From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7230 invoked by alias); 19 Jan 2011 21:15:02 -0000 Received: (qmail 7188 invoked by uid 22791); 19 Jan 2011 21:15:00 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: sourceware.org Received: from mail-ew0-f47.google.com (HELO mail-ew0-f47.google.com) (209.85.215.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 19 Jan 2011 21:14:54 +0000 Received: by ewy28 with SMTP id 28so843361ewy.20 for ; Wed, 19 Jan 2011 13:14:52 -0800 (PST) MIME-Version: 1.0 Received: by 10.227.166.13 with SMTP id k13mr1418623wby.178.1295471691876; Wed, 19 Jan 2011 13:14:51 -0800 (PST) Received: by 10.216.168.201 with HTTP; Wed, 19 Jan 2011 13:14:51 -0800 (PST) Date: Wed, 19 Jan 2011 21:15:00 -0000 Message-ID: Subject: Could someone tell me what is wrong here? From: =?ISO-8859-1?B?TeF06SBTb/Nz?= To: gcc-help@gcc.gnu.org Content-Type: text/plain; charset=ISO-8859-1 X-IsSubscribed: yes Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org X-SW-Source: 2011-01/txt/msg00292.txt.bz2 Dear All, I maintain a program and I seemed to have stumbled into some bug of either the program or gcc. Thanks to Vegard Nossum, we have a really small (101 lines, most of them empty) example to reproduce it. The bug appears when I compile the program with gcc 4.5.1 (I believe it appears for 4.5.0 and 4.5.2 as well), with -O2. The program is meant to print "success", but when compiled with -O2 it returns "failure", while for -O0 works fine. The file is available here: http://planete.inrialpes.fr/~soos/gcc/ as "Main.cpp" and "compile.sh". Machine it is compiled on: distribution: Fedora Core 14 gcc --version: gcc (GCC) 4.5.1 20100924 (Red Hat 4.5.1-4) uname -a: Linux localhost.localdomain 2.6.35.6-45.fc14.i686 #1 SMP Mon Oct 18 23:56:17 UTC 2010 i686 i686 i386 GNU/Linux This bug seemed to have been triggered in the original (>13'000 LOC) program by multiple people, using multiple 4.5.X versions, on different computers&distributions. Does anyone know why I get this bug? Could anyone confirm that this the bug triggers on their architecture, distribution, and compiler version (only >= 4.5.0 seems to be affected)? Thank you in advance, Mate -- Mate Soos Security Research Labs www.srlabs.de www.msoos.org