Changeset 123682 in webkit for trunk/Source/JavaScriptCore/runtime/JSObject.cpp

Timestamp:

Jul 25, 2012, 5:12:58 PM (13 years ago)

Author:

[email protected]

Message:

Remove JSObject::m_inheritorID
​https://bugs.webkit.org/show_bug.cgi?id=88378

Reviewed by Filip Pizlo.

This is rarely used, and not performance critical (the commonly accessed copy is cached on JSFunction),
and most objects don't need an inheritorID (this value is only used if the object is used as a prototype).
Instead use a private named value in the object's property storage.

• dfg/DFGSpeculativeJIT.h:

(JSC::DFG::SpeculativeJIT::emitAllocateBasicJSObject): No need m_inheritorID to initialize!

• jit/JITInlineMethods.h:

(JSC::JIT::emitAllocateBasicJSObject): No need m_inheritorID to initialize!

• llint/LowLevelInterpreter.asm: No need m_inheritorID to initialize!
• runtime/JSGlobalData.h:

(JSGlobalData): Added private name 'm_inheritorIDKey'.

• runtime/JSGlobalThis.cpp:

(JSC::JSGlobalThis::setUnwrappedObject): resetInheritorID is now passed a JSGlobalData&.

• runtime/JSObject.cpp:

(JSC::JSObject::visitChildren): No m_inheritorID to be marked.
(JSC::JSFinalObject::visitChildren): No m_inheritorID to be marked.
(JSC::JSObject::createInheritorID): Store the newly created inheritorID in the property map. Make sure
it's got the DontEnum attribute!!

• runtime/JSObject.h:

(JSObject):
(JSC::JSObject::resetInheritorID): Remove the inheritorID from property storage.
(JSC):
(JSC::JSObject::inheritorID): Read the inheritorID from property storage.

File:

• trunk/Source/JavaScriptCore/runtime/JSObject.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/runtime/JSObject.cpp

@@ -108 +108 @@
     }
 
-    if (thisObject->m_inheritorID)
-        visitor.append(&thisObject->m_inheritorID);
-
 #if !ASSERT_DISABLED
     visitor.m_isCheckingForDefaultMarkViolation = wasCheckingForDefaultMarkViolation;
@@ -137 +134 @@
         thisObject->m_outOfLineStorage.set(storage, StorageBarrier::Unchecked);
     }
-
-    if (thisObject->m_inheritorID)
-        visitor.append(&thisObject->m_inheritorID);
 
     size_t storageSize = thisObject->structure()->inlineSizeForKnownFinalObject();
@@ -581 +575 @@
 Structure* JSObject::createInheritorID(JSGlobalData& globalData)
 {
+    ASSERT(!getDirectLocation(globalData, globalData.m_inheritorIDKey));
+
     JSGlobalObject* globalObject;
     if (isGlobalThis())
@@ -587 +583 @@
         globalObject = structure()->globalObject();
     ASSERT(globalObject);
-    m_inheritorID.set(globalData, this, createEmptyObjectStructure(globalData, globalObject, this));
-    ASSERT(m_inheritorID->isEmpty());
-    return m_inheritorID.get();
+
+    Structure* inheritorID = createEmptyObjectStructure(globalData, globalObject, this);
+    ASSERT(inheritorID->isEmpty());
+
+    PutPropertySlot slot;
+    putDirectInternal<PutModeDefineOwnProperty>(globalData, globalData.m_inheritorIDKey, inheritorID, DontEnum, slot, 0);
+    return inheritorID;
 }