From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id 0A66C3858D32 for ; Mon, 18 Sep 2023 10:30:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 0A66C3858D32 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 0E79B21A2D; Mon, 18 Sep 2023 10:30:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1695033036; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=imh9FUScReT+mOJNL0VM0CmVP/gSTA9QGpcSYamabRQ=; b=E8a+u0cs9ghhrIJ6agKaG8RREM6XNGZuoJAiHkqXFAWyoHEoCrdMqK3EEQDm6OP8B2IM/9 dvmwXIm8xgJXVB7DqwJDPMsfmsubOKKHWalJnIIgr/uly/zYClCT2x0slwCrkncXUUqWqq WBmkn+xsXSzofp+g/vs70LyXzxv3mKk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1695033036; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=imh9FUScReT+mOJNL0VM0CmVP/gSTA9QGpcSYamabRQ=; b=6E918YN38dYTeywkYzqYlAubhxwaJPnY4nOB+GY5lqr6N5SHFN9e9yO0dTe2qq6HFrmqnU 9ZisS0caSY9OjVBg== Received: from hawking.nue2.suse.org (unknown [10.168.4.11]) by relay2.suse.de (Postfix) with ESMTP id EE0262C143; Mon, 18 Sep 2023 10:30:35 +0000 (UTC) Received: by hawking.nue2.suse.org (Postfix, from userid 17005) id F1DBC4A0370; Mon, 18 Sep 2023 12:30:35 +0200 (CEST) From: Andreas Schwab To: Paul Floyd via Gcc Cc: Paul Floyd Subject: Re: Safe transposition of logical and operands In-Reply-To: <12c6db0e-10cf-eef6-6209-77da64738897@free.fr> (Paul Floyd via Gcc's message of "Sun, 17 Sep 2023 21:33:21 +0200") References: <12c6db0e-10cf-eef6-6209-77da64738897@free.fr> X-Yow: I've read SEVEN MILLION books!! Date: Mon, 18 Sep 2023 12:30:35 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,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: On Sep 17 2023, Paul Floyd via Gcc wrote: > However, Valgrind thinks that these transpositions can't be done when > there are potentially trapping memory loads like *f. *f is not doing any pointer dereference. It just reads the _M_payload member of f. -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."