void MPI_Send(void *buf, int count, MPI_Datatype datatype,
              int dest, int tag, MPI_Comm comm) {
  $atom {
    int size;
    
    switch (datatype) {
    case MPI_INT:
      buf = (int*)buf;
      size = count*sizeof(int); 
      break;
    case MPI_FLOAT:
      buf = (float*)buf;
      size = count*sizeof(float);
      break;
    case MPI_DOUBLE:
      buf = (double*)buf;
      size = count*sizeof(double);     
      break;
    case MPI_CHAR:
      buf = (char*)buf;
      size = count*sizeof(char);
      break;
    default:
      printf("Unsupported datatype %d\n", datatype);
      $assert $false;    
    }
    $message out = $message_pack(rank, dest, tag, buf, size);
    $comm_enqueue(comm, out);
  }
}

void MPI_Recv(void *buf, int count, MPI_Datatype datatype,
              int source, int tag, MPI_Comm comm, MPI_Status *status) {
  $message in = $comm_dequeue(comm, source, rank, tag);
  $atom {
    int size;
    
    switch (datatype) {
    case MPI_INT:
      buf = (int*)buf;
      size = count*sizeof(int); 
      break;
    case MPI_FLOAT:
      buf = (float*)buf;
      size = count*sizeof(float);
      break;
    case MPI_DOUBLE:
      buf = (double*)buf;
      size = count*sizeof(double);     
      break;
    case MPI_CHAR:
      buf = (char*)buf;
      size = count*sizeof(char);
      break;
    default:
      printf("Unsupported datatype %d\n", datatype);
      $assert $false;    
    }
    $message_unpack(in, buf, size);
    status->source = in.source;
    status->tag = in.tag;
    status->size = in.size;
  }
}

$when (__start);