From patchwork Tue Feb 6 17:43:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 1895864 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=KCb7+ifK; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=sourceware.org (client-ip=2620:52:3:1:0:246e:9693:128c; helo=server2.sourceware.org; envelope-from=libc-alpha-bounces+incoming=patchwork.ozlabs.org@sourceware.org; receiver=patchwork.ozlabs.org) Received: from server2.sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TTrGy5t6Dz23gb for ; Wed, 7 Feb 2024 04:44:42 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id AD9053858415 for ; Tue, 6 Feb 2024 17:44:40 +0000 (GMT) X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by sourceware.org (Postfix) with ESMTPS id 7ECC03858418 for ; Tue, 6 Feb 2024 17:43:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 7ECC03858418 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linaro.org ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 7ECC03858418 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::42a ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1707241421; cv=none; b=j3fZVAShQsM1CNNc2G/fU0AbheeTIIJO2ulM9BrfYL6xO5UKF0aCuIC+l9efx5jgGWMFXPgrZFcyli+2P9lQnkpHctrdRAjM6hY5OA1wFKoNVoOT63l9ljIQDPaWPM81U1feJlrEAIRIXHLd5oq6VFgFYgKi8xktXIxYDSJf8yo= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1707241421; c=relaxed/simple; bh=QybbG1EfGsJYvEBRrGGIS59qa0NkKuxbzLTdVztndRo=; h=DKIM-Signature:From:To:Subject:Date:Message-Id:MIME-Version; b=qM5/SmfwtMW0Lnm5X9pVIUtXsMMv7lucSaLh6CMJ+nGr5LGYOuE0c/8TWENj77SAjM4xJUfuzNHP3TM6zCs/mMNT2DUssxmIQmGRryeNZ58NSIbNqi7RsWucb7u3LztIhkjwlzNTTQCIn7P9yotf9IL7xmC/QvzfjpnXhb3uxt0= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-6e053b272b0so1018176b3a.1 for ; Tue, 06 Feb 2024 09:43:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1707241416; x=1707846216; darn=sourceware.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=7Eqs7odOLczXzBnPknEqO+pOqBAHuRBbgACFj6VnnJ0=; b=KCb7+ifKFH1gn6GXqPYUYkVp1tn9qbrIehL+YHmDmYtDt73Ms/eJgelESV/DFrOva+ lKEz1ergyZ4Pl26X//yoDcQC2u/YNvNQrj2yOTWPDqGBJ6NbvT18VN3czoH14hi+KtCH eO3F5lGiqmCCimsv/qrUVyDo4vH7MgcUrbMWvZ+6xwWZW1ZRNRbnksATK90B9q6KkDJT 2665oNF8wsl1rhIlhfXAvjFhn2pRcLWXL0sPXI+M6J4WZlQ5zoLS38nGKDTY3eAOwFQF I8c91J5713KFnpaOCLT8aX4u2VH2KKdekarQKlqAWvjYh8SO67uQLWUscipvkSlLMXIP wzjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707241416; x=1707846216; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7Eqs7odOLczXzBnPknEqO+pOqBAHuRBbgACFj6VnnJ0=; b=f+CcQyHh1mPjhehs1XZBwkIzsgELcaAuQa/waaK3q9Y5CU0eo2500727OGa/VcEJgO XT/LZRFjvhOD36RSo94KwINSeTAK4I0s/LZcTwvO2vXEkZC1LdruA19pz1Y2RAw8lJub vLhXzuBnVLK8VPkiYnn3hfnU/mxs8IGxIlF39GRJqWS3yUJt0KyDONZbrSAigNQKi7dx kuX/yutbo+fxEzccqHxE4KiMuUbBD3Cv39VAK8IPPYZ/4Lnrphw3x1riK3emaleWNfgz FiKKP4qTHPBfXFZ7hRByfY1sKCw1OuK71ti3zL3QmRuHPeCJVyPINo0hm9z5mInz1Uui EJjg== X-Gm-Message-State: AOJu0YxWmH6FOA1c5R+5v4caRlYdUgYM5l3lhOUtFqsHdYlbeoUzv0k+ 4T00zFYqwj2pLgYgNA11QHM0o4rb0rqYtc80NDKJUYedO+mg/zF5e1FtLJjapZOd3l/PBMhasFZ I X-Google-Smtp-Source: AGHT+IE2GniskUcmD+7xXvptIHIZr6O0djYur2PAnbgUY5BMKjtZBNlGxBOccLMW/HKtnRe1jpO7Og== X-Received: by 2002:a05:6a00:1e16:b0:6d9:bc39:e5ac with SMTP id gx22-20020a056a001e1600b006d9bc39e5acmr240273pfb.6.1707241416092; Tue, 06 Feb 2024 09:43:36 -0800 (PST) X-Forwarded-Encrypted: i=0; AJvYcCVAxAASQ3ZbLLoTC3JtX07y/rw0RU9Odr/DZCoEOjdDdztK9mQxfEUr+/s1w7Hk9HTJZ7MlmtaYrN8XjU4EJq4S+uBqNy2Xi8/1S0uAgpQ13xa4ZUkWdzFt3Hmhu4SBucB7tuDRm9EkMDwLhMJ5txNXEZ8Doxd1vqWkzi4jYXJi53TaaM2wbwPy/Q== Received: from mandiga.. ([2804:1b3:a7c0:378:b5ab:9c4b:bdc3:2870]) by smtp.gmail.com with ESMTPSA id d22-20020aa78696000000b006e04a659ed6sm2248598pfo.67.2024.02.06.09.43.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Feb 2024 09:43:35 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Cc: "H . J . Lu" , Noah Goldstein , Sajan Karumanchi , bmerry@sarao.ac.za, pmallapp@amd.com Subject: [PATCH v2 3/3] x86: Expand the comment on when REP STOSB is used on memset Date: Tue, 6 Feb 2024 14:43:22 -0300 Message-Id: <20240206174322.2317679-4-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240206174322.2317679-1-adhemerval.zanella@linaro.org> References: <20240206174322.2317679-1-adhemerval.zanella@linaro.org> MIME-Version: 1.0 X-Spam-Status: No, score=-12.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, 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: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces+incoming=patchwork.ozlabs.org@sourceware.org --- sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S index 9984c3ca0f..97839a2248 100644 --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S @@ -21,7 +21,9 @@ 2. If size is less than VEC, use integer register stores. 3. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores. 4. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores. - 5. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with + 5. On machines ERMS feature, if size is greater or equal than + __x86_rep_stosb_threshold then REP STOSB will be used. + 6. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with 4 VEC stores and store 4 * VEC at a time until done. */ #include