From owner-freebsd-arch@FreeBSD.ORG Thu Jul 12 22:18:18 2007 Return-Path: X-Original-To: freebsd-arch@FreeBSD.org Delivered-To: freebsd-arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 86F1616A400 for ; Thu, 12 Jul 2007 22:18:18 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from mail.farley.org (farley.org [67.64.95.201]) by mx1.freebsd.org (Postfix) with ESMTP id 4935C13C48C for ; Thu, 12 Jul 2007 22:18:18 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from thor.farley.org (thor.farley.org [192.168.1.5]) by mail.farley.org (8.14.1/8.14.1) with ESMTP id l6CMK5CL032706; Thu, 12 Jul 2007 17:20:05 -0500 (CDT) (envelope-from scf@FreeBSD.org) Date: Thu, 12 Jul 2007 17:17:57 -0500 (CDT) From: "Sean C. Farley" To: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= In-Reply-To: <86hco95lg8.fsf@dwp.des.no> Message-ID: <20070712170748.W8789@thor.farley.org> References: <20070711134721.D2385@thor.farley.org> <20070711221338.GC20178@turion.vk2pj.dyndns.org> <200707112221.l6BML722062857@apollo.backplane.com> <20070711183217.C2385@thor.farley.org> <86lkdl5osc.fsf@dwp.des.no> <20070712161200.I8789@thor.farley.org> <86hco95lg8.fsf@dwp.des.no> MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="0-1811604476-1184278677=:8789" X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.1 X-Spam-Checker-Version: SpamAssassin 3.2.1 (2007-05-02) on mail.farley.org Cc: freebsd-arch@FreeBSD.org Subject: Re: Assembly string functions in i386 libc X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Jul 2007 22:18:18 -0000 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --0-1811604476-1184278677=:8789 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Fri, 13 Jul 2007, Dag-Erling Sm=F8rgrav wrote: > "Sean C. Farley" writes: >> On Thu, 12 Jul 2007, Dag-Erling Sm=F8rgrav wrote: >>> The first rule of optimization is: don't do it. >>> The second rule of optimization is: don't do it yet. >>> The third rule of optimization is: don't optimize what you haven't >>> measured. >> I am a rule breaker at least for the first two. :) I tried to >> follow the third rule. >> >>> Can you show us an actual application that spends a significant part >>> of its run time in strlen()? >> My test program that loops over strlen(). > > So the answer is no, and you don't understand the third rule which you > claim to follow. I never claimed to succeed; I only tried. The two types of tests I can think would be useful were execution of strlen() by itself and within a common program. I had thought I had tested the first type of test. The second one I did later with different versions of strlen() using diff. What types of tests would have been better? I know about gprof for finding where a specific program is spending its time, but I was focusing on the strlen() call. Also, having two different versions in the source tree is still puzzling me. Sean --=20 scf@FreeBSD.org --0-1811604476-1184278677=:8789--