Theano/Theano — pull request #2070 by nouiz (2014-09-01 18:42:21+00:00)
Title: Opt inc sub

New optimization that remove useless IncSubtensor or convert it to Subtensor in some cases, we when where overwriting(or incrementing the input init to 0) the full input.

If we had step of -1, we convert to a subtensor.