/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

/* -- Begin Profiling Symbol Block for routine MPI_Get_address */

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Get_address = PMPI_Get_address

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Get_address  MPI_Get_address

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Get_address as PMPI_Get_address

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Get_address(const void *location, MPI_Aint * address)

    __attribute__ ((weak, alias("PMPI_Get_address")));

#endif

/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build

   the MPI routines */

#ifndef MPICH_MPI_FROM_PMPI

#undef MPI_Get_address

#define MPI_Get_address PMPI_Get_address

#endif

#undef FUNCNAME

#define FUNCNAME MPI_Get_address

#undef FCNAME

#define FCNAME "MPI_Get_address"

/*@

   MPI_Get_address - Get the address of a location in memory

Input Parameters:

. location - location in caller memory (choice)

Output Parameters:

. address - address of location (address integer)

   Notes:

    This routine is provided for both the Fortran and C programmers.

    On many systems, the address returned by this routine will be the same

    as produced by the C '&' operator, but this is not required in C and

    may not be true of systems with word- rather than byte-oriented

    instructions or systems with segmented address spaces.

    This routine should be used instead of 'MPI_Address'.

.N SignalSafe

.N Fortran

 In Fortran, the integer type is always signed.  This can cause problems

 on systems where the address fits into a four byte unsigned integer but

 the value is larger than the largest signed integer.  For example, a system

 with more than 2 GBytes of memory may have addresses that do not fit within

 a four byte signed integer.  Unfortunately, there is no easy solution to

 this problem, as there is no Fortran datatype that can be used here (using

 a longer integer type will cause other problems, as well as surprising

 users when the size of the integer type is larger that the size of a pointer

 in C).  In this case, it is recommended that you use C to manipulate

 addresses.

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_OTHER

@*/

int MPI_Get_address(const void *location, MPI_Aint * address)

{

    int mpi_errno = MPI_SUCCESS;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_GET_ADDRESS);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_GET_ADDRESS);

    /* Validate parameters and objects (post conversion) */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_ERRTEST_ARGNULL(address, "address", mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */

    /* SX_4 needs to set CHAR_PTR_IS_ADDRESS

     * The reason is that it computes the different in two pointers in

     * an "int", and addresses typically have the high (bit 31) bit set;

     * thus the difference, when cast as MPI_Aint (long), is sign-extended,

     * making the absolute address negative.  Without a copy of the C

     * standard, I can't tell if this is a compiler bug or a language bug.

     */

#ifdef CHAR_PTR_IS_ADDRESS

    *address = MPIR_VOID_PTR_CAST_TO_MPI_AINT((char *) location);

#else

    /* Note that this is the "portable" way to generate an address.

     * The difference of two pointers is the number of elements

     * between them, so this gives the number of chars between location

     * and ptr.  As long as sizeof(char) represents one byte,

     * of bytes from 0 to location */

    *address = MPIR_VOID_PTR_CAST_TO_MPI_AINT((char *) location - (char *) MPI_BOTTOM);

#endif

    /* The same code is used in MPI_Address */

    /* ... end of body of routine ... */

#ifdef HAVE_ERROR_CHECKING

  fn_exit:

#endif

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_GET_ADDRESS);

    return mpi_errno;

    /* --BEGIN ERROR HANDLING-- */

#ifdef HAVE_ERROR_CHECKING

  fn_fail:

    {

        mpi_errno =

            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,

                                 "**mpi_get_address", "**mpi_get_address %p %p", location, address);

    }

    mpi_errno = MPIR_Err_return_comm(0, FCNAME, mpi_errno);

    goto fn_exit;

#endif

    /* --END ERROR HANDLING-- */

}