* add expand_as op, test=develop

* add expand_as op,test=develop

* add expand_as op,test=develop

* add nn.py, test=develop

* delele paddle_enforce, test=develop

* add data type check, test=develop

* polish error messages, test=develop

* polish error messages, test=develop

* Remove support for the CPU architecture matmul, test=develop

* fix syntax bug, test=develop

* modified group_norm's unittest for pass statement, test=develop

* fix group_norm's bug: scale or bias is None which causes segmentation fault, test=develop

fix conv_transpose's bug: compatible with Anylayout setting: cherry-pick 20589

* fix recurrent bug
test=develop

* Fix while op bug
test=release/1.6

* add unit test
test=release/1.6

* Add seq2seq api related code (#19820)

* fix expand bug  (#20340)

* fix expand bug test=develop

* fix style test=develop

* fix style test=develop

* fix style test=develop

* fix style test=develop

* Fix the assign data check (#20564)

* Fix the assign data check. test=develop

* Fix test_assign_op.py. test=develop

* Update API.spec

Refine error message of transpose. fix en doc about unsqueeze, unstack, transpose, multiplex. test=develop, test=document_preview, test=document_fix (#20594)

* support reshape doubel grad, test=develop

* fix reshape double grad, pass converage, test=develop

* fix review, test=develop

1. fill_constant support Tensor;
2. fix bug in backward.py: using fill_constant instead of fill_constant_batch_size_like
3. fix bug in ExpandGradOp.
test=release/1.6 (#20521)

* Add input check and refine error message

* Refine test case and comments

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* fix_conv_grad_grad

* fix_bug, test=develop

* fix error message for elementwise_add/mul;test=develop

* edit error message;test=develop

* add input type and dtype check for accuracy_op

* add input type and dtype check for accuracy_op

* modify python error on accuracy_op,add test=develop

* modify details on accuracy_op, test=develop

* test float16, test=develop

* add warning, test=develop

Fix api doc example bug and polish square doc (#20491)

test=develop
test=document_fix

* Refine topk stack squeeze api en doc

test=develop
test=document_fix

* refine api.spec and returns

test=develop
test=document_fix
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

test=develop, test=release/1.6, test=document_fix

* refine eng doc for hard_sigmoid op
test=develop
test=document_fix

* refine the description of hard_sigmoid
 test=develop
test=document_fix

* update API.spec
test=document_fix

* Refine the decription of parameters of HardSigmoid op
test=develop, test=document_fix

* Update API.spec for hard_sigmoid op
test=develop, test=document_fix

* fix elementwise floordiv mod; test=develop

* restore nn.py; test=release/1.6

* change floordiv, mod  doc; test=release/1.6

* fix APIs: relu, relu6, hash

test=develop
test=document_fix

* fix relu6 doc

test=develop
test=document_fix

* fix API.spec

test=develop
test=document_fix

* add description link for hash

test=develop
test=document_fix

* fix API:cos, exp, ceil, elu, brelu English doc
test=develop
test=document_fix

* cherry-pick fix prroi op test=develop test=release/1.6

* Fix transpiler en doc (#20149)

* test=develop,test=document_fix,fix transpiler doc,add API.spec

* test=develop,test=document_fix,fix transpiler doc,add API.spec

modify en api doc

- leaky_relu
- less_than 
- log
- logical_and
- logical_or
- logical_xor
- logical_not

Cherrypick  en doc: reorder_lod_tensor_by_rank , map_reader, WeightNormParamAttr, io.compose  (#20463)

* modify map_reader en doc (#20229)

* modify WeightNormParamAttr en doc (#20218)

* modify reorder_lod_tensor_by_rank en doc

* modify compose en doc (#20217)

* add api check in fc test=develop

* enforce shape error info of sum op test=develop

* fix spelling test=develop

* print x_dims info test=develop

* enhance shape error info test=develop

test=release/1.6, test=document_fix

test=release/1.6, test=document_fix

* refine en doc. test=develop. test=document_fix

enhance shape error messages for reshape op.
test=release/1.6

* Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into api_fix

* test=release/1.6, test=document_fix

* Delete PadFuntion, include padding.h instead.

* move function(IsSymmetricPadding) from conv_cudnn_op.cu/conv_transpose_cudnn_op.cu to padding.h.

* Add detailed error messages for nce layer

* Fix some problems

* Fix unit test coverage

test=release/1.6