Duplicated computation of decoder outputs?

Thanks for mentioning `raw_rnn` in tutorial 2 as I completely don't know about this function before. But the document is a bit not clear for me... May I ask a question? In tutorial 2, is the `decoder_logits` computed of all time steps the same as what has been computed (`output_logits`) in the `loop_fn`? If so, can we save time by reusing the latter ones?