* Refactor to create abstract ParallelOpCombiner

* First draft of CombineParallelDense

* Begin to work on tests

* Test

* Refactor to move out more common code

* Clean up

* Fix

* Remove statics

* fix wording

* Start to add combine_parallel_op_batch

* Resolve PR comments

* Resolve PR comments

* dummy change to retrigger CI

* Change special case from bias_add to add

* Revert special case change

* Ignore units check

* dummy change to retrigger CI

* dummy change to re-trigger CI

* Improve docs

* Update docs

* Update docs

* Qnn Dense layer.

* Reformatting code.

* Reformatting code and making the test case more readable.

* Fixing lint issues.

* Fixing test method names to pass the nose related configurations.

* Aligning the code for code style.

Rebasing. Empty commit.

Clang-format styling.

* Refactor.

* update

* update

* update

* update

* update

* update

* [Relay] [Quantization] WIP - Common files for the qauntization work.

* [Relay] [Quantization] WIP - Prototyping requantize op.

* Requantize operator implementation.

Requantize converts one quantized tensor representation to another quantized
representation. The PR has following implementation features

- Requantize operator defined in qnn namespace - relay.qnn.requantize
- Lowering of the requantize to exisiting Relay operators
- Integer fixed point implementation of requantize
    - Two rounding modes - FE_UPWARDS (round towards infinity) and
    FE_AWAY_FROM_ZERO (std::round behavior)
- Floating point implementation as well, that can act as reference or can be
used for devices when FP32 computation is not used.
- Unit test cases

Relevant Issue - https://github.com/dmlc/tvm/issues/2351

Credit to TFLite and GemmLowp to provide reference implementations.

* Typo and lint fixes.

* Doc fix.

* Uncommenting the lint script (fixing mistake).

* Modifying the unit tests.

* Moving C++ files into src/relay/qnn

* Moving python files to python/tvm/relay/qnn. Some minor fixes.

* Moving the attrs.h inside the include directory.

* Pushing files that I forgot earlier. Changing util location.

* Incorporating comments. API change. Lint fixes.

* Modifying the GetFixedPointMultiplierShift API as per comments.

* Forgot the dialect change.

* Changing rewrite to qnn_lower.

* Renaming Quantize to Qnn for clarity.

* Remove use_int_domain.

* Incorportaing review comments.

* Adding API doc for QNN dialect.

* Move the qnn_lower pass to transform namespace.

* Moving from expr to module. Adding namespace in C++.

* Minor sentence rewrites. Added qnn namespace.

* Added the API doc.

* Chanding default out_dtype to int8. Adding a test with in/out_dtype as uint8.

* Style fixes. Better error messages.

* Adding documentation.

* More documentation fixes.

* Adding out dtype check for requantize.

* Adding corner case for FP32 to fixed point conversion.

* Adding extra line.

* Documentation fix.

* Adding static inline.

* Incorporating jackwish comment. Removed idtype from requantize lowering.

* Removing Quantize/Dequantize code. Restricting Requantize to (u)int8/int32.

* Style fixes.

* Fix the docs.

* Move to Legalize API.

* Add LayerNorm op

* update

* fix

* Add mean_std and mean_variance

* add std and update doc

* add license

* x

* lint

* x

* fix

* fix doc

* [Relay] C++ GraphRuntimeCodegen

* [Test] Deprecate Python2

* [Python3] Add Py2 check

* Update _pyversion.py

* [Python3] Update test

* Add gradient operator tutorial docs

* Incorporate Steven's and Ziheng's feedback

* Remove TODO about `collapse_sum_like`

* Add more examples

* [HEADER] ASF header dir=include

* [HEADER] ASF Header dir=src

* [HEADER] ASF Header -dir=python

* [HEADER] ASF header dir=topi

* [HEADER] ASF Header dir=nnvm

* [HEADER] ASF Header -dir=tutorials

* [HEADER] ASF Header dir=tests

* [HEADER] ASF Header -dir=docker

* fix whitespace

* [HEADER] ASF Header -dir=jvm

* [HEADER] ASF Header -dir=web

* [HEADER] ASF Header --dir=apps

* [HEADER] ASF Header --dir=vta

* [HEADER] ASF Header -dir=go

* temp

* [HEADER] ASF Header --dir=rust

* [HEADER] Add ASF Header --dir=cmake

* [HEADER] ASF Header --dir=docs

* [HEADER] Header for Jenkinsfile

* [HEADER] ASF Header to toml and md

* [HEADER] ASF Header to gradle

* Finalize rat cleanup

* Fix permission

* Fix java test

* temporary remove nnvm onnx test

add test

remove dead code

stash

do it

add more test

* 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

* [QUANTIZE] Quantization implementation.

* Update.

* Update.

* Update.

* Update.

* 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

* [PASS] Avoid recursion in FoldScaleAxis

* remove GetForwardScale

* [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