From: buers AT gmx DOT de (Dieter Buerssner)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: SIGFPE
Date: 11 Feb 2000 10:10:50 GMT
Lines: 22
Message-ID: <880n79$jush$1@fu-berlin.de>
References: <200002101809 DOT SAA01894 AT burdock DOT restall DOT net>
NNTP-Posting-Host: 195.252.187.196
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: fu-berlin.de 950263850 654225 195.252.187.196 (16 [17104])
X-Posting-Agent: Hamster/1.3.8.0
User-Agent: Xnews/2.11.08
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

djgpp AT delorie DOT com (Peter Restall) wrote in 
<200002101809 DOT SAA01894 AT burdock DOT restall DOT net>:

>     if (c != 0.0)
>     {
>          temp  = 1.0 / c;

The last statement may overflow (to Infinity), and thus may cause
a floating point exception, i.e when c is a subnormal/denormal 
number. This might cause your problem. (I think it is very 
unfortunate, that this often used idom - divide only when the
divisor != 0 - can fail, but it really can fail, in the sense that
the result will be an unexpected Infinity, that may trigger an
exception.) You should compile your program with debugging information
(-g) and execute it with fsdb. Set a breakpoint at the start of
this offending function, and single step through the function,
while looking at the NPX pane. This should give you some hints.

Regards,
Dieter