From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18590 invoked by alias); 2 May 2012 13:05:39 -0000 Received: (qmail 18558 invoked by uid 22791); 2 May 2012 13:05:38 -0000 X-SWARE-Spam-Status: No, hits=-3.4 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from atrey.karlin.mff.cuni.cz (HELO atrey.karlin.mff.cuni.cz) (195.113.26.193) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 02 May 2012 13:05:04 +0000 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 4018) id 7861EF092A; Wed, 2 May 2012 15:05:03 +0200 (CEST) Date: Wed, 02 May 2012 13:05:00 -0000 From: Jan Hubicka To: "burnus at gcc dot gnu.org" Cc: gcc-bugs@gcc.gnu.org Subject: Re: [Bug fortran/51267] loop optimization error using LOC function Message-ID: <20120502130503.GD2163@atrey.karlin.mff.cuni.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-IsSubscribed: yes Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-05/txt/msg00109.txt.bz2 I am surprised that this does not happen already at PRE :) Without volatile attribute there is really nothing that prevents GCC from doing this optimization and unfortunately I don't think we provide way to prevent it without this big hammer. We have fpcr register defined for the control word that is accepted in clobber list, but there is no way to express use of this I think. Honza