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

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.scons (modified) (2 diffs)

trunk/JavaScriptCore/JavaScriptCore.scons

@@ -50 +50 @@
     'runtime/BooleanObject.cpp',
     'runtime/BooleanPrototype.cpp',
+    'runtime/ByteArray.cpp',
     'runtime/CallData.cpp',
     'runtime/Collector.cpp',
@@ -73 +74 @@
     'runtime/JSActivation.cpp',
     'runtime/JSArray.cpp',
+    'runtime/JSByteArray.cpp',
     'runtime/JSCell.cpp',
     'runtime/JSFunction.cpp',