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From: urjlew@uncecs.edu (Rostyk Lewyckyj)
Newsgroups: comp.arch
Subject: Re: F.P. vs. arbitrary-precision (was: Killer Micro II)
Summary: Is the set of all sets a set?
Message-ID: <1990Sep10.215549.26260@uncecs.edu>
Date: 10 Sep 90 21:55:49 GMT
References: <3755@osc.COM> <4513@taux01.nsc.com> <119244@linus.mitre.org>
Organization: UNC Educational Computing Service
Lines: 30
Xref: dummy dummy:1
X-OldUsenet-Modified: added Xref
In article <119244@linus.mitre.org>, bs@linus.mitre.org (Robert D. Silverman) writes:
> The four basic operations of arithmetic are +, -, x, /. Any computer that
> can't perform them on its atomic data units [whatever the word size is]
> is a joke.
>
> --
> Bob Silverman
> #include
> Mitre Corporation, Bedford, MA 01730
> "You can lead a horse's ass to knowledge, but you can't make him think"
If the basic unit for representing a number is a word, then to handle
the product of two numbers you may well need a double word. But then
you must provide operations to handle double words. So then the double
word becomes a basic unit, and so on ad infinitum. If in addition to
+, -, and x, you want to handle /, then you most certainly need either
something like floating point, or some variant of rational fraction
representation with arbitrary precision for the numerator and denominator
Now if you want to handle irrationals, then even more you need something
like floating point. Choose your own precision.
Finally scaledd integer is really no different from floating point,
except that floating point is at least standardized (IEEE) , and
assisted by hardware. Imagine having to work with user's programs
where everybody is doing scaled integer arithmetic in his own way.
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Reply-To: Rostyslaw Jarema Lewyckyj
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