17.2.409. MPI_Type_match_size

MPI_Type_match_size - Returns an MPI datatype of a given type and size

17.2.409.1. SYNTAX

17.2.409.1.1. C Syntax

#include <mpi.h>

int MPI_Type_match_size(int typeclass, int size,
     MPI_Datatype *type)

17.2.409.1.2. Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TYPE_MATCH_SIZE(TYPECLASS, SIZE, TYPE, IERROR)
     INTEGER TYPECLASS, SIZE, TYPE, IERROR

17.2.409.1.3. Fortran 2008 Syntax

USE mpi_f08
MPI_Type_match_size(typeclass, size, datatype, ierror)
     INTEGER, INTENT(IN) :: typeclass, size
     TYPE(MPI_Datatype), INTENT(OUT) :: datatype
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

17.2.409.2. INPUT PARAMETERS

  • typeclass: Generic type specifier (integer).

  • size: Size, in bytes, of representation (integer).

17.2.409.3. OUTPUT PARAMETERS

  • type: Datatype with correct type and size (handle).

  • IERROR: Fortran only: Error status (integer).

17.2.409.4. DESCRIPTION

The function returns an MPI datatype matching a local variable of type (typeclass, size). The returned type is a reference (handle) to a predefined named datatype, not a duplicate. This type cannot be freed.

The value of typeclass may be set to one of MPI_TYPECLASS_REAL, MPI_TYPECLASS_INTEGER, or MPI_TYPECLASS_COMPLEX, corresponding to the desired datatype.

MPI_type_match_size can be used to obtain a size-specific type that matches a Fortran numeric intrinsic type: first call MPI_Sizeof to compute the variable size, then call MPI_Type_match_size to find a suitable datatype. In C use the sizeof builtin instead of MPI_Sizeof.

It is erroneous to specify a size not supported by the compiler.

17.2.409.5. ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.

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 the MPI man page for a full list of MPI error codes.