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MPI_Type_size(3) man page (version 1.8.8)

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Name

MPI_Type_size, MPI_Type_size_x - Returns the number of bytes occupied by entries in a data type.

Syntax

C Syntax


#include <mpi.h>
int MPI_Type_size(MPI_Datatype datatype, int *size)
int MPI_Type_size_x(MPI_Datatype datatype, MPI_Count *size)

Fortran Syntax


INCLUDE ’mpif.h’
MPI_TYPE_SIZE(DATATYPE, SIZE, IERROR)
    INTEGER    DATATYPE, SIZE, IERROR
MPI_TYPE_SIZE_X(DATATYPE, SIZE, IERROR)
    INTEGER    DATATYPE
        INTEGER(KIND=MPI_COUNT_KIND) SIZE
        INTEGER IERROR

C++ Syntax


#include <mpi.h>
int Datatype::Get_size() const

Input Parameter

datatype
Datatype (handle).

Output Parameters

size
Datatype size (integer).

IERROR
Fortran only: Error status (integer).

Description

MPI_Type_size returns the total size, in bytes, of the entries in the type signature associated with datatype; i.e., the total size of the data in a message that would be created with this datatype. Entries that occur multiple times in the datatype are counted with their multiplicity. For either function, if the size parameter cannot express the value to be returned (e.g., if the parameter is too small to hold the output value), it is set to MPI_UNDEFINED.

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++ functions 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.

Fortran 77 Notes

The MPI standard prescribes portable Fortran syntax for the SIZE argument of MPI_Type_size_x only for Fortran 90. FORTRAN 77 users may use the non-portable syntax


     INTEGER*MPI_COUNT_KIND SIZE

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


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