Implementing the MPI-3.0 Fortran 2008 Binding

MPI-3.0 defines a new interface for the Fortran 2008 language standard. This is the first Fortran support method for MPI that is consistent with the Fortran standard. This paper introduces our implementation of the Fortran 2008 binding in MPICH. Issues discussed include the binding framework, the implementation of wrapper functions, and the implementation of named constants. Our implementation is neat, efficient, and portable, in the sense that we limit the layers of wrappers, avoid Fortran-specific initialization, avoid unnecessary runtime overhead in wrappers, and rely only on standard Fortran and C.