"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;

  %6:3 = "tf.UnidirectionalSequenceLstm"(%arg, %1, %1, %1, %1, %2, %2, %2, %2, %3, %3, %3, %3, %3, %3, %3, %5, %5, %4, %4) {_tflite_input_indices = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19], device = ""} : (tensor<28x1x28xf32>, tensor<16x28xf32>, tensor<16x28xf32>, tensor<16x28xf32>, tensor<16x28xf32>, tensor<16x16xf32>, tensor<16x16xf32>, tensor<16x16xf32>, tensor<16x16xf32>,...