Finds the location of the maximal element in a vector.
MPI mapping mpi_allreduce with the MPI_MAXLOC reduction function identifier
Invalid data types This routine is invalid for (int_8) data!
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=real_8), | intent(inout), | CONTIGUOUS | :: | msg(:) |
Find location of maximum element among these data (input). |
|
integer, | intent(in) | :: | gid |
Message passing environment identifier |
SUBROUTINE mp_maxloc_dv(msg, gid)
!! Finds the location of the maximal element in a vector.
!!
!! MPI mapping
!! mpi_allreduce with the MPI_MAXLOC reduction function identifier
!!
!! Invalid data types
!! This routine is invalid for (int_8) data!
REAL(kind=real_8), CONTIGUOUS, INTENT(INOUT) :: msg(:)
!! Find location of maximum element among these data (input).
INTEGER, INTENT(IN) :: gid
!! Message passing environment identifier
CHARACTER(LEN=*), PARAMETER :: routineN = 'mp_maxloc_dv'
INTEGER :: handle, ierr
#if defined(__parallel)
INTEGER :: msglen
REAL(kind=real_8), ALLOCATABLE :: res(:)
#endif
ierr = 0
IF ("d" .EQ. "l" .AND. real_8 .EQ. int_8) THEN
DBCSR_ABORT("Maximal location not available with long integers @ "//routineN)
END IF
CALL timeset(routineN, handle)
#if defined(__parallel)
msglen = SIZE(msg)
ALLOCATE (res(1:msglen))
CALL mpi_allreduce(msg, res, msglen/2, MPI_2DOUBLE_PRECISION, MPI_MAXLOC, gid, ierr)
IF (ierr /= 0) CALL mp_stop(ierr, "mpi_allreduce @ "//routineN)
msg = res
DEALLOCATE (res)
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_maxloc_dv