Date: Sun, 12 Aug 2012 23:09:12 -0000 From: Stephen Montgomery-Smith <stephen@missouri.edu> To: Steve Kargl <sgk@troutmask.apl.washington.edu> Cc: Diane Bruce <db@db.net>, John Baldwin <jhb@freebsd.org>, David Chisnall <theraven@freebsd.org>, Bruce Evans <bde@freebsd.org>, Bruce Evans <brde@optusnet.com.au>, David Schultz <das@freebsd.org>, Peter Jeremy <peter@rulingia.com>, Warner Losh <imp@bsdimp.com> Subject: Re: Use of C99 extra long double math functions after r236148 Message-ID: <5007AD41.9070000@missouri.edu> Resent-Message-ID: <20120812230905.GK20453@server.rulingia.com> In-Reply-To: <5007826D.7060806@missouri.edu> References: <20120714120432.GA70706@server.rulingia.com> <20120717084457.U3890@besplex.bde.org> <5004A5C7.1040405@missouri.edu> <5004DEA9.1050001@missouri.edu> <20120717200931.U6624@besplex.bde.org> <5006D13D.2080702@missouri.edu> <20120718205625.GA409@troutmask.apl.washington.edu> <500725F2.7060603@missouri.edu> <20120719025345.GA1376@troutmask.apl.washington.edu> <50077987.1080307@missouri.edu> <20120719032706.GA1558@troutmask.apl.washington.edu> <5007826D.7060806@missouri.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format. --------------000500050401010706080607 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit I did a ULP test on clog. The test code is attached. (Not the cleanest code, I know, but it does the job.) It needs the mpfr and unuran ports installed. To my shock, I found that under certain circumstances, the ULP in the real part was huge. The problem is when hypot(x,y) is close to 1, because then the real part of clog is close to zero. I was seeing ULPs in the thousands. I struggled to find a solution, and now I think I have the ULP down to about 2. I am going to work on it more tomorrow to see if I can get ULP down even further. --------------000500050401010706080607--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5007AD41.9070000>