Add collectives for allgather, allreduce, bcast and reduce

[simgrid.git] / src / smpi / colls / bcast-flattree.c

diff --git a/src/smpi/colls/bcast-flattree.c b/src/smpi/colls/bcast-flattree.c
new file mode 100644 (file)
index 0000000..693d83d
--- /dev/null
+++ b/src/smpi/colls/bcast-flattree.c
@@ -0,0 +1,37 @@
+#include "colls.h"
+
+int
+smpi_coll_tuned_bcast_flattree(void *buff, int count, MPI_Datatype data_type,
+                               int root, MPI_Comm comm)
+{
+  MPI_Request *req_ptr;
+  MPI_Request *reqs;
+
+  int i, rank, num_procs;
+  int tag = 1;
+
+  MPI_Comm_rank(comm, &rank);
+  MPI_Comm_size(comm, &num_procs);
+
+  if (rank != root) {
+    MPI_Recv(buff, count, data_type, root, tag, comm, MPI_STATUS_IGNORE);
+  }
+
+  else {
+    reqs = (MPI_Request *) malloc((num_procs - 1) * sizeof(MPI_Request));
+    req_ptr = reqs;
+
+    // Root sends data to all others
+    for (i = 0; i < num_procs; i++) {
+      if (i == rank)
+        continue;
+      MPI_Isend(buff, count, data_type, i, tag, comm, req_ptr++);
+    }
+
+    // wait on all requests
+    MPI_Waitall(num_procs - 1, reqs, MPI_STATUSES_IGNORE);
+
+    free(reqs);
+  }
+  return MPI_SUCCESS;
+}