* Add shapeof op in topi

* Add relay shape_of op

* Add constant folding for shape_of

* Allow shape op to specify dtype

* Add mxnet converter for shape_array

* lint

* lint

* Add doc

* start adding reverse

* reverse updated

* reverse uses topi::flip

* typo fixed

* comment addressed

* exp simplified

* tile and repeat operator added in rely

* fix pylint

* fix make warnings

* comments addressed

* fix lint error

* comment addressed

* add stack op frontend

* concate moved

* topi stack added

* stack added

* fix stack bugs and tested

* conv2d alterlayout udpated for relay

* fix pylint

* fix cmake warnings

* cmake warnings fixed

* move layout.h & layout.cc from relay to tvm

* change ConvertLayout in relay to bijectiveLayout->Forward/backward

* add first test case

* add LayoutAxis

* add LayoutAxis struct and compiles

* simplify BijectiveLayout rule consturct

* polish func name for Layout, move impl to .cc, remove Layout::defined(), add defined() checker

* partially add layout py support

* add layout test cases

* add doc for tvm.layout & tvm.bijective_layout

* fix lint

* fix lint

* fix layout name generation bug

* fix layout typo

* address comments and add topi.layout_transform

* layout.h->data_layout.h, test_lang_layout.py->test_lang_data_layout.py

* Add arange op

* Update docs

* Fix bug

* add sanity check in relay and mxnet frontend mapping

* lint

* nits

* pylint

* don't allow empty output from arange

* Remove empty test for arange

* Fix bug and update doc

* Enable reverse in reshape

* Fix lint and typo

* Put reverse_reshape into a separate op

* Fix pylint

* [QUANTIZE] Quantization implementation.

* Update.

* Update.

* Update.

* Update.

* [RELAY] Fix ops in packed layout

* Fix style

* init

staging on

final save before staging

save

init ver

init ver

ll stuff

save

add failing test

add file

pass test

fix error

huh?

save

Add test changes

Fix fusion with nested tuples

Fix reverse mode test

More hacking

Clean up AD

Hacking on reverse mode

Fix issue in reverse

save

fix lint

fix lint

fix lint

save

save

fix

support neg

address some comment

add back file

save

save

* save

* save

* save

* lint

* fix lint

* save

* fix

* Add cast op
* Rename dtype_cast to cast
* Add additional safety check for String2TVMType
* Add missing relay op docs

* [RELAY] Finish alter op pass

* [RELAY] AlterOpLayout Pass

* fix broadcast operators

* fix broadcast operators

* fix broadcast operators

* Support concatenate

* address comments

* address comments

* add comments

* rebase

* [RELAY][PASS] FoldScaleAxis Forward

* Introduce helper function type_as

* Update per review comment

* Fix according to comments

* [RELAY] BiasAdd, MLP, Resnet testing

* fix review comments