…ytorch#589)

onnx/onnx@910db3b

IFU 20200221

Update seq2seq_translation_tutorial.py

* Separate interface for all exprs in a fusion as we should only be working on exprs required to produce outputs.

* Dropped off a nolint flag.

* Add some todos

* Remove mutate on fusion as it's never used and was accessing all exprs/vals in the fusion instead of those used to produce registered outputs.

* Remove traversing exprs in fusion not used to produce registered outputs in IterVisitor.

* Update tests.

* Minor cleanup.

* Re-enable printing all exprs in fusion.

* Minor cleanup.

* Cleanup IterVisitor.

* Refactor val origin so it's a member in Val.

* Move origin, is_output, and is_input to val member function, return nullptr origin if is_input.

* Refactor is_input/output to is_fusion_input/is_fusion_output.

* Refactor uses to be a member of Val instead of Fusion.

* Clear dead Exprs from TV->uses.

* Move fusion copy to a function that can return the ir_cloner used.

* Manual example with multiple kernels.

* Merge fixes.

* Basic mechanism to divide fusion into segments based on simple rule.

* Minor cleanup.

* Convert segments back to fusions.

* A lot of cleanup, running segmented fusion still in progress.

* Runtime for segmented fusion WIP.

* rename segment file

* refactor scheduler interface

* refactor; use heuristics matching;

* fix fusion logic and multifusion runtime

* add scheduler registry

* add normalization detection

* integrate scheduler registry in fusionSegRT

* use scheduling matching for fusion segment(WIP)

* cleanup and bug fix

* minor cleanup

* merge fix

* segment fusion only if orig fusion cannot schedule

* clang-format & clang-tidy

* clang-tidy

* clang-tidy

* clang-tidy

* rename;comment;refactor caching;

* minor cleanups

* minor cleanup

* allow mismatched broadcast normalizationSchedule

* allow mismatched broadcast in normalization

* rework red and norm canSchedule; minor fix

* style fix; unify debug print

* clang-tidy

* clang format

* clang format

* clang-tidy

* minor cleanup

Co-authored-by: shmsong <shisong@umich.edu>

…torch#589)