Finds the maximum of a datum with the result left on all processes.
MPI mapping mpi_allreduce
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=real_8), | intent(inout) | :: | msg |
Find maximum among these data (input) and maximum (output) |
||
integer, | intent(in) | :: | gid |
Message passing environment identifier |
SUBROUTINE mp_max_d (msg, gid)
!! Finds the maximum of a datum with the result left on all processes.
!!
!! MPI mapping
!! mpi_allreduce
REAL(kind=real_8), INTENT(INOUT) :: msg
!! Find maximum among these data (input) and maximum (output)
INTEGER, INTENT(IN) :: gid
!! Message passing environment identifier
CHARACTER(LEN=*), PARAMETER :: routineN = 'mp_max_d'
INTEGER :: handle, ierr, msglen
ierr = 0
CALL timeset(routineN, handle)
msglen = 1
#if defined(__parallel)
CALL mpi_allreduce(MPI_IN_PLACE, msg, msglen, MPI_DOUBLE_PRECISION, MPI_MAX, gid, ierr)
IF (ierr /= 0) CALL mp_stop(ierr, "mpi_allreduce @ "//routineN)
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_max_d