原始PR：#30485，#30507

[cherry-pick] support layer_norm fp16 in dygraph amp (#30430)

完善static.load的var_list参数。
当加载的是多个小文件时，Tensor列表可以是所有加载文件中Tensor的子集。
原始PR：#30457

cherry-pick #30536

* add 2.0 API: device_guard

* support transformer v2.0

* fix range op crash in dygraph xpu place

* Modify the calculation logic of LambOptimizer (#29313)

* Modify the calculation logic of LambOptimizer

* Modify the calculation logic of LambOptimizer

* Modify the calculation logic of LambOptimizer

* add pad and concat double grad

* resolve conflict

* add fp16 support for tril_triu op (#30186)

* add VecCastCUDAKernel (#30296)
Co-authored-by: Nfurnace <34057289+windstamp@users.noreply.github.com>

* test=develop, fix fleet.metrics(mse, rmse, mae)

Cherry-pick PR 30103. Add Inplace strategy (Output reuse Input Varbase) in dygraph (#30103) (#30496)

* 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

* fix test_cross_entropy_loss error because of reshape2

* add inplace strategy

* add elementwise_add sub

* let backward op not use inplace

* grad op do not use inplace

* fix memory increase error and add leaf error message

* delete selected_rows

* change op_function

* little change

* solve HandleViewBetweenInputAndOutput

* add unittest and leaf error message

* merge view error

* optimize op_function_generator format and support sum inplace op

* fix format of basic_engine

* fix format for framework

* little change of variable wrapper

* add reshape, squeeze, unsqueeze, scatter api

* add relu elu tanh softmax inplace api

* fix test_squeeze_op unittest

* fix test_relu_op unittest

* fix comment problems

* delete sample code of inplace api

* add reference of grad_pending_nodes in basic_engine

* fix unittest name

* add inplace apis into wlist

* fix error message

* add PADDLE_ENFORCE for set grad op twice

* fix head file error

* Cherry-pick 30072, add dispenable input for core.ops.reshape2/expand/slice (#30072)

* add dispenable input 'shape' for core.ops.reshape2

* add dispenable inputs for core.ops.reshape2/expand/slice

* add ut

* save reshape update in pr 30180

* save reshape update v2 in pr 30180
Co-authored-by: NLeo Chen <chenqiuliang@baidu.com>

* add transpose double grad test=develop (#29600)

* add transpose double grad test=develop

* cherry-pick test=develop

* test=develop, add distributed_infer (#30300)

* test=develop, add distributed_infer

* test=develop, fix unittest cmakefile conflict

* test=develop, fix test_dist_fleet_base

[Cherry-pick] Fix prune input bug of jit.save

cheryy-pick of #30384

* optimize memcpy perf for kunlun (#30291)

* optimize memcpy perf for kunlun

* remove useless unitest for kunlun mean

* minor

* fix bug that cann't find mkldnn(kunlun) (#30394)

* Add double grad for conv_transpose (#29706)

* add double grad for conv_transpose

* register cudnn conv double grad for depthwise conv (#29807)

* fix bug of celoss when using ignore_index and reduction (#30180)

* 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 bug of celoss when using ignore_index and reduction (#30180)

* 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

* change to tensor copy sync

* change to tensor copy sync

* make copy_to safe when use TensorCopy

* refine code

* add ut

* add cudapinned garbagecollector

* add testcase: cpu place -> cuda pinned place

* fix datanorm error msg (#30294)

* Optimize the error message of framework. (#30134)

* modify error message based on comments (#30189)

* modify error message based on comments

* edit code according to review.

* Correct spelling according to review.

