* Check output shape when setting memory layout for slice op.

* Miscellaneous fusion and other optimizations for inception-resnetv2
- ConvBias Batchnorm folding
- ConvBias Affine folding
- Check if MKLDNN can slice a given layout and select layouts
  appropriately

* Fixed unit test and bug in conv bias pattern

* Addressed PR feedback

* Addressed PR feedback

* WIP input * weights rnn optimization

* concat + slcing + replacing new node works

* WIP unit test case of fusing rnn inputs

* - Added unit test case for fusing rnn input weights
- registered CPURnnMatFusion_v1/v2 in codegen and DEX

* fixed redeclaration of a variable

* Refactored rnn input traformation passes into a single pass

* Refactored CPURnnMatFusion call back functions

* change random generator range to include -ve values in unit test

* address PR comments

* dont fuse if the shape of the data slices dont match

* rename files

* rename runtime TensorView to Tensor

* rename HostTensorView to HostTensor

* Add CPU horizontal fusion pass for inception.

* Name change.

* Move horizontal fusion to cpu_fusion.

* Change horizontal fusion pass for inception to a general horizontal fusion pass.
Add a unit test conv_horizontal_fusion to cpu_fusion.

* Rename files.

* Correct cpu_fusion.hpp.

* Add NGRAPH_DEBUG.

* Set native layout when input format of slice is nChw16c or nChw8c and lower bound of
channels is not a multiple of 16 or 8.

* Remove "view"
Simplify layout

* Fix merge error

* fix build error

* PR1602. IntelGPU backend. Compilation fixed.

* add unsupported_op exception

* unsupported_op test

* add printout of unsupported op in model

* fix GPU dispatcher check

* fix test designation

* catch exceptions on single file runs too

* add unsupported_op exception where needed

* remove unsupported_op class

* add unassigned op exception

* add unit test

* catch unsupported op in nbench

* add cpu test back

* update all latest merges

* mode change

* Add conv add fusion

* Updated file permissions and cpu_fusion order

* Formatted code using maint/apply-code-format.sh

* Fixed minor review comments

* Use NODE_VALIDATION_ASSERT instead of throw ngraph_error;\nupgrade baseline and fix issues

* Some more fixes

* use line comments instead of multiline comments for license header

* update more

* update new files

* more header updates

* style

disabled RNN test to workaround RNN unit test failure on MAC due to bug in MKLDNN scratchpad creation (#1502)

* normalize comments

* address review comments

* Fold affine transformations on 4d convolution

* Handle more cases for affine parameters

* Style fix

* enable parameter validation for all unit tests

* Dex non-mkldnn version of clipped relu

* Change to static_cast

* Switch to using mkldnn memory descriptors for layout

* More changes for using mkldnn descriptor instead of format

* Removed mkldnn format from cpu layout descriptor. TODO - shuffle folding

* Rotate mkldnn layouts on transpose

* Modifications to builder reshape to skip rotated layouts

* More fixes to layouts and removes axis order from cpu layout descriptor

* Code cleanup

* Removed shuffle folding pass since the functionality is subsumed by the layout pass

* Canonicalize a few more formats to keep MKLDNN happy.

* Style fixes

* Style fixes

* Style fixes

* Addressed PR feedback and added reshape passthrough for non-transpose cases

* Adjust named formats for weights tensors to keep MKLDNN happy

* Style fixes

* resolved merge issues

* cpu loop kernel fusion pass

*  remove extra code

* bounded relu test

* address scotts feedback

* CPU Direct Execution: Implement ConvertLayout and refactor

* CPU Direct Execution: Implement Convolution

* 1) Adds computation reuse to direct execution
2) Add avg_pool, broadcast and convolution_bias to direct execution
3) Moved some computation reuse utility functions to graph_utils

* Use lists instead of vectors to avoid reallocation overheads

* - Added convolution variants to direct execution
- Removed ConvolutionBiasRelu, use ConvolutionBias instead
- Reduced code duplication by moving functionality to mkldnn_emitter
  from cpu_emitter

* Style fix

* Moved mkldnn build_convolution to a templated method

* Style fix

* refactored mkldnn conv bprop builders

* Style fix

* hacking to support dot of 3 by 2 inputs with gemm_batch.

* clean up.

* declare sigmoid for core fusion

* add simple test for sigmoid

* info fusion status

* cp op as main op

* builds as expected

* move sigmoid fusion code

* add reference kernel

* sigmoid bprop reference kernel and clang-format

* add delta to bprop

* fprop called

* compiles bprop

* move tests

* serializer support

* address comments in code

* add doc

* naming similar to core ops

* fix failing test

* fix failing test

* address clang issue

* more changes

* change test macro

* 1. Added MKLDNNN BoundedRelu op support for Relu6
2. CpuLayout && CPU assignment pass for BoundedRelu Op
3. Unit test inter v/s CPU for BoundedReluOp
4. MKLDNN and default emitter code for BoundedReluOp

* Removed Debug prints

* 1. Added support for boundedrelu to work on any constant literal
2. unit test case for rank2, rank3, rank4 for bounded relu without serialized graph

* Removed is_six() method

* Reshape bias to 1D for conv + bias bprop fusion

* Reshape goe2 back to 2D before replacing

* added shape checks to validate conv+bias op.

* removed conv+bias backprop merge for separate PR review.

* fixed conv_bias_bprop test.

* minor changes to error messages.

