From: Paul Brannan <pbrannan@...>
Date: 2002-09-06T05:06:47+09:00
Subject: Re: Best GC for Ruby?

On Fri, Sep 06, 2002 at 04:48:47AM +0900, William Djaja Tjokroaminata wrote:
> Regarding the test suites, is it really that much more complicated than
> the corresponding test suites for FixNum and BigNum?  For a first cut,
> probably we can sacrifice exponent rather than mantissa and have the same
> logic as the conversion between FixNum and BigNum when we have FixFloat
> (31-bit 'float') and BigFloat (pure, native 64-bit 'double').  (People who
> do numerical computations extensively and care about precision should have
> used NArray, anyway.)

Yes, it's a LOT more complicated.

See:
  http://www.netlib.org/fp/ucbtest.tgz
  http://www.math.utah.edu/~beebe/software/ieee/

for some code that tests correct floating point operation.  There are
many many more things that can go wrong with floating point operations
than with integer operations; hitting all these cases is a job best left
to the experts.

Paul