/* -*- Mode: C++; c-basic-offset:4 ; -*- */
/*
 *
 *  (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"

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

int main(int argc, char *argv[])
{
    int errs = 0;
    int *sendbuf = 0, *recvbuf = 0;
    int leftGroup, i, count, rank, rsize;
    MPI::Intercomm comm;
    MPI::Datatype datatype;

    MTest_Init();

    datatype = MPI::INT;
    while (MTestGetIntercomm(comm, leftGroup, 4)) {
        if (comm == MPI::COMM_NULL)
            continue;
        rank = comm.Get_rank();
        for (count = 1; count < 65000; count = 2 * count) {
            sendbuf = new int[count];
            recvbuf = new int[count];
            /* Get an intercommunicator */
            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;
            try {
                comm.Allreduce(sendbuf, recvbuf, count, datatype, MPI::SUM);
            }
            catch(MPI::Exception e) {
                errs++;
                MTestPrintError(e.Get_error_code());
            }
            /* In each process should be the sum of the values from the
             * other process */
            rsize = comm.Get_remote_size();
            if (leftGroup) {
                for (i = 0; i < count; i++) {
                    if (recvbuf[i] != -i * rsize) {
                        errs++;
                        if (errs < 10) {
                            cout << "recvbuf[" << i << "] = " << recvbuf[i] << "\n";
                        }
                    }
                }
            } else {
                for (i = 0; i < count; i++) {
                    if (recvbuf[i] != i * rsize) {
                        errs++;
                        if (errs < 10) {
                            cout << "recvbuf[" << i << "] = " << recvbuf[i] << "\n";
                        }
                    }
                }
            }
            delete[]sendbuf;
            delete[]recvbuf;
        }
        MTestFreeComm(comm);
    }

    MTest_Finalize(errs);
    return 0;
}
