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. */
15 int main( int argc, char **argv )
17 double *vecout, *invec;
19 int count, minsize = 2;
23 MTest_Init( &argc, &argv );
25 while (MTestGetIntracommGeneral( &comm, minsize, 1 )) {
26 if (comm == MPI_COMM_NULL) continue;
27 /* Determine the sender and receiver */
28 MPI_Comm_rank( comm, &rank );
29 MPI_Comm_size( comm, &size );
31 for (count = 1; count < 9000; count = count * 2) {
32 invec = (double *)malloc( count * sizeof(double) );
33 vecout = (double *)malloc( size * count * sizeof(double) );
35 for (i=0; i<count; i++) {
36 invec[i] = rank*count+i;
38 MPI_Allgather( invec, count, MPI_DOUBLE,
39 vecout, count, MPI_DOUBLE, comm );
40 for (i=0; i<count*size; i++) {
44 fprintf( stderr, "vecout[%d]=%d\n",
53 MTestFreeComm( &comm );
56 /* Do a zero byte gather */
57 MPI_Allgather( MPI_IN_PLACE, -1, MPI_DATATYPE_NULL, NULL, 0, MPI_BYTE, MPI_COMM_WORLD );
59 MTest_Finalize( errs );