From owner-freebsd-numerics@FreeBSD.ORG Wed May 29 00:06:23 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 1E0A0AA8 for ; Wed, 29 May 2013 00:06:23 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) by mx1.freebsd.org (Postfix) with ESMTP id DCFC66B6 for ; Wed, 29 May 2013 00:06:22 +0000 (UTC) Received: from troutmask.apl.washington.edu (localhost.apl.washington.edu [127.0.0.1]) by troutmask.apl.washington.edu (8.14.6/8.14.6) with ESMTP id r4T06MqY053909; Tue, 28 May 2013 17:06:22 -0700 (PDT) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.14.6/8.14.6/Submit) id r4T06MI4053908; Tue, 28 May 2013 17:06:22 -0700 (PDT) (envelope-from sgk) Date: Tue, 28 May 2013 17:06:22 -0700 From: Steve Kargl To: Stephen Montgomery-Smith Subject: Re: Patches for s_expl.c Message-ID: <20130529000622.GA53899@troutmask.apl.washington.edu> References: <20130528172242.GA51485@troutmask.apl.washington.edu> <20130529062437.V4648@besplex.bde.org> <20130528225310.GA53144@troutmask.apl.washington.edu> <51A53B1A.9040607@missouri.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51A53B1A.9040607@missouri.edu> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-numerics@freebsd.org 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 00:06:23 -0000 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. :( -- Steve