* update gcc8 in python3 ci docker

* change cuda 10.2

* update cudnn8

* nvidia error cuda10.2-cudnn8-centos6 images

* fix third cache

* fix approveals message;test=document_fix

* fix approveals message;test=document_fix

* Add example for cache and buffered, test=develop, test=document_fix

* polish some lost error msg

* add some math file to white list

* polish detail based reviewer commnet

* default open dygraph mode

* fix CI-Mac

* fix Mac-CI other unittest file

* fix CI-Py3

* fix test_communicator_geo and test_buffer_shared_memory_reuse_pass

* add enable_static to fix CI-Py3

* add enable_static to fix CI-coverage

* delete try except

Add *.bat file for building compile environment on windows

* resolve the issue of curl having same exit code with paddle build failed

* modifed the value of exit code

* simplify the code
Co-authored-by: Nchalsliu <45041955+chalsliu@users.noreply.github.com>

* add approve check of the CI task on windows

* fix style

[CI] Change RD for check_op_desc from (liym27, zhhsplendid, Aurelius84, lanxianghit or phlrain) to (cyj1986, Superjomn) (#26828)

* add set_default_type for tensor

* fix doc

* fix doc

* Add RNN related apis in paddl.nn
test=develop

* new rnn api, cell almost done

* add new progresses in rnn APIs for 2.0

* refine rnn APIs and docstrings.

* add unittets

* disable gpu tests when paddle is not compiled with cuda support

* remove unnecessary imports

* fix docstring

* add to no_sample wlist

* backport to python2 to avoid yield from

* add **kwargs, fix typos

* update docstrings for birnn

* rename argument for SimpleRNN and SimpleRNNCell, fix sample code

* add default value for initial_states in fluid.layers.birnn
Co-authored-by: Nguosheng <guosheng@baidu.com>

* add gen_alias_mapping.sh

* Fix pip2 opencv-python version

* opencv-python==4.2.0.32

* fix whell version

* Move paddle/incubate/hapi/metrics to paddle/metric
* Add Precision, Recall and Auc metric

test=develop

* use alias name instead of original name for alias API

* refine log message

* test=develop,test=document_fix, remove the out args

* Revert "test=develop,test=document_fix, remove the out args"

This reverts commit f430799b.

* test=develop,test=document_fix, remove the out args

* remove all  the out args

* remove all  the out args

* test=develop, remove all  the out args

* test=develop, remove all  the out args

* test=develop, remove out args in matmul testcase

* test=develop, fix the bugs of out args testcase in logsumexp

* test=develop, fix the bugs of out args testcase in elementwise_add

* test=develop, fix the bugs of out args testcase in elementwise_div

* test=develop, fix the bugs of out args testcase in activation

* test=develop, fix the bugs of out args testcase in addcmul

* test=develop, fix the bugs of out args

* test=develop, fix the bugs of out args in API example

* test=develop, fix the bugs of out args in kron testcase

* test=develop, fix the bugs of out args in kron testcase

* test=develop, remove out args

* test=develop, remove out args

* test=develop, fix the coverage

* test=develop, polish codestyle

* test=develop, Update math.py

* test=develop, polish codestyle

* test=develop, polish codestyle

* test=develop, polish codestyle

* test=develop, polish codestyle

* test=develop, polish the test_activation_op.py

* test=develop, Update math.py

* test=develop, fix the failed CI

* test=develop, add core.ops

* test=develop, add core.ops change clamp to clip

* test=develop, add core.ops change clamp to clip

* test=develop, write testcase for clamp OP

* Refine Model

1. Take the network (instance of Layer) as the input of Model.
2. Refine set_dict/load_dict of Layer.
3. Refine Input interface, so update code sample about Input