Changeset 36735 in webkit for trunk/JavaScriptCore/kjs/JSActivation.cpp

Timestamp:

Sep 21, 2008, 1:37:01 AM (17 years ago)

Author:

[email protected]

Message:

2008-09-21 Cameron Zwarich <​[email protected]>

Reviewed by Maciej Stachowiak.

Bug 20815: 'arguments' object creation is non-optimal
<​https://bugs.webkit.org/show_bug.cgi?id=20815>

Fix our inefficient way of creating the arguments object by only
creating named properties for each of the arguments after a use of the
'delete' statement. This patch also speeds up access to the 'arguments'
object slightly, but it still does not use the array fast path for
indexed access that exists for many opcodes.

This is about a 20% improvement on the V8 Raytrace benchmark, and a 1.5%
improvement on the Earley-Boyer benchmark, which gives a 4% improvement
overall.

JavaScriptCore:

• kjs/Arguments.cpp: (JSC::Arguments::Arguments): (JSC::Arguments::mark): (JSC::Arguments::getOwnPropertySlot): (JSC::Arguments::put): (JSC::Arguments::deleteProperty):
• kjs/Arguments.h: (JSC::Arguments::ArgumentsData::ArgumentsData):
• kjs/IndexToNameMap.h: (JSC::IndexToNameMap::size):
• kjs/JSActivation.cpp: (JSC::JSActivation::createArgumentsObject):
• kjs/JSActivation.h: (JSC::JSActivation::uncheckedSymbolTableGet): (JSC::JSActivation::uncheckedSymbolTableGetValue): (JSC::JSActivation::uncheckedSymbolTablePut):
• kjs/JSFunction.h: (JSC::JSFunction::numParameters):

LayoutTests:

• fast/js/arguments-expected.txt: Added.
• fast/js/arguments.html: Added.
• fast/js/resources/arguments.js: Added.

File:

• trunk/JavaScriptCore/kjs/JSActivation.cpp (modified) (2 diffs)

trunk/JavaScriptCore/kjs/JSActivation.cpp

@@ -162 +162 @@
 }
 
-JSObject* JSActivation::createArgumentsObject(ExecState* exec)
+Arguments* JSActivation::createArgumentsObject(ExecState* exec)
 {
     Register* callFrame = d()->registers - d()->functionBody->generatedByteCode().numLocals - RegisterFile::CallFrameHeaderSize;
@@ -172 +172 @@
 
     ArgList args(argv, argc);
-    return new (exec) Arguments(exec, function, args, this);
+    int firstArgumentIndex = -d()->functionBody->generatedByteCode().numLocals + 1;
+    return new (exec) Arguments(exec, function, args, this, firstArgumentIndex, argv);
 }