Changeset 259583 in webkit for trunk/Source/JavaScriptCore/dfg/DFGNode.cpp

Timestamp:

Apr 6, 2020, 11:48:04 AM (5 years ago)

Author:

Justin Michaud

Message:

Allow deleteById to be cached in the DFG
​https://bugs.webkit.org/show_bug.cgi?id=208664

Reviewed by Saam Barati.

JSTests:

• microbenchmarks/delete-property-allocation-sinking.js: Added.

(assert):
(noInline.assert.blackbox):
(noInline.blackbox.doAlloc1):
(noInline.doAlloc1):

• microbenchmarks/polyvariant-delete-property.js: Added.

(assert):
(blackbox):
(noInline.blackbox.polyvariant):
(doAlloc1):
(noInline.doAlloc1.doAlloc2):
(noInline.doAlloc2):

• stress/delete-property-dfg-inline.js: Added.

(assert):
(noInline.assert.assert_throws):
(noInline.assert_throws.blackbox):
(noInline.blackbox.testSingleStructure.doAlloc1):
(noInline.blackbox.testSingleStructure):
(noInline.testSingleStructure.testInlineSingleStructure.doDelete2):
(noInline.testSingleStructure.testInlineSingleStructure.doAlloc2):
(noInline.testSingleStructure.testInlineSingleStructure):
(noInline.testInlineSingleStructure.testExit.doDelete3):
(noInline.testInlineSingleStructure.testExit):
(noInline.testExit.testSingleStructureMiss.doAlloc4):
(noInline.testExit.testSingleStructureMiss):
(noInline.testSingleStructureMiss.testSingleStructureMissStrict.string_appeared_here.doAlloc5):
(noInline.testSingleStructureMiss.testSingleStructureMissStrict):
(noInline.testSingleStructureMissStrict.testSingleStructureMissNonConfigurable.doAlloc6):
(noInline.testSingleStructureMissStrict.testSingleStructureMissNonConfigurable):
(noInline.testSingleStructureMissNonConfigurable.testSingleStructureEmpty.doAlloc7):
(noInline.testSingleStructureMissNonConfigurable.testSingleStructureEmpty):
(noInline.testSingleStructureEmpty.testPolymorphic.doDelete8):
(noInline.testSingleStructureEmpty.testPolymorphic):
(noInline.testPolymorphic.testPolyvariant.doDelete9):
(noInline.testPolymorphic.testPolyvariant.polyvariant):
(noInline.testPolymorphic.testPolyvariant):
(noInline.testPolyvariant.testConstantFolding.doDelete10):
(noInline.testPolyvariant.testConstantFolding):
(noInline.testConstantFolding.testObjectSinking.doAlloc11):
(noInline.testConstantFolding.testObjectSinking):
(noInline.testObjectSinking.testProxy.doAlloc12):
(noInline.testObjectSinking.testProxy.noInline.doDelete12):
(noInline.testObjectSinking.testProxy):
(noInline.testProxy.testTypedArray.doDelete12):
(noInline.testProxy.testTypedArray):
(noInline.testTypedArray.testMissMixed.doDelete13):
(noInline.testTypedArray.testMissMixed):
(noInline.testMissMixed.testMissNonMixed.doDelete14):
(noInline.testMissMixed.testMissNonMixed):
(noInline.testMissNonMixed.testByVal.doDelete15):
(noInline.testMissNonMixed.testByVal):

Source/JavaScriptCore:

When we see that the deleteById inline cache only saw one structure, we inline it into the DFG. This involves
creating a new node, FilterDeleteByStatus, and then turning these DeleteById nodes into a FilterDeleteByStatus,
CheckStructure, PutByOffset, then PutStructure (or just a CheckStructure in the case of a miss). The logic for
pessimising this optimization is the same as for PutById, giving inlined functions the opportunity to use only
the DFG profiling information, while everything else uses the DFG+Baseline information.

This also adds a MultiDeleteByOffset node, for the case when there are multiple structures seen by the delete. If
all of the cases are the same kind of miss, then we only emit a CheckStructure and constant.

Finally, if we see a delete by val with a single identifier, we inline that too.

This patch removes a dead code path from deleteProperty that checks if we need to nuke the object's butterfly.
This also fixes a bug where we were checking the neutering status of typed arrays for named properties when we should
only check for indexed properties. The behavior of this now matches for all tiers including when cached.

The benchmark shows a 2x improvement on polyvariant-delete-property, and a 50% improvement on delete-property-allocation-sinking.

• CMakeLists.txt:
• JavaScriptCore.xcodeproj/project.pbxproj:
• Sources.txt:
• bytecode/AccessCase.cpp:

(JSC::AccessCase::createDelete):
(JSC::AccessCase::generateImpl):

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::getICStatusMap):

• bytecode/DeleteByIdVariant.cpp: Added.

