* use exhaustive_search for float16

* tune algo only when dtype is float16

* - condidate fix to issue #25537

test=develop

* - UT for transpose NHWC

test=develop

* Add avx instructions check

* Small fix

* Change function name

* Change uint to unsigned int

* test=develop, optimize geo communicator 

* add gloo initializer, test=develop

* Add support for mkldnn ops types selection with FLAGS in dygraph

* use regex to match DNNL verbose

* python3 encoding fix

* include ncclRecv and ncclSend, test=develop

* add gloo initializer, test=develop

* add float64 input to ctc_loss

* modified error message of  warpctc

* update repo and tag of warpctc

* add test for warpctc with float64 input

* modified warpctc.cmake to make sure build always

* resolved sample code bug of warpctc

* add core.ops in warpctc dygraph

* fix a bug of test

* 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