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

/*

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include <stdlib.h>

#include "mpitest.h"

int add(double *, double *, int *, MPI_Datatype *);

/*

 * User-defined operation on a long value (tests proper handling of

 * possible pipelining in the implementation of reductions with user-defined

 * operations).

 */

int add(double *invec, double *inoutvec, int *len, MPI_Datatype * dtype)

{

    int i, n = *len;

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

        inoutvec[i] = invec[i] + inoutvec[i];

    }

    return 0;

}

int main(int argc, char **argv)

{

    MPI_Op op;

    int i, rank, size, bufsize, errcnt = 0;

    double *inbuf, *outbuf, value;

    MTest_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &size);

    MPI_Op_create((MPI_User_function *) add, 1, &op);

    bufsize = 1;

    while (bufsize < 100000) {

        inbuf = (double *) malloc(bufsize * sizeof(double));

        outbuf = (double *) malloc(bufsize * sizeof(double));

        if (!inbuf || !outbuf) {

            fprintf(stderr, "Could not allocate buffers for size %d\n", bufsize);

            errcnt++;

            break;

        }

        value = (rank & 0x1) ? 1.0 : -1.0;

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

            inbuf[i] = value;

            outbuf[i] = 100.0;

        }

        MPI_Allreduce(inbuf, outbuf, bufsize, MPI_DOUBLE, op, MPI_COMM_WORLD);

        /* Check values */

        value = (size & 0x1) ? -1.0 : 0.0;

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

            if (outbuf[i] != value) {

                if (errcnt < 10)

                    printf("outbuf[%d] = %f, should = %f\n", i, outbuf[i], value);

                errcnt++;

            }

        }

        free(inbuf);

        free(outbuf);

        bufsize *= 2;

    }

    MPI_Op_free(&op);

    MTest_Finalize(errcnt);

    return MTestReturnValue(errcnt);

}