From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1778) id 0FD63385828B; Mon, 3 Oct 2022 22:02:11 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0FD63385828B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1664834531; bh=7PTCjmXL3P4aG0yjFcYZEmwy/ih0c0+RW/6qkvl/+Wc=; h=From:To:Subject:Date:From; b=gXqE9xN5OVG8IwnUTE++6uaL+sCLX7WzExFwNALx01fJHqsc5c93zE6b9mFU5omN2 wq5zQpbwn/x3V9ivJXPhycF7wRpI7o3nqGhcmAbQT5/FMcBjBSRS+H/dAyXj4CBvbm dzWn1rABhj1+vImj6yqaPCgwClI5SMjBUaSsXHM4= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Aurelien Jarno To: glibc-cvs@sourceware.org Subject: [glibc/release/2.34/master] x86-64: Require BMI2 for AVX2 str(n)casecmp implementations X-Act-Checkin: glibc X-Git-Author: Aurelien Jarno X-Git-Refname: refs/heads/release/2.34/master X-Git-Oldrev: 95f5089d4a57cd1e738be908c7a628cb7d0ce512 X-Git-Newrev: 414fc856ff4e011e62b88a21d30294637a152dc7 Message-Id: <20221003220211.0FD63385828B@sourceware.org> Date: Mon, 3 Oct 2022 22:02:11 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=414fc856ff4e011e62b88a21d30294637a152dc7 commit 414fc856ff4e011e62b88a21d30294637a152dc7 Author: Aurelien Jarno Date: Mon Oct 3 23:16:46 2022 +0200 x86-64: Require BMI2 for AVX2 str(n)casecmp implementations 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 Reviewed-by: Noah Goldstein (cherry picked from commit 10f79d3670b036925da63dc532b122d27ce65ff8) Diff: --- 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 8d649e263e..ca64b34c14 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -386,13 +386,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strcasecmp, IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_evex) IFUNC_IMPL_ADD (array, i, strcasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_avx2) IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strcasecmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, strcasecmp, @@ -407,13 +410,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strcasecmp_l, IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_l_evex) IFUNC_IMPL_ADD (array, i, strcasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_l_avx2) IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strcasecmp_l_avx2_rtm) IFUNC_IMPL_ADD (array, i, strcasecmp_l, @@ -542,13 +548,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strncasecmp, IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_evex) IFUNC_IMPL_ADD (array, i, strncasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_avx2) IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strncasecmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, strncasecmp, @@ -564,13 +573,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strncasecmp_l, IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + & CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_l_evex) IFUNC_IMPL_ADD (array, i, strncasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_l_avx2) IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strncasecmp_l_avx2_rtm) IFUNC_IMPL_ADD (array, i, strncasecmp_l, diff --git a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h index 40819caf5a..e61d6e9497 100644 --- a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h +++ b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h @@ -32,6 +32,7 @@ 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, BMI2) && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load)) { if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)