simple FORTRAN code for GEMPAK that fails on 64-bit Linux machines

[David Ovens]

Gembuds,

It turns out that g77 is storing these real functions as real*8 under
64-bit Linux systems.  There are two work-around solutions:

 1) explicitly declare the pr_sped (or any such GEMPAK function) you
    are using as real*8, e.g.,
      program test
      real*8 pr_sped
      call in_bdta(iret)
      u = 5
      v = 4
      spd = pr_sped(u,v)
      print *,'spd = ',spd
      stop
      end
    This works for 64-bit ifort on the 64-bit Linux machines that have
    used 64-bit g77/gcc to compile the GEMPAK libraries.  So the
    compile sequence looks like:
     source /usr/local/intel/fce/9.0/bin/ifortvars.csh # 64-bit ifort
     setenv GEMLIB /gemdir/NAWIPS-5.9.4/os/linux64/lib # 64-bit GEMLIB
     ifort test.f $GEMLIB/gemlib.a -lg2c
     
 2) use 32-bit ifort, 32-bit g2c, and 32-bit GEMPAK libraries.  On a
    64-bit RedHat box this was accomplished this way:
     source /usr/local/intel/fc/9.0/bin/ifortvars.csh # note fc not fce
     setenv GEMLIB /gemdir/NAWIPS-5.9.4/os/linux/lib  # note linux not linux64
     ifort test.f $GEMLIB/gemlib.a \
     /usr/lib/gcc/x86_64-redhat-linux/3.4.3/32/libg2c.a  # note /32/libg2c.a

Another possible solution is to build GEMPAK with ifort.  We have
managed to do this in the past, but have found that a handful of
programs are fouled up.

Thanks to Harry Edmon for figuring this out.

David
-- 
David Ovens		 e-mail: ovens at atmos.washington.edu
Research Meteorologist    phone: (206) 685-8108
Dept of Atm. Sciences      plan: Real-time MM5 forecasting for the
Box 351640                        Pacific Northwest
University of Washington          http://www.atmos.washington.edu/mm5rt
Seattle, WA  98195               Weather Graphics and Loops
                                  http://www.atmos.washington.edu/~ovens/loops

On Tue, Apr 24, 2007 at 10:16:37PM -0700, David Ovens wrote:
> Gembuds,
> 
> I guess this must be an 'ifort' problem because I just figured out how
> to compile this on 64-bit machines with 'g77' and it works!
>   g77 -fno-second-underscore test.f $GEMLIB/gemlib.a;a.out
>   spd =   6.40312433
> 
> Still, can anyone get 'ifort' to work on this code on a 64-bit Linux
> box?
> 
> David
> -- 
> David Ovens		 e-mail: ovens at atmos.washington.edu
> Research Meteorologist    phone: (206) 685-8108
> Dept of Atm. Sciences      plan: Real-time MM5 forecasting for the
> Box 351640                        Pacific Northwest
> University of Washington          http://www.atmos.washington.edu/mm5rt
> Seattle, WA  98195               Weather Graphics and Loops
>                                   http://www.atmos.washington.edu/~ovens/loops
> 
> 
> On Tue, Apr 24, 2007 at 10:09:07PM -0700, David Ovens wrote:
> > Gembuds,
> > 
> > I have this incredibly simple FORTAN code, test.f, that works fine on
> > 32-bit Linux machines with any version of GEMPAK, but that fails
> > miserably on all of my 64-bit Linux machines with any version of
> > GEMPAK (I've tried 5.9.4 and 5.8.3ag3 specially built for 64-bit).  I
> > am curious if anyone out there can successfully run this on a 64-bit
> > Linux machine.  And, if you can, please share your
> > $NAWIPS/config/Makefile.linux.
> > 
> > Code test.f:
> >       program test
> >       call in_bdta(iret)
> >       u = 5
> >       v = 4
> >       spd = pr_sped(u,v)
> >       print *,'spd = ',spd
> >       stop
> >       end
> > 
> > Compile and run:
> >   ifort test.f $GEMLIB/gemlib.a -lg2c; a.out
> > 
> > Correct answer:
> >  spd =    6.403124    
> > 
> > 64-bit Linux box answer:
> >  spd =  -1.0842022E-19
>