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MPI_Type_get_true_extent(3) man page (version 1.3.4)

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NAME

       MPI_Type_get_true_extent - Returns the true lower bound and extent of a
       data type's corresponding typemap, ignoring MPI_UB and MPI_LB  markers.

SYNTAX


C Syntax

       #include <mpi.h>
       int MPI_Type_get_true_extent(MPI_Datatype datatype,
            MPI_Aint *true_lb, MPI_Aint *true_extent)

Fortran Syntax (see FORTRAN 77 NOTES)

       INCLUDE 'mpif.h'
       MPI_TYPE_GET_TRUE_EXTENT(DATATYPE, TRUE_LB, TRUE_EXTENT, IERROR)
            INTEGER   DATATYPE, IERROR
            INTEGER(KIND=MPI_ADDRESS_KIND) TRUE_LB, TRUE_EXTENT

C++ Syntax

       #include <mpi.h>
       void MPI::Datatype::Get_true_extent(MPI::Aint& true_lb,
            MPI::Aint& true_extent) const

INPUT PARAMETER

       datatype  Data type for which information is wanted (handle).

OUTPUT PARAMETERS

       true_lb   True lower bound of data type (integer).

       true_extent
                 True size of data type (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       The  true_lb  parameter  returns the offset of the lowest unit of store
       that is addressed by the data type, that is, the  lower  bound  of  the
       corresponding typemap, ignoring MPI_LB markers. The true_extent parame-
       ter returns the true size of the data type, that is, the extent of  the
       corresponding typemap, ignoring MPI_LB and MPI_UB markers, and perform-
       ing no rounding for alignment.

       The true_extent is the minimum number of bytes of memory  necessary  to
       hold a data type, uncompressed.

       See  Section 4.14.3 of the MPI-2 standard for more detailed definitions
       of these parameters in relation to the typemap.

FORTRAN 77 NOTES

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

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.

1.3.4                            Nov 11, 2009      MPI_Type_get_true_extent(3)

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