Newsgroups: comp.arch Path: utzoo!henry From: henry@zoo.toronto.edu (Henry Spencer) Subject: denormalized numbers Message-ID: <1990Nov28.173640.7185@zoo.toronto.edu> Organization: U of Toronto Zoology References: <897@sibyl.eleceng.ua.OZ> <13342@encore.Encore.COM> <46866@apple.Apple.COM> Date: Wed, 28 Nov 90 17:36:40 GMT In article khb@chiba.Eng.Sun.COM (chiba) writes: >Those who have codes like this, usually think everything is OK, worked >fine on their ----- (fill in CDC, Honeywell, Univac, VAX, etc.) and >are perfectly happy with flush to zero semantics. Of course, sometimes this is "worked fine" for suitable values of "worked"! Long ago, we had a system with software emulation of hardware floating-point. Then we got the hardware version. The one noticeable difference in behavior was that the hardware trapped division by zero and the software hadn't. You would be amazed at how many users came in complaining that their "fully debugged" programs had stopped working. I hope none of the pre-changeover results found their way into anybody's paper or thesis... -- "The average pointer, statistically, |Henry Spencer at U of Toronto Zoology points somewhere in X." -Hugh Redelmeier| henry@zoo.toronto.edu utzoo!henry