message: Optimize away NoOp in the common case where num_inputs=num_ouputs=2
diff: @@ -164,7 +164,7 @@ void DependencyOptimizer::OptimizeNode(int node_idx,
  const auto output_nodes = node_map_->GetOutputs(node->name());
  const int num_outputs = output_nodes.size();
  const int num_inputs = node->input_size();
  - if (num_inputs > 1 && num_outputs > 1) {
  + if (num_inputs * num_outputs > num_inputs + num_outputs) {
  return;
  }
  VLOG(1) << "***** Rerouting input around " << node->name();
  