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

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include <stdlib.h>

#include "mpitest.h"

/*

static char MTEST_Descrip[] = "Test MPI_Exscan";

*/

int main(int argc, char *argv[])

{

    int errs = 0;

    int rank, size;

    int minsize = 2, count;

    int *sendbuf, *recvbuf, i;

    MPI_Comm comm;

    MTest_Init(&argc, &argv);

    /* The following illustrates the use of the routines to

     * run through a selection of communicators and datatypes.

     * Use subsets of these for tests that do not involve combinations

     * of communicators, datatypes, and counts of datatypes */

    while (MTestGetIntracommGeneral(&comm, minsize, 1)) {

        if (comm == MPI_COMM_NULL)

            continue;

        MPI_Comm_rank(comm, &rank;;

        MPI_Comm_size(comm, &size);

        for (count = 1; count < 65000; count = count * 2) {

            sendbuf = (int *) malloc(count * sizeof(int));

            recvbuf = (int *) malloc(count * sizeof(int));

            for (i = 0; i < count; i++) {

                sendbuf[i] = rank + i * size;

                recvbuf[i] = -1;

            }

            MPI_Exscan(sendbuf, recvbuf, count, MPI_INT, MPI_SUM, comm);

            /* Check the results.  rank 0 has no data */

            if (rank > 0) {

                int result;

                for (i = 0; i < count; i++) {

                    result = rank * i * size + ((rank) * (rank - 1)) / 2;

                    if (recvbuf[i] != result) {

                        errs++;

                        if (errs < 10) {

                            fprintf(stderr, "Error in recvbuf[%d] = %d on %d, expected %d\n",

                                    i, recvbuf[i], rank, result);

                        }

                    }

                }

            }

#if MTEST_HAVE_MIN_MPI_VERSION(2,2)

            /* now try the MPI_IN_PLACE flavor */

            for (i = 0; i < count; i++) {

                sendbuf[i] = -1;        /* unused */

                recvbuf[i] = rank + i * size;

            }

            MPI_Exscan(MPI_IN_PLACE, recvbuf, count, MPI_INT, MPI_SUM, comm);

            /* Check the results.  rank 0's data must remain unchanged */

            for (i = 0; i < count; i++) {

                int result;

                if (rank == 0)

                    result = rank + i * size;

                else

                    result = rank * i * size + ((rank) * (rank - 1)) / 2;

                if (recvbuf[i] != result) {

                    errs++;

                    if (errs < 10) {

                        fprintf(stderr, "Error in recvbuf[%d] = %d on %d, expected %d\n",

                                i, recvbuf[i], rank, result);

                    }

                }

            }

#endif

            free(sendbuf);

            free(recvbuf);

        }

        MTestFreeComm(&comm);

    }

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}