Changeset 36802 in webkit for trunk/JavaScriptCore/VM/Machine.cpp

Timestamp:

Sep 23, 2008, 12:46:55 AM (17 years ago)

Author:

[email protected]

Message:

JavaScriptCore:

2008-09-23 Maciej Stachowiak <​[email protected]>

Reviewed by Darin.

• speed up instanceof some more ​https://bugs.webkit.org/show_bug.cgi?id=20818

~2% speedup on EarleyBoyer

The idea here is to record in the StructureID whether the class
needs a special hasInstance or if it can use the normal logic from
JSObject.

Based on this I inlined the real work directly into
cti_op_instanceof and put the fastest checks up front and the
error handling at the end (so it should be fairly straightforward
to split off the beginning to be inlined if desired).

I only did this for CTI, not the bytecode interpreter.

• API/JSCallbackObject.h: (JSC::JSCallbackObject::createStructureID):
• ChangeLog:
• VM/Machine.cpp: (JSC::Machine::cti_op_instanceof):
• kjs/JSImmediate.h: (JSC::JSImmediate::isAnyImmediate):
• kjs/TypeInfo.h: (JSC::TypeInfo::overridesHasInstance): (JSC::TypeInfo::flags):

WebCore:

2008-09-23 Maciej Stachowiak <​[email protected]>

Reviewed by Darin.

• speed up instanceof some more ​https://bugs.webkit.org/show_bug.cgi?id=20818

~2% speedup on EarleyBoyer

(WebCore updates.)

• bindings/js/JSQuarantinedObjectWrapper.h: (WebCore::JSQuarantinedObjectWrapper::createStructureID):

File:

• trunk/JavaScriptCore/VM/Machine.cpp (modified) (2 diffs)

trunk/JavaScriptCore/VM/Machine.cpp

@@ -4293 +4293 @@
 {
     ExecState* exec = ARG_exec;
+    JSValue* value = ARG_src1;
     JSValue* baseVal = ARG_src2;
-
+    JSValue* proto = ARG_src3;
+
+    if (UNLIKELY(JSImmediate::isAnyImmediate(value, baseVal, proto)))
+        goto slow_cases;
+
+    JSCell* valueCell = static_cast<JSCell*>(value);
+    JSCell* baseCell = static_cast<JSCell*>(baseVal);
+    JSCell* protoCell = static_cast<JSCell*>(proto);
+
+    if (UNLIKELY(!valueCell->isObject() | !baseCell->isObject() | !protoCell->isObject()))
+        goto slow_cases;
+
+    if (UNLIKELY((baseCell->structureID()->typeInfo().flags() & (ImplementsHasInstance | OverridesHasInstance)) != ImplementsHasInstance))
+        goto slow_cases;
+
+    JSObject* testPrototype = static_cast<JSObject*>(static_cast<JSObject*>(valueCell)->prototype());
+
+    if (testPrototype == proto)
+        return jsBoolean(true);
+
+    while (testPrototype != jsNull()) {
+        testPrototype = static_cast<JSObject*>(testPrototype->prototype());
+        if (testPrototype == proto)
+            return jsBoolean(true);
+    }
+
+    return jsBoolean(false);
+
+ slow_cases:     
     if (!baseVal->isObject()) {
         CodeBlock* codeBlock = ARG_codeBlock;
@@ -4303 +4332 @@
     }
 
-    JSObject* baseObj = static_cast<JSObject*>(baseVal);
-    JSValue* basePrototype = ARG_src3;
-    JSValue* result = jsBoolean(baseObj->structureID()->typeInfo().implementsHasInstance() ? baseObj->hasInstance(exec,  ARG_src1, basePrototype) : false);
+    baseCell = static_cast<JSCell*>(baseVal);
+    if (!baseCell->structureID()->typeInfo().implementsHasInstance())
+        return jsBoolean(false);
+
+    if (!proto->isObject()) {
+        throwError(exec, TypeError, "instanceof called on an object with an invalid prototype property.");
+        VM_CHECK_EXCEPTION(JSValue*);
+    }
+        
+    if (!value->isObject())
+        return jsBoolean(false);
+
+    ASSERT(baseCell->structureID()->typeInfo().implementsHasInstance());
+
+    JSValue* result = jsBoolean(static_cast<JSObject*>(baseCell)->hasInstance(exec, value, proto));
     VM_CHECK_EXCEPTION_AT_END();
+
     return result;
 }