From d9196d4f3fa9997388655813ddd236426a16dd92 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Mon, 3 Oct 2022 23:46:11 +0200
Subject: [PATCH 153/155] x86-64: Require BMI2 for AVX2 (raw|w)memchr
implementations
The AVX2 memchr, rawmemchr and wmemchr implementations use the 'bzhi'
and 'sarx' instructions, which belongs to the BMI2 CPU feature.
Fixes: acfd088a1963 ("x86: Optimize memchr-avx2.S")
Partially resolves: BZ #29611
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit e3e7fab7fe5186d18ca2046d99ba321c27db30ad)
---
sysdeps/x86_64/multiarch/ifunc-impl-list.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index fec8790c1156..7c84963d92ca 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -69,10 +69,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& CPU_FEATURE_USABLE (BMI2)),
__memchr_evex_rtm)
X86_IFUNC_IMPL_ADD_V3 (array, i, memchr,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__memchr_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, memchr,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__memchr_avx2_rtm)
/* ISA V2 wrapper for SSE2 implementation because the SSE2
@@ -335,10 +337,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& CPU_FEATURE_USABLE (BMI2)),
__rawmemchr_evex_rtm)
X86_IFUNC_IMPL_ADD_V3 (array, i, rawmemchr,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__rawmemchr_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, rawmemchr,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__rawmemchr_avx2_rtm)
/* ISA V2 wrapper for SSE2 implementation because the SSE2
@@ -927,10 +931,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& CPU_FEATURE_USABLE (BMI2)),
__wmemchr_evex_rtm)
X86_IFUNC_IMPL_ADD_V3 (array, i, wmemchr,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__wmemchr_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, wmemchr,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__wmemchr_avx2_rtm)
/* ISA V2 wrapper for SSE2 implementation because the SSE2
--
2.38.0
