1 //exclude from clang static analysis, as there is an intentional uninitialized value passed to MPI calls.
2 #ifndef __clang_analyzer__
8 #define BUFSIZE (1024 * 1024)
9 #define BOUNDED(sz) ((sz) < BUFSIZE ? (sz) : BUFSIZE)
11 static void setup_recvbuf(int nprocs, int** recvbuf, int** displs, int** counts, int** rcounts)
13 *recvbuf = malloc(BUFSIZE * nprocs * sizeof(int));
14 for (int i = 0; i < BUFSIZE * nprocs; i++)
17 *displs = malloc(nprocs * sizeof(int));
18 *counts = malloc(nprocs * sizeof(int));
19 *rcounts = malloc(nprocs * sizeof(int));
20 for (int i = 0; i < nprocs; i++) {
21 (*displs)[i] = i * BUFSIZE;
22 (*counts)[i] = BOUNDED(i);
23 (*rcounts)[i] = (*counts)[i];
27 int main(int argc, char** argv)
33 MPI_Init(&argc, &argv);
34 MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
35 MPI_Comm_rank(MPI_COMM_WORLD, &rank);
37 int* sendbuf = malloc(BUFSIZE * nprocs * sizeof(int));
38 for (int i = 0; i < BUFSIZE * nprocs; i++)
41 int* alltoallvcounts = malloc(nprocs * sizeof(int));
42 for (int i = 0; i < nprocs; i++)
43 alltoallvcounts[i] = BOUNDED(i + rank);
50 setup_recvbuf(nprocs, &recvbuf, &displs, &counts, &rcounts);
52 // first test, with unallocated non significative buffers
53 MPI_Barrier(MPI_COMM_WORLD);
54 MPI_Bcast(sendbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
55 MPI_Gather(&sendbuf[rank * BUFSIZE], BUFSIZE, MPI_INT, recvbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
56 MPI_Scatter(recvbuf, BUFSIZE, MPI_INT, sendbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
57 MPI_Gatherv(&sendbuf[rank * BUFSIZE], BOUNDED(rank), MPI_INT, recvbuf, rcounts, displs, MPI_INT, 0, MPI_COMM_WORLD);
58 MPI_Scatterv(recvbuf, counts, displs, MPI_INT, sendbuf, BOUNDED(rank), MPI_INT, 0, MPI_COMM_WORLD);
59 MPI_Reduce(sendbuf, recvbuf, BUFSIZE, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD);
62 setup_recvbuf(nprocs, &recvbuf, &displs, &counts, &rcounts);
64 MPI_Barrier(MPI_COMM_WORLD);
65 MPI_Bcast(sendbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
66 MPI_Gather(&sendbuf[rank * BUFSIZE], BUFSIZE, MPI_INT, recvbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
67 MPI_Scatter(recvbuf, BUFSIZE, MPI_INT, sendbuf, BUFSIZE, MPI_INT, 0, MPI_COMM_WORLD);
68 MPI_Gatherv(&sendbuf[rank * BUFSIZE], BOUNDED(rank), MPI_INT, recvbuf, rcounts, displs, MPI_INT, 0, MPI_COMM_WORLD);
69 MPI_Scatterv(recvbuf, counts, displs, MPI_INT, sendbuf, BOUNDED(rank), MPI_INT, 0, MPI_COMM_WORLD);
70 MPI_Reduce(sendbuf, recvbuf, BUFSIZE, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD);
71 MPI_Allgather(sendbuf, BUFSIZE, MPI_INT, recvbuf, BUFSIZE, MPI_INT, MPI_COMM_WORLD);
72 MPI_Alltoall(recvbuf, BUFSIZE, MPI_INT, sendbuf, BUFSIZE, MPI_INT, MPI_COMM_WORLD);
73 MPI_Allgatherv(sendbuf, BOUNDED(rank), MPI_INT, recvbuf, rcounts, displs, MPI_INT, MPI_COMM_WORLD);
74 MPI_Alltoallv(recvbuf, alltoallvcounts, displs, MPI_INT, sendbuf, alltoallvcounts, displs, MPI_INT, MPI_COMM_WORLD);
75 MPI_Allreduce(sendbuf, recvbuf, BUFSIZE, MPI_INT, MPI_MAX, MPI_COMM_WORLD);
76 MPI_Reduce_scatter(sendbuf, recvbuf, rcounts, MPI_INT, MPI_MAX, MPI_COMM_WORLD);
77 MPI_Scan(sendbuf, recvbuf, BUFSIZE, MPI_INT, MPI_MAX, MPI_COMM_WORLD);
78 MPI_Exscan(sendbuf, recvbuf, BUFSIZE, MPI_INT, MPI_MAX, MPI_COMM_WORLD);
79 MPI_Barrier(MPI_COMM_WORLD);
81 free(alltoallvcounts);