From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29120 invoked by alias); 8 Nov 2007 16:45:24 -0000 Received: (qmail 29077 invoked by uid 22791); 8 Nov 2007 16:45:23 -0000 X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 08 Nov 2007 16:45:18 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.1) with ESMTP id lA8GjG7l019834; Thu, 8 Nov 2007 11:45:16 -0500 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [10.11.255.20]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lA8GjG4Z010196; Thu, 8 Nov 2007 11:45:16 -0500 Received: from free.oliva.athome.lsd.ic.unicamp.br (vpn-14-122.rdu.redhat.com [10.11.14.122]) by pobox.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lA8GjEhV014974; Thu, 8 Nov 2007 11:45:15 -0500 Received: from free.oliva.athome.lsd.ic.unicamp.br (localhost.localdomain [127.0.0.1]) by free.oliva.athome.lsd.ic.unicamp.br (8.14.1/8.14.1) with ESMTP id lA8GjBAd012627; Thu, 8 Nov 2007 14:45:11 -0200 Received: (from aoliva@localhost) by free.oliva.athome.lsd.ic.unicamp.br (8.14.1/8.14.1/Submit) id lA8Gj98k012626; Thu, 8 Nov 2007 14:45:09 -0200 To: Eric Botcazou Cc: gcc-patches@gcc.gnu.org Subject: Re: loc_mentioned_in_p invokes undefined behavior References: <200711081227.47743.ebotcazou@libertysurf.fr> From: Alexandre Oliva Errors-To: aoliva@oliva.athome.lsd.ic.unicamp.br Date: Thu, 08 Nov 2007 16:45:00 -0000 In-Reply-To: <200711081227.47743.ebotcazou@libertysurf.fr> (Eric Botcazou's message of "Thu\, 8 Nov 2007 12\:27\:47 +0100") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: 2007-11/txt/msg00433.txt.bz2 On Nov 8, 2007, Eric Botcazou wrote: >> Given this additional investigation, I propose that the patch goes in >> as I first posted it. > I conducted it too before answering your initial message. There is no > undefined behavior, the predicate was written ages ago for reload, let's > not take any gratuitous risk here. I don't see any risk whatsoever. All 3 uses are evidently dealing with rtx. Do you know of something I don't? I wouldn't mind turning the predicate into a void*, if that would make you more comfortable about risk management, but just changing the XVECEXP test while leaving a known inconsistency behind seems like bad engineering practice to me. -- Alexandre Oliva http://www.lsd.ic.unicamp.br/~oliva/ FSF Latin America Board Member http://www.fsfla.org/ Red Hat Compiler Engineer aoliva@{redhat.com, gcc.gnu.org} Free Software Evangelist oliva@{lsd.ic.unicamp.br, gnu.org}