* Update `paddle.clamp`

rename to `paddle.clip`
add fast path for dygraph mode
remove `out`
rename `input` -> `x`
update doc sample

* Fix leftover `Variable` wording

* Indent doc with spaces

* Remove `:alias` in docs

* Update `enable_imperative` -> `disable_static`

* Remove `imperative`

also trigger CI

* Update tests for better coverage

* Rebase to fix `cosine_similarity`

* Fix `cosine_similarity` some more

* fixed static module

* solve conflict

* Add Distribution base class, Uniform class and Normal class

* release Distribution class and Normal, Uniform class

* Add Doc args explaination

* save distributions.py and process in distribution.py

* delete useless function in test_distribution

* Add NormalNumpy test class

* Add probs in NormalNumpy

* add distribution to paddle init

* Add Distribution base class and name attribute unittest

* Change Doc

* Change Doc

* adjust format

* Fixed Doc Code

* implement probs and change Variable to Tensor

* Add name for all functions and add name unittest

* support int datatype

* Add dynamic mode

* optimize test_distribution static and dygraph

* add adaptive_avg_pool2d

* add adaptive_avg_pool3d

Remove cudnn conv in Unittest because the cudnn conv, which is assigned to OP owner, hasn't been fixed.

update the test_mean test case

Fix the API of bce loss and add functional API binary_cross_entropy 

* fix static dataloader default pin memory set

* fix related unittests

disable test_dist_fleet_ctr

* Add new API: paddle.prod

test=develop

* verify correctness of dy2static model by using paddle-inference api

* update python doc style

* disable UT temp

* add print test_dist UT elapsed time

* UT elapsed time optimize

* Rename `Input` into `InputSpec`

* remove alias

* add weight_norm, test=develop

(1) Add api paddle.reshape(x, shape, name); 

(2) Use Tensor replaces Variable. test=develop

* add save/load for parameter server

* Rename `Input` into `InputSpec`

* fix argument place of Input api

* enhance add parameter check for layer

* add unittest for coverage

* remove uninit test case

* enrich unittest ccase

* trigger ci check

* add input.py  file

* write input.py

* fix init file

* add unit tests

* fix dygraph and input shape

* Revert "fix dygraph and input shape"

This reverts commit 89ad8664.

* fixed pylint

* fix deprecated

* fix old op

* fix old op

* set check_dygraph=True

* Revert "set check_dygraph=True"

This reverts commit a8e93e33.

* test commit

* fix doc and change test file name

* rename input

* add unittest, test=develop

* use paddle.data instead of fluid.data, test=develop

* add pad func

* add pad

* test=develop, add pad op and apis

* restore pad2d

* test=develop, fix paddl declare

* fix pad interface

* test=develop, fix pad

* test=develop, add all pad api and cos_sim

* test=develop, remove padding default value

* test=develop, rename var to tensor

* test=develop, add more tests

* test=develop, rename tovar to totensor

* test=develop, fix init

* test=develop, add more test

* test=develop, add more tests

* reduce the execution time of affine_channel op unittests

* support ps-gpu

* add zero norm, inf norm support for p_norm op

* fix the invalid argument check, fix the dtype problem in test case.

* 1.Fix api sum:(1) input->sum; (2)dim->axis; (3)keep_dim->keepdim.

* 2. fix bug when len(axis) == len(x.shape). 

* add Sampler/SequenceSampler/RandomSampler. test=develop

* add SyncBatchNorm,test=develop