Changeset 165135 in webkit for trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp

Timestamp:

Mar 5, 2014, 3:33:21 PM (11 years ago)

Author:

[email protected]

Message:

JSCell::m_gcData should encode its information differently
​https://bugs.webkit.org/show_bug.cgi?id=129741

Reviewed by Geoffrey Garen.

We want to keep track of three GC states for an object:

1. Not marked (which implies not in the remembered set)
2. Marked but not in the remembered set
3. Marked and in the remembered set

Currently we only indicate marked vs. not marked in JSCell::m_gcData. During a write
barrier, we only want to take the slow path if the object being stored to is in state #2.
We'd like to make the test for state #2 as fast as possible, which means making it a
compare against 0.

• dfg/DFGOSRExitCompilerCommon.cpp:

(JSC::DFG::osrWriteBarrier):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::checkMarkByte):
(JSC::DFG::SpeculativeJIT::writeBarrier):

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

(JSC::DFG::SpeculativeJIT::writeBarrier):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::writeBarrier):

• ftl/FTLLowerDFGToLLVM.cpp:

(JSC::FTL::LowerDFGToLLVM::allocateCell):
(JSC::FTL::LowerDFGToLLVM::emitStoreBarrier):

• heap/Heap.cpp:

(JSC::Heap::clearRememberedSet):
(JSC::Heap::addToRememberedSet):

• jit/AssemblyHelpers.h:

(JSC::AssemblyHelpers::checkMarkByte):

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

(JSC::JIT::checkMarkByte):
(JSC::JIT::emitWriteBarrier):

• jit/Repatch.cpp:

(JSC::writeBarrier):

• llint/LowLevelInterpreter.asm:
• llint/LowLevelInterpreter32_64.asm:
• llint/LowLevelInterpreter64.asm:
• runtime/JSCell.h:

(JSC::JSCell::mark):
(JSC::JSCell::remember):
(JSC::JSCell::forget):
(JSC::JSCell::isMarked):
(JSC::JSCell::isRemembered):

• runtime/JSCellInlines.h:

(JSC::JSCell::JSCell):

• runtime/StructureIDBlob.h:

(JSC::StructureIDBlob::StructureIDBlob):

File:

• trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp

@@ -5043 +5043 @@
         isNotCell = m_jit.branchTest64(JITCompiler::NonZero, valueGPR, GPRInfo::tagMaskRegister);
 
-    JITCompiler::Jump definitelyNotMarked = genericWriteBarrier(m_jit, ownerGPR);
+    JITCompiler::Jump ownerNotMarkedOrAlreadyRemembered = checkMarkByte(m_jit, ownerGPR);
     storeToWriteBarrierBuffer(ownerGPR, scratch1, scratch2);
-    definitelyNotMarked.link(&m_jit);
+    ownerNotMarkedOrAlreadyRemembered.link(&m_jit);
 
     if (!isKnownCell(valueUse.node()))
@@ -5057 +5057 @@
         isNotCell = m_jit.branchTest64(JITCompiler::NonZero, valueGPR, GPRInfo::tagMaskRegister);
 
-    JITCompiler::Jump definitelyNotMarked = genericWriteBarrier(m_jit, owner);
+    JITCompiler::Jump ownerNotMarkedOrAlreadyRemembered = checkMarkByte(m_jit, owner);
     storeToWriteBarrierBuffer(owner, scratch1, scratch2);
-    definitelyNotMarked.link(&m_jit);
+    ownerNotMarkedOrAlreadyRemembered.link(&m_jit);
 
     if (!isKnownCell(valueUse.node()))