/* -*- 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 "mpitest.h"

#include <stdlib.h>

#include <stdio.h>

/* Gather data from a vector to contiguous.  Use IN_PLACE */

int main(int argc, char **argv)

{

    MPI_Datatype vec;

    double *vecin, *vecout;

    MPI_Comm comm;

    int count, minsize = 2;

    int root, i, n, stride, errs = 0;

    int rank, size;

    MTest_Init(&argc, &argv);

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

        if (comm == MPI_COMM_NULL)

            continue;

        /* Determine the sender and receiver */

        MPI_Comm_rank(comm, &rank;;

        MPI_Comm_size(comm, &size);

        for (root = 0; root < size; root++) {

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

                n = 12;

                stride = 10;

                vecin = (double *) malloc(n * stride * size * sizeof(double));

                vecout = (double *) malloc(size * n * sizeof(double));

                MPI_Type_vector(n, 1, stride, MPI_DOUBLE, &vec;;

                MPI_Type_commit(&vec;;

                for (i = 0; i < n * stride; i++)

                    vecin[i] = -2;

                for (i = 0; i < n; i++)

                    vecin[i * stride] = rank * n + i;

                if (rank == root) {

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

                        vecout[rank * n + i] = rank * n + i;

                    }

                    MPI_Gather(MPI_IN_PLACE, -1, MPI_DATATYPE_NULL,

                               vecout, n, MPI_DOUBLE, root, comm);

                }

                else {

                    MPI_Gather(vecin, 1, vec, NULL, -1, MPI_DATATYPE_NULL, root, comm);

                }

                if (rank == root) {

                    for (i = 0; i < n * size; i++) {

                        if (vecout[i] != i) {

                            errs++;

                            if (errs < 10) {

                                fprintf(stderr, "vecout[%d]=%d\n", i, (int) vecout[i]);

                            }

                        }

                    }

                }

                MPI_Type_free(&vec;;

                free(vecin);

                free(vecout);

            }

        }

        MTestFreeComm(&comm);

    }

    /* do a zero length gather */

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    if (rank == 0) {

        MPI_Gather(MPI_IN_PLACE, -1, MPI_DATATYPE_NULL, NULL, 0, MPI_BYTE, 0, MPI_COMM_WORLD);

    }

    else {

        MPI_Gather(NULL, 0, MPI_BYTE, NULL, 0, MPI_BYTE, 0, MPI_COMM_WORLD);

    }

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}