"output_arg: { name: 'Concat' type: DT_FLOAT} "
    "output_arg: { name: "
    "'LastState' type: DT_FLOAT } output_arg: { name: 'Output' type: DT_FLOAT} "
    "attr : { name: '_tflite_input_indices' type: 'list(int)'}";

constexpr mlir::StringRef kUnidirectionalSequenceRnnOp =
    "name: 'UnidirectionalSequenceRnn' input_arg: {name: 'Input' type: "
    "DT_FLOAT} input_arg: { name: 'Weights' type: DT_FLOAT } "

constexpr char kUnidirectionalSequenceLstm[] = "tf.UnidirectionalSequenceLstm";
constexpr char kUnidirectionalSequenceRnn[] = "tf.UnidirectionalSequenceRnn";
constexpr char kTfLiteInputIndices[] = "_tflite_input_indices";

// Legalize operations in functions.
class LegalizeTFPass : public impl::LegalizeTFPassBase<LegalizeTFPass> {
 public:
  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(LegalizeTFPass)
  LegalizeTFPass() = default;