From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by sourceware.org (Postfix) with ESMTPS id 3580E38300B0 for ; Wed, 15 Jun 2022 00:25:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3580E38300B0 Received: by mail-pf1-x42d.google.com with SMTP id 187so9971641pfu.9 for ; Tue, 14 Jun 2022 17:25:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ajCvJTsH/tvpQt+PLBmfpjsPJIBwvL8M2w05/GHXrW4=; b=IxbrVbFnKIwo6wbEAyCL24fNI5nfkPcuIqp2FvUapECM/e5Yhj9UenogsYmZLQlUIo 86sfMnU6mg4NcUSwVjCHscuirT0ZOeZF2WMArtPl6MmRDwuRIOFZ6tfVLuDGcLvNSXNo dtXBKWwEdh761Fob+yjnqDMg9raePyDUTTJlSSLoza8niDqotg+02zjChuZ1ZrdwaWWN WyE8sbmBYe+8XvPiqQdFLqk0XqkybIxbg4w6BzFwrfd9rLyQruia7WlT/3m0wLWois7E ByPr4AVtf5ep8snyQWk5iC4HpWN8+Ba6IGMhLLSr8mSGTbPOrjAkNxQ74ME7eRT3VgZ5 x7OQ== X-Gm-Message-State: AOAM532y0otB64pP/yM9/1aSx1rNfHqo2XsNwJSHp9VhB+G+4Jca04Ur lnBEeGWzhFHTskbC1HL0N/kguGcpo5w= X-Google-Smtp-Source: ABdhPJwY39aT9nCmhckK6JsSCyzdCJXMybDbmLHLi/EzS167QOFPJu7SKeIY2kr60Vgx0dDIFmjx7w== X-Received: by 2002:a05:6a00:c89:b0:51c:2ad8:47ad with SMTP id a9-20020a056a000c8900b0051c2ad847admr7219646pfv.42.1655252741123; Tue, 14 Jun 2022 17:25:41 -0700 (PDT) Received: from noah-tgl.. ([2600:1010:b00a:24b5:2ca1:5b17:18d:7e5e]) by smtp.gmail.com with ESMTPSA id p1-20020a170903248100b0016796cdd802sm7877530plw.19.2022.06.14.17.25.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jun 2022 17:25:40 -0700 (PDT) From: Noah Goldstein To: libc-alpha@sourceware.org Subject: [PATCH v1 3/3] x86: Add sse42 implementation to strcmp's ifunc Date: Tue, 14 Jun 2022 17:25:33 -0700 Message-Id: <20220615002533.1741934-3-goldstein.w.n@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220615002533.1741934-1-goldstein.w.n@gmail.com> References: <20220615002533.1741934-1-goldstein.w.n@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Jun 2022 00:25:43 -0000 This has been missing since the the ifuncs where added. The performance of SSE4.2 is preferable to to SSE2. Measured on Tigerlake with N = 20 runs. Geometric Mean of all benchmarks SSE4.2 / SSE2: 0.906 --- sysdeps/x86_64/multiarch/strcmp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sysdeps/x86_64/multiarch/strcmp.c b/sysdeps/x86_64/multiarch/strcmp.c index a248c2a6e6..9c1677724c 100644 --- a/sysdeps/x86_64/multiarch/strcmp.c +++ b/sysdeps/x86_64/multiarch/strcmp.c @@ -28,6 +28,7 @@ extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden; extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned) attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden; extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden; extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden; extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden; @@ -52,6 +53,10 @@ IFUNC_SELECTOR (void) return OPTIMIZE (avx2); } + if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_2) + && !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2)) + return OPTIMIZE (sse42); + if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load)) return OPTIMIZE (sse2_unaligned); -- 2.34.1