* Enable self-concat to broadcast replacement for a single concat.

* Update tests.
Co-authored-by: Scott Cyphers <diyessi@users.noreply.github.com>
Co-authored-by: Robert Kimball <robert.kimball@intel.com>

* Affine lowering support for
    1) GreaterEq
    2) LessEq
    3) Equal
    4) NotEqual

* - cast result op from i1 to i8 for comparision operators

* Addressed PR comments

* Style fix

* - style check
- use select instead of zero_extendi durinng CompOp lowering

* - fix style
- use createOneConstant and createZeroConstant helpers in select intrinsic

* Use NG_U8_TYPE_ID for BooleanType in ngraph dialect

* Diable CE and Softmax unit test in MLIR

* - LIT parser test for comparision ops

* - Affine dailect LIT tests for Comparision Ops

* Address PR feedback

* fix typo

* - use `cast` to deduce element Type
- add more strict type checking to LIT Test

* fix CHECK label's for comparision ops

* Use UInt8 in verification logic for CMP op's

* - use UInt8 for the resultOp verification Logic in CMP op
- fix unit test failures

* Update license to new year

* Pick up some strays

* [MLIR] Update MLIR/LLVM repo

I need it to get MemRef lowering override mechanism (291a309d).

* Fix style
Co-authored-by: Scott Cyphers <diyessi@users.noreply.github.com>

* wip

* Use AlignedBuffer instead of vector for performance

* cleanup

* More cleanup

* Revert Constant change
Co-authored-by: Scott Cyphers <diyessi@users.noreply.github.com>

* update matmul fprop

* clean up

*  - emit mlkddn for LRN only for normalizing acorss/within channel

* - remove explicit checking of axes in lrn builder
Co-authored-by: Jayaram Bobba <jayaram.bobba@intel.com>

* Backprop matmul maybe works - due to internal error with /usr/bin/ar issue file truncated, I could`t check it

* fix error

* clean up

* update

* fix style
Co-authored-by: baojun <32073718+baojun-nervana@users.noreply.github.com>

* Pass _GLIBCXX_USE_CXX11_ABI to protobuf

- this change allows building nGraph with newer GLIBC: v5.1+

* Specify _GLIBCXX_USE_CXX11_ABI only when NGRAPH_USE_CXX_ABI is defined

* first version

* Added constant cast

* Updated ref implementation

* Fixed out element type

* Added UT

* Code refactor

* - update external_mlir_prebuilt.cmake to support pre built MLIR

* fix typo

* - unify prebuilt and external pull, build "mlir" cmake logic
- throw cmake error if MLIR_LLVM_PREBUILT_PATH is not specified when -DNGRAPH_USE_PREBUILT_MLIR=True

* use pre_validate function

* use pre_validate

* The stack operator support for a engine:
1) Added the package of stack tests
2) Added stack fused operator
3) Modified cmake file to support stack operator

* 1) Support for a v0 version

* Stack.cpp file is modified
1) Removed unused function

* The stack.cpp file is modified:
1) Empty line was removed: [line: 72]

* Modification of test/backend/fused_op.in.cpp file
1) [line 1340], fall back to the previous version of comment

* Code refactoring:
1) Comment message is different, adjusted to get much more details about stack operator
2) Seralize.cpp file is adjusted to work with stack operator

* Added:
1)generated_adjoints has not implemented yet.
2)int64_t -> size_t

* The variable stored negative value was removed from the code

* Source files: code-format check

* Added included

* fix error

* set output type

* Some type info cleanups/improvements

* Missed change

* Added scatterND op to ONNX importer.

* Added ScatterND FusedOp.

* Removed unnecessary files.

* Added op to config files.

* Changed input order.

* Fixed validation checking.

* Added suport for int64 in ScatterNDAdd op.

* Changed test.

* Disabled test for plaidML.

* Code refactoring

* Added tests.

This PR fixes some of the inconveniences that we had with lit in nGraph
and aligns configuration files with MLIR/LLVM.
In particular:
  - `make install` is not needed to run lit test with the latest
    compiled version of testing tools (ngraph-opt).
  - LD_LIBRARY_PATH doesn't need to be modified.

* [MLIR] Update MLIR/LLVM repos

To have access to unranked memrefs.

* Fix MLIR forward again to fix lit test in MLIR repo

* [ TI ] TensorIterator m_num_iterations fix

* style

* POC of Split ConstantFolding

* Removed unused code

* code styles

* Added constant folding variadic split file

* Added variadic split + UT

* Update VariadicSplit tests

* set output type

* set output type

* [MLIR]Add clang flag and skip bf16 tests for MLIR.

* Address PR feedback.

* First debug version of support ND input

* Added type_prop tests

* Implemented ND support for SpaceToDepth

* Added type_prop tests for SpaceToDepth

* Added fused op tests

* code refactor

* Fixed DepthToSpaceMode::BLOCKS_FIRST

* Code review remarks introduced

* Code review ramarks. Part.2

* Using NODE_VALIDATION_CHECK introduced

* Add fluid layout converter

* remove const

* Fixed bin constant ops

* Added export

* Fixed buffer size

* Fixed code style

* Add upgrade and downgrade pass for GroupConvolutionBackpropData ops

- Add up/downgrade passes for GroupConvolutionBackpropData operators
- Improve decompose operatorion of v0::GroupConvolutionBackpropData to support N-dimensional data
- Add UT for up/downgrade passes.

* Remove unused variable