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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 v2 5/6] x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations
Date: Sun,  2 Oct 2022 14:34:23 +0200	[thread overview]
Message-ID: <20221002123424.3079805-6-aurelien@aurel32.net> (raw)
In-Reply-To: <20221002123424.3079805-1-aurelien@aurel32.net>

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
---
 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 4ee28c99bd..1c8afa229f 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -575,13 +575,19 @@ __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
@@ -794,13 +800,18 @@ __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
-- 
2.35.1


  parent reply	other threads:[~2022-10-02 12:34 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-02 12:34 [PATCH v2 0/6] x86: Fix AVX2 string functions requiring BMI1, BMI2 or LZCNT (BZ #29611) Aurelien Jarno
2022-10-02 12:34 ` [PATCH v2 1/6] x86: include BMI1 and BMI2 in x86-64-v3 level Aurelien Jarno
2022-10-02 21:07   ` Noah Goldstein
2022-10-02 12:34 ` [PATCH v2 2/6] x86-64: Require BMI2 for AVX2 str*cmp and wcs(n)cmp implementations Aurelien Jarno
2022-10-02 21:08   ` Noah Goldstein
2022-10-03 16:19     ` Sunil Pandey
2022-10-03 17:35       ` Aurelien Jarno
2022-10-03 17:50         ` Noah Goldstein
2022-10-03 18:43           ` Sunil Pandey
2022-10-03 19:21             ` Aurelien Jarno
2022-10-03 19:59               ` Aurelien Jarno
2022-10-03 20:51                 ` Sunil Pandey
2022-10-02 12:34 ` [PATCH v2 3/6] x86-64: Require BMI2 for AVX2 (raw|w)memchr implementations Aurelien Jarno
2022-10-02 21:08   ` Noah Goldstein
2022-10-02 12:34 ` [PATCH v2 4/6] x86-64: Require LZCNT for AVX2 memrchr implementation Aurelien Jarno
2022-10-02 21:08   ` Noah Goldstein
2022-10-02 12:34 ` Aurelien Jarno [this message]
2022-10-02 21:08   ` [PATCH v2 5/6] x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations Noah Goldstein
2022-10-02 12:34 ` [PATCH v2 6/6] x86-64: Require BMI2 for AVX2 memrchr implementation Aurelien Jarno
2022-10-02 21:09   ` Noah Goldstein
2022-10-02 16:21 ` [PATCH v2 0/6] x86: Fix AVX2 string functions requiring BMI1, BMI2 or LZCNT (BZ #29611) Noah Goldstein
2022-10-02 18:09   ` Aurelien Jarno
2022-10-02 21:11     ` Noah Goldstein
2022-10-03 17:36       ` Aurelien Jarno
2022-10-03 17:51         ` Noah Goldstein

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