* test=develop, optimize geo communicator 

* polish BuildStrategy api doc & example

* polish ExecutionStrategy api doc & example

* polish details

* unique op for cuda is added

* add support for cuda

* Add cuda support for unique op.

* Add support for int32_t and int64_t.

* For old version, process by cpu

* Add VisitDataType for thrust

* add gloo initializer, test=develop

 optimize the error meesage for detetion_map_op

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

* use regex to match DNNL verbose

* python3 encoding fix

* Fix clip_by_norm_op error message. test=develop

* test=develop

* test=develop

* enhance array_to_lod_tensor_op lod_tensor_to_array_op errors information. test=develop

* iCafe 9009: Optimize the error message of OP.

* Optimize the error message of GatherTreeOP.

* fix the speed&memory of matmul

* fix the comment

* fix the memory copy

* fix the windows ci

* add unittests and op version register for tensorrt_subgraph_pass

* rename to test_trt_subgraph_pass.py

* fix softmax converter diff when padding dim=1

* fix error

* fix error

* fix error

* merge develop

* add paddle.fluid._cuda_synchronize, test=develop

* fix bug about core_avx core_noavx, test=develop

* delete CPUPlace and XPUPlace, test=develop

* enhance error messages of lookup_tale, merge_ids, data_norm

* fix

* fix error msg in .cu

* Support assignment to a Variable in dynamic mode. Note: not deal with backward.

* Rewrite VarBase __setitem__ for high-performance.

* try to test 3 means to do __setitem__ and test the performance of 3 means.

* Retain the means of the highest performance: C++ code and don't trace op.

* include ncclRecv and ncclSend, test=develop

* add gloo initializer, test=develop

* Error message opt, test=develop

* solve comments, test=develop

* fix typo, 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

register log double grad kernel for cpu and cuda

* fix sgd/momentum/dpsgd/rmsprop error message

* refine broadcast_op_handle

* refine some error messages

* refine some files

* fix bug

* fix bug

* fix bug

* follow comments

* follow comments

* fix test_dist_fleet_heter_ctr & peformance update

fix cpplint error for the autmic max/min

* refine err msg

* follow comments

This reverts commit 29f1560d.

* add xpu in heter mode
test=develop

* BOOST_CONST_GET; PADDLE_THROW
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* refine
test=develop

* refine
test=develop

* refine
test=develop

* refine code
test=develop

* fix bn double grad, test=develop

* update, test=develop

* add fp16 for matmul

add abs support double grad for the api 2.0