X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/5ccd28f1840b96133373adb39ded06788a8152e1..03a4b33b7689362cd3459b64810779ce55bc3a52:/src/smpi/colls/alltoallv-ring-light-barrier.c

diff --git a/src/smpi/colls/alltoallv-ring-light-barrier.c b/src/smpi/colls/alltoallv-ring-light-barrier.c
new file mode 100644
index 0000000000..7a42ab90d6
--- /dev/null
+++ b/src/smpi/colls/alltoallv-ring-light-barrier.c
@@ -0,0 +1,67 @@
+#include "colls_private.h"
+/*****************************************************************************
+
+ * Function: alltoall_ring_light_barrier
+
+ * Return: int
+
+ * Inputs:
+    send_buff: send input buffer
+    send_count: number of elements to send
+    send_type: data type of elements being sent
+    recv_buff: receive output buffer
+    recv_count: number of elements to received
+    recv_type: data type of elements being received
+    comm: communicator
+
+ * Descrp: Function works in P - 1 steps. In step i, node j - i -> j -> j + i.
+           Light barriers are inserted between communications in different
+           phases.
+
+ * Auther: Ahmad Faraj
+
+ ****************************************************************************/
+int
+smpi_coll_tuned_alltoallv_ring_light_barrier(void *send_buff, int *send_counts, int *send_disps,
+                                            MPI_Datatype send_type,
+                                            void *recv_buff, int *recv_counts, int *recv_disps,
+                                            MPI_Datatype recv_type,
+                                            MPI_Comm comm)
+{
+  MPI_Aint send_chunk, recv_chunk;
+  MPI_Status s;
+  int i, src, dst, rank, num_procs, next_dst, next_src;
+  int tag = 1;
+
+  char send_sync = 'a', recv_sync = 'b';
+  char *send_ptr = (char *) send_buff;
+  char *recv_ptr = (char *) recv_buff;
+
+  rank = smpi_comm_rank(comm);
+  num_procs = smpi_comm_size(comm);
+  send_chunk = smpi_datatype_get_extent(send_type);
+  recv_chunk = smpi_datatype_get_extent(recv_type);
+
+  smpi_mpi_sendrecv(send_ptr + send_disps[rank] * send_chunk, send_counts[rank], send_type, rank, tag,
+               recv_ptr + recv_disps[rank] * recv_chunk, recv_counts[rank], recv_type, rank, tag,
+               comm, &s);
+
+  for (i = 1; i < num_procs; i++) {
+    src = (rank - i + num_procs) % num_procs;
+    dst = (rank + i) % num_procs;
+
+    smpi_mpi_sendrecv(send_ptr + send_disps[dst] * send_chunk, send_counts[dst], send_type,
+                 dst, tag, recv_ptr + recv_disps[src] * recv_chunk, recv_counts[src],
+                 recv_type, src, tag, comm, &s);
+
+    if ((i + 1) < num_procs) {
+      next_src = (rank - (i + 1) + num_procs) % num_procs;
+      next_dst = (rank + (i + 1) + num_procs) % num_procs;
+      smpi_mpi_sendrecv(&send_sync, 1, MPI_CHAR, next_src, tag,
+                   &recv_sync, 1, MPI_CHAR, next_dst, tag, comm, &s);
+
+    }
+  }
+
+  return MPI_SUCCESS;
+}