From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 7FEE23856DC0; Mon, 3 Oct 2022 21:56:09 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7FEE23856DC0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1664834169; bh=Pj6SzH3WIkJc/gr5dbXt/qUuTAKYvyESSkXzlm/4muY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=nfIiI59s7kLzabuxa/npLAt0WmF6gfaunJRYP70mItrhsmwWq5rByKcDD4vExVm/U pwNre3s+8Pi7No2kTTvwlePH3HDMUYUp3QHObKTOHZitv/UoDGLP6ksBHM5prNts2u jKnWwQUuCe8WkKXbEbT3vxg7I55rnmpls/9d8Zes= From: "cvs-commit at gcc dot gnu.org" To: glibc-bugs@sourceware.org Subject: [Bug string/29611] Optimized AVX2 string functions unconditionally use BMI2 instructions Date: Mon, 03 Oct 2022 21:56:06 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: string X-Bugzilla-Version: 2.31 X-Bugzilla-Keywords: X-Bugzilla-Severity: critical X-Bugzilla-Who: cvs-commit at gcc dot gnu.org X-Bugzilla-Status: REOPENED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: goldstein.w.n at gmail dot com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D29611 --- Comment #49 from cvs-commit at gcc dot gnu.org --- The release/2.35/master branch has been updated by Aurelien Jarno : https://sourceware.org/git/gitweb.cgi?p=3Dglibc.git;h=3D1523fbedff44273c15c= b60e269872ff761f574c7 commit 1523fbedff44273c15cb60e269872ff761f574c7 Author: Aurelien Jarno Date: Mon Oct 3 23:16:46 2022 +0200 x86-64: Require BMI2 for AVX2 wcs(n)cmp implementations The AVX2 wcs(n)cmp 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 f31a5a884ed84bd37032729d4d1eb9d06c9f3c29) --- Comment #50 from cvs-commit at gcc dot gnu.org --- The release/2.35/master branch has been updated by Aurelien Jarno : https://sourceware.org/git/gitweb.cgi?p=3Dglibc.git;h=3Dc85a45acacd6f2ecaa6= 6128364e5621e0cdcab1b commit c85a45acacd6f2ecaa66128364e5621e0cdcab1b Author: Aurelien Jarno Date: Mon Oct 3 23:16:46 2022 +0200 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 (cherry picked from commit e3e7fab7fe5186d18ca2046d99ba321c27db30ad) --=20 You are receiving this mail because: You are on the CC list for the bug.=