Changeset 34265 in webkit for trunk/JavaScriptCore/kjs/JSImmediate.h

Timestamp:

May 30, 2008, 1:10:38 PM (17 years ago)

Author:

[email protected]

Message:

Reviewed by Darin.

​https://bugs.webkit.org/show_bug.cgi?id=19180
speed up SunSpider by optimizing immediate number cases

Also fixed a JavaScriptCore regression seen on PowerPC - we didn't clip left shift
parameter to 0...31.

0.5% improvement on SunSpider overall, although a 8.5 regression on bitops-3bit-bits-in-byte.

• VM/Machine.cpp: (KJS::Machine::privateExecute): Added fast paths for >>> and <<.

• kjs/JSImmediate.h: (KJS::JSImmediate::toTruncatedUInt32): Added. Same as getTruncatedInt32, but casts the result to unsigned.

File:

• trunk/JavaScriptCore/kjs/JSImmediate.h (modified) (2 diffs)

trunk/JavaScriptCore/kjs/JSImmediate.h

@@ -168 +168 @@
     static JSObject* toObject(const JSValue*, ExecState*);
     static UString toString(const JSValue*);
+    static uint32_t toTruncatedUInt32(const JSValue*);
     static JSType type(const JSValue*);
 
@@ -220 +221 @@
     uintptr_t bits = unTag(v);
     return (bits != 0) & (JSImmediate::getTag(v) != UndefinedType);
+}
+
+ALWAYS_INLINE uint32_t JSImmediate::toTruncatedUInt32(const JSValue* v)
+{
+    ASSERT(isImmediate(v));
+    return static_cast<uint32_t>(reinterpret_cast<intptr_t>(v) >> 2);
 }