptCore/dfg/DFGDoesGC.cpp
Source/JavaScriptCore/dfg/DFGDriver.cpp
Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
Source/JavaScriptCore/dfg/DFGNode.h
Source/JavaScriptCore/dfg/DFGNodeType.h
Source/JavaScriptCore/dfg/DFGOperations.cpp
Source/JavaScriptCore/dfg/DFGPredictionPropagationPhase.cpp
Source/JavaScriptCore/dfg/DFGSafeToExecute.h
Source/JavaScriptCore/dfg/DFGSpeculativeJIT32_64.cpp
Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp
Source/JavaScriptCore/dfg/DFGTierUpCheckInjectionPhase.cpp
Source/JavaScriptCore/ftl/FTLCapabilities.cpp
Source/JavaScriptCore/heap/Heap.cpp
Source/JavaScriptCore/jit/BinarySwitch.h
Source/JavaScriptCore/jit/ClosureCallStubRoutine.cpp [deleted file]
Source/JavaScriptCore/jit/ClosureCallStubRoutine.h [deleted file]
Source/JavaScriptCore/jit/JITCall.cpp
Source/JavaScriptCore/jit/JITCall32_64.cpp
Source/JavaScriptCore/jit/JITOperations.cpp
Source/JavaScriptCore/jit/JITOperations.h
Source/JavaScriptCore/jit/JITStubRoutine.h
Source/JavaScriptCore/jit/JITWriteBarrier.h
Source/JavaScriptCore/jit/PolymorphicCallStubRoutine.cpp [new file with mode: 0644]
Source/JavaScriptCore/jit/PolymorphicCallStubRoutine.h [new file with mode: 0644]
Source/JavaScriptCore/jit/Repatch.cpp
Source/JavaScriptCore/jit/Repatch.h
Source/JavaScriptCore/jit/ThunkGenerators.cpp
Source/JavaScriptCore/jit/ThunkGenerators.h
Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
Source/JavaScriptCore/runtime/Options.h
Source/JavaScriptCore/runtime/VM.cpp
Source/JavaScriptCore/runtime/VM.h