* [Eager] Support eager grad interface, draft version

* Support eager grad interface with allow_unused and multi startup_op

* Fix code format

* Fix allow_unused case, return PyNone if tensor not initialize

* Support output's stop_gradient related to create_graph

* Support grad exception case in eager mode, fix coverage CI

* Update ToPyObject, return PyNone if not initialize

* AccumulationNode add FLAGS_retain_grad_for_all_tensor

* Fix ci issue

* Fix CI issue

* fix, use core.eager.Tensor

* Add func SetBufferSlotRankZeros for GradTensorHolder

* Support retain_graph by using ClearTensorWrappers

* Support retain_graph by using ClearTensorWrappers

* Update retain_graph and no_grad_vars related test case

* Update code gen logic for ClearTensorWrappers

* Fix by override statement

* fix override func args

* Support retain_graph, update unit tests

* Updated ClearTensorWrappers logic

* fix grad python interface

* Use deep copy and update unit tests

* Polish code

* Polish code

* Fix CI issue, Deep copy only use when user set grad_tensors

* Fix CI, use Backward instead RunBackward

* Fix CI, Declare kernel explicitly in test file

* Polish, remove vector of TensorWrapper

* Refactor the logic of grad/backward, polish codes

* Update code after merge upstream develop

* Polish after merge upstream develop

* Update to adapt new GradNodeBase superclass

* Fix error introduced during conflict resolution

* Update purify potential_startup_nodes logic

* Fix errors

* Polish code

* Remove useless args for ToPyObject

* Remove useless TensorWrappersSet

* Fix code-format, re-install pre-commit

* Fix pre-process logic for potential_startup_ops

* Update unit tests, use eager mode

* for test_mnist.py

* remove comments

* using type() replace isinstance()

* valid vars for run program OP in io.py

* open test_mnist in eager_gurad for coverage

* Optimize performance

* optimiaze c++ api performance

* remove unsed code

* fix paddle throw

* updata format

* fix copy_ problem by doing it with phi copy

* improve test coverage

* refactor copy with sr kernel

* Move the computation of moving average scale to device

* Use register to save local maximum in a thread

* infrt add trt engine

* fix register

* file generate

* fix ci error

* fix conflict

* add copyright

* update

* update

* update

* update engine name

* refactor trt code

* update

* update

* update

* update

* fix conflict

* update

* fix compile with cuda

* segment pool support for int int64 kernel.

* add support in python api

* Optimize the computation of log_softmax

* modify the var name

* init commit

* correct namespace

* Add yaml config for pool2d

* Fix CI error

* Fix code format error

* [Phi] Migrate mode_op and mode_grad_op into Phi

* fix omp

* add ifdef

* migrate infershape

* modify according reviewer

* Refactor elementwise op grad classes

* Add more refactor changes

* Revert set layout and format deletion

* Fix failing elementwise test

* Quantize elementwise mul op

* Parametrize elementwise functions

* Fix code formatting

* Modify save_quant_model.py to support differnet input and output filenames

* Correct wrong order of arguments

* Fix tile_op inferShape

* fix style

* align to cn docs

* add parameter `weight_decay`

restructure conv

* move roi_align_grad kernel

* move roi_align grad kernel and infershape to phi

* remove roi_align infershape

* [PHI] Migrate roll op

* 【phi】migrate eigh op to phi (#40213)

* migrate eigh to phi

* optimize code

* modify code according to comment

* conflict resolution

* [PHI] Migrate roll op

* [PHI] Fix converage of roll_sig

* [PHI] Fix infermate of roll_sig

* [Phi] Fix unittest coverage of roll op

* [PHI] Fix infermeta in unary

* [PHI] Fix parameter type of roll op

* [PHI] Fix parameter type of roll op

* [PHI] Fix parameter of roll op
Co-authored-by: Ncrystal <62974595+Zjq9409@users.noreply.github.com>

* [PHI] Migrate index_select op

* [PHI] Fix bug in test_variable

* [PHI] migrate index_select op

* [kp]fix bug that cannot fallback to CPU normally in XPU KP

* fix bug in static graph

* migrate multiplex op kernel

* migrate qr cpu kernel

* migrate tril_triu op kernel

* fix multiplex kernel

* add kernel sig

* fix dependence and bug

* fix multiplex error

* fix npu include error

* fix conflict

* fix conflict and delete tril_triu

* fix date and multiplex input

* adapt header file order

* fix header file include

* fix conflict

* delete cholesky_solve_op.h

* delete triangular_solve_op.h

* move reduce kernels into one file

* rename reduce_prod to prod

* move reduce sum/mean from math_kernel into reduce_kernel

* rm comment

* add grid sample phi kernel

* add grid sample phi kernel and remove original kernel

* replace mutable_data by alloc