Changeset 100880 in webkit for trunk/Source/JavaScriptCore/dfg/DFGJITCompiler.cpp

Timestamp:

Nov 20, 2011, 8:45:17 PM (14 years ago)

Author:

[email protected]

Message:

Inline caches that refer to otherwise dead objects should be cleared
​https://bugs.webkit.org/show_bug.cgi?id=72311

Reviewed by Geoff Garen.

DFG code blocks now participate in the weak reference harvester fixpoint
so that they only consider themselves to be live if either they are
currently executing, or their owner is live and all of their weak references
are live. If not, the relevant code blocks are jettisoned.

Inline caches in both the old JIT and the DFG are now cleared if any of
their references are not marked at the end of a GC.

This is performance-neutral on SunSpider, V8, and Kraken. With the clear-
all-code-on-GC policy that we currently have, it shows a slight reduction
in memory usage. If we turn that policy off, it's pretty easy to come up
with an example program that will cause ToT to experience linear heap
growth, while with this patch, the heap stays small and remains at a
constant size.

• assembler/ARMv7Assembler.h:

(JSC::ARMv7Assembler::readCallTarget):

• assembler/MacroAssemblerARMv7.h:

(JSC::MacroAssemblerARMv7::readCallTarget):

• assembler/MacroAssemblerX86.h:

(JSC::MacroAssemblerX86::readCallTarget):

• assembler/MacroAssemblerX86_64.h:

(JSC::MacroAssemblerX86_64::readCallTarget):

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::visitAggregate):
(JSC::CodeBlock::performTracingFixpointIteration):
(JSC::CodeBlock::visitWeakReferences):
(JSC::CodeBlock::finalizeUnconditionally):
(JSC::CodeBlock::stronglyVisitStrongReferences):
(JSC::MethodCallLinkInfo::reset):
(JSC::ProgramCodeBlock::jettison):
(JSC::EvalCodeBlock::jettison):
(JSC::FunctionCodeBlock::jettison):

• bytecode/CodeBlock.h:

(JSC::CodeBlock::reoptimize):
(JSC::CodeBlock::shouldImmediatelyAssumeLivenessDuringScan):

• bytecode/Instruction.h:

(JSC::PolymorphicAccessStructureList::visitWeak):

• bytecode/StructureStubInfo.cpp:

(JSC::StructureStubInfo::visitWeakReferences):

• bytecode/StructureStubInfo.h:

(JSC::isGetByIdAccess):
(JSC::isPutByIdAccess):
(JSC::StructureStubInfo::reset):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::link):

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

(JSC::DFG::dfgRepatchByIdSelfAccess):
(JSC::DFG::dfgResetGetByID):
(JSC::DFG::dfgResetPutByID):

• dfg/DFGRepatch.h:

(JSC::DFG::dfgResetGetByID):
(JSC::DFG::dfgResetPutByID):

• jit/JIT.h:
• jit/JITPropertyAccess.cpp:

(JSC::JIT::resetPatchGetById):
(JSC::JIT::resetPatchPutById):

• jit/JITPropertyAccess32_64.cpp:

(JSC::JIT::resetPatchGetById):
(JSC::JIT::resetPatchPutById):

• jit/JITStubs.cpp:

(JSC::DEFINE_STUB_FUNCTION):

• jit/JITWriteBarrier.h:

(JSC::JITWriteBarrierBase::clearToMaxUnsigned):

File:

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

trunk/Source/JavaScriptCore/dfg/DFGJITCompiler.cpp

@@ -158 +158 @@
         CodeLocationCall callReturnLocation = linkBuffer.locationOf(m_propertyAccesses[i].m_functionCall);
         info.callReturnLocation = callReturnLocation;
-        info.u.unset.deltaCheckImmToCall = differenceBetweenCodePtr(linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCheckImmToCall), callReturnLocation);
+        info.deltaCheckImmToCall = differenceBetweenCodePtr(linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCheckImmToCall), callReturnLocation);
         info.deltaCallToStructCheck = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToStructCheck));
 #if USE(JSVALUE64)
-        info.u.unset.deltaCallToLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToLoadOrStore));
+        info.deltaCallToLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToLoadOrStore));
 #else
-        info.u.unset.deltaCallToTagLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToTagLoadOrStore));
-        info.u.unset.deltaCallToPayloadLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToPayloadLoadOrStore));
+        info.deltaCallToTagLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToTagLoadOrStore));
+        info.deltaCallToPayloadLoadOrStore = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToPayloadLoadOrStore));
 #endif
         info.deltaCallToSlowCase = differenceBetweenCodePtr(callReturnLocation, linkBuffer.locationOf(m_propertyAccesses[i].m_deltaCallToSlowCase));