Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 579b96614b756c61746ae554282b87c7bf7ac3b0
https://github.com/WebKit/WebKit/commit/579b96614b756c61746ae554282b87c7bf7ac3b0
Author: Yusuke Suzuki <[email protected]>
Date: 2026-01-28 (Wed, 28 Jan 2026)
Changed paths:
M Source/JavaScriptCore/assembler/MacroAssemblerARM64.h
M Source/JavaScriptCore/yarr/YarrJIT.cpp
M Source/JavaScriptCore/yarr/YarrJITRegisters.h
Log Message:
-----------
[JSC] Add SIMD search path for RegExp fast search
https://bugs.webkit.org/show_bug.cgi?id=306308
rdar://168958736
Reviewed by Yijia Huang.
This patch implements SIMD fast prefix search before entering the RegExp
matching. This is something optimized version compared to BM search in
our RegExp for particular patterns. The idea is derievd from V8's SIMD
search[1]. When there are two alternatives which has 4 characters
preceeding, like /aaaa|bbbb/, then we collect these 4 characters and
create 2 mask. And do a SIMD search to find potential starting index
quickly.
Basic idea of the loop body is,
if ((input & mask) != chars) {
// Quick reject - neither pattern can match
advance by 16
} else {
// Check specific patterns
}
And it is extended for SIMD.
v1 = load(cursor)
v2 = load(cursor + 1)
v3 = load(cursor + 2)
v4 = load(cursor + 3)
t1 = (v1 & mask) == chars
t2 = (v2 & mask) == chars
t3 = (v3 & mask) == chars
t4 = (v4 & mask) == chars
r1 = t1 | t2
r2 = t3 | t4
result = tbl2(r1, r2, pattern) // TBL2: extract byte 0 of each 32-bit
word from {r1, r2}
if (result) {
// There is a match
// Doing a scalar loop.
}
[1]: https://chromium-review.googlesource.com/c/v8/v8/+/6918972
* Source/JavaScriptCore/assembler/MacroAssemblerARM64.h:
(JSC::MacroAssemblerARM64::move128ToVector):
* Source/JavaScriptCore/yarr/YarrJIT.cpp:
(JSC::Yarr::MaskedAlternativeInfo::computeMaskForCharacterClass):
(JSC::Yarr::MaskedAlternativeInfo::create):
* Source/JavaScriptCore/yarr/YarrJITRegisters.h:
Canonical link: https://commits.webkit.org/306383@main
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