JLdL 05Nov07.

The functions in the C-to-Fortran interface library depend on the size of
the various types of data involved.  This will be different in 32-bit and
64-bit machines.  Here are the sizes in a few hardware architectures:

Athlon MP: 32-bit i386 machine:

C:		size of short  = 2 bytes
		size of int    = 4 bytes
		size of long   = 4 bytes
		size of float  = 4 bytes
		size of double = 8 bytes

Fortran:	size of integer          = 4 bytes
		size of real             = 4 bytes
		size of double precision = 8 bytes

Opteron64: 64-bit amd64 machine:

C:		size of short  = 2 bytes
		size of int    = 4 bytes
		size of long   = 8 bytes
		size of float  = 4 bytes
		size of double = 8 bytes

Fortran:	size of integer          = 4 bytes
		size of real             = 4 bytes
		size of double precision = 8 bytes

One can see that, in order for the library to work as well in either
type of architecture, the C type "long" should be avoided.

