Re: an FPU problem - nextafter too small?
I discovered a -mieee gcc switch that solves this problem.
Mea culpa.
(it's described only in the info docs, not in man pages )
On Sun, 8 Apr 2001, Dmitrii Pasechnik wrote:
>Date: Sun, 8 Apr 2001 14:34:46 +0200 (MET DST)
>From: Dmitrii Pasechnik <dima@cs.uu.nl>
>To: debian-alpha@lists.debian.org
>Subject: an FPU problem - nextafter too small?
>
>I'm running the latest stable Debian 2.2 on Alpha XL266.
>(alphaev56 processor)
>
>There appears to be a problem with the values returned by
>the function nextafter (see <math.h>).
>Namely, this value (nextafter(0.,1.) returns 4.9407e-324)
>is too small for doing arithmetic operations on it,
>that is, for instance, 2.*nextafter(0.,1.) produces a floating point
>exception.
>This is with gcc (version 2.95.2 20000220 (Debian GNU/Linux))
>and no extra options (except -lm).
>
>The smallest possible value x that still allows for 2.*x with my setup
>is about 1.e-307.
>
>Is this a feature or a bug (in gcc or in glibc ?) ?
>Thanks in advance,
>Dmitrii.
>
--
Dmitrii Pasechnik
e-mail: d.pasechnik@twi.tudelft.nl
http://ssor.twi.tudelft.nl/~dima/
Reply to: