/* -*- 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"
#include "mpicolltest.h"

/*
static char MTEST_Descrip[] = "Simple intercomm allreduce test";
*/

int main(int argc, char *argv[])
{
    int errs = 0, err;
    int *sendbuf = 0, *recvbuf = 0;
    int leftGroup, i, count, rank, rsize;
    MPI_Comm comm;
    MPI_Datatype datatype;

    MTest_Init(&argc, &argv);

    datatype = MPI_INT;
    /* Get an intercommunicator */
    while (MTestGetIntercomm(&comm, &leftGroup, 4)) {
        if (comm == MPI_COMM_NULL)
            continue;
        MPI_Comm_rank(comm, &rank);
        MPI_Comm_remote_size(comm, &rsize);

        /* To improve reporting of problems about operations, we
         * change the error handler to errors return */
        MPI_Errhandler_set(comm, MPI_ERRORS_RETURN);

        for (count = 1; count < 65000; count = 2 * count) {
            /* printf("rank = %d(%d)\n", rank, leftGroup); fflush(stdout); */
            sendbuf = (int *) malloc(count * sizeof(int));
            recvbuf = (int *) malloc(count * sizeof(int));
            if (leftGroup) {
                for (i = 0; i < count; i++)
                    sendbuf[i] = i;
            } else {
                for (i = 0; i < count; i++)
                    sendbuf[i] = -i;
            }
            for (i = 0; i < count; i++)
                recvbuf[i] = 0;
            err = MTest_Allreduce(sendbuf, recvbuf, count, datatype, MPI_SUM, comm);
            if (err) {
                errs++;
                MTestPrintError(err);
            }
            /* In each process should be the sum of the values from the
             * other process */
            if (leftGroup) {
                for (i = 0; i < count; i++) {
                    if (recvbuf[i] != -i * rsize) {
                        errs++;
                        if (errs < 10) {
                            fprintf(stderr, "recvbuf[%d] = %d\n", i, recvbuf[i]);
                        }
                    }
                }
            } else {
                for (i = 0; i < count; i++) {
                    if (recvbuf[i] != i * rsize) {
                        errs++;
                        if (errs < 10) {
                            fprintf(stderr, "recvbuf[%d] = %d\n", i, recvbuf[i]);
                        }
                    }
                }
            }
            free(sendbuf);
            free(recvbuf);
        }
        MTestFreeComm(&comm);
    }

    MTest_Finalize(errs);
    return MTestReturnValue(errs);
}