* support elementwise add, activation, matmul on Baidu Kunlun
* test=kunlun

* minor
* test=kunlun

* reconstuct the xpu directory
* test=kunlun

* minor
* test=kunlun

* minor
* test=kunlun

* minor
* test=kunlun

* minor
* test=kunlun

* minor
* test=kunlun

fix cpplint error for the autmic max/min

fix cuda atomic for ARCH<350 for the automic_max

* fix tensorrt 6 build error. test=develop

* fix. test=develop

* bug fix

* test=develop

* use iwyu clean include, test=develop, test=win

* compilation error, test=develop

* fix compilation error2, test=develop

* fix compilation error3, test=develop

* fix compilation error4, test=develop

* fix compilation error5, test=develop

* fix compilation error6, test=develop

* fix compilation error7, test=develop

* fix compilation error8, test=develop

* fix compilation error8, test=develop

* fix compilation error10, test=develop

* fix compilation error11, test=develop

Add GPU Kernels of Segment Ops,  support, sum, max, min, mean

* [bug fix]:Memory increases after adapting the cudnn version to 8

* [bug fix]cudnnGetConvolutionForwardAlgorithm not defined

* polish some lost error msg

* add some math file to white list

* polish detail based reviewer commnet

* support use add instead of sum to do gradient accumulation

* add inplace addto pass

* add grad_add op and inplace addto pass

* remove debug code

* code refine

* fix bug when sereral sum ops inserts at same op_idx

* fix Flags type

* add addto attribute for conv3d

* fix ut

* code clean

* fix type

* fix cudnn dyload error

enhance reduce op which can reduce tensor with arbitrary rank 

* replace sequence length attr to input

* add lstm cudnn of padding data and refine cudnn codes

* update the demo code and the doc of varbase.backward.

* update the doc of the fake interface `paddle.fluid.Variable`.

* remove BackwardStrategy.

add collective op for cpu using gloo and paddle.distributed.* apis

* Add mechanism for blocking oneDNN cache clearing

* Review changes and Add thread guards

* support Baidu AI Accelerator
  * test=kunlun

* minor
 * test=kunlun

* support xpu op in separate file
 * test=kunlun

* update XPU error message and remove duplicated code

 * test=kunlun

* minor
 * test=kunlun

* minor
 * test=kunlun

* print user-friendly error message

* adjust error sumary

* Change use_quantizer attribute name and data type

* Fix problem with setting attribute

* Add changes due to review

* Small change in function

* Restore use_quantizer attr for compatibility

* add flags_call_stack_level

* update

* refine code

* fix trt plugin registry without trt lib

* support trt4

* refine code style

* Add oneDNN fusion_gru kernel and fix fc+gru pass
test=develop

* Formatting changes
test=develop

* Lint fixes
test=develop

* Add memory::format_tag::any to GRU weights
test=develop

* Fix build with CUDA

* Fix build with CUDA v2

* cunn8 support
test=develop

* fix ci error
test=develop

* develop dynamic shape serilization

* add test param for gelu

* fix bugs

* delete redundant comments

* debug

* fix conflict. test=develop

* fix bug. test=develop

* add trt dynamic shape serialized support

* fix ernie serialized bug
test=develop

* fix codestyle
test=develop

* fix bug
test=develop

* fix bug.test=develop

* modify cmakelist test=develop

* fix bug
test=develop

* fix error message.  test=develop

* fix trt register plugin based on pr#25003

* add trt dynload

* fix deserialization bug of not finding plugin registration

* refine code style

* recover engine key in tensorrt_subgraph_pass

* for ci coverage

* add unittest for deserialization
Co-authored-by: Nhaozech <chenhaoze94@gmail.com>

* refine error stack format

* polish compile traceback format

* polish detail format

* unified signal error format

* refine signal error message

* simplify buffered reader to improve DataLoader performance

* fix 22 failed unittests

* fix cuda pinned context condition

* fix test_reader_reset failed

* fix two failed unittests

* change unittest place

* polish error messaage

* polish cast op GetExpecctedKernelType

* remove debug info in unittest

* Added DNNL cache management for DyGraph

* move FLAGS_use_mkldnn to more general CMakeLists, getu use of the flag in ClearGradients

* missing file

* Fixes after review

* Bringing back original idea of place for 'use_mkldnn' flag to be accessible from platform nad imperative.

* Removed duplicate and added docs

* Fixes for CI

test=develop

* polish install error hint msg, test=develop

* fix variable error, test=develop

* polish hint messgae again

* add bilateral slice op

* Refine PADDLE_ENFORCE in paddle/fluid/platform
test=develop