From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3101 invoked by alias); 17 Jan 2004 14:37:32 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 3094 invoked from network); 17 Jan 2004 14:37:32 -0000 Received: from unknown (HELO nikam.ms.mff.cuni.cz) (195.113.18.106) by sources.redhat.com with SMTP; 17 Jan 2004 14:37:32 -0000 Received: from camelot.ms.mff.cuni.cz (kampanus.ms.mff.cuni.cz [195.113.18.107]) by nikam.ms.mff.cuni.cz (Postfix) with SMTP id 8EB5B4E0CC; Sat, 17 Jan 2004 15:37:32 +0100 (CET) Received: by camelot.ms.mff.cuni.cz (sSMTP sendmail emulation); Sat, 17 Jan 2004 15:37:33 +0100 Date: Sat, 17 Jan 2004 14:37:00 -0000 From: Jan Hubicka To: Roger Sayle Cc: Jan Hubicka , Steven Bosscher , gcc@gcc.gnu.org Subject: Re: [RFC] Contributing tree-ssa to mainline Message-ID: <20040117143733.GR8121@kam.mff.cuni.cz> References: <20040117140145.GI26819@atrey.karlin.mff.cuni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.28i X-SW-Source: 2004-01/txt/msg01054.txt.bz2 > > On Sat, 17 Jan 2004, Jan Hubicka wrote: > > > My greatest disappointment working on GCC's optimizations, is that > > > try as I might I've only ever been able to push Andreas' SPECcpu2000 > > > benchmarks perhaps a percentage point or two higher. This on a platform > > > where Microsoft's compilers score about 20% higher. Intel similarly > > > claims about 20% better performance than GCC on average. > > > > How did you got to this number? > > This is definitly not the case of SPECint scpres I saw. My experience > > is that we are about 2-3% behind AMD published results in 32bit mode. > > The published figures are on Andreas' site for the world to see. > http://www.suse.de/~aj/SPEC/ > > If you click on "SPECint2000 results (permanent runs, non-reportable)" > you get mainline's current performance, which from the graph at the > bottom is just about 400 as of January 17th 2004. > > If you then go to the section entitled "Comparisons with Other Compilers" > and click on the "SPECint200 in 1.2GHZ AMD Athlon", which is described > as "these results should give an indication of how good/bad GCC is", > you'll see a SPEC report with SPECint2000 of 496. And that was with > the Intel 5.0 compiler! > > The difference between 400 and 500 is about 20%. You missed the fact that published results are on 1.2Ghz athlon with more modern core, compared to our testers running 1.33. There are unforutnately no published results for 1.33 Athlons Additionally the settings are more comparable with our peak results as ICC does profile feedback, unrolling, inlining, frame pointer omitting and other stuff in the baseline results. Finally there is noticeable difference caused by runtime library that contains optimized malloc and few other tricks. > > > Perhaps you could provide details of where you 2 or 3% comes from? I did ICC runs with same config options myself on same hardware as periodic testers use. I am not sure I still have the numbers, but I will try to dig out. You can look at http://www.suse.de/~aj/SPEC/amd64 that contains bars for ICC and 32bit compilers. If I compute geometric average myself, i get 878 ICC score. Compare it to 820 produced by GCC peak in 32bit compilation and you get 7% difference and take into account that profile feedback. Then look at my GCC summit paper. It contains tests with similar set of opotimizations and it claims that 7.87% can be gained if Andreas used PDO. I need to produce true runs instead of such a hints, but it is clear that we are not 20% behind at all. Honza > > Roger > --