Changeset 255541 in webkit for trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

Jan 31, 2020, 9:22:47 PM (6 years ago)

Author:

[email protected]

Message:

[JSC] ShrinkToFit some vectors kept by JIT data structures
​https://bugs.webkit.org/show_bug.cgi?id=207085

Reviewed by Mark Lam.

1. We are allocating RareCaseProfile by using SegmentedVector since JIT code is directly accessing to RareCaseProfile*. But when creating RareCaseProfile, we can know how many RareCaseProfiles should we create: RareCaseProfile is created per slow paths of Baseline JIT bytecode. Since we already scan bytecode for the main paths, we can count it and use this number when creating RareCaseProfile.
2. Vectors held by PolymorphicAccess and PolymorphicCallStubRoutine should be kept small by calling shrinkToFit.

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::setRareCaseProfiles):
(JSC::CodeBlock::shrinkToFit):
(JSC::CodeBlock::addRareCaseProfile): Deleted.

• bytecode/CodeBlock.h:
• bytecode/PolyProtoAccessChain.cpp:

(JSC::PolyProtoAccessChain::create):

• bytecode/PolymorphicAccess.cpp:

(JSC::PolymorphicAccess::regenerate):

• bytecode/ValueProfile.h:

(JSC::RareCaseProfile::RareCaseProfile):

• jit/JIT.cpp:

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

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

(JSC::PolymorphicCallStubRoutine::PolymorphicCallStubRoutine):

File:

• trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -1578 +1578 @@
 }
 
-RareCaseProfile* CodeBlock::addRareCaseProfile(BytecodeIndex bytecodeIndex)
+void CodeBlock::setRareCaseProfiles(RefCountedArray<RareCaseProfile>&& rareCaseProfiles)
 {
     ConcurrentJSLocker locker(m_lock);
-    auto& jitData = ensureJITData(locker);
-    jitData.m_rareCaseProfiles.append(RareCaseProfile(bytecodeIndex));
-    return &jitData.m_rareCaseProfiles.last();
+    ensureJITData(locker).m_rareCaseProfiles = WTFMove(rareCaseProfiles);
 }
 
@@ -1957 +1955 @@
     ConcurrentJSLocker locker(m_lock);
 
-#if ENABLE(JIT)
-    if (auto* jitData = m_jitData.get())
-        jitData->m_rareCaseProfiles.shrinkToFit();
-#endif
-    
     if (shrinkMode == EarlyShrink) {
         m_constantRegisters.shrinkToFit();