From owner-freebsd-hackers Wed Apr 26 9: 4:19 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by hub.freebsd.org (Postfix) with ESMTP id 0E79A37BC89; Wed, 26 Apr 2000 09:04:11 -0700 (PDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.9.3/8.9.3) id LAA24991; Wed, 26 Apr 2000 11:03:45 -0500 (CDT) (envelope-from dan) Date: Wed, 26 Apr 2000 11:03:45 -0500 From: Dan Nelson To: Sheldon Hearn Cc: Brooks Davis , Nate Lawson , freebsd-hackers@FreeBSD.ORG, freebsd-ports@FreeBSD.ORG, davidm@hpl.hp.com Subject: Re: floating point exceptions Message-ID: <20000426110345.A13173@dan.emsphone.com> References: <20000425000523.A17224@orion.ac.hmc.edu> <24238.956752200@axl.ops.uunet.co.za> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.1.9i In-Reply-To: <24238.956752200@axl.ops.uunet.co.za>; from "Sheldon Hearn" on Wed Apr 26 14:30:00 GMT 2000 X-OS: FreeBSD 5.0-CURRENT Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In the last episode (Apr 26), Sheldon Hearn said: > On Tue, 25 Apr 2000 00:05:23 MST, Brooks Davis wrote: > > > Is FreeBSD's behavior correct? Why or why not? You can use the > > > included code snippet to verify that this occurs. > > > > FreeBSD has traditionaly violated the IEEE FP standard in this > > regard. This is fixed in 5.0 and I think in 4.0-STABLE (though I > > can't remember what file this is in so I can't check.) > > Huh? I'm pretty sure you've got this backwards. FreeBSD has > traditionally upheld the standard and we only recently decided to go > with the flow in 5.0. No; we held our moral ground against IEEE, until 5.0 when we gave in. The IEEE standard says "trap nothing". For most programs, this is the wrong thing to do, since they are not signal-processing apps or numerical analysis programs and a divide by zero is a coding error. I'd rather have my program die on an unexpected divide by zero than continue with invalid data. Why should we treat (1.0/0.0) any differently from (1/0)? -- Dan Nelson dnelson@emsphone.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message