From owner-freebsd-numerics@FreeBSD.ORG Sun Aug 12 23:05:19 2012 Return-Path: Delivered-To: freebsd-numerics@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 49153106566C for ; Sun, 12 Aug 2012 23:05:19 +0000 (UTC) (envelope-from peter@rulingia.com) Received: from vps.rulingia.com (host-122-100-2-194.octopus.com.au [122.100.2.194]) by mx1.freebsd.org (Postfix) with ESMTP id D60208FC14 for ; Sun, 12 Aug 2012 23:05:18 +0000 (UTC) Received: from server.rulingia.com (c220-239-249-137.belrs5.nsw.optusnet.com.au [220.239.249.137]) by vps.rulingia.com (8.14.5/8.14.5) with ESMTP id q7CN5IOu075689 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 13 Aug 2012 09:05:18 +1000 (EST) (envelope-from peter@rulingia.com) X-Bogosity: Ham, spamicity=0.000000 Received: from server.rulingia.com (localhost.rulingia.com [127.0.0.1]) by server.rulingia.com (8.14.5/8.14.5) with ESMTP id q7CN5Bh5021305 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 13 Aug 2012 09:05:12 +1000 (EST) (envelope-from peter@server.rulingia.com) Received: (from peter@localhost) by server.rulingia.com (8.14.5/8.14.5/Submit) id q7CN5BCo021304 for freebsd-numerics@freebsd.org; Mon, 13 Aug 2012 09:05:11 +1000 (EST) (envelope-from peter) Resent-From: Peter Jeremy Resent-Date: Mon, 13 Aug 2012 09:05:11 +1000 Resent-Message-ID: <20120812230511.GS20453@server.rulingia.com> Resent-To: freebsd-numerics@freebsd.org Received: from vps.rulingia.com (host-122-100-2-194.octopus.com.au [122.100.2.194]) by server.rulingia.com (8.14.5/8.14.5) with ESMTP id q6H4Oc0F070162 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 17 Jul 2012 14:24:39 +1000 (EST) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) by vps.rulingia.com (8.14.5/8.14.5) with ESMTP id q6H4OaYs065923 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 17 Jul 2012 14:24:37 +1000 (EST) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (localhost.apl.washington.edu [127.0.0.1]) by troutmask.apl.washington.edu (8.14.5/8.14.5) with ESMTP id q6H4OYOn087039; Mon, 16 Jul 2012 21:24:34 -0700 (PDT) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.14.5/8.14.5/Submit) id q6H4OYe9087038; Mon, 16 Jul 2012 21:24:34 -0700 (PDT) (envelope-from sgk) From: Steve Kargl Mail-Followup-To: freebsd-numerics@freebsd.org To: Warner Losh Message-ID: <20120717042434.GA87001@troutmask.apl.washington.edu> References: <201207130818.38535.jhb@freebsd.org> <9EB2DA4F-19D7-4BA5-8811-D9451CB1D907@theravensnest.org> <20120713155805.GC81965@zim.MIT.EDU> <20120714120432.GA70706@server.rulingia.com> <20120717084457.U3890@besplex.bde.org> <5004A5C7.1040405@missouri.edu> <5004DEA9.1050001@missouri.edu> <20120717040118.GA86840@troutmask.apl.washington.edu> <6F750F84-34FF-4961-A2EA-F3E67A6872AE@bsdimp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6F750F84-34FF-4961-A2EA-F3E67A6872AE@bsdimp.com> User-Agent: Mutt/1.4.2.3i Cc: Diane Bruce , John Baldwin , David Chisnall , Stephen Montgomery-Smith , Bruce Evans , Bruce Evans , David Schultz , Peter Jeremy Subject: Re: Use of C99 extra long double math functions after r236148 X-BeenThere: freebsd-numerics@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Discussions of high quality implementation of libm functions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Date: Sun, 12 Aug 2012 23:05:19 -0000 X-Original-Date: Mon, 16 Jul 2012 21:24:34 -0700 X-List-Received-Date: Sun, 12 Aug 2012 23:05:19 -0000 On Mon, Jul 16, 2012 at 10:12:21PM -0600, Warner Losh wrote: > > On Jul 16, 2012, at 10:01 PM, Steve Kargl wrote: > > > On Mon, Jul 16, 2012 at 10:40:25PM -0500, Stephen Montgomery-Smith wrote: > >> > >> I came up with pseudo code that looks a bit like this. > >> > >> complex casinh(complex z) { > >> double x = z.re, y = z.im; > >> > >> if (y==0) > >> return asinh(x); > >> if (x==0) { > >> if (fabs(y)<=1) return I*asin(y); > >> else return signum(y)* ( > >> log(fabs(y)+sqrt(y*y-1)) > >> + I*PI/2); > > > > Stop. Please see msun/src/math_private.h. You cannot > > use I in any expression. gcc in base and clang do not > > do the arithmetic correctly. See msun/src/s_ccosh.c > > for how one might approach writing these functions. > > Also, consult n1256.pdf for x,y = +-0, +-inf, nan. > > There are specific requirements that must be met. > > Yes. Pseudo code is OK for following the flow, but look at the > exp code for why that's not entirely sufficient. You have to be > extremely fussy about all kinds of things. Then again, exp is a > lot more important to get right than the complex trig functions... > > The pseudo code is a good place to start, but it just the barest > start in the integration process... I can't tell whether you agree with my urging of caution or whether your being sarcastic. The pseudo-code as written simply does not apply once one looks at n1256.pdf. -- Steve