+ sendsize = smpi_datatype_size(sendtype);
+ recvsize = smpi_datatype_size(recvtype);
+ // Local copy from root
+ memcpy(&((char*)recvbuf)[root * recvcount * recvsize], sendbuf, sendcount * sendsize * sizeof(char));
+ // Receive buffers from senders
+ requests = xbt_new(MPI_Request, size - 1);
+ index = 0;
+ for(src = 0; src < size; src++) {
+ if(src != root) {
+ requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[src * recvcount * recvsize], recvcount, recvtype, src, system_tag, comm);
+ index++;
+ }
+ }
+ // Wait for completion of irecv's.
+ smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+ xbt_free(requests);
+ }
+}
+
+void smpi_mpi_gatherv(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int* recvcounts, int* displs, MPI_Datatype recvtype, int root, MPI_Comm comm) {
+ int system_tag = 666;
+ int rank, size, src, index, sendsize;
+ MPI_Request* requests;
+
+ rank = smpi_comm_rank(comm);
+ size = smpi_comm_size(comm);
+ if(rank != root) {
+ // Send buffer to root
+ smpi_mpi_send(sendbuf, sendcount, sendtype, root, system_tag, comm);
+ } else {
+ sendsize = smpi_datatype_size(sendtype);
+ // Local copy from root
+ memcpy(&((char*)recvbuf)[displs[root]], sendbuf, sendcount * sendsize * sizeof(char));
+ // Receive buffers from senders
+ requests = xbt_new(MPI_Request, size - 1);
+ index = 0;
+ for(src = 0; src < size; src++) {
+ if(src != root) {
+ requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[displs[src]], recvcounts[src], recvtype, src, system_tag, comm);
+ index++;
+ }
+ }
+ // Wait for completion of irecv's.
+ smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+ xbt_free(requests);
+ }
+}
+
+void smpi_mpi_allgather(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm) {
+ int system_tag = 666;
+ int rank, size, other, index, sendsize, recvsize;
+ MPI_Request* requests;