Changeset 58935 in webkit for trunk/JavaScriptCore/runtime

Timestamp:

May 6, 2010, 9:58:02 PM (15 years ago)

Author:

[email protected]

Message:

Bug 38714 - Add result caching for Math.sin

Reviewed by Geoff Garen.

Math.sin is frequently called with the same operand, caching the result should
improve performance. CachedTranscendentalFunction adds a generic mechanism to
cache results for pure functions with the signature "double func(double)", and
where NaN maps to NaN.

CachedTranscendentalFunction uses a very simple hash function designed to be
fast to execute since we cannot cache the result, and trivial to JIT generate,
should we wish to do so.

• JavaScriptCore.xcodeproj/project.pbxproj:
• runtime/CachedTranscendentalFunction.h: Added.

(JSC::CachedTranscendentalFunction::CachedTranscendentalFunction):
(JSC::CachedTranscendentalFunction::~CachedTranscendentalFunction):
(JSC::CachedTranscendentalFunction::operator()):
(JSC::CachedTranscendentalFunction::initialize):
(JSC::CachedTranscendentalFunction::hash):

• runtime/JSGlobalData.h:
• runtime/MathObject.cpp:

(JSC::mathProtoFuncSin):

• wtf/Platform.h:

Location:

trunk/JavaScriptCore/runtime

Files:

• CachedTranscendentalFunction.h (added)
• JSGlobalData.h (modified) (2 diffs)
• MathObject.cpp (modified) (1 diff)

trunk/JavaScriptCore/runtime/JSGlobalData.h

@@ -30 +30 @@
 #define JSGlobalData_h
 
+#include "CachedTranscendentalFunction.h"
 #include "Collector.h"
 #include "DateInstanceCache.h"
@@ -213 +214 @@
 #endif
 
+        CachedTranscendentalFunction<sin> cachedSin;
+
         void resetDateCache();
 

trunk/JavaScriptCore/runtime/MathObject.cpp

@@ -224 +224 @@
 JSValue JSC_HOST_CALL mathProtoFuncSin(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
-    return jsDoubleNumber(exec, sin(args.at(0).toNumber(exec)));
+    return exec->globalData().cachedSin(exec, args.at(0).toNumber(exec));
 }