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mpi_type_lb(3openmpi) [osx man page]

MPI_Type_lb(3OpenMPI)													     MPI_Type_lb(3OpenMPI)

NAME

       MPI_Type_lb  - Returns the lower bound of a data type. This may differ from zero if the type was constructed using MPI_LB. Use of this rou-
       tine is deprecated.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Type_lb(MPI_Datatype datatype, MPI_Aint *displacement)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_TYPE_LB(DATATYPE, DISPLACEMENT, IERROR)
	    INTEGER   DATATYPE, DISPLACEMENT, IERROR

INPUT PARAMETER

       datatype  Datatype (handle).

OUTPUT PARAMETERS

       displacement
		 Displacement of lower bound from origin, in bytes (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       Note that use of this routine is deprecated as of MPI-2. Please use MPI_Type_get_extent instead.

       This deprecated routine is not available in C++.

       MPI_Type_lb returns the lower bound of a data type.

       The "pseudo-datatypes," MPI_LB and MPI_UB, can be used, respectively, to mark the lower bound (or the upper bound)  of  a  datatype.  These
       pseudo-datatypes  occupy  no  space  (extent  (MPI_LB) = extent (MPI_UB) =0. They do not affect the size or count of a datatype, and do not
       affect the context of a message created with this datatype. However, they do affect the definition of the extent of a datatype and,  there-
       fore, affect the outcome of a replication of this datatype by a datatype constructor.

       In general, if

	   Typemap = {(type0, disp0), ..., (type(n-1), disp(n-1)}

       then the lower bound of Typemap is defined to be

			 (min(j) disp(j)			  if no entry has
	   lb(Typemap) = (					  basic type lb
			 (min(j) {disp(j) such that type(j) = lb} otherwise

       Similarly, the upper bound of Typemap is defined to be

			 (max(j) disp(j) + sizeof((type(j)) + e   if no entry has
	   ub(Typemap) = (					  basic type ub
			 (max(j) {disp(j) such that type(j) = ub} otherwise

       Then

	   extent(Typemap) = ub(Typemap) - lb(Typemap)

       If  type(i)  requires  alignment  to  a	byte address that is a multiple of k(i), then e is the least nonnegative increment needed to round
       extent(Typemap) to the next multiple of max(i) k(i).

ERRORS

       Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func-
       tions  do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except  for
       I/O  function  errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be
       used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

SEE ALSO

       MPI_Type_get_extent

Open MPI 1.2							  September 2006					     MPI_Type_lb(3OpenMPI)

Check Out this Related Man Page

MPI_Type_get_extent(3OpenMPI)											     MPI_Type_get_extent(3OpenMPI)

NAME

       MPI_Type_get_extent - Returns the lower bound and extent of a data type.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Type_get_extent(MPI_Datatype datatype, MPI_Aint *lb,
	    MPI_Aint *extent)

Fortran Syntax (see FORTRAN 77 NOTES)
       INCLUDE 'mpif.h'
       MPI_TYPE_GET_EXTENT(DATATYPE, LB, EXTENT, IERROR)
	    INTEGER   DATATYPE, IERROR
	    INTEGER(KIND=MPI_ADDRESS_KIND) LB, EXTENT

C++ Syntax
       #include <mpi.h>
       void MPI::Datatype::Get_extent(MPI::Aint& lb, MPI::Aint& extent)
	    const

INPUT PARAMETER

       datatype  Data type (handle).

OUTPUT PARAMETERS

       lb	 Lower bound of data type (integer).

       extent	 Data type extent (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_Type_get_extent returns the lower bound and the extent of datatype.

NOTE

       Use of MPI_Type_get_extent is strongly recommended over the old MPI-1 functions MPI_Type_extent and MPI_Type_lb.

FORTRAN 77 NOTES
       The  MPI standard prescribes portable Fortran syntax for the LB and EXTENT arguments only for Fortran 90. FORTRAN 77 users may use the non-
       portable syntax

	    INTEGER*MPI_ADDRESS_KIND LB
       or
	    INTEGER*MPI_ADDRESS_KIND EXTENT

       where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length of the declared integer in bytes.

ERRORS

       Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func-
       tions  do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except  for
       I/O  function  errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be
       used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

Open MPI 1.2							  September 2006				     MPI_Type_get_extent(3OpenMPI)
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