Mail Archives: djgpp/1995/02/24/11:57:34
On Thu, 23 Feb 1995, Erwin Kok wrote:
> ... 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) ... My advise
is check if any variables are NAN's.
Bill Davidson <bdavidson AT ra DOT isisnet DOT com> replied:-
> 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.
Again, please, either by re-posting this CTRL87.C program or in some other
way, let the djgpp user be able to enter a state where floats and doubles that
become INF or NaN are passed through arithmetic normally and don't make the
program abort. I used to run on a CDC mainframe where I could do that, and it
was very handy: 1/0=INF; 1/INF=0; 0/0=NaN; log(0)=-INF; exp(-INF)=0; etc.
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