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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)

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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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