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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-05-22 15:09:50 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-06-08 05:07:18 -0700 |
| commit | e0f20b5a54a803ab753f2e2cc1fce7729fa23f81 (patch) | |
| tree | efc375c0e6a600533d48bd6f8abbe386b3f4927e /posix | |
| parent | 83c22fae4287c5fb9c3c43edc16779dcfbc2fa7b (diff) | |
| download | glibc-e0f20b5a54a803ab753f2e2cc1fce7729fa23f81.tar.gz | |
x86-64: Optimize strchr/strchrnul/wcschr with AVX2
Optimize strchr/strchrnul/wcschr with AVX2 to search 32 bytes with vector
instructions. It is as fast as SSE2 versions for size <= 16 bytes and up
to 1X faster for or size > 16 bytes on Haswell. Select AVX2 version 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/multiarch/Makefile (sysdep_routines): Add
strchr-sse2, strchrnul-sse2, strchr-avx2, strchrnul-avx2,
wcschr-sse2 and wcschr-avx2.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add tests for __strchr_avx2,
__strchrnul_avx2, __strchrnul_sse2, __wcschr_avx2 and
__wcschr_sse2.
* sysdeps/x86_64/multiarch/strchr-avx2.S: New file.
* sysdeps/x86_64/multiarch/strchr-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/strchr.c: Likewise.
* sysdeps/x86_64/multiarch/strchrnul-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/strchrnul-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/strchrnul.c: Likewise.
* sysdeps/x86_64/multiarch/wcschr-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/wcschr-sse2.S: Likewise.
* sysdeps/x86_64/multiarch/wcschr.c: Likewise.
* sysdeps/x86_64/multiarch/strchr.S: Removed.
Diffstat (limited to 'posix')
0 files changed, 0 insertions, 0 deletions