RankedTensorType::get({3}, builder->getType<TF::StringType>());

  // Add MLIR module's fingerprint to compile metadata.
  uint64_t mlir_fingerprint = tensorflow::Fingerprint64(txt_module);
  metadata.set_mlir_fingerprint(mlir_fingerprint);

  std::string txt_metadata;
  if (tpu_compile_metadata_debug) {
    ::tensorflow::protobuf::TextFormat::Printer printer;
    printer.SetExpandAny(true);