Merge pull request !4137 from andy_wangrui/master

Merge pull request !4151 from ZPaC/master-fix-ps-training-precision-error

Merge pull request !4163 from hangq/master

Merge pull request !4118 from xutianchun/quant_0807

Merge pull request !4096 from lianliguang/unify-primitive-and-generate-graph

Merge pull request !4152 from hangq/master

Merge pull request !4157 from yangruoqi713/lite

Merge pull request !3909 from yangjie159/fix-get-subgraph-input

Merge pull request !4105 from liangzelang/change-mem-pools-management

Merge pull request !4150 from JoyLvliang/enable-the-identity-op-can-be-eliminated-in-pynative-mode

Merge pull request !4153 from chenjianping/lite_dev2

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Merge pull request !4156 from sunsuodong/fix_populate_parameter

Merge pull request !4149 from h.farahat/to_device_bug

Merge pull request !4146 from sunsuodong/leaky_relu

Merge pull request !4140 from liuwenhao/master

Merge pull request !4148 from fuzhiye/tmp

Merge pull request !4106 from yeyunpeng2020/master_kchw

Merge pull request !4139 from pengyongrong/concat_debug_pr

Merge pull request !4041 from chengxb7532/master

Merge pull request !4145 from 张学同/to_merge

Merge pull request !4112 from fuzhiye/tmp

2. add fp32 data type cast op register

Merge pull request !3932 from zhangzheng/open

Merge pull request !3963 from lyvette/tflite_parser