* add sparse embedding & load vars for 2.0

Change-Id: I36b59ed5f015189dc9d9d2e34a9357722d369f1b

* fix hdfs gloo

Change-Id: Ia84d579053720ad804183e54c9a04b4f031c79c6

* fix gloo hdfs

Change-Id: I5ab982fd483cddc10adcdef0b8aa83aca976cb9e

* move loadvar/sparse embedding from incubute to static

Change-Id: I57081d3545ad2efab78c72420d2162c0eacaf3a0

* disable test_pipeline

* fix error

* rename sendrecv.proto to namespace paddle.distributed

* split ps with distributed

* add save tensor support
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

* fix bug of using ignore_index and reduction,test=develop

* fix bug of celoss when using ignore_index and reduction, test=develop

* improve performance when ignore_index=-100, test=develop

* add test in test_cross_entropy_loss.py for coverage rate, test=develop

* rm comment in test_cross_entropy_loss.py, test=develop

* del  hard code of "float64" in python/paddle/nn/functional/loss.py, test=develop

* change mask to a more simplified implementation, test=develop

* del comment in python/paddle/nn/functional/loss.py, test=develop

* del hard code and change mask to a more simplified implementation, test=develop

* change mask to a more simplified implementation, test=develop

* change mask to a more simplified implementation, test=develop

* fix elugradgrad test fail and error message opt

* fix unitest,test=develop

* Update prroi_pool_op.h

fix error message

* opt message,test=develop

* fix ci fail,test=develop

* Fix the accuracy problem of allclose op when using float64 data type in static mode.

* Format the code style.

* fix cmake
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

Support vector<double> as type of op attribute and op set_value suppport vector<double> as value (#30126)

* type promotion for grad

* add type promotion for div op

* disable ut test_tsm on windows

* fix error

* add ut execuate time

* add alias from  fluid.layers.auc to static.auc

* Update __init__.py

* Fix bug for 'save mutiple method'

* To pass coverage.

* edit code to pass coverage.

* edit code to pass coverage.

* add unittest for coverage.

* change for coverage.

* edit for coverage.

* modify error message based on comments

* edit code according to review.

* Correct spelling according to review.

* use wget to replace curl to download the lcov file

* add cache for lcov

Add clone method for static Variable so that this interface will be same as dygraph. It fixed some bugs in dy2stat

 add the op error message for the matmul xpu 

* delete paddle.nn.functional.assign

* fix dynamic to static error

* fix warning and no grad

* optimize softmax forward

reduce the  occupied size  of memory for the fused pattern of elementwise_add Op and activation Op(relu Op for example) (#29885)

* add view strategy on squeeze,unsqueeze,reshape,flatten

* add squeeze unittest

* add unittests

* use View strategy as name rather than Reuse Allacation

* fix view api doc

* fix format

* use core.ops when input of reshape2 is Tensor

* fix test_cross_entropy_loss error because of reshape2

* delete selected_rows

* change op_function

* little change

* solve HandleViewBetweenInputAndOutput

* - Added UT for testing elementwise_mul caching

* lint fixes