Re: Ideas for rewrite of libm-test

[Ulrich Drepper <drepper at cygnus dot com>]

Andreas Jaeger <aj@suse.de> writes:

> But if we want to describe the overall error of a function, we should
> use relative errors like 2^-63.  

Actually, the unit should be ULP (units of least precision).  Take a
look at the libm test web page I've written
(http://www.cygnus.com/~drepper/libm/) to see how to compute it.

> Btw. I'd like to read a little bit more about this topic.  I've read
> already a number of articles from the different ACM journals but if
> anybody has more pointers to relevant literature, please tell me.

The most important article is "What Every Computer Scientist Should
Know About FLoating-Point Arithmetic" by David Goldberg in ACM
Computing Surveys, March 1991.  For testing "The UNIX System Math
Library, a Status Report" by Silverstein, Sommars, and Tao in Usenix
Winter '90 is interesting.

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