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GGitHub[libc] add an SVE implementation of strlen (#167259)

8751f26a创建于 2025年11月11日历史提交

文件	最后提交记录	最后更新时间
CMakeLists.txt	[libc] add an SVE implementation of strlen (#167259) This PR creates an SVE-based implementation for strlen by translating from the AOR code in tree. Microbenchmark shows improvements against NEON when N>=64. Although both implementations fall behind glibc by a large margin, this may be a good start point to explore SVE implementations. Together with the PR: 1. Added two more tests of strlen with special nul symbols. 2. Added strlen's fuzzer and fix a typo in previous heap fuzzer. === strlen(16 bytes) === libc: 1.56115 ns/call, 9.54499 GiB/s neon: 1.59393 ns/call, 9.34867 GiB/s sve: 1.66097 ns/call, 8.97134 GiB/s === strlen(64 bytes) === libc: 2.06967 ns/call, 28.7991 GiB/s neon: 2.59914 ns/call, 22.9325 GiB/s sve: 2.58628 ns/call, 23.0465 GiB/s === strlen(256 bytes) === libc: 3.74165 ns/call, 63.7202 GiB/s neon: 8.98243 ns/call, 26.5428 GiB/s sve: 7.36426 ns/call, 32.3751 GiB/s === strlen(1024 bytes) === libc: 10.5327 ns/call, 90.5438 GiB/s neon: 34.363 ns/call, 27.7529 GiB/s sve: 26.9329 ns/call, 35.4092 GiB/s === strlen(4096 bytes) === libc: 37.7304 ns/call, 101.104 GiB/s neon: 145.911 ns/call, 26.144 GiB/s sve: 103.208 ns/call, 36.9612 GiB/s === strlen(1048576 bytes) === libc: 9623.4 ns/call, 101.478 GiB/s neon: 36138.2 ns/call, 27.023 GiB/s sve: 26605.6 ns/call, 36.7051 GiB/s	8 个月前
bcmp_fuzz.cpp	[libc] move bcmp, bzero, bcopy, index, rindex, strcasecmp, strncasecmp to strings.h (#118899) docgen relies on the convention that we have a file foo.cpp in libc/src/\<header\>/. Because the above functions weren't in libc/src/strings/ but rather libc/src/string/, docgen could not find that we had implemented these. Rather than add special carve outs to docgen, let's fix up our sources for these 7 functions to stick with the existing conventions the rest of the codebase follows. Link: #118860 Fixes: #118875	1 年前
memcmp_fuzz.cpp	[libc] Add memcmp / bcmp fuzzers (#77741)	2 年前
strcmp_fuzz.cpp	[libc] Mass replace enclosing namespace (#67032) This is step 4 of https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079	2 年前
strcpy_fuzz.cpp	[libc] Mass replace enclosing namespace (#67032) This is step 4 of https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079	2 年前
strlen_fuzz.cpp	[libc] add an SVE implementation of strlen (#167259) This PR creates an SVE-based implementation for strlen by translating from the AOR code in tree. Microbenchmark shows improvements against NEON when N>=64. Although both implementations fall behind glibc by a large margin, this may be a good start point to explore SVE implementations. Together with the PR: 1. Added two more tests of strlen with special nul symbols. 2. Added strlen's fuzzer and fix a typo in previous heap fuzzer. === strlen(16 bytes) === libc: 1.56115 ns/call, 9.54499 GiB/s neon: 1.59393 ns/call, 9.34867 GiB/s sve: 1.66097 ns/call, 8.97134 GiB/s === strlen(64 bytes) === libc: 2.06967 ns/call, 28.7991 GiB/s neon: 2.59914 ns/call, 22.9325 GiB/s sve: 2.58628 ns/call, 23.0465 GiB/s === strlen(256 bytes) === libc: 3.74165 ns/call, 63.7202 GiB/s neon: 8.98243 ns/call, 26.5428 GiB/s sve: 7.36426 ns/call, 32.3751 GiB/s === strlen(1024 bytes) === libc: 10.5327 ns/call, 90.5438 GiB/s neon: 34.363 ns/call, 27.7529 GiB/s sve: 26.9329 ns/call, 35.4092 GiB/s === strlen(4096 bytes) === libc: 37.7304 ns/call, 101.104 GiB/s neon: 145.911 ns/call, 26.144 GiB/s sve: 103.208 ns/call, 36.9612 GiB/s === strlen(1048576 bytes) === libc: 9623.4 ns/call, 101.478 GiB/s neon: 36138.2 ns/call, 27.023 GiB/s sve: 26605.6 ns/call, 36.7051 GiB/s	8 个月前
strstr_fuzz.cpp	[libc] Mass replace enclosing namespace (#67032) This is step 4 of https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079	2 年前