/* -*- 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 "mpitestconf.h"
#ifdef HAVE_IOSTREAM
// Not all C++ compilers have iostream instead of iostream.h
#include <iostream>
#ifdef HAVE_NAMESPACE_STD
// Those that do often need the std namespace; otherwise, a bare "cout"
// is likely to fail to compile
using namespace std;
#endif
#else
#include <iostream.h>
#endif
#include "mpitestcxx.h"

void uop(const void *invec, void *inoutvec, int count, const MPI::Datatype & datatype)
{
    int i;
    int *cin = (int *) invec, *cout = (int *) inoutvec;

    for (i = 0; i < count; i++) {
        cout[i] = cin[i] + cout[i];
    }
}

int main(int argc, char **argv)
{
    MPI::Op sumop;
    MPI::Intracomm comm = MPI::COMM_WORLD;
    int errs = 0;
    int size, i, count;

    MTest_Init();

    sumop.Init(uop, true);
    size = comm.Get_size();

    for (count = 1; count < 66000; count = count * 2) {
        int *vin, *vout;
        vin = new int[count];
        vout = new int[count];

        for (i = 0; i < count; i++) {
            vin[i] = i;
            vout[i] = -1;
        }
        comm.Allreduce(vin, vout, count, MPI::INT, sumop);
        for (i = 0; i < count; i++) {
            if (vout[i] != i * size) {
                errs++;
                if (errs < 10)
                    cerr << "vout[" << i << "] = " << vout[i] << endl;
            }
        }

        delete[]vin;
        delete[]vout;
    }

    sumop.Free();
    MTest_Finalize(errs);
    return 0;
}