This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
Re: Bug with g77 and -mieee on Alpha Linux
I wrote:
> Dave Love wrote:
> > >>>>> "JCB" == <craig@jcb-sc.com> writes:
> > JCB> Hardly. it's a *precise* description of what Toon constantly
> > JCB> advocates: the idea that any program written to exploit the full
> > JCB> range of IEEE 754 *values* (not even using *features* like
> > JCB> signalling NaNs, trapping on inexact, etc.) is inherently
> > JCB> *wrong*,
> > I don't recall so, though perhaps that's what he thinks; it's
> > obviously silly.
> Whoops, I hope I didn't say this - as Dave writes: It's obviously
> silly.
You know what - I actually wrote what Craig said above (at least, some
of it):
- - - - - - - 8< - - - - - - - - - - - 8< - - - - - - - - - - - -
Of course, I *still* think that a program generating denormals (and
getting underflow to zero) is wrong: All of a sudden there's a number
in the algorithm that's treated as "normal" (while it is _de_normal) -
and now you can't divide by it.
I cannot glean inside Martin's nonlinear equations, but the following
description:
<QUOTE>
Perhaps, but while solving highly nonlinear sets of equations, like in
analog circuit simulators nearly anything can appear. Nobody knows,
where newton will bring you. You can decide to make smaller newton
corrections only a f t e r you have the bad ones and thus you have to
deal with these bad numbers somehow.
</QUOTE>
to *me* sounds like a grave mis-use of Newton-Raphson root finding.
- - - - - - - 8< - - - - - - - - - - - 8< - - - - - - - - - - - -
I hope it's clear from this excerpt that I was commenting on Martin
Kahlert's problem - not on "Programs generating denormals" in general.
Bweh - perhaps I should take a course in Strunk and White.
:-/
[ To make matters worse - it wasn't even a problem in Martin's code -
it turned out NINT(X) was wrongly generated :-( ]
--
Toon Moene (toon@moene.indiv.nluug.nl)
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
Phone: +31 346 214290; Fax: +31 346 214286
GNU Fortran: http://world.std.com/~burley/g77.html