Changeset 119795 in webkit for trunk/Source/JavaScriptCore/runtime/JSObject.h

Timestamp:

Jun 7, 2012, 9:25:58 PM (13 years ago)

Author:

[email protected]

Message:

DFG should inline prototype chain accesses, and do the right things if the
specific function optimization is available
​https://bugs.webkit.org/show_bug.cgi?id=88594

Patch by Filip Pizlo <​[email protected]> on 2012-06-07
Reviewed by Gavin Barraclough.

Looks like a 3% win on V8.

• bytecode/CodeBlock.h:

(JSC::Structure::prototypeForLookup):
(JSC):

• bytecode/GetByIdStatus.cpp:

(JSC::GetByIdStatus::computeFromLLInt):
(JSC):
(JSC::GetByIdStatus::computeForChain):
(JSC::GetByIdStatus::computeFor):

• bytecode/GetByIdStatus.h:

(JSC::GetByIdStatus::GetByIdStatus):
(JSC::GetByIdStatus::isSimple):
(JSC::GetByIdStatus::chain):
(JSC::GetByIdStatus::specificValue):
(GetByIdStatus):

• bytecode/StructureSet.h:

(StructureSet):
(JSC::StructureSet::singletonStructure):

• bytecode/StructureStubInfo.h:

(JSC::StructureStubInfo::initGetByIdProto):
(JSC::StructureStubInfo::initGetByIdChain):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleGetById):

• dfg/DFGRepatch.cpp:

(JSC::DFG::tryCacheGetByID):

• jit/JITStubs.cpp:

(JSC::JITThunks::tryCacheGetByID):

• runtime/JSGlobalObject.h:

(JSC::Structure::prototypeForLookup):
(JSC):

• runtime/Structure.h:

(Structure):

File:

• trunk/Source/JavaScriptCore/runtime/JSObject.h (modified) (6 diffs)

trunk/Source/JavaScriptCore/runtime/JSObject.h

@@ -237 +237 @@
         static size_t offsetOfInlineStorage();
         static size_t offsetOfPropertyStorage();
-        static size_t offsetOfInheritorID();
 
         static JS_EXPORTDATA const ClassInfo s_info;
@@ -265 +264 @@
         JSObject(JSGlobalData&, Structure*, PropertyStorage inlineStorage);
         
-        void resetInheritorID()
-        {
-            m_inheritorID.clear();
+        void resetInheritorID(JSGlobalData& globalData)
+        {
+            removeDirect(globalData, globalData.m_inheritorIDKey);
         }
 
@@ -304 +303 @@
 
         StorageBarrier m_propertyStorage;
-        WriteBarrier<Structure> m_inheritorID;
+
+#if USE(JSVALUE32_64)
+        // FIXME: keep the size of JSObject a multiple of 64-bits, so that the
+        // internal storage is aligned. We can remove this when we remove JSCell's
+        // direct ClassInfo pointer.
+        void* sixtyFourBitAlign;
+#endif
     };
 
@@ -312 +317 @@
 #define JSFinalObject_inlineStorageCapacity 6
 #else
-#define JSNonFinalObject_inlineStorageCapacity 2
-#define JSFinalObject_inlineStorageCapacity 4
+#define JSNonFinalObject_inlineStorageCapacity 3
+#define JSFinalObject_inlineStorageCapacity 5
 #endif
 
@@ -418 +423 @@
 }
 
-inline size_t JSObject::offsetOfInheritorID()
-{
-    return OBJECT_OFFSETOF(JSObject, m_inheritorID);
-}
-
 inline bool JSObject::isGlobalObject() const
 {
@@ -515 +515 @@
 inline Structure* JSObject::inheritorID(JSGlobalData& globalData)
 {
-    if (m_inheritorID) {
-        ASSERT(m_inheritorID->isEmpty());
-        return m_inheritorID.get();
+    if (WriteBarrierBase<Unknown>* location = getDirectLocation(globalData, globalData.m_inheritorIDKey)) {
+        Structure* inheritorID = jsCast<Structure*>(location->get());
+        ASSERT(inheritorID->isEmpty());
+        return inheritorID;
     }
     return createInheritorID(globalData);