From: Cees Wesseling <Wesseling AT frw DOT ruu DOT nl>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: -O2, FPU error, I am confused
Date: Wed, 18 Sep 1996 11:32:44 +0100
Organization: Utrecht University
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To: djgpp AT delorie DOT com
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I recieved a numnber of E-mails pointing me to fixed version
of libm.a to solve the problem Carlo mentioned and I recognized.

> Carlo Nervi wrote:
> >
> > my program works fine under djgpp v1.12, but exit with SIGFPE
> > exception under djgpp v2.00. Using fsdb something strange happen:
> > sometimes it exit with a Underflow exception, but sometime else
> > running under fsdb the program runs, but with wrong numeric results.
> >
> > Finally I was able to catch the problem: by using -O2 or -O3
> > optimization switches the problem persist, whereas by using -O

In my naive view, I think: Hey the function that crashes on me does not 
use any of the math-functions. It is just a lot of +,-,/ and * .
Is it possible then that the FPU stack is already messed when
entering the function? Or does even +,-, etc. implies library calls? 

-- 
 Cees Wesseling              | PO BOX 80.115   | 
 Dept. of Physical Geography | 3508 TC Utrecht | phone: (+31) 30 2532768   
 Utrecht University          | the Netherlands | fax:   (+31) 30 2540604