message: [NCCL] minor bug fix
diff: @@ -615,7 +615,7 @@ ncclComm_t Op::init_nccl_comms_task(const Task* task,
  {
  // Must be an index space launch
  assert(task->is_index_space);
  - ncclUniqueId ncclId = *((const ncclUniqueId*) task->local_args);
  + ncclUniqueId ncclId = *((const ncclUniqueId*) task->args);
  int allRanks = task->index_domain.get_volume();
  assert(task->index_domain.contains(task->index_point));
  int myRank = 0;
  @@ -1642,6 +1642,8 @@ void FFModel::compile(LossType loss_type,
  // init all nccl communicators
  std::map<MappingTagID, ParallelConfig>::iterator iter;
  for (iter = config.strategies.begin(); iter != config.strategies.end(); iter++) {
  + // only init nccl for GPU parallel configurations
  + if (iter->second.device_type != ParallelConfig::GPU) continue;
  std::map<MappingTagID, ParallelConfig>::const_iterator it2;
  bool found = false;
  // Reuse nccl comms for same parallel config
  @@ -1657,7 +1659,7 @@ void FFModel::compile(LossType loss_type,
  TaskLauncher launcher(NCCL_GETUNIQUEID_TASK_ID, TaskArgument(NULL, 0));
  Future future = runtime->execute_task(ctx, launcher);
  ncclUniqueId ncclId = future.get_result<ncclUniqueId>();
  - IndexSpace task_is = get_task_is(iter->second);
  + IndexSpace task_is = get_or_create_task_is(iter->second);
  ArgumentMap argmap;
  IndexLauncher index_launcher(NCCL_INIT_COMMS_TASK_ID, task_is,
  TaskArgument(&ncclId, sizeof(ncclUniqueId)), argmap,
  