From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2354 invoked by alias); 6 Oct 2009 21:41:33 -0000 Received: (qmail 2345 invoked by uid 22791); 6 Oct 2009 21:41:32 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00 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; Tue, 06 Oct 2009 21:41:27 +0000 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 4018) id F173DF09A7; Tue, 6 Oct 2009 23:41:08 +0200 (CEST) Date: Tue, 06 Oct 2009 21:41:00 -0000 From: Jan Hubicka To: Toon Moene Cc: gcc mailing list Subject: Re: LTO: Speedup. Message-ID: <20091006214108.GB9046@atrey.karlin.mff.cuni.cz> References: <4ACBA42B.8040107@moene.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4ACBA42B.8040107@moene.org> User-Agent: Mutt/1.5.13 (2006-08-11) X-IsSubscribed: yes 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: 2009-10/txt/msg00123.txt.bz2 > L.S., > > On our weather forecasting code (compiled with -O3 -flto and linked with > -O3 -flto -fwhole-program) I get a speedup of 65 seconds per time step > in the model integration vs. 75 seconds with -O3 alone. There is bug making -fwhole-program disabled with LTO compilations. I hope to get this fixed in mainline tomorrow. It will be interesting to see how much difference -fwhole-program makes for you. Also ipa-sra was finally enabled at -O2 and I would be greatly interested if it makes any difference (in general it should help to fortran codebases by eliminating need to pass stuff around by reference) Honza