1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
4 * (C) 2003 by Argonne National Laboratory.
5 * See COPYRIGHT in top-level directory.
13 /* Gather data from a vector to contiguous. Use IN_PLACE */
15 int main(int argc, char **argv)
19 int count, minsize = 2;
23 MTest_Init(&argc, &argv);
25 while (MTestGetIntracommGeneral(&comm, minsize, 1)) {
26 if (comm == MPI_COMM_NULL)
28 /* Determine the sender and receiver */
29 MPI_Comm_rank(comm, &rank);
30 MPI_Comm_size(comm, &size);
32 for (count = 1; count < 9000; count = count * 2) {
33 vecout = (double *) malloc(size * count * sizeof(double));
35 for (i = 0; i < count; i++) {
36 vecout[rank * count + i] = rank * count + i;
38 MPI_Allgather(MPI_IN_PLACE, -1, MPI_DATATYPE_NULL, vecout, count, MPI_DOUBLE, comm);
39 for (i = 0; i < count * size; i++) {
43 fprintf(stderr, "vecout[%d]=%d\n", i, (int) vecout[i]);