Changeset 279053 in webkit

Timestamp:

Jun 20, 2021 2:48:03 AM (13 months ago)

Author:

ysuzuki@apple.com

Message:

[JSC] Add ValueOf fast path in toPrimitive
​https://bugs.webkit.org/show_bug.cgi?id=226948

Reviewed by Ross Kirsling.

JSTests:

• microbenchmarks/valueof-via-toprimitive.js: Added.

Source/JavaScriptCore:

Add fast path for Object.prototype.valueOf function call since we
sometimes encounter this case in Speedometer2/EmberJS-Debug-TodoMVC.

ToT Patched

value-of-call 65.7169+-0.6192 ^{45.0986+-0.0830} definitely 1.4572x faster

• runtime/JSCJSValue.cpp:

(JSC::JSValue::toStringSlowCase const):

• runtime/JSObject.cpp:

(JSC::callToPrimitiveFunction):

Location:

trunk

Files:

• JSTests/ChangeLog (modified) (1 diff)
• JSTests/microbenchmarks/valueof-via-toprimitive.js (added)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/runtime/JSCJSValue.cpp (modified) (1 diff)
• Source/JavaScriptCore/runtime/JSObject.cpp (modified) (1 diff)

trunk/JSTests/ChangeLog

@@ +1 @@
+2021-06-20  Yusuke Suzuki  <ysuzuki@apple.com>
+
+        [JSC] Add ValueOf fast path in toPrimitive
+        https://bugs.webkit.org/show_bug.cgi?id=226948
+
+        Reviewed by Ross Kirsling.
+
+        * microbenchmarks/valueof-via-toprimitive.js: Added.
+
 2021-06-17  Saam Barati  <sbarati@apple.com>
 

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2021-06-20  Yusuke Suzuki  <ysuzuki@apple.com>
+
+        [JSC] Add ValueOf fast path in toPrimitive
+        https://bugs.webkit.org/show_bug.cgi?id=226948
+
+        Reviewed by Ross Kirsling.
+
+        Add fast path for Object.prototype.valueOf function call since we
+        sometimes encounter this case in Speedometer2/EmberJS-Debug-TodoMVC.
+
+                                       ToT                     Patched
+
+            value-of-call        65.7169+-0.6192     ^     45.0986+-0.0830        ^ definitely 1.4572x faster
+
+        * runtime/JSCJSValue.cpp:
+        (JSC::JSValue::toStringSlowCase const):
+        * runtime/JSObject.cpp:
+        (JSC::callToPrimitiveFunction):
+
 2021-06-20  Robin Morisset  <rmorisset@apple.com>
 

trunk/Source/JavaScriptCore/runtime/JSCJSValue.cpp

@@ -435 +435 @@
     }
 
-    ASSERT(isCell());
-    JSValue value = asCell()->toPrimitive(globalObject, PreferString);
+    ASSERT(isObject()); // String, Symbol, and HeapBigInt are already handled.
+    JSValue value = asObject(asCell())->toPrimitive(globalObject, PreferString);
     RETURN_IF_EXCEPTION(scope, errorValue());
     ASSERT(!value.isObject());

trunk/Source/JavaScriptCore/runtime/JSObject.cpp

@@ -2235 +2235 @@
     }
 
+    if constexpr (key == CachedSpecialPropertyKey::ValueOf) {
+        if (function == globalObject->objectProtoValueOfFunction())
+            return JSValue();
+    }
+
     auto callData = getCallData(vm, function);
     if (callData.type == CallData::Type::None) {