From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20928 invoked by alias); 29 Mar 2012 08:27:15 -0000 Received: (qmail 20849 invoked by uid 22791); 29 Mar 2012 08:27:08 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,TW_AV,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from sunsite.ms.mff.cuni.cz (HELO sunsite.mff.cuni.cz) (195.113.15.26) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 29 Mar 2012 08:26:49 +0000 Received: from sunsite.mff.cuni.cz (localhost [127.0.0.1]) by sunsite.mff.cuni.cz (8.14.5/8.14.5) with ESMTP id q2T8QlVZ025792; Thu, 29 Mar 2012 10:26:47 +0200 Received: (from jj@localhost) by sunsite.mff.cuni.cz (8.14.5/8.14.5/Submit) id q2T8QlJ7025791; Thu, 29 Mar 2012 10:26:47 +0200 Date: Thu, 29 Mar 2012 08:27:00 -0000 From: Jakub Jelinek To: =?iso-8859-1?Q?D=E2niel?= Fraga Cc: gcc@gcc.gnu.org Subject: Re: gcc 4.7: -march=corei7-avx bug? Message-ID: <20120329082646.GF6148@sunsite.ms.mff.cuni.cz> Reply-To: Jakub Jelinek References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2012-03/txt/msg00458.txt.bz2 On Thu, Mar 29, 2012 at 04:53:45AM -0300, Dâniel Fraga wrote: > I tried to compile Firefox 11 with gcc 4.7 optimized with: > > -O3 -march=corei7-avx (I have a core i7 2700k) > > But Firefox segfaults (backtrace provided, although it seems > not very useful): > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52762 > > If I compile with -march=corei7 it runs perfectly. > > Maybe a gcc bug? Maybe. Or maybe firefox bug. > How can I help you to debug this? Build with debug info, try to understand why it crashed, build a minimal testcase out of it, attach it to the PR. Or you could use a brute force method, if -march=corei7 works, but -march=corei7-avx doesn't, do a binary search on firefox built with some corei7 and some corei7-avx object files, until you find the problematic compilation unit. Jakub