From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17884 invoked by alias); 1 Mar 2004 07:27:19 -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 17877 invoked from network); 1 Mar 2004 07:27:18 -0000 Received: from unknown (HELO mail.codesourcery.com) (65.74.133.6) by sources.redhat.com with SMTP; 1 Mar 2004 07:27:18 -0000 Received: (qmail 16935 invoked from network); 1 Mar 2004 07:27:17 -0000 Received: from taltos.codesourcery.com (zack@66.92.218.83) by mail.codesourcery.com with DES-CBC3-SHA encrypted SMTP; 1 Mar 2004 07:27:17 -0000 Received: by taltos.codesourcery.com (sSMTP sendmail emulation); Sun, 29 Feb 2004 23:27:17 -0800 To: Theo de Raadt Cc: Andrew Pinski , tech@openbsd.org, Marc Espie , "gcc@gcc.gnu.org List" Subject: Re: gcc and compiling speed References: <200403010349.i213nxpD008197@cvs.openbsd.org> <8765dpqkpq.fsf@egil.codesourcery.com> <20040301071403.GA8953@tetto.gentiane.org> From: Zack Weinberg Date: Mon, 01 Mar 2004 07:27:00 -0000 In-Reply-To: <20040301071403.GA8953@tetto.gentiane.org> (Marc Espie's message of "Mon, 1 Mar 2004 08:14:04 +0100") Message-ID: <87wu65owmi.fsf@egil.codesourcery.com> User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2004-03/txt/msg00038.txt.bz2 Marc Espie writes: >> What you don't realize, perhaps, is just how data-driven gcc (any >> version) is. I could spend weeks tuning gcc to work well on mozilla >> and it could make no. difference. whatsoever. to how long it takes to >> compile OpenBSD core. Thank you. > I'm just busy with various things, including an upcoming OpenBSD release, > and a move between apartments, but I'll provide this preprocessed source > as soon as it gets on the top list of my things to do. > > On the other hand, what you're saying is plain bullshit, Zack. The slowdown > of gcc3 vs. gcc2 is NOT dependent on the set of source files. You misunderstand. I do not deny that gcc 3.3 is slower than gcc 2.95 for almost all C input (*please* be specific about minor version numbers - 3.0, 3.[12], 3.3, 3.4, and mainline are all very different beasts). I have observed the slowdown myself, in fact. What I said was that speeding up GCC for one set of source files is unlikely to speed it up for another. This is *also* true. And this is why we keep asking you for your test cases. (If we get *enough* test cases, we can cover all the code paths and speed the compiler up in general, but we aren't there yet.) zw