* 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

* fix warning and no grad

[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

[cherry-pick] Async drop scope in executor (#29714)

cherry-pick #30147，For op set_value, check input's rank < 7

[cherry pick] Add detailed error message for curandStatus_t, cublasStatus_t, cusolverStatus_t (#30161) (#30280)

为curandStatus_t、cublasStatus_t、cusolverStatus_t添加详细的报错信息。
原始PR：#30161

* 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

 add cast cuda kernel

cherry-pick #29352

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.

* improve dropout (#29465)

* improve drop out

* add VectorizedRandomGeneratorWithGenerator

* fix bug

* modify according to comments

* improve dropout grad (#29605)

* improve grad perf

* fix the bug of dropout_grad (#29813)

* Softmax vectorization (#29404)

* vec softmax fw

* vec softmax bw

* add a message argument for compiler compatibility

* optimize softmax forward (#30217)

* optimize softmax forward
Co-authored-by: Nzlsh80826 <zlsh80826@gmail.com>

* fix tensor shape bug

* fix op_num

* clean code

* Quantization supports 2.0 APIs

* Fix the error of save_quantized_model

* 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

* add aarch64 and sunway kunlun lib

* minor

* optimize elementwise_add for kunlun

* update kunlun dependence

* minor

* minor

[Cherry-Pick 2.0] In creation.assgin, reuse implamention code of layers.tensor.assign to avoid maintain two code (#30227) (#30236)

cherry-pick #30227

[cherry-pick] [Dy2Stat] Don't convert to paddle.shape if var_x.shape is not negetive #29965 (#30235)

* [Cherry-Pick 2.0] [Dy2Stat] Don't convert to paddle.shape if var_x.shape is not negetive (#29965)

1. When x is Variable, call nn.shape(x) only in following cases:
 1）The shape of x is used in control flow condition.
 2）The dim to be used is negetive
2. When x is Variable, but x.shape or x.shape[idx] doesn't contain negetive value, don't convert to paddle.shape()

* [Cherry-Pick 2.0] [Dy2Stat] Use Paddle2.0 api paddle.tensor.array_* (#30156)

* Optimizer trans momentum (#29597)

* merge amp related function in Momentum from paddle.fluid.contrib.optimizer into paddle.optimizer.

* Add unittest for 2.0  Momentum API.

* fix some bugs in weight_decay.

* add alias for fluid.contrib.mixed_precision (#29562)

* add alias for fluid.contrib.mixed_precision

* add static.amp into setup.pu.in (#29621)

* add static.amp into setup.pu.in

* add unittest for api

* fix a bug in multi_precision_fp16 unittest. (#29756)

[cherry-pick 2.0] Fix bug: In dynamic mode, if start or end is negetive, __getitem__  return wrong result(#30003) (#30146)

1. when slice_item is a slice:
 1) the start of __getitem__ should be std::max(start, 0) if slice
 2) the start of __getitem__ should be std::min(end, dim)
2. when slice_item is an integer, it should be in [-dim_len, dim_len)
3. Fix error message to use accurate data

1. Type of index: int, slice(step must be 1).

2. Type of value:
 (1) int32, int64, float32, bool;
 (2) numpy.array(int32, int64, float32, bool);<Note: float64 is not supported>
 (3) paddle.Tensor(int32, int64, float32, float64, bool);

* fix beam search bug

* add dygraph unittest

* update dynamic_decode argument doc

* add warning info for state which has no lengths attribute

* simplify prepared op impl to improve performance

* fix kunlun compile error

* continue fix kunlun compile error

* only transform diff place when dtype diff

* fix failed unittests

* remove useless file

* polish impl by review comment

* Add Lookahead and ModelAverage Optimizer (#30004)

* test=develop, add model_average and lookahead

* Improve Index select cuda kernel (#30139)

* test=develop, add index_select_cuda kernel

* fix syncbn convet

* add unittest

* Simplify the options of spawn based on fleetrun (#30144)

* Simplify the options of spawn based on fleetrun

* polish details

* polish doc details

* cleanup enum test=develop (#29294)
Co-authored-by: Ngongweibao <weibao.gong@gmail.com>

* Support storage of large parameters (#29988)

* Support storage of large parameters

* Reduce the complexity of the unittest

* Reduce the complexity of the unittest,commented out unittest for

* add unittest for static.save/load

* Increase the timeout threshold of 'test_static_save_load'

* Increase the timeout threshold of 'test_static_save_load'

* Increase the timeout threshold of 'test_static_save_load' and 'test_paddle_save_load'

* Increase the timeout threshold of 'test_static_save_load' and 'test_paddle_save_load'

* Extend the timeout for the (#30151)

* Improve performance of elementwise_add grad op (#29187)

* pass stop_gradient for cast op

* improve performance of elementwise_add grad

* use tensor copy async

* dygraph branch

* fix dygraph branch

* add ut

* make gelu fp16 computing more robust (#29484)

* Add fast path for dropout when p == 0  (#29553)

* add fast path for p == 0 in dropout

* add ut