// subgraphn
  //    |
  // current_subgraph   <- aggregated cost
  std::unordered_map<InferenceDeviceType, GraphView,
                     InferenceDeviceType::inference_device_type_hash>
      aggregated_cost_with_decisions;
};

// If the output is produced by a callop, will return the callop, otherwise,
// will return nullptr.
inline func::CallOp GetProducerCallOpOrNull(Value output) {