1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
3 * (C) 2015 by Argonne National Laboratory.
4 * See COPYRIGHT in top-level directory.
14 /* Following should always work for -n 8 256, -N 32, using longs */
15 #define COUNT 1048576*32
18 /* Following will fail for -n 8 unless gather path is 64 bit clean */
19 #define COUNT (1024*1024*128+1)
21 #define VERIFY_CONST 100000000L
23 int main(int argc, char *argv[])
30 MPI_Init(&argc, &argv);
31 MPI_Comm_rank(MPI_COMM_WORLD, &rank);
32 MPI_Comm_size(MPI_COMM_WORLD, &size);
34 if (size < (ROOT+1)) {
35 fprintf(stderr, "At least %d processes required\n", ROOT+1);
36 MPI_Abort(MPI_COMM_WORLD, 1);
39 sendbuf = malloc(COUNT * sizeof(long));
40 if (sendbuf == NULL) {
41 fprintf(stderr, "PE %d:ERROR: malloc of sendbuf failed\n", rank);
43 for (i = 0; i < COUNT; i++) {
44 sendbuf[i] = (long) i + (long) rank *VERIFY_CONST;
48 recvbuf = malloc(COUNT * sizeof(long) * size);
49 if (recvbuf == NULL) {
50 fprintf(stderr, "PE %d:ERROR: malloc of recvbuf failed\n", rank);
52 for (i = 0; i < COUNT * size; i++) {
53 recvbuf[i] = -456789L;
57 MPI_Gather(sendbuf, COUNT, MPI_LONG, recvbuf, COUNT, MPI_LONG, ROOT, MPI_COMM_WORLD);
61 for (i = 0; i < size; i++) {
62 for (j = 0; j < COUNT; j++) {
63 if (recvbuf[i * COUNT + j] != i * VERIFY_CONST + j) {
64 printf("PE 0: mismatch error");
65 printf(" recbuf[%d * %d + %d] = ", i, COUNT, j);
66 printf(" %ld,", recvbuf[i * COUNT + j]);
67 printf(" should be %ld\n", i * VERIFY_CONST + j);
82 MPI_Barrier(MPI_COMM_WORLD);