From owner-freebsd-stable@FreeBSD.ORG Fri Nov 10 22:24:48 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9E46C16A415 for ; Fri, 10 Nov 2006 22:24:48 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from sccrmhc14.comcast.net (sccrmhc14.comcast.net [204.127.200.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0AC1843D5C for ; Fri, 10 Nov 2006 22:24:45 +0000 (GMT) (envelope-from jdc@koitsu.dyndns.org) Received: from icarus.home.lan (c-67-174-220-97.hsd1.ca.comcast.net[67.174.220.97]) by comcast.net (sccrmhc14) with ESMTP id <2006111022244301400qf2l6e>; Fri, 10 Nov 2006 22:24:43 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 607A41FA01D; Fri, 10 Nov 2006 14:24:34 -0800 (PST) Date: Fri, 10 Nov 2006 14:24:34 -0800 From: Jeremy Chadwick To: "Jason C. Wells" Message-ID: <20061110222434.GA76724@icarus.home.lan> Mail-Followup-To: "Jason C. Wells" , freebsd-stable References: <4554D43E.5010700@highperformance.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4554D43E.5010700@highperformance.net> X-PGP-Key: http://jdc.parodius.com/pubkey.asc User-Agent: Mutt/1.5.13 (2006-08-11) Cc: freebsd-stable Subject: Re: Compiler Options X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Nov 2006 22:24:48 -0000 On Fri, Nov 10, 2006 at 11:34:22AM -0800, Jason C. Wells wrote: > I have set CPUTYPE=p3 in make.conf. When I compile my kernel I see > -march=pentium3 as I expect. I also see -mno-mmx and -mno-sse are set > which I do not expect given that -march=pentium3 is used. I presume > that I want MMX and SSE since my processor supports it. What options do > I set and where do I set them to get a kernel properly tuned for pentium3? The kernel will "support" MMX and SSE -- that is, any programs (root or userland) which use MMX/SSE will work just fine. That is: any programs built with gcc can indeed support MMX and SSE operations. The kernel itself _will not_ use any SSE or MMX operations when built. This is because these optimisations are known to break the FreeBSD kernel. This applies to all i386 architectures, and probably 64-bit architectures too (not sure). CPUTYPE=p3 (or pentium4, or any other type) will not change this behaviour. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |