* Add lookahead optimizer

* add unittest for lookahead optimizer

test=develop

* add doc string for LookaheadOptimizer

test=develop
test=document_preview

* add API spec for lookahead

test=develop
test=document_preview

* modify api spec

test=develop
test=document_preview

* modified doc string

* modify the test file

test=develop
test=document_preview

* modify doc string

test=develop
test=document_preview

* Fix arg do_model_average in param_attr

test=develop

* Update api spec

test=develop

* use PE for compiler
test=develop

* add diag init in Uniform_random op test=develop

* modify api.spec test=develop

* fix unform_batch_size_like maker test=develop

* add diag_num and diag_step assert check test=develop

test=develop, test=document_preview

* add matrch_matrix_tensor op test=develop

* fix ignore unittest if with_mkl=off test=develop

* clean code and rm is_test param test=develop

* modify API.spec test=develop

* rm useless code in search_compute.h test=develop

* modify api.spec test=develop

* modify default_grad.spec test=develop

* Add API test code test=develop

* clean code in search_computer.h

* modify PADDLE_ENFORCE and clean search_compute.h test=develop

* fix code style test=develop

* imporve the doc of decorate_reader API, test=develop

* udpate API.spec, test=develop

* remove unused inference_transpiler unit-tests

test=develop

* remove InferenceTranspiler usage in quantize_transpiler.py

test=develop

* Add padding support for crf_decoding

* Fixes in comupte kernel

test=develop

* Update API Spec

test=develop

* Update API.spec

test=develop

* Avoid using paddle_enforce

test=develop

* Fix enforce

test=develop

Remove is_test parameter of FC op. The parameter is_test is not used anywhere.

* change the default value of summarize from -1 to 20 in Print op to improve ease of use, test=develop

* change the doc of API Print to make the document easier to understand, test=develop

* instag lod tensor impl

* First PR for instag

* First PR for instag

* Before adding Selection Rows.

* Change name from instag to filter_instag, add upgrade the impl of filter_instag

* Change name from instag to filter_instag, add upgrade the impl of filter_instag

* Fix yapf error in gradient_checker.py to pass Travis-CI

* Fix Filter Instag Grad test=develop

* Fix Filter Instag Grad test=develop

* 1) Fix API.spec, add filter_instag Op. 2) Add Vector Support for CUDA. test=develop

* Impl Loss_weight and empty output handler

* change Loss Weight datatype to Float32, and add Loss Weight as 2nd output

* 1) Support Tensor Input(without LOD) 2) Add Unit test

* Filter By Instag Final test=develop

* Update API.spec for filter_by_instag test=develop

* Update API.spec for filter_by_instag 2 test=develop

* Add Filter By Instag Coverage

* code format of test_layers.py

* code format test_layers.py test=develop

* Make API args more readable test=develop

* Make API args more readable and pass code format test=develop

* Filter By Instag Op, Rename Map to Index Map test=develop

* Filter By Instag Op, code format err in filter_by_instag_op.cc  test=develop

* Filter by instag op: code format of cpp files test=develop

* Filter by instag Op: Api spec modification test=develop

* Filter by instag Op: Api spec doc id modification test=develop

* Filter by instag Op: Api spec and doc preview  test=develop test=document_preview

* Filter By Instag Op, fix doc erro test=document_preview test=develop

* Filter By Instag Op, fix doc err and Api spec test=document_preview test=develop

* Filter By Instag Op, fix Api spec test=document_preview test=develop

* Filter By Instag Op, fix Paddle Encoforce deprecated warning test=document_preview test=develop

* Filter By Instag Op, fix Paddle Encoforce deprecated and code format warning test=document_preview test=develop

test=document_preview
test=develop
Fix the error of op `ones_like` document, change the output variable from x to out.

* add hard_swish activation op (new op)
test=develop

* remove redundancy files

* modify document content of HardSwish OP

* add API test in test_layers.py

* add dynamic_graph for test_hard_swish

* fix overflow by int32 mul test=develop

* fix reference nullptr

* fix codestyle test=develop

* modify to point in ContextProjectFunctor test=develop

* modify to point in ContextProjectFunctor test=develop

* modify . to -> test=develop

* refine embedding padding_idx doc test=develop

* fix math:padding_idx preview bug test=develop

* modify API.spec test=develop

* fix spell error test=develop

* refine dtype parm desc test=develop

add save cache model api in fleet& add slots shuffle in dataset module & add metric op to calculate ctr related metrics (#18871)

* add ctr related metric layer test=develop

* add save cache and slots shuffle test=develop

* add save cache and slots shuffle test=develop

* fix error

* fix error

* fix style for ci

* fix for comments

* change SlotsShuffle input to std::strinf for generality

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix stylr

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* change non-const reference to pointer

* fix style

* fix style

* fix style test=develop

* fix style  test=develop

* add return ins num in ctr metric op

* change dtype to float in metric_op.py

* fix error test=develop

* fix style test=develop

* fix API spec

* fix API spec

* fix API spec test=develop

* add UT test=develop

* add eye op,test=document_preview test=develop

* fix the API.spec, test=develop

* fix the document, test=document_preview test=develop

* add unitest for CI coverage, test=develop

* add trilinear interp. test=develop

* fix unittest. test=develop

* add python api and test_layers. test=develop

* refine API.spec. test=develop

* fix format. test=develop

* add python API test. test=develop

* format code. test=develop

* refine code strcuture. test=develop

* fix format

* fix doc. test=develop

* fix converage. test=develop

* fix format. test=develop

* update roi doc in roi_pool and roi_align, test=develop

* fix overflow by int32 mul test=develop

* fix reference nullptr

* fix codestyle test=develop

* modify to point in ContextProjectFunctor test=develop

* modify to point in ContextProjectFunctor test=develop

* modify . to -> test=develop

* add var_conv_2d op test=develop

* edit api.spec test=develop

* ignore unittest if with_mkl=off test=develop

* fix python3 division test=develop

* fix ignore unittest bug test=develop

* remove useless code test=develop

* modify api.spec test=develop

* modify default_grad.spec test=develop

* fix profiler doc error, test=develop

* update API.spec, test=develop

* fix g_param shape mismatch in WeightNormParamAttr

* add comment to show why insert reshape in startup_program
test=develop

* update exe.run

* test=develop test=document_preview

* Update API.spec

* test=develop
Add the op of unique_with_counts, the op is calc the unqiue input of data, and output the corresponding indices and count of data.

* test=develop
Check the input and dtype in the op of unique_with_counts

* test=develop
test=document_preview
update the API.spec for `unique_with_counts`, at the same time, optimize the python api in the op of `unique_with_count`

* test=develop
test=document_preview
Fix some python api problem in the op of `unique_with_counts`, and change the error messsage in this op.

* Fix some API problem in the op of `unique_with_counts`
test=develop
test=document_preview

* test=develop
test=document_preview
Fix the api sample of op `unique_with_counts`, and update api.spec

* support center loss
* change tensor copy  api to high level api tensorcopy

* test=develop rewrite the center_loss cuda_kernel to make it faster
and add document of the center loss api,also update test function

* test=document_preview test=develop
update document of center loss

* test=document_preview test=develop
modify API.spec modify test code remove nouse const_cast

Update conv2d transpose link

test=develop

* replace link

* update api.spec

* fix mistake

* fix logical APIs

test=develop

test=document_preview

* fix isfinite

* update matmul comments

* update API.spec

test=document_preview

test=develop

* update API.spec

test=document_preview

test=develop

* update API.spec

test=document_preview

test=develop

* Make lod reset op support for append lod level.

* Fix API.spec
test=develop

* Fix unitest.
test=develop

* Add python api for lod append.
test=develop

* Fix API.spec
test=develop

* Fix format of doc.
test=develop

* Fix unitest.
test=develop

* Fix doc.
test=develop

Modify auc doc. Add output variable description, previously was the scalar type, now changed to the tuple type.test=develop (#18771)

* supports distributed classification training
* update API.spec
* fix evenly division in python3
* change "index_range" to "index_num" in shard_index operator
test=document_preview
test=develop

* fix clip_by_norm doc, test=develop