Bug 229834 – Improve performance by using StringView, not "const StringView&"

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Template Framework

[Darin Adler]

Improve performance by using StringView, not "const StringView&"

[Darin Adler]

Created attachment 437204 [details]
Patch

[Myles C. Maxfield]

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 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 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]

Created attachment 437312 [details]
Patch

[Radar WebKit Bug Importer]

<rdar://problem/82946272>

[EWS]

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].