Merge pull request !3701 from ling/pad

Merge pull request !3405 from gziyan/fix_optimizer_parallel

Merge pull request !3656 from limingqi107/master

Merge pull request !3691 from XunDeng/pp_poc_v3

Merge pull request !3631 from kisnwang/fix-subgraph-maketuple-error

Merge pull request !3653 from panfengfeng/add_epoch_num_description_master

Merge pull request !3672 from hexia/fix_input_check

Merge pull request !3661 from shenwei41/sw_master

Merge pull request !3664 from hanjun996/master

Merge pull request !3668 from ougongchang/fix_collect_dataset

Merge pull request !3522 from wanghua/c75_tinybert

Merge pull request !3660 from meixiaowei/master

Merge pull request !3665 from zhouyaqiang0/master

Merge pull request !3341 from tom_chen/maxpool_with_argmax

We collect graph and dataset graph in begin stage before,
If there compile graph fail in GPU, we also collect graph
and dataset graph to summary dir, it will confuse user.

So we collect graph and dataset graph in step end stage now,
If there compile graph fail, we will not collect graph and dataset
graph.

Merge pull request !3651 from jiangzhiwen/dataset/change_num_samples

Merge pull request !3625 from hewei/optimize_tensor_data

Merge pull request !3644 from liyong126/fix_mindrecord_bug

Merge pull request !3638 from geekun/yjk_master

Merge pull request !3643 from huanghui/communication-op-fusion

Merge pull request !3489 from lvchangquan/master

Merge pull request !3594 from wangqiuliang/fix-batchnorm-under-mix-precision-in-pynative

Merge pull request !3630 from laiyongqiang/refnode_input_fix

Merge pull request !3635 from panfengfeng/fix_dataset_train_gil_of_gpu_master

Merge pull request !3627 from guozhijian/fix_device_occupied_tdt_hung

Merge pull request !3624 from yanghaitao/yht_generator_timeout

Merge pull request !3574 from hewei/rename_user_data_func

Merge pull request !3637 from thlinh/dev_Jul28_lower_checking_threshold

Replace std::vector<T> with std::unique_ptr<T[]> for tensor data storage,
it prevent unintended data initialization when data is lazy allocated.

Merge pull request !3603 from jiangzhiwen/fix_column_names_exceeded

Merge pull request !3620 from 张学同/to_merge