From owner-freebsd-questions@FreeBSD.ORG Tue Feb 10 12:14:39 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8738816A4CE for ; Tue, 10 Feb 2004 12:14:39 -0800 (PST) Received: from mout.perfora.net (mout.perfora.net [217.160.230.40]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6DACB43D1F for ; Tue, 10 Feb 2004 12:14:39 -0800 (PST) (envelope-from roop@hqst.com) Received: from [217.160.230.51] (helo=smtp.perfora.net) by mout.perfora.net with esmtp (Exim 3.35 #1) id 1AqeHH-0007mq-00 for questions@freebsd.org; Tue, 10 Feb 2004 15:14:39 -0500 Received: from [24.82.165.92] (helo=hqst.com) by smtp.perfora.net with asmtp (Exim 3.35 #1) id 1AqeHG-0001fu-00 for questions@FreeBSD.org; Tue, 10 Feb 2004 15:14:39 -0500 Message-ID: <40293BB6.5060005@hqst.com> Date: Tue, 10 Feb 2004 12:14:46 -0800 From: Roop Nanuwa User-Agent: Mozilla Thunderbird 0.5+ (Windows/20040207) X-Accept-Language: en-us, en MIME-Version: 1.0 To: questions@FreeBSD.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: How about them optimizations? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Feb 2004 20:14:39 -0000 Part of my current /etc/make.conf on my 5.2-CURRENT box looks like: CPUTYPE= athlon-xp CFLAGS= -O2 -pipe -fomit-frame-pointer -mmmx -msse -m3dnow -mfpmath=sse COPTFLAGS= -O -pipe Now what I'm wondering is if those extras like mmmx msse actually do anything. The only reason they're in there is because I saw them on a website about what people use to optimize gentoo. I had nothing better to do so I recompiled the world with them. I didn't really notice anything good or bad happening after that. I did have to mess around with a couple of makefiles to get around the strict-aliasing problem that O2 introduces. Besides that, though, are there any advantages or disadvantages to compiling with those optimizations and switches? Does -mfpmath=sse actually do anything relevent for the FreeBSD world? I know what the GCC manual says about it but I'd rather hear some real world info. An enquiring mind wants to know. --roop