Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 33a5272cf9acb5e290cb58b1ec6b5a9a1ef1ee70
https://github.com/WebKit/WebKit/commit/33a5272cf9acb5e290cb58b1ec6b5a9a1ef1ee70
Author: Sosuke Suzuki <[email protected]>
Date: 2026-08-04 (Tue, 04 Aug 2026)
Changed paths:
A JSTests/microbenchmarks/locale-compare-with-locales.js
A JSTests/stress/string-locale-compare-locales-cache.js
M Source/JavaScriptCore/runtime/JSGlobalObject.cpp
M Source/JavaScriptCore/runtime/JSGlobalObject.h
M Source/JavaScriptCore/runtime/StringPrototype.cpp
Log Message:
-----------
[JSC] Cache the collator for `String#localeCompare` with a string locale
https://bugs.webkit.org/show_bug.cgi?id=320962
Reviewed by Yusuke Suzuki.
`String#localeCompare(that, locale)` created a fresh IntlCollator on
every call whenever `locales` was not undefined, running full option
probing, resolveLocale and ucol_open per comparison. This makes the
common sort comparator pattern
`items.sort((a, b) => a.name.localeCompare(b.name, "en"))` very slow.
This patch adds a single-entry per-JSGlobalObject cache keyed by the
locale string, used when `locales` is a string and `options` is
undefined. In that case examining the arguments has no observable side
effects, so reusing the collator is not observable (V8 caches the
collator under the same condition).
baseline patched
locale-compare-with-locales 111.1431+-2.0657 ^ 2.0815+-0.0727
^ definitely 53.3946x faster
locale-compare 0.9404+-0.0560 0.9292+-0.0475
might be 1.0120x faster
Tests: JSTests/microbenchmarks/locale-compare-with-locales.js
JSTests/stress/string-locale-compare-locales-cache.js
* JSTests/microbenchmarks/locale-compare-with-locales.js: Added.
* JSTests/stress/string-locale-compare-locales-cache.js: Added.
(shouldBe):
* Source/JavaScriptCore/runtime/JSGlobalObject.cpp:
(JSC::JSGlobalObject::visitChildrenImpl):
(JSC::JSGlobalObject::cachedLocaleCompareCollator):
* Source/JavaScriptCore/runtime/JSGlobalObject.h:
* Source/JavaScriptCore/runtime/StringPrototype.cpp:
(JSC::JSC_DEFINE_HOST_FUNCTION):
Canonical link: https://commits.webkit.org/318542@main
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