* XPU support eager mode

* add unittest for XPU eager mode

* minor bugfix

* minor bugfix, test=kunlun

* correct copyright info

* 1. remove unsed vars/funcs
2. ProcessGroupBKCL inherit from ProcessGroupStream

* bugfix for fp16 in eager mode multi-card, test=kunlun

* rebase & fix a few issues

* use new processgroup interface, test=kunlun

* fix compile issue, test=kunlun

* refactor: send, recv, send_partial, recv_partial

* refactor: rm useless const ref

* [CustomDevice] GetCCLComm add custom device support

* update

* update

* update

* fix no sync bugs

* update

* update task chain

fix: update wait chain

feat: add `GetDeviceContext` for gloo

* fix oom

* fix dev

* update

* update
Co-authored-by: NLiYuRio <liyuruijx@163.com>
Co-authored-by: NForFishes <2282912238@qq.com>

* Fix bug of reduce_sum op. When input.numel() > INT32_MAX, its result
is wrong.

* support pure bfloat16

* support bf16 linear

* update PR to pass CI

* tiny fix where_grad_kernel.cu

* Support bfloat16 type for reducer and sharding.

* Fix some bug.

* Polish code.

* Polise code.

* Add bfloat16 datatype in fill_grad kernels.
Co-authored-by: Nsneaxiy <sneaxiy@126.com>

* make dense_contents_ lazy init

* update legacy dygraph

* fix legacy dygraph bug

* update brpc version;test=develop

* [CustomDevice] add custom ccl 2/2

* update

* update

* update launch

* remove cudaDeviceContext

* remove more template

* fix rocm compile

* remove alias name CUDADeviceContext

* fix compile

* fix tests

* revert changes

* init

* move CUDAStream to phi

* fix compilation

* merge develop

* add stream_owned_ member

* split cuda_stream.h

* fix cpu compile

* fix constructor

* fix bug

* fix windows compile

* fix inference test_levit

* fix windows tests

* fix conflict

* new pg apis

* add docs of new apis

* update

* fix coverage

* update

* fix bug

* fix reduce scatter

* fix api

* update
Co-authored-by: NForFishes <2282912238@qq.com>

* fix init()

* delete test_device_context

* replace CPUDeviceContext with CPUContext

* fix test_scalar

* remove dot_op.cc

* fix compile

* boost::variant -> paddle::variant

* boost::variant.apply_visit -> paddle::visit

* Update pybind_boost_hraders.h

* Fix CINN compilation errors

* Revert FetchResultType