/* -*- 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[] = "A simple test of Reduce with all choices of root process";
*/

int main(int argc, char *argv[])
{
    int errs = 0;
    int rank, size, root;
    int *sendbuf, *recvbuf, i;
    int minsize = 2, count;
    MPI_Comm comm;

    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 (count = 1; count < 130000; count = count * 2) {
            sendbuf = (int *) malloc(count * sizeof(int));
            recvbuf = (int *) malloc(count * sizeof(int));
            for (root = 0; root < size; root++) {
                for (i = 0; i < count; i++)
                    sendbuf[i] = i;
                for (i = 0; i < count; i++)
                    recvbuf[i] = -1;
                MPI_Reduce(sendbuf, recvbuf, count, MPI_INT, MPI_SUM, root, comm);
                if (rank == root) {
                    for (i = 0; i < count; i++) {
                        if (recvbuf[i] != i * size) {
                            errs++;
                        }
                    }
                }
            }
            free(sendbuf);
            free(recvbuf);
        }
        MTestFreeComm(&comm);
    }

    MTest_Finalize(errs);
    MPI_Finalize();
    return 0;
}
