Changeset 39625 in webkit for trunk/JavaScriptCore/JavaScriptCore.exp

Timestamp:

Jan 5, 2009, 3:57:09 PM (16 years ago)

Author:

[email protected]

Message:

CanvasPixelArray performance is too slow
<​https://bugs.webkit.org/show_bug.cgi?id=23123>

Reviewed by Gavin Barraclough

JavaScriptCore:
The fix to this is to devirtualise get and put in a manner similar to
JSString and JSArray. To do this I've added a ByteArray implementation
and JSByteArray wrapper to JSC. We can then do vptr comparisons to
devirtualise the calls.

This devirtualisation improves performance by 1.5-2x in my somewhat ad
hoc tests.

WebCore:
Remove the WebCore CanvasPixelArray implementation and replace
CPA usage with JSC::ByteArray. Replace the JSCanvasPixelArray
wrapper with an explicitly instantiated JSByteArray put on the
JSImageData object as an ordinary ReadOnly, DontDelete property.

File:

• trunk/JavaScriptCore/JavaScriptCore.exp (modified) (2 diffs)

trunk/JavaScriptCore/JavaScriptCore.exp

@@ -100 +100 @@
 __ZN3JSC10throwErrorEPNS_9ExecStateENS_9ErrorTypeEPKc
 __ZN3JSC10throwErrorEPNS_9ExecStateENS_9ErrorTypeERKNS_7UStringE
+__ZN3JSC11JSByteArray15createStructureEPNS_7JSValueE
+__ZN3JSC11JSByteArrayC1EPNS_9ExecStateEN3WTF10PassRefPtrINS_9StructureEEEPNS_9ByteArrayEPKNS_9ClassInfoE
 __ZN3JSC11JSImmediate12nonInlineNaNEv
 __ZN3JSC11JSImmediate8toObjectEPNS_7JSValueEPNS_9ExecStateE
@@ -247 +249 @@
 __ZN3JSC8evaluateEPNS_9ExecStateERNS_10ScopeChainERKNS_10SourceCodeEPNS_7JSValueE
 __ZN3JSC8jsStringEPNS_12JSGlobalDataERKNS_7UStringE
+__ZN3JSC9ByteArray6createEm
 __ZN3JSC9CodeBlockD1Ev
 __ZN3JSC9CodeBlockD2Ev