* Directory migration, test=develop

* Change imperative from paddle init to paddle framework, test=develop

* Fixed jit bug, test=develop

* default static mode, test=develop

* fixed format and create parameter belongs to framework, test=develop

* Fixed import package, test=develop

* fix __init__ format, test=develop

* fixed alias problem

* fixed paddle.enable_imperative problems, test=develop

* Add unittest

* delete install_check comment

* Fixed unittest timeout

* fixed unittest error

* move Program default_xx_program to static package

* optimize unittest method

* fixed framework __init__ format

* fixed jit path

* delete alias

* move jit to paddle

* Fixed unittest format

* fixed paddle.default_main_program

* Fixed save load API in paddle __init__.py

* fixed ci paddle.imperative.to_variable

* add the support for multi-node training

update cumsum api and fix up the cumsum op

* fix prelu for compatibility with saved model of old version

* reshape alpha

* Add oneDNN relu6 op

* Lint fixes

* fix merge3 test=develop

* add paddle.fleet.AsyncOptimizer
Co-authored-by: Ndongdaxiang <dongdaxiang@baidu.com>

* add pin memory control

* fix buffered reader init problem

* fix unittest error

* add unittest for coverage

* add cuda pinned place branch

* add unittest

* add skip when not gpu

* support multi-ps training mode for fleetrun; test=develop

* enable check_dygraph for mkldnn activation tests

* TestMKLDNNSwishDim4 float32->self.dtype

* refine unsqueeze, test=develop

* update unsqueeze, test=develop

* refine unsqueeze, test=develop

* refine unsqueeze, test=develop

* update

* remove None, test=develop

* follow comments

* support bool

* update doc

* follow comments

* merge develop

[Dy2Stat-ErrorMessage]Optimize error value to improve readability when error raised in runtime.  (#25970)

* don't remove op_callstack

* [Dy2Stat-ErrorMessage] Optimize error value to improve readability if error raised in run-time. 
  1. update op_callstack with original information;
  2. simplify error value to improve readability if error raised in run-time.

* Fix error in Python3. 

* add limit support for load_dygraph loading jit.save result

* simplify unittest

* add unittests for coverage

* remove encoding limit of loading extra var info

* [Dy2Stat-ErrorMessage]Enhance original error and create new exception. test=develop

* Delete redundant code and change func name to create_and_update_origin_info_map. 

* optimize loop_transformer. 

* fix bug in print_transformer.

* Modify code according to the comments.

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

* fleet_util move to paddle.fleet
Co-authored-by: NWuHaobo <wuhaobo1994@gmail.com>
Co-authored-by: Ntangwei12 <tangwei12@baidu.com>

* move dataset to fleet
test=develop

* fix
test=develop

* fix
test=develop

* fix
test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* Add oneDNN fusion_gru kernel and fix fc+gru pass
test=develop

* Formatting changes
test=develop

* Lint fixes
test=develop

* Add memory::format_tag::any to GRU weights
test=develop

* Fix build with CUDA

* Fix build with CUDA v2

update the sort api, delete unused ouput index tensor

Add dgc to fleet meta optimizer, rm dgc from optimizer all

* generate context during compile

* Add some error messages for the op without double grads.

* fix the test_imperative_double_grad UT.

* add apply for Layer

* add fleetrun command for distributed running; test=develop

Update the code for the compare ops for the broadcast function

* fix eval() sync problem

* add unittest

* modify according reviewer

* fix unittest failed

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

* delete out in inverse

* 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

* split meta optimizer files
* add graph execution in execution, update two properties in DistributedStrategy, unit tests for these features

* add localsgd meta optimizer

* add pipeline optimizer