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Article #11809Re: IEEE floating point
From: Henry Spencer
Date: Sat, 25 May 1991 22:25
Date: Sat, 25 May 1991 22:25
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In article <9105250030.AA08036@ucbvax.Berkeley.EDU> jbs@WATSON.IBM.COM writes: >...don't believe it addresses the main sources of error. I also don't >believe that IEEE FP is well-designed. Exactly why do you believe nu- >merical problems using IEEE FP are more likely to be obvious and pre- >dictable than numerical problems using IBM hex (for example)? ... A proper response to this would basically be a detailed defence of IEEE FP's more controversial design decisions. I have neither the time nor, really, the expertise to do this. However, salvation arriveth from an unexpected direction. :-) Go read "What Every Computer Scientist Should Know About Floating-Point Arithmetic", by David Goldberg, in the latest (March) issue of ACM Computing Surveys; doing so will enlighten you in detail on the subject. I will confine myself to observing that IBM hex FP is the only FP format I know of that made half the FP instructions -- the single-precision ones -- just about useless to most programmers. -- "We're thinking about upgrading from | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 to SunOS 3.5." | henry@zoo.toronto.edu utzoo!henry
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Newsgroups: comp.arch Path: arc1-ca.pugleaf.net!utzoo!henry From: henry@zoo.toronto.edu (Henry Spencer) Subject: Re: IEEE floating point Message-ID: <1991May25.222551.16365@zoo.toronto.edu> Date: Sat, 25 May 1991 22:25:51 GMT References: <9105250030.AA08036@ucbvax.Berkeley.EDU> Organization: U of Toronto Zoology