mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2024-11-21 01:12:26 +08:00
Code Issues Packages Projects Releases Wiki Activity

x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations

Browse Source 
The AVX2 strrchr and wcsrchr implementation uses the 'blsmsk'
instruction which belongs to the BMI1 CPU feature and the 'shrx'
instruction, which belongs to the BMI2 CPU feature.

Fixes: df7e295d18 ("x86: Optimize {str|wcs}rchr-avx2")
Partially resolves: BZ #29611

Reviewed-by: Noah Goldstein  <goldstein.w.n@gmail.com>
(cherry picked from commit 7e8283170c)
This commit is contained in:
Aurelien Jarno 2022-10-03 23:16:46 +02:00
parent 36d6b9be3d
commit e570b865b5
2 changed files with 15 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sysdeps/x86_64/multiarch/ifunc-avx2.h
View File

@ -30,6 +30,7 @@ IFUNC_SELECTOR (void)
const struct cpu_features* cpu_features = __get_cpu_features ();
if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
&& CPU_FEATURE_USABLE_P (cpu_features, BMI1)
&& CPU_FEATURE_USABLE_P (cpu_features, BMI2)
&& CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
&& CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))

17
sysdeps/x86_64/multiarch/ifunc-impl-list.c
View File

@ -498,15 +498,21 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
/* Support sysdeps/x86_64/multiarch/strrchr.c. */
IFUNC_IMPL (i, name, strrchr,
IFUNC_IMPL_ADD (array, i, strrchr,
CPU_FEATURE_USABLE (AVX2),
(CPU_FEATURE_USABLE (AVX2)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)),
__strrchr_avx2)
IFUNC_IMPL_ADD (array, i, strrchr,
(CPU_FEATURE_USABLE (AVX2)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__strrchr_avx2_rtm)
IFUNC_IMPL_ADD (array, i, strrchr,
(CPU_FEATURE_USABLE (AVX512VL)
&& CPU_FEATURE_USABLE (AVX512BW)),
&& CPU_FEATURE_USABLE (AVX512BW)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)),
__strrchr_evex)
IFUNC_IMPL_ADD (array, i, strrchr, 1, __strrchr_sse2))
@ -687,15 +693,20 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
/* Support sysdeps/x86_64/multiarch/wcsrchr.c. */
IFUNC_IMPL (i, name, wcsrchr,
IFUNC_IMPL_ADD (array, i, wcsrchr,
CPU_FEATURE_USABLE (AVX2),
(CPU_FEATURE_USABLE (AVX2)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)),
__wcsrchr_avx2)
IFUNC_IMPL_ADD (array, i, wcsrchr,
(CPU_FEATURE_USABLE (AVX2)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__wcsrchr_avx2_rtm)
IFUNC_IMPL_ADD (array, i, wcsrchr,
(CPU_FEATURE_USABLE (AVX512VL)
&& CPU_FEATURE_USABLE (AVX512BW)
&& CPU_FEATURE_USABLE (BMI1)
&& CPU_FEATURE_USABLE (BMI2)),
__wcsrchr_evex)
IFUNC_IMPL_ADD (array, i, wcsrchr, 1, __wcsrchr_sse2))