From owner-freebsd-numerics@FreeBSD.ORG Wed May 29 01:21:19 2013 Return-Path: Delivered-To: freebsd-numerics@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 2E775467 for ; Wed, 29 May 2013 01:21:19 +0000 (UTC) (envelope-from s.montgomerysmith@gmail.com) Received: from mail-ie0-x232.google.com (mail-ie0-x232.google.com [IPv6:2607:f8b0:4001:c03::232]) by mx1.freebsd.org (Postfix) with ESMTP id F2BE7A79 for ; Wed, 29 May 2013 01:21:18 +0000 (UTC) Received: by mail-ie0-f178.google.com with SMTP id f4so7240082iea.37 for ; Tue, 28 May 2013 18:21:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:message-id:date:from:user-agent:mime-version:to:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; bh=vZGvRyAYMcXbSQd+Pef+ozY2WNuHDSVSkodRKHfc5CE=; b=L+ejsyWiYDzrzqDLg7R9uQ+Bk32Dl+DULmlvMZsdCPyO5lhO+FeTkquPr5KtBAr1tv AqD91GrLc59FPmMIgnp4/ZaGY7SmE7qrz7MRTkDAlAMgPeaieWt5GoImICPp96T2F2kt +31Tx+X2k/V2nLt3U5n6+Eyfkg8/sGAbCOjCFg7rT8TYptZzKXELM2f45RH3ZGopiQuL sJ0IFeJa3bV0Fq3o5HfWkXkZcGJORreUKVWz+LSwWHH1qczA89eNxYLRecPJ4MIIqXlN Dnkf8mjkhwdjODCMbHJ/VtPQFKo1QCGuTa4b0kWV3lFPADTk4/bV060mVyQ3yIPhaQAP GMkQ== X-Received: by 10.42.84.73 with SMTP id k9mr140386icl.50.1369790478756; Tue, 28 May 2013 18:21:18 -0700 (PDT) Received: from [192.168.0.11] (50-82-246-58.client.mchsi.com. [50.82.246.58]) by mx.google.com with ESMTPSA id o10sm20679318igh.2.2013.05.28.18.21.16 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 28 May 2013 18:21:17 -0700 (PDT) Sender: Stephen Montgomery-Smith Message-ID: <51A5580C.9000607@missouri.edu> Date: Tue, 28 May 2013 20:21:16 -0500 From: Stephen Montgomery-Smith User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: freebsd-numerics@freebsd.org Subject: Re: Patches for s_expl.c References: <20130528172242.GA51485@troutmask.apl.washington.edu> <20130529062437.V4648@besplex.bde.org> <20130528225310.GA53144@troutmask.apl.washington.edu> <51A53B1A.9040607@missouri.edu> <20130529000622.GA53899@troutmask.apl.washington.edu> In-Reply-To: <20130529000622.GA53899@troutmask.apl.washington.edu> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-numerics@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Discussions of high quality implementation of libm functions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 May 2013 01:21:19 -0000 On 05/28/2013 07:06 PM, Steve Kargl wrote: > On Tue, May 28, 2013 at 06:17:46PM -0500, Stephen Montgomery-Smith wrote: >> On 05/28/2013 05:53 PM, Steve Kargl wrote: >> >>> Given that I've merged, unmerged, remerged, disremerged, and >>> undisremerged numerous diffs over the last 2+ years, I am not >>> surprise that there are issues with the patches. I'm neither >>> an expert in floating arithmetic nor style(9). If I understand >>> half of what you write when you annotate one of your diffs, I >>> feel lucky. >>> >>> (Un)fortunately, I only have a few hours this week to work on >>> expl/expm1l, and then I'll disappear again for a month or two >>> (due to work and life). (Un)fortunately, theraven (under the >>> pretense of core) has threaten to completely rendered libm into >>> a crippled useless mess by mapping all unimplemented long double >>> functions to their double cousins. When/if it comes to pass >>> that I have to untangle whatever theraven does, I'll likely >>> just walk away from libm hacking. >> >> I think it is better to commit "as is" if you cannot make all the changes. >> >> As for me, I don't really understand the need to be so consistent with >> style, nor to get every last drop of optimization. In particular, >> regarding style, I think it is like people talking different languages. >> You could insist that everyone speak a common language, but it is far >> better for the intellectual commons if people learn other peoples' >> languages. >> >> Anyway, I think it is better for Steve to commit, and then for Bruce to >> make changes later on. >> > > It's too late. In making some change since the last time I test > has introduced a massive regression in the computation of expm1l. > > laptop-kargl:kargl[204] ./testl -n 5 -b > prec: 64 > For x in [-64.0000:-0.1659], 5M expm1l calls in 2.176513 seconds. > For x in [-0.1659:0.1659], 5M expm1l calls in 0.415051 seconds. > For x in [0.1659:11356.0000], 5M expm1l calls in 0.550342 seconds. > > Notice, the first interval is now 4 to 5 times slower than the > other intervals. This was not the case with an older version > of the code. > > :( I think it is still better to commit. Then figure out where the regression was later, when you have time.