From nobody Tue Dec 14 21:51:06 2021 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 053DC18E9BB1; Tue, 14 Dec 2021 21:51:09 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "troutmask", Issuer "troutmask" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JDBs847rqz3s5w; Tue, 14 Dec 2021 21:51:08 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (localhost [127.0.0.1]) by troutmask.apl.washington.edu (8.16.1/8.16.1) with ESMTPS id 1BELp6iq050409 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 14 Dec 2021 13:51:06 -0800 (PST) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.16.1/8.16.1/Submit) id 1BELp69M050408; Tue, 14 Dec 2021 13:51:06 -0800 (PST) (envelope-from sgk) Date: Tue, 14 Dec 2021 13:51:06 -0800 From: Steve Kargl To: Mark Murray Cc: freebsd-hackers@freebsd.org, freebsd-current@freebsd.org Subject: Re: What to do about tgammal? Message-ID: <20211214215106.GA50381@troutmask.apl.washington.edu> References: <20211204185352.GA20452@troutmask.apl.washington.edu> <20211213022223.GA41440@troutmask.apl.washington.edu> <813F29E3-8478-4282-9518-5943DE7B5492@FreeBSD.org> List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <813F29E3-8478-4282-9518-5943DE7B5492@FreeBSD.org> X-Rspamd-Queue-Id: 4JDBs847rqz3s5w X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-ThisMailContainsUnwantedMimeParts: N On Tue, Dec 14, 2021 at 06:26:13PM +0000, Mark Murray wrote: > > This is now visible for review at > https://reviews.freebsd.org/D33444 > I see imp lamented that that fact that he is not sufficiently versed in the numerical methods used (neither am I!). bde use to be my go-to reviewer, but he's no longer with us. To allay fears, I've tested 5 million values distributed in the intervals of the various approximations. Here's the result Interval max ULP x at Max ULP [6,1755.1] 0.873414 at 1.480588145237629047468e+03 [1.0662,6] 0.861508 at 1.999467927053585410537e+00 [1.01e-17,1.0661] 0.938041 at 1.023286481537296307856e+00 [-1.9999,-1.0001] 3.157770 at -1.246957268051453610329e+00 [-2.9999,-2.0001] 2.987659 at -2.220949465449893090070e+00 Note, 1.01e-17 can be reduced to soemthing like 1.01e-19 or 1.01e-20. -- Steve