Re: isnan in fortran

[Mike Miller]

On Tue, Apr 10, 2012 at 12:44:07PM +0200, c. wrote:
> I am regularly building Octave on OSX withg gcc/gfortran 4.2.1
> [...]
> I need to locally apply the following patch (which I keep in my hq
> patch queue), as gfortran 4.2 does not have isnan:
> [...]
> Does anyone know a cleaner and portable way how these functions could
> be made to work with fortran compilers that do not have ISNAN?

I run into the same problem, RHEL 5.x with gcc 4.1.2.

Your patch is simpler and more correct than mine, which was to just
revert that cset or just comment out the entire IF..ENDIF.  Unless I
happen to have the gcc44-gfortran rpm installed, which Red Hat does
provide but is not in a standard install.

+1 to replacing this with a portable F77 solution.  If there is one...

A quick search suggests (X.NE.X) may be the best alternative, at least
for IEEE 754 systems.

-- 
mike