Function RemovePrecedingNode

tensorflow/lite/delegates/gpu/common/model.h:479–499

// to_remove inputs.
template <typename TensorT>
Status RemovePrecedingNode(Graph<TensorT>* graph, const Node* to_remove,
                           const Node* to_keep) {
  // Make sure all outputs from to_remove are consumed by to_keep.
  for (auto output : graph->FindOutputs(to_remove->id)) {
    auto consumers = graph->FindConsumers(output->id);
    if (consumers.size() > 1 ||
        (consumers.size() == 1 && consumers[0] != to_keep)) {
      return InvalidArgumentError(
          "Output from to_remove node has other consumers");
    }
  }

  // Update all references
  for (auto input : graph->FindInputs(to_remove->id)) {
    RETURN_IF_ERROR(graph->AddConsumer(to_keep->id, input->id));
  }
  for (auto output : graph->FindOutputs(to_remove->id)) {
    RETURN_IF_ERROR(graph->DeleteValue(output->id));
  }
  return graph->DeleteNode(to_remove->id);
}

// Removes to_remove node that follows to_keep node only if to_remove has inputs
// that are produced by to_keep. to_keep inherits all to_remove inputs.