From 7e8283170c5d6805b609a040801d819e362a6292 Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Mon, 3 Oct 2022 23:46:11 +0200 Subject: [PATCH] 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 --- sysdeps/x86/isa-level.h | 1 + sysdeps/x86_64/multiarch/ifunc-avx2.h | 1 + sysdeps/x86_64/multiarch/ifunc-impl-list.c | 17 ++++++++++++++--- 3 files changed, 16 insertions(+), 3 deletions(-) diff --git a/sysdeps/x86/isa-level.h b/sysdeps/x86/isa-level.h index bbb90f5c5e..06f6c9663e 100644 --- a/sysdeps/x86/isa-level.h +++ b/sysdeps/x86/isa-level.h @@ -79,6 +79,7 @@ /* ISA level >= 3 guaranteed includes. */ #define AVX_X86_ISA_LEVEL 3 #define AVX2_X86_ISA_LEVEL 3 +#define BMI1_X86_ISA_LEVEL 3 #define BMI2_X86_ISA_LEVEL 3 #define LZCNT_X86_ISA_LEVEL 3 #define MOVBE_X86_ISA_LEVEL 3 diff --git a/sysdeps/x86_64/multiarch/ifunc-avx2.h b/sysdeps/x86_64/multiarch/ifunc-avx2.h index f1741083fd..f2f5e8a211 100644 --- a/sysdeps/x86_64/multiarch/ifunc-avx2.h +++ b/sysdeps/x86_64/multiarch/ifunc-avx2.h @@ -36,6 +36,7 @@ IFUNC_SELECTOR (void) const struct cpu_features *cpu_features = __get_cpu_features (); if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2) + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI1) && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2) && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, LZCNT) && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features, diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c index ec1c5b55fb..00a91123d3 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -578,13 +578,19 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strrchr, X86_IFUNC_IMPL_ADD_V4 (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) X86_IFUNC_IMPL_ADD_V3 (array, i, strrchr, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI1) + && CPU_FEATURE_USABLE (BMI2)), __strrchr_avx2) X86_IFUNC_IMPL_ADD_V3 (array, i, strrchr, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI1) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strrchr_avx2_rtm) /* ISA V2 wrapper for SSE2 implementation because the SSE2 @@ -797,13 +803,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, X86_IFUNC_IMPL_ADD_V4 (array, i, wcsrchr, (CPU_FEATURE_USABLE (AVX512VL) && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI1) && CPU_FEATURE_USABLE (BMI2)), __wcsrchr_evex) X86_IFUNC_IMPL_ADD_V3 (array, i, wcsrchr, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI1) + && CPU_FEATURE_USABLE (BMI2)), __wcsrchr_avx2) X86_IFUNC_IMPL_ADD_V3 (array, i, wcsrchr, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI1) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __wcsrchr_avx2_rtm) /* ISA V2 wrapper for SSE2 implementation because the SSE2