From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hall.aurel32.net (hall.aurel32.net [IPv6:2001:bc8:30d7:100::1]) by sourceware.org (Postfix) with ESMTPS id 3CB5B3856DC2 for ; Mon, 3 Oct 2022 21:56:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3CB5B3856DC2 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=aurel32.net Authentication-Results: sourceware.org; spf=none smtp.mailfrom=aurel32.net DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=aurel32.net ; s=202004.hall; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Content-Type:From:Reply-To: Subject:Content-ID:Content-Description:X-Debbugs-Cc; bh=b0SK/lXGzNRbxP5GFYWBuITPKD1n5H604IBXTq30qdo=; b=fcYCsBmcxhog/All/+G86j8RoB 8T3kvKDQrk7whUn8YNIuEdoF6y/c/ilbg+wseQAqrU4wO/R4DntRreQbLj/zhRJvhoxOiR86IFlxO N2soOeXCnaCDOSB2E6j0nv9eT69WRmsobK3b3DELgGh4QdoXCFr0isSFcZAvzHN+yNWB1EfVvhRid e4xmSgSXTkadIbJxpKrMiKev19N3odnADTpKFLFUM06LdW7Lb7yKUQtrSpX85J5SsxKKtIlCpZFzO 3Cf3CdPaekxXaskIwFex01fK3WeVIzpOl7RSpkjIKzeXzMpTFiid7a9/pUQ3GXtkvnsFO9n/lrgLW AG2fNADw==; Received: from [2a01:e34:ec5d:a741:8a4c:7c4e:dc4c:1787] (helo=ohm.rr44.fr) by hall.aurel32.net with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ofTQ9-00GL4U-OG; Mon, 03 Oct 2022 23:56:17 +0200 Received: from aurel32 by ohm.rr44.fr with local (Exim 4.96) (envelope-from ) id 1ofTQ8-00DozN-2o; Mon, 03 Oct 2022 23:56:16 +0200 From: Aurelien Jarno To: libc-stable@sourceware.org Cc: Aurelien Jarno , Noah Goldstein Subject: [COMMITTED 2.35 5/8] x86-64: Require BMI2 for AVX2 wcs(n)cmp implementations Date: Mon, 3 Oct 2022 23:56:11 +0200 Message-Id: <20221003215614.3294221-5-aurelien@aurel32.net> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221003215614.3294221-1-aurelien@aurel32.net> References: <20221003215614.3294221-1-aurelien@aurel32.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-13.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_PASS,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: 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) --- sysdeps/x86_64/multiarch/ifunc-impl-list.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c index b27ae975e4..5824554b4e 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -711,10 +711,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, /* Support sysdeps/x86_64/multiarch/wcscmp.c. */ IFUNC_IMPL (i, name, wcscmp, IFUNC_IMPL_ADD (array, i, wcscmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __wcscmp_avx2) IFUNC_IMPL_ADD (array, i, wcscmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __wcscmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, wcscmp, @@ -727,10 +729,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, /* Support sysdeps/x86_64/multiarch/wcsncmp.c. */ IFUNC_IMPL (i, name, wcsncmp, IFUNC_IMPL_ADD (array, i, wcsncmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __wcsncmp_avx2) IFUNC_IMPL_ADD (array, i, wcsncmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __wcsncmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, wcsncmp, -- 2.35.1