diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2015-01-30 06:50:20 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2015-01-30 15:37:58 -0800 |
| commit | 5f3d0b78e011d2a72f9e88b0e9ef5bc081d18f97 (patch) | |
| tree | 8eabf127206283d2421bc40b6bc44e123e346598 /sysdeps/x86_64/multiarch/mempcpy.S | |
| parent | b658fdd82b4524cf6a39881d092caa23f63d93ac (diff) | |
| download | glibc-5f3d0b78e011d2a72f9e88b0e9ef5bc081d18f97.tar.gz | |
Use AVX unaligned memcpy only if AVX2 is available
memcpy with unaligned 256-bit AVX register loads/stores are slow on older
processorsl like Sandy Bridge. This patch adds bit_AVX_Fast_Unaligned_Load
and sets it only when AVX2 is available.
[BZ #17801]
* sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
Set the bit_AVX_Fast_Unaligned_Load bit for AVX2.
* sysdeps/x86_64/multiarch/init-arch.h (bit_AVX_Fast_Unaligned_Load):
New.
(index_AVX_Fast_Unaligned_Load): Likewise.
(HAS_AVX_FAST_UNALIGNED_LOAD): Likewise.
* sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Check the
bit_AVX_Fast_Unaligned_Load bit instead of the bit_AVX_Usable bit.
* sysdeps/x86_64/multiarch/memcpy_chk.S (__memcpy_chk): Likewise.
* sysdeps/x86_64/multiarch/mempcpy.S (__mempcpy): Likewise.
* sysdeps/x86_64/multiarch/mempcpy_chk.S (__mempcpy_chk): Likewise.
* sysdeps/x86_64/multiarch/memmove.c (__libc_memmove): Replace
HAS_AVX with HAS_AVX_FAST_UNALIGNED_LOAD.
* sysdeps/x86_64/multiarch/memmove_chk.c (__memmove_chk): Likewise.
Diffstat (limited to 'sysdeps/x86_64/multiarch/mempcpy.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/mempcpy.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sysdeps/x86_64/multiarch/mempcpy.S b/sysdeps/x86_64/multiarch/mempcpy.S index cdf1dab62b..2eaacdf049 100644 --- a/sysdeps/x86_64/multiarch/mempcpy.S +++ b/sysdeps/x86_64/multiarch/mempcpy.S @@ -37,7 +37,7 @@ ENTRY(__mempcpy) testl $bit_Fast_Copy_Backward, __cpu_features+FEATURE_OFFSET+index_Fast_Copy_Backward(%rip) jz 2f leaq __mempcpy_ssse3_back(%rip), %rax - testl $bit_AVX_Usable, __cpu_features+FEATURE_OFFSET+index_AVX_Usable(%rip) + testl $bit_AVX_Fast_Unaligned_Load, __cpu_features+FEATURE_OFFSET+index_AVX_Fast_Unaligned_Load(%rip) jz 2f leaq __mempcpy_avx_unaligned(%rip), %rax 2: ret |