From owner-freebsd-chat@FreeBSD.ORG Thu Jan 15 10:42:19 2004 Return-Path: Delivered-To: freebsd-chat@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3960416A4CE for ; Thu, 15 Jan 2004 10:42:19 -0800 (PST) Received: from mail2.speakeasy.net (mail2.speakeasy.net [216.254.0.202]) by mx1.FreeBSD.org (Postfix) with ESMTP id C093743D5A for ; Thu, 15 Jan 2004 10:42:12 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 21963 invoked from network); 15 Jan 2004 18:42:12 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 15 Jan 2004 18:42:12 -0000 Received: from 10.50.40.206 (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.10/8.12.10) with ESMTP id i0FIg2M0082122; Thu, 15 Jan 2004 13:42:02 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Kris Kennaway , Christer Solskogen Date: Thu, 15 Jan 2004 11:24:54 -0500 User-Agent: KMail/1.5.4 References: <2303.148.121.98.106.1074172159.squirrel@mail.carebears.mine.nu> <20040115154105.GA13188@xor.obsecurity.org> In-Reply-To: <20040115154105.GA13188@xor.obsecurity.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200401151124.56182.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) cc: chat@freebsd.org Subject: Re: CFLAGS and such X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jan 2004 18:42:19 -0000 On Thursday 15 January 2004 10:41 am, Kris Kennaway wrote: > On Thu, Jan 15, 2004 at 02:09:19PM +0100, Christer Solskogen wrote: > > When a release('make release' og TIER) is made, is there some kind of > > optimization using CPUTYPE or CFLAGS? > > If yes, what? If no, why? > > CFLAGS has the default value of "-O -pipe". Further > (e.g. CPU-specific) optimizations are not used by default, because > FreeBSD releases are required to work on anything down to a 386 (5.x > kernels excepted). Incorrect. We use -mcpu=pentiumpro which optimizes the code flow for a PII or later, but still only uses i386 instructions. Thus, we do optimize for more recent CPUs while still generating code that will run on all CPUs. Check the gcc info pages for the difference between -march and -mcpu on i386 and -mcpu and -mtune on all other archs. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org