(JSC::DeleteByIdVariant::DeleteByIdVariant):
(JSC::DeleteByIdVariant::~DeleteByIdVariant):
(JSC::DeleteByIdVariant::operator=):
(JSC::DeleteByIdVariant::attemptToMerge):
(JSC::DeleteByIdVariant::writesStructures const):
(JSC::DeleteByIdVariant::visitAggregate):
(JSC::DeleteByIdVariant::markIfCheap):
(JSC::DeleteByIdVariant::dump const):
(JSC::DeleteByIdVariant::finalize):
(JSC::DeleteByIdVariant::dumpInContext const):

• bytecode/DeleteByIdVariant.h: Added.

(JSC::DeleteByIdVariant::oldStructure const):
(JSC::DeleteByIdVariant::newStructure const):
(JSC::DeleteByIdVariant::result const):
(JSC::DeleteByIdVariant::offset const):
(JSC::DeleteByIdVariant::isPropertyUnset const):
(JSC::DeleteByIdVariant::identifier const):
(JSC::DeleteByIdVariant::overlaps):

• bytecode/DeleteByStatus.cpp: Added.

(JSC::DeleteByStatus::appendVariant):
(JSC::DeleteByStatus::computeForBaseline):
(JSC::DeleteByStatus::DeleteByStatus):
(JSC::DeleteByStatus::computeForStubInfoWithoutExitSiteFeedback):
(JSC::DeleteByStatus::computeFor):
(JSC::DeleteByStatus::slowVersion const):
(JSC::DeleteByStatus::merge):
(JSC::DeleteByStatus::filter):
(JSC::DeleteByStatus::singleIdentifier const):
(JSC::DeleteByStatus::visitAggregate):
(JSC::DeleteByStatus::markIfCheap):
(JSC::DeleteByStatus::finalize):
(JSC::DeleteByStatus::dump const):

• bytecode/DeleteByStatus.h: Added.
• bytecode/ICStatusMap.h:
• bytecode/RecordedStatuses.cpp:

(JSC::RecordedStatuses::operator=):
(JSC::RecordedStatuses::addDeleteByStatus):
(JSC::RecordedStatuses::visitAggregate):
(JSC::RecordedStatuses::markIfCheap):

• bytecode/RecordedStatuses.h:

(JSC::RecordedStatuses::forEachVector):

• dfg/DFGAbstractInterpreterInlines.h:

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

• dfg/DFGArgumentsEliminationPhase.cpp:
• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleDeleteById):
(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGClobberize.h:

(JSC::DFG::clobberize):

• dfg/DFGClobbersExitState.cpp:

(JSC::DFG::clobbersExitState):

• dfg/DFGConstantFoldingPhase.cpp:

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

• dfg/DFGDoesGC.cpp:

(JSC::DFG::doesGC):

• dfg/DFGFixupPhase.cpp:

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

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::dump):

• dfg/DFGGraph.h:
• dfg/DFGMayExit.cpp:
• dfg/DFGNode.cpp:

(JSC::DFG::MultiDeleteByOffsetData::writesStructures const):

• dfg/DFGNode.h:

(JSC::DFG::Node::hasMultiDeleteByOffsetData):
(JSC::DFG::Node::multiDeleteByOffsetData):
(JSC::DFG::Node::hasDeleteByStatus):
(JSC::DFG::Node::deleteByStatus):

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

(JSC::DFG::safeToExecute):

• dfg/DFGSpeculativeJIT32_64.cpp:

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

• dfg/DFGSpeculativeJIT64.cpp:

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

• dfg/DFGTypeCheckHoistingPhase.cpp:

(JSC::DFG::TypeCheckHoistingPhase::identifyRedundantStructureChecks):
(JSC::DFG::TypeCheckHoistingPhase::identifyRedundantArrayChecks):

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

(JSC::FTL::canCompile):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::compileNode):
(JSC::FTL::DFG::LowerDFGToB3::compileMultiDeleteByOffset):

• runtime/JSGenericTypedArrayViewInlines.h:

(JSC::JSGenericTypedArrayView<Adaptor>::deleteProperty):

• runtime/JSObject.cpp:

(JSC::JSObject::deleteProperty):

• runtime/Structure.h:
• runtime/StructureInlines.h:

(JSC::Structure::mayHaveIndexingHeader const): Deleted.
(JSC::Structure::canCacheDeleteIC const): Deleted.

File:

• trunk/Source/JavaScriptCore/dfg/DFGNode.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/dfg/DFGNode.cpp

@@ -58 +58 @@
 }
 
+bool MultiDeleteByOffsetData::writesStructures() const
+{
+    for (unsigned i = variants.size(); i--;) {
+        if (variants[i].writesStructures())
+            return true;
+    }
+    return false;
+}
+
 void BranchTarget::dump(PrintStream& out) const
 {