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From: cramer@kontron.UUCP (Clayton Cramer)
Newsgroups: net.lang
Subject: Re: Integer division
Message-ID: <576@kontron.UUCP>
Date: Wed, 5-Mar-86 18:11:16 EST
Article-I.D.: kontron.576
Posted: Wed Mar  5 18:11:16 1986
Date-Received: Sat, 8-Mar-86 03:05:38 EST
References: <11603@ucbvax.BERKELEY.EDU> <4917@alice.UUCP>
Organization: Kontron Electronics, Irvine, CA
Lines: 31

> In article <736@abic.UUCP> jst@abic.UUCP (Shack Toms) writes:
> >> In article <731@abic.UUCP> jst@abic.UUCP (Shack Toms) writes:
> >> >However:  One might use a%b<0 iff a<0 in an algorithm which printed
> >> >the value of an integer in a given radix.  The least significant
> >> >digit of a in radix b would then be |a%b|.  :-)
> >> 
> >> So would |a|%b, and it works under either convention.  :-)
> >
> >Except that |a| is not available for the full range of a.  In
> >particular, on a 16 bit computer |-32768| is not expressible.
> 
> I don't know about you, but I'm too paranoid about the least negative
> number to begin with.  In fact, I try not to get close, if possible.
> 
> Frankly, if it's a question of a language getting integer division done
> correctly on -32767 to 32767 or getting it done incorrectly on -32768
> to 32767, I think there is no debate about which is preferable.  Or,
> to express my point in less prejudicial terms: in arguing A vs B in a
> language, the question of what happens with the least negative number 
> is almost always irrelevant.
> 
> ucbvax!brahms!weemba	Matthew P Wiener/UCB Math Dept/Berkeley CA 94720

In my experience, people start caring about least negative numbers when
they want to use these weird values in the form:

#define		CantHappenFlag -32768

so that they can test for absurd values.  Instead, these people should be
using enumerated types.  (I will admit to doing things like this before
some gave me a C book with enumerated types described in it.)