* fix correctness of the communicator

* fix a bug in send thread when sending var context is empty, test=develop

* add lookup_table_prefetch_op and prefetch optimize, test=develop

* remove remote prefetch GPU supported

* word2vec force with CPU, test=develop

* test dist remote lookup table force with CPU, test=develop

* enabel test_parallel_dygraph_se_resnext
test=develop

* supports multiple NCCL communicators preserved in NCCLCommContext
test=develop

* add ut for c_comm_init_all operator and fix cuda resource release problem
test=develop

* improve sequence_conv api doc test=develop

* add warning for padding param test=develop

modify into deprecated

* support tensor input with padding for warpctc op

* merge with develop

* test=develop

* modified python API examples test=develop

* nn.py is modified for code coverage test=develop

* update documents info about warpctc op in API.spec test=develop

* add test_warpctc_with_padding in test_layers test=develop

* add warning log for cuda_version back to warpctc_op.cc

* modify API.spec for warpctc op test=develop

* modify API.spec

* update warpctc test to new CompiledProgram API test=develop

* modify code examples for warpctc op test=develop

* modify API.spec for warpctc op test=develop

* modify API.spec for warpctc op test=develop

* fix optimizer bug
test=develop

* fix bug of getting bool Flags from os.environ, test=develop

* add empty loss_name in CompiledProgram for inplace grad test, test=develop

* python inference api supports numpy and add unit test, fix unit test fail in test_slim_int8_googlenet and test_slim_int8_mobilenet

test=develop

This PR fix problem with issue #18096 , which raise an error for user to specify the error about load dir is wrong

* 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

* test=develop,Optimized error reporting information

* test=develop,add importscipy unittest

* test=develop, rename the file and function

* add default getItem

* test=develop, fix has_attr disabled error in Layer

* test=develop, fix GroupNorm and deepcf bug on attrs

 add fleet_desc config feature & multi_sparse table,

* use PE for compiler
test=develop

* Implement the operator with sprase matrix multiply

* Update the URL of mklml library.

test=develop

* Disable MKLML implematation when using no-linux.

test=develop

* optimize bp with mkl sparse matrix
test=develop

* add pybind interface to get all inplace ops, test=develop

* enhance OpTest to check whether the consistency of operator when using and not using inplace, test=develop

* handle corner cases in op_test, test=develop

* support outputs without tensor holder_, like XShape in reshape_op, test=develop

* fix bug, some op has GradOpMaker, but actually no grad_op in OpInfoMap, test=develop

* use reshape_grad instead of reshape in FlattenGradOp, test=develop

* fix error debug dims info for variables like XShape, test=develop

* change computational order in sum_op to relieve computation difference using inplace, test=develop

* add inplace_atol to check group_norm, and skip inplace_grad for mkldnn, test=develop

* follow sneaxiy's comments, test=develop

* remove unused DefaultGradOpDescMaker in mkldnn op, 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

* update parallel.py
test=develop

* increase test_parallel_executor_seresnext time limit
test=develop

* split test_parallel_executor_seresnext
test=develop

* temporally disable reduce_and_allreduce test because of the random failure.
test=develop

* split gpu and cpu
test=develop

* add elementwise_mul_mkldnn UT with [conv + elt_mul + conv] to cover avx512=True branch
test=develop

* change a typo.
test=develop

distribute launch : add use_paddlecloud argument 

* fix mask rcnn bug:
1. affine channel fuse (diff)
2. condition block op (memory leak)
3. merge lod tensor op (diff)
4. memroy optim (diff)
test=develop

* fix ci aboud PADDLE_ENFOCE
fix merge lod infer op ut
test=develop

* 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

add fl_listen_and_serv op for Federated_learning and fl_distribute_transpiler add this op to pserver program . This op just listen the endpoint and sum&scale.

add python coverage launch when WITH_COVERAGE=ON

* fix REGISTER_OP_WITHOUT_GRADIENT
test=develop

Unset unittests http_proxy env to avoid timeout.

* remove unused inference_transpiler unit-tests

test=develop

* remove InferenceTranspiler usage in quantize_transpiler.py

test=develop

* Fix recurrent op fails

For the variable used in outter block,
copy sub block's grad variable to outter block

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Fix unicode error

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Refine test code

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Fix seq2seq case fails

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* remove unreasonable code.

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Refine code according to comment

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

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

* integrations problem
test=develop

* add batch_norm_mkldnn_op backward-reuse test and guassian seed=0 test
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

* 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

Polish fleet API to support cuda collective mode and nccl2 mode

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