TF_Output grad_inputs[1];
      const float grad_inputs_val[] = {1.0, 1.0, 1.0, 1.0};
      TF_Operation* grad_inputs_op =
          FloatConst2x2(graph_, s_, grad_inputs_val, "GradInputs");
      grad_inputs[0] = TF_Output{grad_inputs_op, 0};
      TF_AddGradientsWithPrefix(graph_, prefix, outputs, noutputs, inputs,
                                ninputs, grad_inputs, s_, grad_outputs);
    } else {