+void smpi_mpi_scatterv(void *sendbuf, int *sendcounts, int *displs,
+ MPI_Datatype sendtype, void *recvbuf, int recvcount,
+ MPI_Datatype recvtype, int root, MPI_Comm comm)
+{
+ int system_tag = 666;
+ int rank, size, dst, index;
+ MPI_Aint lb = 0, sendext = 0;
+ MPI_Request *requests;
+
+ rank = smpi_comm_rank(comm);
+ size = smpi_comm_size(comm);
+ if(rank != root) {
+ // Recv buffer from root
+ smpi_mpi_recv(recvbuf, recvcount, recvtype, root, system_tag, comm,
+ MPI_STATUS_IGNORE);
+ } else {
+ // FIXME: check for errors
+ smpi_datatype_extent(sendtype, &lb, &sendext);
+ // Local copy from root
+ smpi_datatype_copy((char *)sendbuf + displs[root] * sendext, sendcounts[root],
+ sendtype, recvbuf, recvcount, recvtype);
+ // Send buffers to receivers
+ requests = xbt_new(MPI_Request, size - 1);
+ index = 0;
+ for(dst = 0; dst < size; dst++) {
+ if(dst != root) {
+ requests[index] =
+ smpi_isend_init((char *)sendbuf + displs[dst] * sendext, sendcounts[dst],
+ sendtype, dst, system_tag, comm);
+ index++;
+ }
+ }
+ // Wait for completion of isend's.
+ smpi_mpi_startall(size - 1, requests);
+ smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+ xbt_free(requests);
+ }
+}
+
+void smpi_mpi_reduce(void *sendbuf, void *recvbuf, int count,
+ MPI_Datatype datatype, MPI_Op op, int root,
+ MPI_Comm comm)
+{
+ int system_tag = 666;
+ int rank, size, src, index;
+ MPI_Aint lb = 0, dataext = 0;
+ MPI_Request *requests;
+ void **tmpbufs;
+
+ rank = smpi_comm_rank(comm);
+ size = smpi_comm_size(comm);
+ if(rank != root) {
+ // Send buffer to root
+ smpi_mpi_send(sendbuf, count, datatype, root, system_tag, comm);
+ } else {
+ // FIXME: check for errors
+ smpi_datatype_extent(datatype, &lb, &dataext);
+ // Local copy from root
+ if (sendbuf && recvbuf)
+ smpi_datatype_copy(sendbuf, count, datatype, recvbuf, count, datatype);
+ // Receive buffers from senders
+ //TODO: make a MPI_barrier here ?
+ requests = xbt_new(MPI_Request, size - 1);
+ tmpbufs = xbt_new(void *, size - 1);
+ index = 0;
+ for(src = 0; src < size; src++) {
+ if(src != root) {
+ // FIXME: possibly overkill we we have contiguous/noncontiguous data
+ // mapping...
+ tmpbufs[index] = xbt_malloc(count * dataext);
+ requests[index] =
+ smpi_irecv_init(tmpbufs[index], count, datatype, src,
+ system_tag, comm);
+ index++;
+ }
+ }
+ // Wait for completion of irecv's.
+ smpi_mpi_startall(size - 1, requests);
+ for(src = 0; src < size - 1; src++) {
+ index = smpi_mpi_waitany(size - 1, requests, MPI_STATUS_IGNORE);
+ XBT_DEBUG("finished waiting any request with index %d", index);
+ if(index == MPI_UNDEFINED) {
+ break;
+ }
+ if(op) /* op can be MPI_OP_NULL that does nothing */
+ smpi_op_apply(op, tmpbufs[index], recvbuf, &count, &datatype);
+ }
+ for(index = 0; index < size - 1; index++) {
+ xbt_free(tmpbufs[index]);
+ }
+ xbt_free(tmpbufs);
+ xbt_free(requests);