From owner-freebsd-current@FreeBSD.ORG Wed May 21 18:27:13 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 E25E137B401 for ; Wed, 21 May 2003 18:27:13 -0700 (PDT) Received: from lakemtao07.cox.net (lakemtao07.cox.net [68.1.17.114]) by mx1.FreeBSD.org (Postfix) with ESMTP id E649D43F75 for ; Wed, 21 May 2003 18:27:12 -0700 (PDT) (envelope-from mezz7@cox.net) Received: from sysinfo.mezzweb.com ([68.103.37.247]) by lakemtao07.cox.net (InterMail vM.5.01.04.05 201-253-122-122-105-20011231) with ESMTP id <20030522012711.SFRU4514.lakemtao07.cox.net@sysinfo.mezzweb.com>; Wed, 21 May 2003 21:27:11 -0400 To: Jon Lido References: <200305201025.30296.jlido@goof.com> <200305201216.10964.jlido@goof.com> <20030520180004.GA2372@HAL9000.homeunix.com> <200305201512.27174.jlido@goof.com> <20030522011014.GC27806@dragon.nuxi.com> Message-ID: Content-Type: text/plain; charset=utf-8; format=flowed From: Jeremy Messenger MIME-Version: 1.0 Date: Wed, 21 May 2003 20:13:19 -0500 In-Reply-To: <20030522011014.GC27806@dragon.nuxi.com> User-Agent: Opera7.11/Linux M2 build 406 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 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 01:27:14 -0000 On Wed, 21 May 2003 18:10:14 -0700, David O'Brien wrote: > 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. Perhaps, it should be add in the errata? Also, add the comments in the make.conf. Cheers, Mezz >> 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. -- bsdforums.org 's moderator, mezz.