Defining a HAVE_J0 in config.h for gfortran?

[Richard Henderson]

On Wed, Aug 11, 2004 at 08:27:45PM -0700, Steve Kargl wrote:
> I'm contemplating adding j0, j0f, j1, j1f, y0, y0f, y1, and y1f
> intrinsic functions to gfortran for compatibility with g77.  In
> gcc/libgfortran I can modify configure.ac with a line similar to
> 
> AC_CHECK_LIB([m],[j0],[AC_DEFINE([HAVE_J0],[1],[libm includes j0])])
> 
> to check that j0 is present in libm.  I however need the HAVE_J0
> symbol in gcc/gcc/fortran.  There is no configure.ac in this 
> directory, so I need some other way to define HAVE_J0.  Any pointers
> would be appreciate.

You don't want anything in the front end.  Define the intrinsics
all the time (modulo standards conformance).

Then you either provide the function in libgfortran, or just let
it be resolved (or not) by libm.

If they do come out unresolved for a particular system, then they
do.  Unlike the other intrinsics being discussed, the bessel functions
are not required for other Fortran standard conformance.  I don't
know that we should be trying to remedy every deficiency in the
system libm...


r~