* restore to gcc8.2

* test=document_fix

* Add unit tests

* matmul_v2 + activation

* matmuls + elementwise_add

* matmul_v2 postops

* transform matmul to v2

* opcompat

* fix fusing matmul with multipe outs

* add shape constraints

* remove unused vars

* change pass order

* - Unit tests to be debugged

- fix

- refactor

- diagnostic

- more diagnostic

- fix

- Fix number two

- fix

- fix

- fix

- alpha added

- more fixes

- compilation fix

- removed diagnostic code

- cosmetic fixes

* lint

* add alpha constraint

* merge matmul refactor

* trigger CI

* - fix

* - another fix

* code style

* add support for matmul+elementwise_add+activation

* code style

* fix bfloat16 bugs

* change append_binary to append_sum
Co-authored-by: NJacek Czaja <jacek.czaja@intel.com>

* add name attribute to code-block, test=document_fix

* remove redundant labels, test=document_fix

* remove redundant labels (from upstream), test=document_fix

* more COPY-FROM (try multiple code example), test=document_fix

* empty commit, try to trigger PR-CI-build

* fix some `Examples:` format issues

* fix some ci errors

* add rnn

* first commit

* add fp16 ctest files for compare op

* add cpu register of float16 for compare ops

* add merged_momentum *test=kunlun

* add merged_momentum *test=kunlun

* add fp16 to merged_momentum,*test=kunlun

* [Eager] fix slice's input mistake

* add tests for slice

* phi_fill_diagonal_tensor

* delete extra lines

* update

* add legacy api test

* rename sig

* phi_generate_proposals_v2

* remove old kernels

* optest add eager_check

* del lod

* update

* update

* update test_detection with_lod

* update nms_util

* remove old nms_util.h

* fix conflicts

* mv unused file

* revert backward.h

* revert lu_unpack kernel

* rm .cu file

* Update lu_unpack_kernel.cc

* format phi yaml

* convert support multi block.

* update

* Move Function classes to a sub dir

* Format code

* [XPU] fleet dist_model support xpu. test=kunlun

* [XPU] fleet dist_model support xpu. test=kunlun

* move unittest file location. test=kunlun

Set the lr var's dtype to fp32 when create a fp16 lr var in optimizer if user not mean to use global fp16. (#44840)

* add paddle.bucketize api

add paddle.bucketize api

* updata paddle.bucketize code style.

* upgrade unittests/test_bucketize_api.py.

* update tests/unittests/test_bucketize_api.py file.

* 修改bucketize API 的英文参数描述

* c++ property deserialization

* fix for comment

* more error info

* fix exception info

* fix ci

* fix compile

* fix layer test ci

* phi_fill_diagonal

* remove old kernels

* update

* update attr args

* refix

* update

* [CustomDevice] add custom ccl 2/2

* update

* update

* update launch

* add sequence_unpad for xpu,*test=kunlun

* add sequence_unpad, *test=kunlun

* fix bug in testcase,should not be sequence_pad,*test=kunlun