mp_sum_dv Subroutine

      SUBROUTINE mp_sum_dv(msg, gid)
      !! Element-wise sum of a rank-1 array on all processes.
      !! @note see mp_sum_d

         REAL(kind=real_8), CONTIGUOUS, INTENT(INOUT)     :: msg(:)
         !! Vector to sum and result
         TYPE(mp_comm_type), INTENT(IN)                      :: gid

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

         INTEGER                                  :: handle, ierr
#if defined(__parallel)
         INTEGER                                  :: msglen
#endif

         ierr = 0
         CALL timeset(routineN, handle)

#if defined(__parallel)
         msglen = SIZE(msg)
         IF (msglen > 0) THEN
            CALL mpi_allreduce(MPI_IN_PLACE, msg, msglen, MPI_DOUBLE_PRECISION, MPI_SUM, gid%handle, ierr)
            IF (ierr /= 0) CALL mp_stop(ierr, "mpi_allreduce @ "//routineN)
         END IF
         CALL add_perf(perf_id=3, msg_size=msglen*real_8_size)
#else
         MARK_USED(msg)
         MARK_USED(gid)
#endif
         CALL timestop(handle)
      END SUBROUTINE mp_sum_dv