rewriter.getUnknownLoc(), rewriter.getNoneType(),
          rewriter.getUnitAttr());
      op.getInputGateBiasMutable().assign(none_value);
      return success();
    }

    if (EqualsZero(op.getProjectionBias())) {
      auto none_value = rewriter.create<TFL::NoValueOp>(
          rewriter.getUnknownLoc(), rewriter.getNoneType(),
          rewriter.getUnitAttr());
      op.getProjectionBiasMutable().assign(none_value);