From owner-freebsd-bugs Fri Feb 20 20:36:58 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id UAA23766 for freebsd-bugs-outgoing; Fri, 20 Feb 1998 20:36:58 -0800 (PST) (envelope-from owner-freebsd-bugs@FreeBSD.ORG) Received: from mailhub.nc.com (mailhub.nc.com [207.88.25.3]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id UAA23760 for ; Fri, 20 Feb 1998 20:36:55 -0800 (PST) (envelope-from neil@causality.com) Received: (from proxy@localhost) by mailhub.nc.com (8.6.12/8.6.9) id UAA26755; Fri, 20 Feb 1998 20:35:54 -0800 Received: from riscbsd2.client.nc.com(172.17.8.89) by mailhub.nc.com via smap (V2.0) id xma026745; Fri, 20 Feb 98 20:35:40 -0800 Message-ID: <34EE57FE.5B1234BB@causality.com> Date: Sat, 21 Feb 1998 04:28:46 +0000 From: "Neil A. Carson" Organization: Causality Limited X-Mailer: Mozilla 4.04 [en] (X11; I; FreeBSD 3.0-971225-SNAP i386) MIME-Version: 1.0 To: Bruce Evans CC: jkh@time.cdrom.com, bugs@FreeBSD.ORG Subject: Re: Floating point errors References: <199802210421.PAA18491@godzilla.zeta.org.au> Content-Type: multipart/mixed; boundary="------------28F9CE6FBD154640E393D5D8" Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org This is a multi-part message in MIME format. --------------28F9CE6FBD154640E393D5D8 Content-Type: multipart/alternative; boundary="------------E38193502F41B5AE5C4DA609" --------------E38193502F41B5AE5C4DA609 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Bruce Evans wrote: > Wrong. I feel that it is more useful to die rather than possibly > run incorrectly. Programmers who actually understand FP exceptions > can easily change the default exception mask (I changed it 3 years > ago on my systems). The technical correctness of this is debatable. > It prevents the math libraries from being ANSI conformant, but the math > libraries have more serious ANSI conformance bugs. I don't plan to > change the exception handling until the other bugs are fixed. Are the conformance bugs quite major? We had to write a collection of FP emulator code that was completely ANSI conformant (for one reason or another, to pass the Java compliance tests here at Oracle) for the ARM, as it doesn't have an FPU of any sort. Of course, programmers who understand FP exceptions can easily change stuff, but the mathematicians/physicians (who are in this case quite computer-illiterate and only like to do the bear minimumof code to get something to 'work') in my case are unaware of the set mask call. Of course, as a reverse, one could argue that as a result their stuff shouldn't work anyway! Not that of course this is of any direct relevance to my small evaluation here anyway, as I also have a number of NetBSD machines around; maybe I'm just waffling so I'll shut up now. If I can be of assistance with any stuff, let me know. Regards, Neil --------------E38193502F41B5AE5C4DA609 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Bruce Evans wrote:
Wrong.  I feel that it is more useful to die rather than possibly
run incorrectly.  Programmers who actually understand FP exceptions
can easily change the default exception mask (I changed it 3 years
ago on my systems).  The technical correctness of this is debatable.
It prevents the math libraries from being ANSI conformant, but the math
libraries have more serious ANSI conformance bugs.  I don't plan to
change the exception handling until the other bugs are fixed.
Are the conformance bugs quite major? We had to write a collection of FP emulator code that was completely ANSI conformant (for one reason or another, to pass the Java compliance tests here at Oracle) for the ARM, as it doesn't have an FPU of any sort. Of course, programmers who understand FP exceptions can easily change stuff, but the mathematicians/physicians (who are in this case quite computer-illiterate and only like to do the bear minimumof code to get something to 'work') in my case are unaware of the set mask call. Of course, as a reverse, one could argue that as a result their stuff shouldn't work anyway! Not that of course this is of any direct relevance to my small evaluation here anyway, as I also have a number of NetBSD machines around; maybe I'm just waffling so I'll shut up now.

If I can be of assistance with any stuff, let me know.

    Regards,

    Neil
  --------------E38193502F41B5AE5C4DA609-- --------------28F9CE6FBD154640E393D5D8 Content-Type: text/x-vcard; charset=us-ascii; name="vcard.vcf" Content-Transfer-Encoding: 7bit Content-Description: Card for Neil A. Carson Content-Disposition: attachment; filename="vcard.vcf" begin: vcard fn: Neil A. Carson n: Carson;Neil A. email;internet: neil@causality.com x-mozilla-cpt: ;0 x-mozilla-html: FALSE version: 2.1 end: vcard --------------28F9CE6FBD154640E393D5D8-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message