Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.csd.uwm.edu!cs.utexas.edu!uunet!portal!cup.portal.com!mmm
From: mmm@cup.portal.com (Mark Robert Thorson)
Newsgroups: comp.arch
Subject: Re: Making Rounding Modes Usable
Message-ID: <21453@cup.portal.com>
Date: 20 Aug 89 03:26:46 GMT
References: <1989Jul21.035825.27704@cs.rochester.edu> <6421@uklirb.UUCP>
Organization: The Portal System (TM)
Lines: 14

This reminds of something I once heard one of the two principal architects
of the NS16032 microprocessor say (quoted approximately):  "There's only
one use for rounding!  If you run the program once rounding up, then
run it again rounding down, you get a value for noise in your application."

This also reminds me of a table I once saw in a research journal for
economists.  It compared the results of running the same program (doing
multiple regression analysis) in several different environments.  If I
remember correctly, the program computed a single numeric value.  DEC
and IBM had about three digits of accuracy, which was among the best.
Some vendors only had one or two digits.  CDC got the sign wrong.

(The above-mentioned events occurred 8-12 years ago, and undoubtedly do not
reflect upon the current products of any of the fine manufacturers named.)