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| author | H.J. Lu <hjl.tools@gmail.com> | 2022-02-07 05:55:15 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2022-02-08 15:58:56 -0800 |
| commit | 3d9f171bfb5325bd5f427e9fc386453358c6e840 (patch) | |
| tree | 5caeddafa6cb494bbe102c34f7f2ee630f5d83cf /sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S | |
| parent | dc98eeeb952f59bdbd51da0409e732756fe30170 (diff) | |
| download | glibc-3d9f171bfb5325bd5f427e9fc386453358c6e840.tar.gz glibc-3d9f171bfb5325bd5f427e9fc386453358c6e840.tar.xz glibc-3d9f171bfb5325bd5f427e9fc386453358c6e840.zip | |
x86-64: Optimize bzero
memset with zero as the value to set is by far the majority value (99%+ for Python3 and GCC). bzero can be slightly more optimized for this case by using a zero-idiom xor for broadcasting the set value to a register (vector or GPR). Co-developed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Diffstat (limited to 'sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S index 6370021506..5d8fa78f05 100644 --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S @@ -19,6 +19,9 @@ vpbroadcastb d, %VEC0; \ movq r, %rax +# define BZERO_ZERO_VEC0() \ + vpxorq %XMM0, %XMM0, %XMM0 + # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ vpbroadcastd d, %VEC0; \ movq r, %rax |