From owner-freebsd-current@FreeBSD.ORG Wed May 21 18:10:30 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1E92B37B401 for ; Wed, 21 May 2003 18:10:30 -0700 (PDT) Received: from dragon.nuxi.com (trang.nuxi.com [66.93.134.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5871543F75 for ; Wed, 21 May 2003 18:10:29 -0700 (PDT) (envelope-from obrien@NUXI.com) Received: from dragon.nuxi.com (obrien@localhost [127.0.0.1]) by dragon.nuxi.com (8.12.9/8.12.9) with ESMTP id h4M1AETY027995; Wed, 21 May 2003 18:10:14 -0700 (PDT) (envelope-from obrien@dragon.nuxi.com) Received: (from obrien@localhost) by dragon.nuxi.com (8.12.9/8.12.9/Submit) id h4M1AEjS027994; Wed, 21 May 2003 18:10:14 -0700 (PDT) Date: Wed, 21 May 2003 18:10:14 -0700 From: "David O'Brien" To: Jon Lido Message-ID: <20030522011014.GC27806@dragon.nuxi.com> References: <200305201025.30296.jlido@goof.com> <200305201216.10964.jlido@goof.com> <20030520180004.GA2372@HAL9000.homeunix.com> <200305201512.27174.jlido@goof.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200305201512.27174.jlido@goof.com> User-Agent: Mutt/1.4i X-Operating-System: FreeBSD 5.0-CURRENT Organization: The NUXI BSD Group X-Pgp-Rsa-Fingerprint: B7 4D 3E E9 11 39 5F A3 90 76 5D 69 58 D9 98 7A X-Pgp-Rsa-Keyid: 1024/34F9F9D5 cc: freebsd-current@FreeBSD.ORG Subject: Re: gcc/libm floating-point bug? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: freebsd-current@FreeBSD.ORG List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 May 2003 01:10:30 -0000 On Tue, May 20, 2003 at 03:12:27PM -0400, Jon Lido wrote: > On Tuesday 20 May 2003 02:00 pm, David Schultz wrote: > > On Tue, May 20, 2003, Jon Lido wrote: > > > Well, I do have a P4, and had built everything with -march=pentium4. > > > However, rebuilding the kernel and modules with -march=pentium3 produces > > > the same results. > > > > This isn't a kernel problem, so you need to rebuild libm and libc > > without -march=pentium4. You really don't want to be using the > > Pentium 4 optimizations in gcc 3.2 anyway; the generated code is > > generally slower. gcc 3.3 has fixes for a number of the bugs, but > > I don't know about the performance problems. > > Yes, this was the problem. I rebuilt world with -march=pentium3 and that did > the trick. Honest question of you -- I'll assume you're subscribed to freebsd-current@. How have you missed all the warnings from myself and others not to trust the -march=pentium4 optimizations? I honestly want to know so we can figure out a better way of getting the word out. > I'm not sure how CPUTYPE gets handled, but perhaps p4 should expand to > -march=pentium3, if possible. I feel some will screem if we take away the ability to use -march=pentium4 in places they know for sure will work. Unix is about mechanisms, not policy.