From: Aurelien Jarno <aurelien@aurel32.net>
To: libc-alpha@sourceware.org
Cc: Noah Goldstein <goldstein.w.n@gmail.com>,
"H . J . Lu" <hjl.tools@gmail.com>,
Sunil K Pandey <skpgkp2@gmail.com>,
Aurelien Jarno <aurelien@aurel32.net>
Subject: [PATCH v3 2/8] x86-64: Require BMI2 for AVX2 str(n)casecmp implementations
Date: Mon, 3 Oct 2022 21:59:38 +0200 [thread overview]
Message-ID: <20221003195944.3274548-3-aurelien@aurel32.net> (raw)
In-Reply-To: <20221003195944.3274548-1-aurelien@aurel32.net>
The AVX2 str(n)casecmp implementations use the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Partially fixes: b77b06e0e296 ("x86: Optimize strcmp-avx2.S")
Partially resolves: BZ #29611
---
sysdeps/x86_64/multiarch/ifunc-impl-list.c | 28 +++++++++++++++------
sysdeps/x86_64/multiarch/ifunc-strcasecmp.h | 1 +
2 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index a71444eccb..d208fae4bf 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -448,13 +448,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL (i, name, strcasecmp,
X86_IFUNC_IMPL_ADD_V4 (array, i, strcasecmp,
(CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)),
+ && CPU_FEATURE_USABLE (AVX512BW)
+ && CPU_FEATURE_USABLE (BMI2)),
__strcasecmp_evex)
X86_IFUNC_IMPL_ADD_V3 (array, i, strcasecmp,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__strcasecmp_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, strcasecmp,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__strcasecmp_avx2_rtm)
X86_IFUNC_IMPL_ADD_V2 (array, i, strcasecmp,
@@ -470,13 +473,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL (i, name, strcasecmp_l,
X86_IFUNC_IMPL_ADD_V4 (array, i, strcasecmp,
(CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)),
+ && CPU_FEATURE_USABLE (AVX512BW)
+ && CPU_FEATURE_USABLE (BMI2)),
__strcasecmp_l_evex)
X86_IFUNC_IMPL_ADD_V3 (array, i, strcasecmp,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__strcasecmp_l_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, strcasecmp,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__strcasecmp_l_avx2_rtm)
X86_IFUNC_IMPL_ADD_V2 (array, i, strcasecmp_l,
@@ -638,13 +644,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL (i, name, strncasecmp,
X86_IFUNC_IMPL_ADD_V4 (array, i, strncasecmp,
(CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)),
+ && CPU_FEATURE_USABLE (AVX512BW)
+ && CPU_FEATURE_USABLE (BMI2)),
__strncasecmp_evex)
X86_IFUNC_IMPL_ADD_V3 (array, i, strncasecmp,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__strncasecmp_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, strncasecmp,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__strncasecmp_avx2_rtm)
X86_IFUNC_IMPL_ADD_V2 (array, i, strncasecmp,
@@ -660,13 +669,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL (i, name, strncasecmp_l,
X86_IFUNC_IMPL_ADD_V4 (array, i, strncasecmp,
(CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)),
+ & CPU_FEATURE_USABLE (AVX512BW)
+ && CPU_FEATURE_USABLE (BMI2)),
__strncasecmp_l_evex)
X86_IFUNC_IMPL_ADD_V3 (array, i, strncasecmp,
- CPU_FEATURE_USABLE (AVX2),
+ (CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)),
__strncasecmp_l_avx2)
X86_IFUNC_IMPL_ADD_V3 (array, i, strncasecmp,
(CPU_FEATURE_USABLE (AVX2)
+ && CPU_FEATURE_USABLE (BMI2)
&& CPU_FEATURE_USABLE (RTM)),
__strncasecmp_l_avx2_rtm)
X86_IFUNC_IMPL_ADD_V2 (array, i, strncasecmp_l,
diff --git a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
index 68646ef199..7622af259c 100644
--- a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
+++ b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
@@ -34,6 +34,7 @@ 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, BMI2)
&& X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
AVX_Fast_Unaligned_Load, ))
{
--
2.35.1
next prev parent reply other threads:[~2022-10-03 19:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-03 19:59 [PATCH v3 0/8] x86: Fix AVX2 string functions requiring BMI1, BMI2 or LZCNT (BZ #29611) Aurelien Jarno
2022-10-03 19:59 ` [PATCH v3 1/8] x86: include BMI1 and BMI2 in x86-64-v3 level Aurelien Jarno
2022-10-03 21:11 ` Noah Goldstein
2022-10-03 19:59 ` Aurelien Jarno [this message]
2022-10-03 21:11 ` [PATCH v3 2/8] x86-64: Require BMI2 for AVX2 str(n)casecmp implementations Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 3/8] x86-64: Require BMI2 for AVX2 strcmp implementation Aurelien Jarno
2022-10-03 21:12 ` Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 4/8] x86-64: Require BMI2 for AVX2 strncmp implementation Aurelien Jarno
2022-10-03 21:11 ` Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 5/8] x86-64: Require BMI2 for AVX2 wcs(n)cmp implementations Aurelien Jarno
2022-10-03 21:11 ` Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 6/8] x86-64: Require BMI2 for AVX2 (raw|w)memchr implementations Aurelien Jarno
2022-10-03 21:12 ` Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 7/8] x86-64: Require BMI2 and LZCNT for AVX2 memrchr implementation Aurelien Jarno
2022-10-03 21:12 ` Noah Goldstein
2022-10-03 19:59 ` [PATCH v3 8/8] x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations Aurelien Jarno
2022-10-03 21:12 ` Noah Goldstein
2022-10-03 20:47 ` [PATCH v3 0/8] x86: Fix AVX2 string functions requiring BMI1, BMI2 or LZCNT (BZ #29611) Sunil Pandey
2022-10-03 21:11 ` Noah Goldstein
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