Bug 46260

Summary: Reduce the number of BOL checks in YARR Interpreter
Product: WebKit Reporter: Peter Varga <pvarga>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, commit-queue, ggaren, msaboff
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
proposed patch none

Peter Varga
Reported 2010-09-22 06:32:31 PDT
The "Yarr JIT code checks BOL (^) each time through loop when in subexpression" (https://bugs.webkit.org/show_bug.cgi?id=45787) optimization slows down the YARR Interpreter. The reason of the slow-down is the modification extends the tree which is generated by the regex parser. The Interpreter doesn't perform the BOL optimization therefore it does some unnecessary matches. The optimization should be implemented in the YARR Interpreter as well.
Attachments
proposed patch (6.72 KB, patch)
2010-09-22 06:37 PDT, Peter Varga 		no flags
DetailsFormatted DiffDiff
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Peter Varga
Comment 1 2010-09-22 06:37:35 PDT
Created attachment 68363 [details] proposed patch performance results: ref mod regexp-dna: - 283.3ms +/- 0.1% 282.5ms +/- 2.2% v8-regexp: 1.51x as fast 2426.7ms +/- 0.1% 1611.1ms +/- 0.7%
Gavin Barraclough
Comment 2 2010-09-22 12:05:14 PDT
Comment on attachment 68363 [details] proposed patch Looks great!
WebKit Commit Bot
Comment 3 2010-09-23 01:40:22 PDT
Comment on attachment 68363 [details] proposed patch Clearing flags on attachment: 68363 Committed r68127: <http://trac.webkit.org/changeset/68127>
WebKit Commit Bot
Comment 4 2010-09-23 01:40:27 PDT
All reviewed patches have been landed. Closing bug.
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