From owner-freebsd-questions@FreeBSD.ORG Mon Nov 14 23:39:23 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org 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 5935F16A41F for ; Mon, 14 Nov 2005 23:39:23 +0000 (GMT) (envelope-from chris@childeric.freeserve.co.uk) Received: from smtp-out5.blueyonder.co.uk (smtp-out5.blueyonder.co.uk [195.188.213.8]) by mx1.FreeBSD.org (Postfix) with ESMTP id C444343D49 for ; Mon, 14 Nov 2005 23:39:22 +0000 (GMT) (envelope-from chris@childeric.freeserve.co.uk) Received: from [192.168.10.60] ([82.35.116.100]) by smtp-out5.blueyonder.co.uk with Microsoft SMTPSVC(5.0.2195.6713); Mon, 14 Nov 2005 23:40:13 +0000 Message-ID: <43792010.9010802@childeric.freeserve.co.uk> Date: Mon, 14 Nov 2005 23:38:56 +0000 From: Chris User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051017) X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <20051114102308.7515.GERARD@seibercom.net> <20051114202300.GB98749@xor.obsecurity.org> In-Reply-To: <20051114202300.GB98749@xor.obsecurity.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 14 Nov 2005 23:40:13.0976 (UTC) FILETIME=[C2921980:01C5E974] Subject: Re: Makefile and Kernel Optimizations in 6.0 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Nov 2005 23:39:23 -0000 Kris Kennaway wrote: > P.S. -funroll-loops and -ffast-math are commonly used by people who > don't understand what they mean but like the thrill it gives them to > compile their application with secret optimizations (e.g. the word > "fast" makes them feel excited). However, the former is often not > actually an optimization (which is why it's not on by default), and > the latter can cause incorrect computations (but I think it's > completely irrelevant in the kernel which does not do FP math). Just out of curiosity, what would people who know what they are doing use them for? -funroll-loops sounds like an amusement park :P Chris