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Re: IS_INF bug?
- To: Guile Mailing List <guile at sourceware dot cygnus dot com>
- Subject: Re: IS_INF bug?
- From: Dirk Herrmann <dirk at ida dot ing dot tu-bs dot de>
- Date: Wed, 10 May 2000 11:15:17 +0200 (MEST)
On 9 May 2000, Kalle Olavi Niemitalo wrote:
> Dirk Herrmann <dirk@ida.ing.tu-bs.de> writes:
>
> > I just changed the test to
> > IS_INF(x) ((x) == (x) + 1)
>
> This may misdetect large finite numbers as infinite due to
> roundoff error. The x/2 version has no such problem.
True, I didn't think of that :-( I will undo that change. For now it is
safe anyway, since IS_INF is only used in places where x is known not to
be zero.
However, the handling of special values could need some
improvement. Unfortunately, the systems seem to differ quite a lot with
regard to this.
Ciao,
Dirk