mp_sum_c Subroutine

private subroutine mp_sum_c(msg, gid)

Sums a datum from all processes with result left on all processes.

MPI mapping mpi_allreduce

Arguments

TypeIntentOptionalAttributesName
complex(kind=real_4), intent(inout) :: msg

Datum to sum (input) and result (output)

integer, intent(in) :: gid

Message passing environment identifier


Contents

Source Code


Source Code

      SUBROUTINE mp_sum_c (msg, gid)
      !! Sums a datum from all processes with result left on all processes.
      !!
      !! MPI mapping
      !! mpi_allreduce

         COMPLEX(kind=real_4), INTENT(INOUT)    :: msg
         !! Datum to sum (input) and result (output)
         INTEGER, INTENT(IN)         :: gid
         !! Message passing environment identifier

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

         INTEGER                     :: handle, ierr, msglen

         ierr = 0
         CALL timeset(routineN, handle)

         msglen = 1
#if defined(__parallel)
         CALL mpi_allreduce(MPI_IN_PLACE, msg, msglen, MPI_COMPLEX, MPI_SUM, gid, ierr)
         IF (ierr /= 0) CALL mp_stop(ierr, "mpi_allreduce @ "//routineN)
         CALL add_perf(perf_id=3, msg_size=msglen*(2*real_4_size))
#else
         MARK_USED(msg)
         MARK_USED(gid)
#endif
         CALL timestop(handle)
      END SUBROUTINE mp_sum_c