Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: d21310b806f3d23c9a6c0ea4478221c5eb6eafd7
https://github.com/WebKit/WebKit/commit/d21310b806f3d23c9a6c0ea4478221c5eb6eafd7
Author: Sosuke Suzuki <[email protected]>
Date: 2026-08-24 (Mon, 24 Aug 2026)
Changed paths:
A JSTests/microbenchmarks/regexp-lookbehind-fixed-count-group.js
A JSTests/microbenchmarks/regexp-lookbehind-quantified-group.js
A JSTests/stress/regexp-lookbehind-jit-quantified-groups-unicode.js
A JSTests/stress/regexp-lookbehind-jit-quantified-groups.js
M Source/JavaScriptCore/yarr/YarrJIT.cpp
M Source/JavaScriptCore/yarr/YarrPattern.cpp
Log Message:
-----------
[YARR] Compile lookbehinds containing quantified groups in the JIT
https://bugs.webkit.org/show_bug.cgi?id=322244
Reviewed by Daniel Liu.
A group quantified with anything other than {1} or ? inside a lookbehind, e.g.
(?<=(?:ab)+),
sent the whole pattern to the interpreter.
The counted and ParenContext group opcodes only save, compare and restore the
index, so they
work in either direction. Two checks did depend on it: the lazy group's "try
one more iteration"
test must see the index move down when matching backward, and the optional copy
the parser
splits a backward X{n,m} into must not clear the captures it shares with the
mandatory part
when it backtracks out of zero iterations. Forward code generation is unchanged.
Baseline
Patched
regexp-lookbehind-quantified-group 2598.3586+-382.2034 ^
200.9308+-11.4910 ^ definitely 12.9316x faster
regexp-lookbehind-fixed-count-group 3523.6885+-262.9262 ^
218.0944+-3.0137 ^ definitely 16.1567x faster
Tests: JSTests/microbenchmarks/regexp-lookbehind-fixed-count-group.js
JSTests/microbenchmarks/regexp-lookbehind-quantified-group.js
JSTests/stress/regexp-lookbehind-jit-quantified-groups-unicode.js
JSTests/stress/regexp-lookbehind-jit-quantified-groups.js
* JSTests/microbenchmarks/regexp-lookbehind-fixed-count-group.js: Added.
(let.re):
* JSTests/microbenchmarks/regexp-lookbehind-quantified-group.js: Added.
* JSTests/stress/regexp-lookbehind-jit-quantified-groups-unicode.js: Added.
(shouldBe):
(stringify):
(stringifyIndices):
(shouldBe.stringify):
(a.z):
(shouldBe.stringify.y):
(c.u.exec):
(shouldBe.string_appeared_here.replace):
(shouldBe.stringifyIndices):
(shouldBe.stringifyIndices.y):
* JSTests/stress/regexp-lookbehind-jit-quantified-groups.js: Added.
(shouldBe):
(stringify):
(stringifyIndices):
(shouldBe.stringify):
(shouldBe.stringify.y):
(shouldBe.stringify.y.yb):
(shouldBe.stringify.x):
(b.exec):
(shouldBe.string_appeared_here.replace):
(shouldBe.stringifyIndices):
(shouldBe.stringifyIndices.y):
* Source/JavaScriptCore/yarr/YarrJIT.cpp:
* Source/JavaScriptCore/yarr/YarrPattern.cpp:
(JSC::Yarr::YarrPatternConstructor::quantifyAtom):
Canonical link: https://commits.webkit.org/319743@main
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