Bug 229834

Summary: Improve performance by using StringView, not "const StringView&"
Product: WebKit Reporter: Darin Adler <darin>
Component: Web Template FrameworkAssignee: Darin Adler <darin>
Status: RESOLVED FIXED    
Severity: Normal CC: andersca, benjamin, cdumez, changseok, cmarcelo, dbarton, dino, eric.carlson, esprehn+autocc, ews-watchlist, fmalita, fred.wang, glenn, gyuyoung.kim, jer.noble, keith_miller, kondapallykalyan, mark.lam, mifenton, mmaxfield, msaboff, pdr, philipj, saam, sabouhallawa, schenney, sergio, tzagallo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: All   
OS: All   
Attachments:
Description Flags
Patch
andersca: review+, ews-feeder: commit-queue-
Patch none

Darin Adler
Reported 2021-09-02 15:30:03 PDT
Improve performance by using StringView, not "const StringView&"
Attachments
Patch (45.13 KB, patch)
2021-09-02 15:34 PDT, Darin Adler 		andersca: review+
ews-feeder: commit-queue-
DetailsFormatted DiffDiff
Patch (46.67 KB, patch)
2021-09-03 14:36 PDT, Darin Adler 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Darin Adler
Comment 1 2021-09-02 15:34:00 PDT
Created attachment 437204 [details] Patch
Myles C. Maxfield
Comment 2 2021-09-02 21:55:16 PDT
Comment on attachment 437204 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=437204&action=review > Source/WTF/ChangeLog:11 > + Since StringView is a small structure that fits into two registers, it's not > + good to pass a pointer to it; better performance to pass it by value. Note > + that this is for release builds, not debug builds where StringView has > + significant additional overhead when copying. Was there a measurable performance improvement by doing this?
Darin Adler
Comment 3 2021-09-03 13:59:17 PDT
Comment on attachment 437204 [details] Patch Need a new version of this patch; the iterator part of it is wrong for debug builds.
Darin Adler
Comment 4 2021-09-03 14:05:53 PDT
Comment on attachment 437204 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=437204&action=review >> Source/WTF/ChangeLog:11 >> + significant additional overhead when copying. > > Was there a measurable performance improvement by doing this? I do not expect improvement to be measurable except in a micro-benchmark. As with any change, it’s important to double check we don’t measure a slowdown in any of our larger scale benchmarks, and I tried a couple locally and saw no difference.
Darin Adler
Comment 5 2021-09-03 14:36:34 PDT
Created attachment 437312 [details] Patch
Radar WebKit Bug Importer
Comment 6 2021-09-09 15:30:22 PDT
<rdar://problem/82946272>
EWS
Comment 7 2021-09-09 16:39:47 PDT
Committed r282242 (241525@main): <https://commits.webkit.org/241525@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 437312 [details].
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