MPI_TYPE_UB, MPI_Type_ub

Purpose

Returns the upper bound of a datatype.

C synopsis

#include <mpi.h>
int MPI_Type_ub(MPI_Datatype datatype,MPI_Aint *displacement);

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_TYPE_UB(INTEGER DATATYPE,INTEGER DISPLACEMENT,
            INTEGER IERROR)

Parameters

datatype
     is the datatype (handle) (IN)

displacement
     is the displacement of the upper bound from the origin, in bytes
     (integer) (OUT)

IERROR
     is the FORTRAN return code. It is always the last argument.

Description

This subroutine returns the upper bound of a specific datatype.

The upper bound is the displacement you use in locating the origin byte of
the next instance of datatype for operations that use count and datatype.
In the normal case, ub represents the displacement of the highest address
byte of the datatype + e (where e >= 0 and results in (ub - lb) being a
multiple of the boundary requirement for the most boundary constrained type
in the datatype). If MPI_UB is used in a type constructor, no alignment
adjustment is done so ub is exactly as you set it.

For a type with MPI_UB in its ancestry, the value returned by MPI_TYPE_UB
may not be related to the displacement of the highest address byte (with
rounding). Refer to MPI_TYPE_STRUCT for more informatin on MPI_LB and
MPI_UB.

Notes

MPI_TYPE_GET_EXTENT supersedes MPI_TYPE_UB.

For FORTRAN 64-bit codes, an INTEGER may not be enough to represent the
upper bound. When the upper bound is known to be representable by an
INTEGER, this subroutine remains usable at your own risk. New codes should
always use MPI_TYPE_GET_EXTENT.

Errors

Invalid datatype

MPI not initialized

MPI already finalized

Related information

     MPI_TYPE_LB