* add gradient clip in minimize; test=develop

* fix bug; test=develop

* fix format; test=develop

* move new grad clip to dygraph/grad_clip.py; test=develop

* fix lr decay and grad clip test; test=develop

* seperate dygraph grad clip; test=develop

* fix grad clip test; develop

* fix api spec bug; test=develop

* add blank line, test=develop,test=document_preview

to fix format problem

* update python APIs

test=document_preview test=develop

* update API.spec

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test=develop

* update merge_selected_rows

* update API.spec

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test=develop

* update API.spec

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test=develop

* fix the comment of less_than

test=develop

test=document_preview

* update API.spec

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* update API.spec

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test=document_preview

* update API.spec

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* update API.spec

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* update API

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* [DOC] Fix api docs, test=develop, test=document_preview

* [DOC] Fix api annotation: fluid.layers.tensor_array_to_tensor. test=develop, test=document_preview

* test=develop, test=document_preview

update MD5 of tensor_array_to_tensor

* fix the api example for create_global_var, create_parameter, SGDOptimizer, RMSPropOptimizer, MomentumOptimizer, LarsMomentumOptimizer, FtrlOptimizer
test=develop

* add example for adamoptimizer
fix API.spec
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* test=develop

* test=develop

* Bias correction for exponential moving average

test=develop, test=document_preview

* Fix docs

test=develop, test=document_preview

This reverts commit f34830e2.

test=develop

* Enable sqrt operator for the nGraph Bridge.

test=develop

* Update activation_op.h

test=develop

* fix the bug that sub_scope_ may be null in AnalysisPredictor::Run.

* add more directions about io APIs' docs.

* update the API.spec. test=develop test=document_preview

* add data parallel batch

* gather_op support int64_t index by adding a template typename

* add UT and rename typename

test=develop

* fuse mul and elementwise add to fc

* Reimplement the FC forward operator

* Fix FC MKLDNN integration by transposing weights

* Add FC MKLDNN Pass

test=develop

* FC MKLDNN Pass: change memcpy to std::copy

* Fix MKLDNN FC handling of mismatch input and weights dims

* Lower tolerance for MKL-DNN in resnet50 test

test=develop

* Adjust FC to support MKLDNN Op placement

test=develop

* Adjust Placement Op to set use_mkldnn attribute for graph

test=develop

* MKLDNN FC: fix weights format so that gemm version is called

test=develop

* FC MKLDNN: Remove tolerance decrease from tester_helper

* FC MKL-DNN: Refactor the code, change input reorder to weight reorder

* MKL-DNN FC: Introduce operator caching

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* FC MKL-DNN: Fix the tensor type in ExpectedKernelType

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* FC MKL-DNN: fix style changes

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* FC MKL-DNN: fallback to native on non-supported dim sizes

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* FC MKLDNN: fix CMake paths

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* FC MKLDNN: Refine placement pass graph mkldnn attribute

test=develop

* Fix Transpiler error for fuse_conv_eltwise

test=develop

* Fix missing STL includes in files

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* FC MKL-DNN: Enable new output size computation

Also, refine pass to comply with newest interface.
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* FC MKL-DNN: enable only when fc_mkldnn_pass is enabled

* FC MKL-DNN: Allow Weights to use oi or io format

* FC MKL-DNN: Adjust UT to work with correct dims

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* Enable MKL DEBUG for resnet50 analyzer

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* FC MKL-DNN: Improve Hashing function

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* FC MKL-DNN: Fix shape for fc weights in transpiler

* FC MKL-DNN: Update input pointer in re-used fc primitive

* Add log for not handling fc fuse for unsupported dims

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* FC MKL-DNN: Move transpose from pass to Op Kernel

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* FC MKL-DNN: Disable transpose in unit test

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* FC MKL-DNN: Remove fc_mkldnn_pass from default list

* Correct Flag for fake data analyzer tests

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* FC MKL-DNN: Add comment about fc mkldnn pass disablement

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* FC MKL-DNN: Disable fc in int8 tests

test=develop

* BugFix: fix api comment of paddle.fluid.clip.GradientClipByValue
* test=develop, test=document_preview

* add __str__ method for tensor and lodtensor to support print test=develop

* fix unique_name growth bug in dygraph mode,test=develop

* change generate_tmp to generate_with_ignorable_key,test=develop

test=develop

* fix example; test=develop

* fix api spec; test=develop

* fix api spec; test=develop

* add doc check
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* test=develop,test=document_preview

add blank line to fix format, add one more "import"

* fix bug; test=develop

* fix bug; test=develop

* fix DecayedAdagrad example;
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* add space; test=develop

add Run Prepared Ctx, fix pybind problem

* Fix the example code in some Python API.
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* Fix the example code in some Python API by adding import.
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* This PR adds broadcast for multi-process. And it could be used in dynamic graph to broadcast parameters.

Python examples of fluid.layers.io.double_buffer and some BuildStrategy's methods.

*  Enable assign operator for a ngraph, test=develop

* Cross_entropy operators needs to be updated

* polish_executor_and_add_ctx_cache

* Add exponential moving average

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* Polish documents

test=develop, test=document_preview

* Update API spec

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* test=develop

* test=develop

* fix api example. test=develop

* fix API.spec. test=develop

* fix spectral_norm format. test=develpp

* merge develop

* add import. test=develop

* fix indent. test=develop

* fix indent. test=develop

* add import fluid. test=develop