* fix enforce msg of sum xpu op (#30113)

* enhance error info for py_func (#30138)

* enhance error info for py_func

* update

* fix elugradgrad test fail & error message opt (#30171)

* 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

* Refine PADDLE_ENFORCE Error Messages. test=develop (#30149)

Improve some error messages in parallel_executor.cc, conditional_block_op.cc, recurrent_op.cc

* enhance error message, test=develop (#30220)

* fix error message for distribute_fpn_proposals_op (#30116)

* enhance error msgs of fusion_seqpool_cvm_concat_op.cc, test=develop (#30240)

* just add the op error message for the matmul xpu (#30246)

 add the op error message for the matmul xpu

* enhance error message of nll_loss op test=develop (#30125)

* enhance error message of nll_loss op test=develop
Co-authored-by: Nyaoxuefeng <yaoxuefeng@baidu.com>
Co-authored-by: Nxiemoyuan <71377852+xiemoyuan@users.noreply.github.com>
Co-authored-by: NWeiXin <weixin10@baidu.com>
Co-authored-by: NJack Zhou <zhoushunjie@baidu.com>
Co-authored-by: NWilber <jiweibo@baidu.com>
Co-authored-by: NDouble_V <liuvv0203@163.com>
Co-authored-by: NHuihuang Zheng <zhhsplendid@gmail.com>
Co-authored-by: Nzhang wenhui <frankwhzhang@126.com>
Co-authored-by: Nwangguanzhong <jerrywgz@126.com>
Co-authored-by: N石晓伟 <39303645+Shixiaowei02@users.noreply.github.com>
Co-authored-by: Nwawltor <fangzeyang0904@hotmail.com>
Co-authored-by: Nlijianshe02 <48898730+lijianshe02@users.noreply.github.com>

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

* register OPMaker and Infer Shape Check for fused_elementwise_add (#30259)

[Cherry-pick]Fix the accuracy problem of allclose op when using float64 data type in static mode.(#29890) (#30313)

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

* Format the code style.

* complex gradient matmul  (#29966)

* dot op support complex types

* matmul support complex types

* add test case

* matmul broadcast gradient support complex

* move conjFunctor to complex_functor.h

* change the kron gradient when complex types (#29995)

* type promotion for grad (#30177)

* type promotion for grad

* add type promotion for div op

[Cherry-Pick] Support vector<double> as type of op attribute and op set_value suppport vector<double> as value (#30126) (#30305)

Cherry-Pick #30126
1. Support vector<float64> as type of op attribute.
2. op set_value suppports float64 numpy.array

* 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.

[Cherry-pick PR 29913], add View(reuse allocation) strategy on squeeze, unsqueeze, reshape, flatten op (#29913) (#30258)

* 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

Cherry-pick of PR #30208 , this PR added clone method for static Variable so that this interface will be same as dygraph. It fixed some bugs in dy2stat where users called clone of dygraph Tensor.

cherry-pick #28769, add support for place string representation 

* elementwise_add_grad Op optimization  (#29575)

* optimize for long width for elementwise (#29602)

* refine (#29622)

* delete the code for fp16 optimization because it is not faster than common template code (#29715)

* fix the shape choose of vectorize for cuda

* optimization for fp16 elementwise add (#29744)

* Fix the compiler error for half type (#29799)

* refine the compiler error for half2 operation (#29816)

* fix the compiler error when gcc4 cuda9.0 (#29997)

* Support pure fp16 training for AMP API. (#29544)

* add cast ops before and after unsupported fp16 ops.

* Keep partial net in FP32 pattern.

* Support check_finite_and_unscale and update_loss_scaling for FP16 calculation mode.

* Add fp16 support for adam op.

* add multi precision attr for adam.

* Fix the bug of test_multi_precision_fp16_train UT.

* Code format for CI.

* Fix the redefine error about MPTypeTrait on windows.

* fix bugs of the _create_accumulators func in Momentum.

* fix bug when inserting post cast op.

* Add the update_loss_scaling op in allow_set of UnusedVarCheck.

* Update for ci coverage.

* Add some doc for OptimizerWithMixedPrecision.

* Fix the code style.

* Imporve the doc of `amp_init`.

* Change for fp16 testing if users have the infer program defined in separate way.

* Remove tensor copy in the update_loss_scaling op. (#29426)

* remove tensor copy in the update_loss_scaling op

* not use thrust.

* fix some cuda memory access error.

* fix tensor shape bug

* fix op_num

* clean code

* Optimization grad merge performance (#29784)

* [fleet] combine amp and gradient merge, test=develop (#30086)

* fix assign_op_xpu concat_op_xpu warining (#30120)
Co-authored-by: Nliuyuhui <liuyuhui@baidu.com>

att, cherry-pick of #30219

* fix dynamic to static error

* delete paddle.nn.functional.assign