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authorAurelien Jarno <aurelien@aurel32.net>2022-10-03 23:16:46 +0200
committerAurelien Jarno <aurelien@aurel32.net>2022-10-03 23:53:40 +0200
commit20152a849b34abe83c702b27b7276c96b191b644 (patch)
tree78a8551ef0fa55c8c9fcbc44d9f665432f6649dd
parent02aa1f4a5b6955f2cb384daa4e520d9c8078a078 (diff)
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x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations
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: df7e295d18ff ("x86: Optimize {str|wcs}rchr-avx2") Partially resolves: BZ #29611 Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com> (cherry picked from commit 7e8283170c5d6805b609a040801d819e362a6292)
-rw-r--r--sysdeps/x86_64/multiarch/ifunc-avx2.h1
-rw-r--r--sysdeps/x86_64/multiarch/ifunc-impl-list.c17
2 files changed, 15 insertions, 3 deletions
diff --git a/sysdeps/x86_64/multiarch/ifunc-avx2.h b/sysdeps/x86_64/multiarch/ifunc-avx2.h
index 5cc1e4b0bc..0456fa6efe 100644
--- a/sysdeps/x86_64/multiarch/ifunc-avx2.h
+++ b/sysdeps/x86_64/multiarch/ifunc-avx2.h
@@ -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))
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index a7c8ebbe85..b224e6a644 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -516,15 +516,21 @@ __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))
@@ -705,15 +711,20 @@ __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))