Mircosoft C V5.1 floating point problem.

[John Baldwin]

In article <5587 at castle.ed.ac.uk> elee24 at castle.ed.ac.uk (H Bruce) writes:
>I am working on a large program that has suddenly starting crashing with
>the following error:
>
>floating pointing exection 
>M6101 invalid
> [...deleted...]
>The manual says it is caused by operating on a NAN (not a number !) which is
>not much help.

Can you post some code fragments that show what you're doing in floating point
just prior to the error?  To oversimplify, NAN is a representation chosen to
provide more information than a simple underflow.  A recent article in
_IEEE_Computer_ suggested an enhanced FP representation including some extra
values such as +RAIL and -RAIL (like an op-amp)... you might want to read it.

In general, you've probably reached some kind of intermediate underflow or
overflow condition if you're getting a NAN.

QUESTION: are you using the fast-fp library, the 8087 emulator, or a real
          hardware 8087???  Maybe something isn't getting initialized right?

-- 
John T. Baldwin                      |  johnb at srchtec.uucp
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