Date: Sat, 21 Feb 1998 04:28:46 +0000 From: "Neil A. Carson" <neil@causality.com> To: Bruce Evans <bde@zeta.org.au> Cc: jkh@time.cdrom.com, bugs@FreeBSD.ORG Subject: Re: Floating point errors Message-ID: <34EE57FE.5B1234BB@causality.com> References: <199802210421.PAA18491@godzilla.zeta.org.au>
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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
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Bruce Evans wrote:
<BLOCKQUOTE TYPE=CITE>Wrong. I feel that it is more useful to die
rather than possibly
<BR>run incorrectly. Programmers who actually understand FP exceptions
<BR>can easily change the default exception mask (I changed it 3 years
<BR>ago on my systems). The technical correctness of this is debatable.
<BR>It prevents the math libraries from being ANSI conformant, but the
math
<BR>libraries have more serious ANSI conformance bugs. I don't plan
to
<BR>change the exception handling until the other bugs are fixed.</BLOCKQUOTE>
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 <I>could</I> 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.
<P>If I can be of assistance with any stuff, let me know.
<P> Regards,
<P> Neil
<BR> </HTML>
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