X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1c080fdf88d3dc8cbf7413b1f8b3ce66d475070a..d47debaeffa6807956ee9cc7da90759efe49beda:/src/smpi/sample/reduce.c

diff --git a/src/smpi/sample/reduce.c b/src/smpi/sample/reduce.c
new file mode 100644
index 0000000000..9fc0be2483
--- /dev/null
+++ b/src/smpi/sample/reduce.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <mpi.h>
+
+int main(int argc, char *argv[]) {
+  int rank, size;
+  int i;
+  int *sendbuf, *recvbuf;
+  MPI_Init(&argc, &argv);
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+  MPI_Comm_size(MPI_COMM_WORLD, &size);
+  sendbuf = malloc(sizeof(int) * size);
+  recvbuf = malloc(sizeof(int) * size);
+  for (i = 0; i < size; i++) {
+    sendbuf[i] = 0;
+    recvbuf[i] = 0;
+  }
+  sendbuf[rank] = rank + 1;
+  MPI_Reduce(sendbuf, recvbuf, size, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
+  if (0 == rank) {
+    printf("nodes: ", rank);
+    for (i = 0; i < size; i++) {
+      printf("%d ", recvbuf[i]);
+    }
+    printf("\n");
+  }
+  free(sendbuf);
+  free(recvbuf);
+  MPI_Finalize();
+  return 0;
+}