From:	Jedediah Smith <jedediah AT interlog DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Integer division causes strange behavior
Date:	Sun, 05 Jul 1998 06:27:42 -0700
Organization:	Interlog Internet Services
Lines:	30
Message-ID:	<359F7F4E.3845@interlog.com>
NNTP-Posting-Host:	209-20-0-182.dialin.interlog.com
NNTP-Posting-Time:	5 Jul 1998 07:24:35 GMT
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

A program I am writing uses this function to round toRound up to the
nearest multiple of factor. The function is called thousands of times
and then later on a huge amount of text (about 500k) is output to stdout
using the cout class. While outputting all that text, sometimes right in
the middle of a cout call, the program aborts with some sort of
protection fault and then rhide aborts with an 'FPU not present' fault.
The weird thing is, I have narrowed the problem down to the line marked
with an arrow in the code below. If I take that line out, the program
works fine. I have also tried other alogritms that use / instead of %
and I even tried using the div() function and they all do the same
thing. My program doesn't use any floating point math so I really have
no idea where that rhide error is coming from.

unsigned RoundUp(unsigned toRound, unsigned factor)
{

   --> unsigned modFactor = toRound % factor;
   unsigned ret = toRound;

   if (modFactor != 0)
      ret += factor-modFactor;

   return ret;
}

-- 

      .....
        :edediah
      :.:

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