From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13856 invoked by alias); 27 Nov 2012 14:33:12 -0000 Received: (qmail 13845 invoked by uid 22791); 27 Nov 2012 14:33:12 -0000 X-SWARE-Spam-Status: No, hits=-5.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,FREEMAIL_FROM,KHOP_RCVD_TRUST,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE X-Spam-Check-By: sourceware.org Received: from mail-vb0-f47.google.com (HELO mail-vb0-f47.google.com) (209.85.212.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 27 Nov 2012 14:33:02 +0000 Received: by mail-vb0-f47.google.com with SMTP id e21so10632446vbm.20 for ; Tue, 27 Nov 2012 06:33:01 -0800 (PST) Received: by 10.52.69.201 with SMTP id g9mr21202391vdu.98.1354026781738; Tue, 27 Nov 2012 06:33:01 -0800 (PST) Received: from yakj.usersys.redhat.com (93-34-169-1.ip50.fastwebnet.it. [93.34.169.1]) by mx.google.com with ESMTPS id q7sm10053217vdw.22.2012.11.27.06.32.56 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 27 Nov 2012 06:33:00 -0800 (PST) Message-ID: <50B4CF15.5070809@gnu.org> Date: Tue, 27 Nov 2012 14:33:00 -0000 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Steven Bosscher CC: Eric Botcazou , gcc-patches@gcc.gnu.org, Dominique Dhumieres , hubicka@ucw.cz, Richard Henderson , Jeff Law Subject: Re: Fix twolf -funroll-loops -O3 miscompilation (a semi-latent web.c bug) References: <20121118231540.726263BABA@mailhost.lps.ens.fr> <38690302.TaVonSBHVs@polaris> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2012-11/txt/msg02219.txt.bz2 Il 27/11/2012 13:00, Steven Bosscher ha scritto: > It all > starts with PRE creating a REG_EQUAL note that references the register > that's SET in the insn the note is attached to, but the register is > live after the insn so from that point of view the note is not > invalid. This note seems very very weird. For one thing, it becomes invalid on the very instruction where it is created. I would say that it should not be there. Paolo