Re: [Plplot-devel] libqhull

[Joao C. <jc...@fe...>]

On Saturday 15 March 2003 10:02, Rafael Laboissiere wrote:
> * Joao Cardoso <jc...@fe...> [2003-03-15 01:16]:
> > On Saturday 15 March 2003 00:28, Rafael Laboissiere wrote:
> > > I searched a little bit further and found the excerpt below in the
> > > configure.in file of the GSL project
> > > (http://www.gnu.org/software/gsl/). This autoconf code is doing pretty
> > > much the same thing as your code in sysloc.in, besides an compilation
> > > exercise to check if the flags are really accepted in the alpha
> > > architecture.
> >
> > hmm, I would like a better test, not just that the flag is accepted.
>
> Do you wiush that the compilation exercise be introduced in our
> configure.ac?  I can do it (but not test it fully, since I have no access
> to alpha machines).

It would be nice.

The following program is a minimal test that does not guarantees that nn/csa 
and x21c.c  will run OK. It tests a necessary but not sufficient condition.

The other longer program I posted tests for sufficiency.

#include <math.h>

main()
{
        double x;
        x = sqrt(-1.);
        if (x == x)
                return 1;
        return 0;
}


On a alpha/OSF:

bash-2.01$ cc -ieee po.c -o po -lm && if ./po; then echo yes; else echo no; fi
yes
bash-2.01$ cc po.c -o po -lm && if ./po; then echo yes; else echo no; fi
no
bash-2.01$ gcc po.c -o po -lm && if ./po; then echo yes; else echo no; fi
no
bash-2.01$ gcc -mieee po.c -o po -lm && if ./po; then echo yes; else echo no; 
fi 
yes

On linux:

jcard@jcard:~> gcc  po.c -o po -lm && if ./po; then echo yes; else echo no; fi
yes
jcard@jcard:~> gcc -mieee-fp po.c -o po -lm && if ./po; then echo yes; else 
echo no; fi
yes

On linux it does not seems to make a difference, but -mieee-fp is recomended.

Joao