From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31049 invoked by alias); 3 Sep 2013 19:34:58 -0000 Mailing-List: contact libc-ports-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: libc-ports-owner@sourceware.org Received: (qmail 31037 invoked by uid 89); 3 Sep 2013 19:34:58 -0000 Received: from mail-we0-f179.google.com (HELO mail-we0-f179.google.com) (74.125.82.179) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Tue, 03 Sep 2013 19:34:58 +0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,KHOP_THREADED,NO_RELAYS autolearn=ham version=3.3.2 X-HELO: mail-we0-f179.google.com Received: by mail-we0-f179.google.com with SMTP id t58so5300337wes.10 for ; Tue, 03 Sep 2013 12:34:54 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.194.219.1 with SMTP id pk1mr11469135wjc.36.1378236894686; Tue, 03 Sep 2013 12:34:54 -0700 (PDT) Received: by 10.216.179.5 with HTTP; Tue, 3 Sep 2013 12:34:54 -0700 (PDT) In-Reply-To: <20130903173710.GA2028@domone.kolej.mff.cuni.cz> References: <520894D5.7060207@linaro.org> <5220D30B.9080306@redhat.com> <5220F1F0.80501@redhat.com> <52260BD0.6090805@redhat.com> <20130903173710.GA2028@domone.kolej.mff.cuni.cz> Date: Tue, 03 Sep 2013 19:34:00 -0000 Message-ID: Subject: Re: [PATCH] sysdeps/arm/armv7/multiarch/memcpy_impl.S: Improve performance. From: "Ryan S. Arnold" To: =?UTF-8?B?T25kxZllaiBCw61sa2E=?= Cc: "Carlos O'Donell" , Will Newton , "libc-ports@sourceware.org" , Patch Tracking , Siddhesh Poyarekar Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2013-09/txt/msg00027.txt.bz2 On Tue, Sep 3, 2013 at 12:37 PM, Ond=C5=99ej B=C3=ADlka = wrote: >> I disagree strongly. You *must* come up with a measurable answer and >> looking at a graph is never a solution I'm going to accept. >> > You can have that opinion. > Looking at performance graphs is most powerful technique how to > understand performance. I got most of my improvements from analyzing > these. Are there any open source pipeline analysis tools? I've found the one I've used (proprietary) to be a pretty good indicator of general instruction selection optimization/correctness. Graphs are useful if everyone's agreed which data-sizes and alignment restrictions should be optimized for a particular platform. Ryan