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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-06-09 05:13:15 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-06-09 05:13:31 -0700 |
| commit | 2f5d20ac99b9434a634629282cbb46e2a8d56a1c (patch) | |
| tree | 6a9dcdd8346cd5ad6473b165a404c9961359c6ed /sysdeps/x86_64/multiarch/rawmemchr-sse2.S | |
| parent | 990c32b93a29d8b8d599e10ebca19a260f84cbba (diff) | |
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x86-64: Optimize memchr/rawmemchr/wmemchr with SSE2/AVX2
SSE2 memchr is extended to support wmemchr. AVX2 memchr/rawmemchr/wmemchr
are added to search 32 bytes with a single vector compare instruction.
AVX2 memchr/rawmemchr/wmemchr are as fast as SSE2 memchr/rawmemchr/wmemchr
for small sizes and up to 1.5X faster for larger sizes on Haswell and
Skylake. Select AVX2 memchr/rawmemchr/wmemchr on AVX2 machines where
vzeroupper is preferred and AVX unaligned load is fast.
NB: It uses TZCNT instead of BSF since TZCNT produces the same result
as BSF for non-zero input. TZCNT is faster than BSF and is executed
as BSF if machine doesn't support TZCNT.
* sysdeps/x86_64/memchr.S (MEMCHR): New. Depending on if
USE_AS_WMEMCHR is defined.
(PCMPEQ): Likewise.
(memchr): Renamed to ...
(MEMCHR): This. Support wmemchr if USE_AS_WMEMCHR is defined.
Replace pcmpeqb with PCMPEQ.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
memchr-sse2, rawmemchr-sse2, memchr-avx2, rawmemchr-avx2,
wmemchr-sse4_1, wmemchr-avx2 and wmemchr-c.
* sysdeps/x86_64/multiarch/ifunc-avx2.h: New file.
* sysdeps/x86_64/multiarch/memchr-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/memchr-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/memchr.c: Likewise.
* sysdeps/x86_64/multiarch/rawmemchr-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/rawmemchr-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/rawmemchr.c: Likewise.
* sysdeps/x86_64/multiarch/wmemchr-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/wmemchr-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/wmemchr.c: Likewise.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Test __memchr_avx2, __memchr_sse2,
__rawmemchr_avx2, __rawmemchr_sse2, __wmemchr_avx2 and
__wmemchr_sse2.
Diffstat (limited to 'sysdeps/x86_64/multiarch/rawmemchr-sse2.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/rawmemchr-sse2.S | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/rawmemchr-sse2.S b/sysdeps/x86_64/multiarch/rawmemchr-sse2.S new file mode 100644 index 0000000000..233bbc7552 --- /dev/null +++ b/sysdeps/x86_64/multiarch/rawmemchr-sse2.S @@ -0,0 +1,29 @@ +/* rawmemchr optimized with SSE2. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* Define multiple versions only for the definition in libc. */ +#if IS_IN (libc) +# define __rawmemchr __rawmemchr_sse2 + +# undefine weak_alias +# define weak_alias(__rawmemchr, rawmemchr) +# undef libc_hidden_def +# define libc_hidden_def(__rawmemchr) +#endif + +#include "../rawmemchr.S" |