Re: return value of log()

["Tim Prince" <tprince at computer dot org>]

The math library adopted by cygwin is part of newlib, an entirely
separate project not even oriented to the same type of usage as cygwin
or even the glibc.  I imagine it may be intended not to depend on
running on targets which implement IEEE standard.  If you're using gcc
or g++, it's easy to supply your own behavior by linking your own
version first, or by supplying an in-line definition.  IIRC, all the
math functions test out fairly well on elefunt, except for asinf/acosf.
I don't know why you would write an app to depend on the NaN behavior;
you would at least have to forgo -ffast-math or supply and use your own
isnan() and take other special precautions to make that work.

----- Original Message -----
From: "Kenta MURATA" <muraken2@nifty.com>
To: "Cygwin ML" <cygwin@cygwin.com>
Sent: Wednesday, March 07, 2001 2:10 AM
Subject: return value of log()


> Hi there,
>
> I can't understand that log(x) returns -HUGE_VAL if x < 0.
> Becaus, IEEE definition returns NaN.
>
> Why adopt this implementation?
>
> --
> Kenta Murata <muraken2@nifty.com>
"http://village.infoweb.ne.jp/~muraken/"
>
> --
> Want to unsubscribe from this list?
> Check out: http://cygwin.com/ml/#unsubscribe-simple
>


--
Want to unsubscribe from this list?
Check out: http://cygwin.com/ml/#unsubscribe-simple