Multiplies a set of numbers scattered across a number of processes, then replicates the result.
MPI mapping mpi_allreduce
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
integer(kind=int_4), | intent(inout) | :: | msg |
a number to multiply (input) and result (output) |
||
integer, | intent(in) | :: | gid |
message passing environment identifier |
SUBROUTINE mp_prod_i (msg, gid)
!! Multiplies a set of numbers scattered across a number of processes,
!! then replicates the result.
!!
!! MPI mapping
!! mpi_allreduce
INTEGER(KIND=int_4), INTENT(INOUT) :: msg
!! a number to multiply (input) and result (output)
INTEGER, INTENT(IN) :: gid
!! message passing environment identifier
CHARACTER(LEN=*), PARAMETER :: routineN = 'mp_sum_i'
INTEGER :: handle, ierr, msglen
ierr = 0
CALL timeset(routineN, handle)
msglen = 1
#if defined(__parallel)
CALL mpi_allreduce(MPI_IN_PLACE, msg, msglen, MPI_INTEGER, MPI_PROD, gid, ierr)
IF (ierr /= 0) CALL mp_stop(ierr, "mpi_allreduce @ "//routineN)
CALL add_perf(perf_id=3, msg_size=msglen*int_4_size)
#else
MARK_USED(msg)
MARK_USED(gid)
#endif
CALL timestop(handle)
END SUBROUTINE mp_prod_i