if (!func) {
        assign_unknown_id_to_all(op->getResults());
        return WalkResult::advance();
      }
      const auto& func_info = backtrack_analysis.GetAnalysisForFunc(func);
      for (auto result : filter_resources(op->getResults())) {
        auto passthrough_arg = func_info.GetArg(result.getResultNumber());
        if (passthrough_arg) {
          PropagateInputToOutput(call.getArgOperands()[passthrough_arg.value()],