* collector

* keeping track of inputs; simplifying a merging stratey; adding LKGraph

* LoopKernel Collector

* address feedback

* address feedback 2

* address feedback 3

* inplace compute

* fix warnings

* Initial support for convolution sum fusion

* Added in-place support for conv sum fusion and test cases

* reverting spurious changes

* Bug fix to account for inplace input in conv sum fusion

* fix compilation error

* Addressed PR feedback

* loop kernel + tests

* remove commented out code

* remove commented code; add comments

* copy_with_new_args +test

* add comment

* fix comp errors

* - Added graph pass for fusing RNN op across layer
- Added test case for inter v/s cpu for verifying layer fused RNN
- more sanity checks in the RNN fusion graph pass
- added support to replace the recurrent cell state correctly in the fused RNN op

* Fixed multi layer rnn fusion unit test failure

* Addressed PR comments

*  group conv init

* add GroupConvolution op; refine checks in fusion logic

* add an emitter, cpu assigment

* cpu_layout

* add checks to algebraic simplification

* updating emitter logic for groupconvolution

* working before refactoring

* moving primitive creation logic to mkldnn_emitter

* group convolution graph test

* rename an opt

* address jbobba's feedback

* batch dot pattern wip.

* batch dot pattern wip.

* added batch dot op.

* batch dot compute testing.

* correct gemm parameters.

* renaming matrix fusions passes and update tests.

* clean up.

* clang format.

* more clean ups.

* clang format.

* added CPUBatchDotFusion to default cpu passes.

* added missing header.

* added element type check.

* Support 3-D pool with mkldnn

* Move execute() to test_tools.hpp

* refactor cpworkspaceinsertion for mxnet

* rename mxnet functions to adhere to ngraph naming convention

* define a member static const int in a cpp file to resolve a linking issue

* - Added pattren matcher for LSTM cell

* WIP added support to replace lstm cell instead of subgraph

* WIP LSTM pattern matcher, fuses recurrent cells

* WIP added RNN CPU op

* WIP mkldnn emmiter code for fprop RNN

* WIP RNN mkldnn integration
- Added mkldnn kernel for uni directional LSTM in the CPU emitter

* add a getter for root node

* recurrent graph rewrite

* fix perms, rename match_root -> get_match_root

* fix comp errors

* make match_root return the topmost match; fix tests

* - WIP GetOutputElement for handling multiple LSTM o/ps
- use RecurrentGraphRewrite for replacing node after matching LSTM cells

* WIP LSTM multi Output + debug prints

* moved LSTM fusion to cpu_fusion

* WIP added RNN superfused OP

* WIP towards RNN layer fusion

* WIP multiple output slicing RNN

* WIP RNN mulitple o/ps fusion across layer

* WIP corrected input params for fused RNN OP

* concat corrosponding param's across differnt LSTM to form inputs to RNN fused op

* i) Added  test case for RNN kernel ii) runs without error's

* refactored and moved LSTM class to standalone file

* Rename RNN -> Rnn , LSTM -> Lstm

* WIP replace lstm slices to the consumer op

* Slicing works on multiple RNN layers

* fixed all bugs

* - Added CPU RNN Recurrent Fusion
- Added CPU LSTM fusion
- removed debug code
- style fix

* - Added support to compute src_iter and dst_iter instead of taking zero_memory_desc
- Added unit test to compute one LSTM cell

*  changed RNN op signature to accept number of states in basic unit of RNN(GRU/LSTM/ vanilla RNN) cell

* added sanity checks for RNN op

* Fixed issue related to patching the graph while replacing the RNN sliced outputs

* Fixed issue to feed the input symbols in the order X0, X1, ...Xt to the RNN op

* Added unit test for multi layer RNN fusion

* Removed debug statements

* Added mulitlayered serialized graph ii) fixed compilation issue

* Addressed PR comments

* i) WIP MKLDNN layout for RNN Op ii) added test case for INTERPRETER v/s CPU Rnn results

* - Fixed bug w.r.to src_layer feature size in rnn mkldnn emitter code
- Refactored cpu_fusion rnn test case

* merge origin/master with branch pruthvi/lstm_fusion

* style fix

* Added test case for multiple RNN layers

* i) make rnn as mkldnn op if it meets the constraints ii) assert if rnn is not mkldnn op

* fix unit test failure

* - Added support to reliabily identify the hiddent state and input symbols from the nodes collected by Pattern matcher
- Fixed failing unit tests

* style fix

* - removed "node type" dependency to replace the intermediate LSTM outputs

* Addressed PR comments

* Fix unit test

* - added MKLDNN emitter for LSTM op
- graph pass to concat LSTM input recurrent state tensors
- CPU layout assignment for LSTM Op
- Fixed bug in rnn/lstm unit test's
- made changes to use replace_output instead of replace_node for replacing matched graph nodes in LSTM/RNN fusion pass

(cherry picked from commit d16fc709265cc0a73e60c6d5f6d2878e7b908aca)

* style fix

* Renamed passes and style fixes

* Batch norm folding

* Addressed PR feedback

* Style fixes

* Style fix

* give frontends some flexibility over fusions they would like to run

* address jbobbas feedback

* MaxPoolWithIndices CPU Fusion

* fix test to pass checks in cpu_fusion

* pass test

* clean up

* add a new pass, add layouts

* remove the opt from cpu_fusion

* refactor cpu_layout logic for maxpool, clean up comments

* add comment w.r.t. indices tensor

* rename to cpu_workspace_insertion

* add CPUWorkspaceInsertion pass for TF

* Adding support for mkldnn convolution+bias+relu op to use in batch norm folding

* Style fix

* Style fix