mp_comm_compare Subroutine

   SUBROUTINE mp_comm_compare(comm1, comm2, res)

      INTEGER, INTENT(IN)                                :: comm1, comm2
      INTEGER, INTENT(OUT)                               :: res

      CHARACTER(LEN=*), PARAMETER :: routineN = 'mp_comm_compare'

      INTEGER                                            :: handle, ierr, iout

      ierr = 0
      CALL timeset(routineN, handle)

      iout = 0
      res = 0
#if defined(__parallel)
      CALL mpi_comm_compare(comm1, comm2, iout, ierr)
      IF (ierr /= 0) CALL mp_stop(ierr, "mpi_comm_compare @ "//routineN)
      SELECT CASE (iout)
      CASE (MPI_IDENT)
         res = 0
      CASE (MPI_CONGRUENT)
         res = 1
      CASE (MPI_SIMILAR)
         res = 2
      CASE (MPI_UNEQUAL)
         res = 3
      CASE default
         res = 4
      END SELECT
#else
      MARK_USED(comm1)
      MARK_USED(comm2)
#endif
      CALL timestop(handle)

   END SUBROUTINE mp_comm_compare