Bug 112202

Summary: [iOS] Add optimized version of StringImpl's equal(LChar*,LChar*) for Apple CPUs
Product: WebKit Reporter: Benjamin Poulain <benjamin>
Component: New BugsAssignee: Benjamin Poulain <benjamin>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, cmarcelo, dglazkov, fpizlo, ggaren, ojan.autocc, peter+ews, psolanki, webkit-ews, webkit.review.bot
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
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Patch
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Patch none

Benjamin Poulain
Reported 2013-03-12 15:38:40 PDT
[iOS] Add optimized version of StringImpl's equal(LChar*,LChar*) for Apple CPUs
Attachments
Patch (2.83 KB, patch)
2013-03-12 15:42 PDT, Benjamin Poulain 		no flags
DetailsFormatted DiffDiff
Patch (4.25 KB, patch)
2013-03-12 17:06 PDT, Benjamin Poulain 		no flags
DetailsFormatted DiffDiff
Patch (4.31 KB, patch)
2013-03-13 00:18 PDT, Benjamin Poulain 		no flags
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Benjamin Poulain
Comment 1 2013-03-12 15:42:56 PDT
Created attachment 192827 [details] Patch
Benjamin Poulain
Comment 2 2013-03-12 15:47:42 PDT
<rdar://problem/12437844>
Early Warning System Bot
Comment 3 2013-03-12 16:01:05 PDT
Comment on attachment 192827 [details] Patch Attachment 192827 [details] did not pass qt-ews (qt): Output: http://webkit-commit-queue.appspot.com/results/17174180
Early Warning System Bot
Comment 4 2013-03-12 16:13:42 PDT
Comment on attachment 192827 [details] Patch Attachment 192827 [details] did not pass qt-wk2-ews (qt): Output: http://webkit-commit-queue.appspot.com/results/17074383
WebKit Review Bot
Comment 5 2013-03-12 16:44:08 PDT
Comment on attachment 192827 [details] Patch Attachment 192827 [details] did not pass chromium-ews (chromium-xvfb): Output: http://webkit-commit-queue.appspot.com/results/17201136
Benjamin Poulain
Comment 6 2013-03-12 17:06:08 PDT
Created attachment 192836 [details] Patch
Gavin Barraclough
Comment 7 2013-03-12 18:09:35 PDT
Comment on attachment 192836 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=192836&action=review Looks good! > Source/WTF/wtf/text/StringImpl.h:933 > + "b 66f\n" I think you could invert this to: -> "bneq 66f" "b 0b" And if you then move the label "0:" down a line, you could branch past the cbz: -> "bneq 66f" "cbnz 0b" This would save an unconditional branch from the loop. Don't know if this might help?
Peter Beverloo (cr-android ews)
Comment 8 2013-03-12 18:55:35 PDT
Comment on attachment 192836 [details] Patch Attachment 192836 [details] did not pass cr-android-ews (chromium-android): Output: http://webkit-commit-queue.appspot.com/results/17188165
Benjamin Poulain
Comment 9 2013-03-12 19:27:40 PDT
> > Source/WTF/wtf/text/StringImpl.h:933 > > + "b 66f\n" > > I think you could invert this to: > -> "bneq 66f" "b 0b" > > And if you then move the label "0:" down a line, you could branch past the cbz: > -> "bneq 66f" "cbnz 0b" > > This would save an unconditional branch from the loop. > Don't know if this might help? Good idea! This is faster indeed.
Benjamin Poulain
Comment 10 2013-03-13 00:18:32 PDT
Created attachment 192876 [details] Patch
Benjamin Poulain
Comment 11 2013-03-13 13:46:23 PDT
Committed r145748: <http://trac.webkit.org/changeset/145748>
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