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MPI_Address(3) man page (version 5.0.0rc2)

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Name

MPI_Address - Gets the address of a location in memory -- use of this routine is deprecated.

Syntax

C Syntax


#include <mpi.h>
int MPI_Address(void *location, MPI_Aint *address)

Fortran Syntax


INCLUDE ’mpif.h’
MPI_ADDRESS(LOCATION, ADDRESS, IERROR)
    <type>    LOCATION (*)
    INTEGER    ADDRESS, IERROR

Input Parameter

location
Location in caller memory (choice).

Output Parameters

address
Address of location (integer).
IERROR
Fortran only: Error status (integer).

Description

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

The address of a location in memory can be found by invoking this function. Returns the (byte) address of location.

Example: Using MPI_Address for an array.


REAL A(100,100)

INTEGER I1, I2, DIFF

CALL MPI_ADDRESS(A(1,1), I1, IERROR)

CALL MPI_ADDRESS(A(10,10), I2, IERROR)

DIFF = I2 - I1

! The value of DIFF is 909*sizeofreal; the values of I1 and I2 are
! implementation dependent.

Notes

This routine is provided for both Fortran and C programmers and may be useful when writing portable code. In the current release, the address returned by this routine will be the same as that produced by the C & operator.

C users may be tempted to avoid using MPI_Address and rely on the availability of the address operator &. Note, however, that & cast-expression is a pointer, not an address. ANSI C does not require that the value of a pointer (or the pointer cast to int) be the absolute address of the object pointed at although this is commonly the case. Furthermore, referencing may not have a unique definition on machines with a segmented address space. The use of MPI_Address to "reference" C variables guarantees portability to such machines as well.

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 Also

MPI_Get_address


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