Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: e14189a28e4cb71c4449d328d41cca2851f289e4
https://github.com/WebKit/WebKit/commit/e14189a28e4cb71c4449d328d41cca2851f289e4
Author: Sosuke Suzuki <[email protected]>
Date: 2026-05-27 (Wed, 27 May 2026)
Changed paths:
A JSTests/microbenchmarks/intl-string-tolocalelowercase.js
A JSTests/microbenchmarks/intl-string-tolocaleuppercase.js
A JSTests/stress/to-locale-case-root-fast-path.js
M Source/JavaScriptCore/runtime/StringPrototype.cpp
Log Message:
-----------
[JSC] Add a root-locale fast path to `toLocaleLowerCase` and
`toLocaleUpperCase`
https://bugs.webkit.org/show_bug.cgi?id=315630
Reviewed by Yusuke Suzuki.
toLocaleLowerCase / toLocaleUpperCase always went through ICU
(u_strToLower / u_strToUpper) and always upconverted the string to UTF-16,
even when the resolved locale does not affect case mapping.
Unicode case mapping is locale-independent except for the tailoring locales
az, el, lt, and tr. For every other locale (including the "und" root locale
that results when the locale argument is undefined), the result is identical
to the locale-independent ("root") case conversion, which already has
ASCII/Latin-1 fast paths.
TipOfTree Patched
intl-string-tolocalelowercase 146.4819+-2.1938 ^ 24.6959+-0.5805
^ definitely 5.9314x faster
intl-string-tolocaleuppercase 147.4327+-2.7373 ^ 24.9070+-0.9821
^ definitely 5.9193x faster
Tests: JSTests/microbenchmarks/intl-string-tolocalelowercase.js
JSTests/microbenchmarks/intl-string-tolocaleuppercase.js
JSTests/stress/to-locale-case-root-fast-path.js
* JSTests/microbenchmarks/intl-string-tolocalelowercase.js: Added.
(test):
* JSTests/microbenchmarks/intl-string-tolocaleuppercase.js: Added.
(test):
* JSTests/stress/to-locale-case-root-fast-path.js: Added.
(shouldBe):
* Source/JavaScriptCore/runtime/StringPrototype.cpp:
(JSC::toLocaleCase):
Canonical link: https://commits.webkit.org/313951@main
To unsubscribe from these emails, change your notification settings at
https://github.com/WebKit/WebKit/settings/notifications
