From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by sourceware.org (Postfix) with ESMTPS id D9E1C38555A0 for ; Mon, 31 Oct 2022 17:03:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D9E1C38555A0 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=adacore.com Received: by mail-wm1-x329.google.com with SMTP id n39-20020a05600c3ba700b003cf71011cddso1437656wms.1 for ; Mon, 31 Oct 2022 10:03:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=adacore.com; s=google; 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=Ij9W7pncqqGjjoCx/CRyRZfMLhx7qi+FBSYxDYLdkms=; b=bCsqjwuTsbcdIjiJtJVAPUunqQxeH9LcVPFxgazHDLs54g/G/H42WAU3/luncZV6Ij eHbukuQ8a0QOasZYAOI1tauqRYJRJ6qFiKhyWcSfiFbICjvBAjSsUHXHzkSi2np6NCth XwiN7oCDf1lhCuv1NsxmR0dnH0t1+Jiu8bijX3ObFfst6/Ap0g7wqTN2B8986VZRX8H0 yKCMYXmYF5iD1bL4/stx9idVAzvD05rNZRpinpoGJsWBril4zbIGGUuHktQJfJZtgkox oKuvWPwaQl1Kt7u11f+9iIswaZQcQF7sXyE327NAGZ8XC1jxJtmzF9Q/1LdnYd86cHWr V1CA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=Ij9W7pncqqGjjoCx/CRyRZfMLhx7qi+FBSYxDYLdkms=; b=FgIbmreLSo5v+3XLVK24ffg+X4loAN23qIqvlto8rBpoQtKqM8V0lAMLSgLQAxKBfn 3krZ08SthqJ5i9QClIX3//VjPLovSO8vhRbn7b6QuyLJdif1lOr70keMuUTpqTqluQdi zcCi0mNh/PLz64a9/mvM/nouYw89//5hJuWkBg5CtinFCELjOzhXgCCD9AT5Q32eo9Bn t8HtXJpCuljZpFZ40cGoyA7UT0jVFf96yj8PYzG0uHiu5QClUASelGfccOgNizPRdwI+ mC8wjMhB+tPHUC2vzZX5MsHe0nRAAOQzuyRec71f+1U1JLUZZnLjv0BOY+q5F7+eOkWk R8jw== X-Gm-Message-State: ACrzQf3BF/SYwdJss8FWSASEw8+JHGByeB2kLpHgUh6sK6NabJ8h4NI9 dOJnUd5KaQE3VvjAPPq27iLGpfb7StxJ5A== X-Google-Smtp-Source: AMsMyM7L1h+MVLFD9AapMQhlTiuhCdawoMTpvc6wGNwDmM/bZlM0pZXuCTg7VoRlhE3j61Zpc/Lu2g== X-Received: by 2002:a7b:c845:0:b0:3cf:62af:e353 with SMTP id c5-20020a7bc845000000b003cf62afe353mr9145875wml.43.1667235803666; Mon, 31 Oct 2022 10:03:23 -0700 (PDT) Received: from fomalhaut.localnet ([2a01:e0a:8d5:d990:e654:e8ff:fe8f:2ce6]) by smtp.gmail.com with ESMTPSA id s4-20020a7bc384000000b003c6f3e5ba42sm7797351wmj.46.2022.10.31.10.03.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Oct 2022 10:03:22 -0700 (PDT) From: Eric Botcazou X-Google-Original-From: Eric Botcazou To: Jonathan Wakely Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: Re: [committed] libstdc++: Fix compare_exchange_padding.cc test for std::atomic_ref Date: Mon, 31 Oct 2022 18:03:21 +0100 Message-ID: <8176183.NyiUUSuA9g@fomalhaut> In-Reply-To: References: <20220916202127.579816-1-jwakely@redhat.com> <5772422.MhkbZ0Pkbq@fomalhaut> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,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: > I suppose we could use memcmp on the as variable itself, to inspect > the actual stored padding rather than the returned copy of it. Yes, that's probably the only safe stance when optimization is enabled. -- Eric Botcazou