From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by sourceware.org (Postfix) with ESMTPS id E91FA385842B for ; Fri, 28 Apr 2023 17:43:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E91FA385842B Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=rivosinc.com Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-64115eef620so14304656b3a.1 for ; Fri, 28 Apr 2023 10:43:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1682703822; x=1685295822; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:from:to:cc:subject:date:message-id :reply-to; bh=RoKTd8P5c/Xi0nDf5Z623eDLpJD9D71LBkQ6M2lWc0s=; b=jLNeywTXiYYLr57X1L9G56Cxvu6umO8x9nqSRF1XEecAbWcUTrG1849jaBlaJ4ogs9 77SVRBotSqf8BZ8Hmpk6+LWKRpawblO4hNcA1Hs3T2PL1MPXUm4s0AUhPrfJlFmxZ+fW JtN6s6K8G/2RZkEyxSabbdQPHQI/84542FGKDdVaY4Qpj/lA+BxzNoDWN2x2G9sC8ub4 EcFBEU36w4zun7SJ7AgI8shPxiRpl2hPqeKxxD8N/xYUjDF0H/MO7+5LIZs/du/nX1eR +8zuIigJ7pFniupqG263SaIuw8Rbreil46dum2YScxTs6lK5FnZoim5MST3XLEM2eM7I 5pkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682703822; x=1685295822; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=RoKTd8P5c/Xi0nDf5Z623eDLpJD9D71LBkQ6M2lWc0s=; b=bJmGk11VeDUtrRHotdZfOXWgvE+7xPkm1b0eY7zcBLZV8kbMtUOD7tby+SJy1OjYWD tDUrbtiiVSH+Obsadz7iE9VDtwZRdsE0dNIWavvErESeUwh5srvQJuxkbvLtn8kbRLd5 QLJmGP8Qce+5ySJZuraftxMHlnz+YgP27Dgxxj/otzUd8YWNDUqAGHy/b0XjIB4h7H5P tXGxduap594TxV4jrP/u1eeBOAvllsRpn5i1Jtb2YakK14TY/4bKD7pvaT5JT6ZGBdaV 23MshfzLGqTM8r2OCHjgkIHJzat39COIsP3ZMU+Y17TpzTffYiQuqUVAKt/hs3o5pAgf M2mg== X-Gm-Message-State: AC+VfDxl72wJ/3zdeOVDZvAjUcQrRS2MsMIMYZRkV8UgBYysvDaqAZQG vRvBz2tkx48lyOjFUvUD71mdAw== X-Google-Smtp-Source: ACHHUZ4wx8aUdDbavulSkw1UVaL+FvXeSxfKpSUUAY3Tox8Oxmd0nUWTSUZq1APZquHURBD6eAeEYg== X-Received: by 2002:a05:6a00:179f:b0:63c:56f5:5053 with SMTP id s31-20020a056a00179f00b0063c56f55053mr13890137pfg.13.1682703821940; Fri, 28 Apr 2023 10:43:41 -0700 (PDT) Received: from localhost ([135.180.227.0]) by smtp.gmail.com with ESMTPSA id 12-20020a63030c000000b004fbd91d9716sm13297490pgd.15.2023.04.28.10.43.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Apr 2023 10:43:41 -0700 (PDT) Date: Fri, 28 Apr 2023 10:43:41 -0700 (PDT) X-Google-Original-Date: Fri, 28 Apr 2023 10:43:39 PDT (-0700) Subject: Re: [PATCH v5 06/11] RISC-V: Strengthen atomic stores In-Reply-To: CC: Patrick O'Neill , gcc-patches@gcc.gnu.org, gnu-toolchain@rivosinc.com, Vineet Gupta , Andrew Waterman , kito.cheng@sifive.com, Daniel Lustig , cmuellner@gcc.gnu.org, Andrea Parri , hboehm@google.com From: Palmer Dabbelt To: jeffreyalaw@gmail.com Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,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 List-Id: On Fri, 28 Apr 2023 10:40:15 PDT (-0700), jeffreyalaw@gmail.com wrote: > > > On 4/27/23 10:22, Patrick O'Neill wrote: >> This change makes atomic stores strictly stronger than table A.6 of the >> ISA manual. This mapping makes the overall patchset compatible with >> table A.7 as well. >> >> 2023-04-27 Patrick O'Neill >> >> PR 89835 > Should be "PR target/89835" > >> >> gcc/ChangeLog: >> >> * config/riscv/sync.md: > Needs some text here :-) > > > I'm not objecting to this patch, but I think we've got an option > question about whether or not this approach is too expensive for > existing or soon arriving implementations. > > If the decision on that topic is to just pay the cost, then this patch > is fine. If we decide to make compatibility optional to avoid the > additional cost, then this will need suitable adjustments. IMO the only hardware that's going to be here by gcc-14 and to have enough concurrency for these to matter is the Ventana stuff. I think you're the only one who can figure out if these are slow, at least until that stuff is availiable outside the lab. So are they too slow for you? > > Jeff