* elastic etcd ready

* enable npu alignment

* support flatten_params/grads

* support clip by global norm

* remove memset in coalesce_tensor_op

* fix npu kernel of sum op when input is one tensor

* add ut for flatten_param_grads+regularizer

* fix ut

* fix typo

* Add bf16 support for save and load ops

* Add bf16 test condition

* Add matmul and chagne fluid.io to paddle.static

* Reduce the test duration

* add atan2_op

* fix

* support non-tensor type

* fix unittest failed

* add unittest with prune

* rm unused code

* coverage

* fix two or

* Add lookup_table_v2 BF16

* Reuse lookup table UT

* Change op_type to op_version

* Remove check_dygraph

* Remove skip_check_grad_ci

* - Draft of implementation of refactoring

- compilation fix

* - Fixes after review

* - Removed unnecessary comment

* new api trunc, test=develop

* fix output padding conv

* add repr unittest for conv

* add return when input is tensor

* fix typo

* add pplayer

* add sharedlayerdesc

* use SparseSoftmaxCrossEntropyWithLogits

* fix

* test_slice

* revert test_slice

* add backprob for npu kernel

* fix typo

* fix ut

* fix ut

* refine comments

* return softmax

* Save all the information of 'ParamBase' in 'Layer'.

* edit unittest

add the support for the bool in compare ops

* add reduce_sum_op by add self-kernel

* set all ReduceKernel MPType for accuracy

* add float16 test script which input is integer number

* solve reduce sum float16 check_grad problem

* solve conflict and change test script for CI

* change kernel register for CI

* remove all useless template

* Add digamma_op and unittest

* add digamma_op api

* remove special DigammaCudaKernel and correct some docs

* remove unused headers

* fix api doc error

This reverts commit b2afc8df.

* add warning log for DataLoader output format imcompatible upgrade. test=develop

* Eliminate numerical differences of LayerNorm; fix LayerNorm Nan Bug while large data input

* fix bug while large shape of data input