Mail Archives: djgpp/1995/02/24/03:55:56
On Thu, 23 Feb 1995, Erwin Kok wrote:
> A while ago I had a similar fp-exception:
>
> I made up a program compiled it and it worked (under DJGPP FPU-emulation),
> but when I bought a co-processor, I compiled it and a strange floating-point
> exception appeared...
>
> After a few debugging hours I found that the result from an arithmetic
> statement was NAN (Not A Number), and when you do another statement with a NAN
> an exception appears. So, the FPU-emulator under DJGPP didn't had a problem with
> a NAN it runned right through it. But the real FPU didn't except the NAN and
> gave an exception. So maybe MSC ran through some NAN and when you ported it to
> DJGPP/GRX the exception appeared.
>
> My advise is check if any variabeles are NAN's.
A couple of weeks ago (?) someone posted a lovely little ctrl87.c program
that allows one to diddle the '87 control word. It works like a charm
and allows one to do just this sort of thing without resorting to asm.
Bill Davidson
bdavidson AT ra DOT isisnet DOT com
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