.. _install_or_build_cpp_inference_lib_en:

Install and Compile C++ Inference Library
=============================================

Direct Download and Installation
---------------------------------

..  csv-table:: c++ inference library list
    :header: "version description", "inference library(1.6.1 version)", "inference library(develop version)"
    :widths: 1, 3, 3

    "cpu_avx_mkl", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/1.6.1-cpu-avx-mkl/fluid_inference.tgz>`_", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/latest-cpu-avx-mkl/fluid_inference.tgz>`_"
    "cpu_avx_openblas", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/1.6.1-cpu-avx-openblas/fluid_inference.tgz>`_", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/latest-cpu-avx-openblas/fluid_inference.tgz>`_"
    "cpu_noavx_openblas", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/1.6.1-cpu-noavx-openblas/fluid_inference.tgz>`_", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/latest-cpu-noavx-openblas/fluid_inference.tgz>`_"
    "cuda9.0_cudnn7_avx_mkl", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/1.6.1-gpu-cuda9-cudnn7-avx-mkl/fluid_inference.tgz>`_", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/latest-gpu-cuda9-cudnn7-avx-mkl/fluid_inference.tgz>`_"
    "cuda10.0_cudnn7_avx_mkl", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/1.6.1-gpu-cuda10-cudnn7-avx-mkl/fluid_inference.tgz>`_", "`fluid_inference.tgz <https://paddle-inference-lib.bj.bcebos.com/latest-gpu-cuda10-cudnn7-avx-mkl/fluid_inference.tgz>`_"


Build from Source Code
-----------------------

Users can also compile C++ inference libraries from the PaddlePaddle core code by specifying the following compile options at compile time:

============================  ======================
Option                        Value
============================  ======================
CMAKE_BUILD_TYPE              Release
FLUID_INFERENCE_INSTALL_DIR   Path of installation
WITH_PYTHON                   OFF（recommended）
ON_INFER                      ON（recommended）
WITH_GPU                      ON/OFF
WITH_MKL                      ON/OFF
============================  ======================

It is recommended to configure options according to the recommended values to avoid the link to unnecessary library. Other options can be set if it is necessary.


The following code snippet pulls the latest code from github and specifies the compiling options (you need to replace PADDLE_ROOT with the installation path of the PaddlePaddle inference library):

  .. code-block:: bash

     PADDLE_ROOT=/path/of/capi
     git clone https://github.com/PaddlePaddle/Paddle.git
     cd Paddle
     mkdir build
     cd build
     cmake -DFLUID_INFERENCE_INSTALL_DIR=$PADDLE_ROOT \
           -DCMAKE_BUILD_TYPE=Release \
           -DWITH_PYTHON=OFF \
           -DWITH_MKL=OFF \
           -DWITH_GPU=OFF  \
           -DON_INFER=ON \
           ..
      make
      make inference_lib_dist

After successful compilation, dependencies required by the C++ inference library Will be stored in the PADDLE_ROOT directory. (dependencies including: (1) compiled PaddlePaddle inference library and header files; (2) third-party link libraries and header files; (3) version information and compilation option information)

The directory structure is:

  .. code-block:: text

     PaddleRoot/
     ├── CMakeCache.txt
     ├── paddle
     │   ├── include
     │   │   ├── paddle_anakin_config.h
     │   │   ├── paddle_analysis_config.h
     │   │   ├── paddle_api.h
     │   │   ├── paddle_inference_api.h
     │   │   ├── paddle_mkldnn_quantizer_config.h
     │   │   └── paddle_pass_builder.h
     │   └── lib
     │       ├── libpaddle_fluid.a
     │       └── libpaddle_fluid.so
     ├── third_party
     │   ├── boost
     │   │   └── boost
     │   ├── eigen3
     │   │   ├── Eigen
     │   │   └── unsupported
     │   └── install
     │       ├── gflags
     │       ├── glog
     │       ├── mkldnn
     │       ├── mklml
     │       ├── protobuf
     │       ├── snappy
     │       ├── snappystream
     │       ├── xxhash
     │       └── zlib
     └── version.txt

The version information of the inference library is recorded in version.txt, including Git Commit ID, version of OpenBlas, MKL math library, or CUDA/CUDNN. For example:

  .. code-block:: text

     GIT COMMIT ID: cc9028b90ef50a825a722c55e5fda4b7cd26b0d6
     WITH_MKL: ON
     WITH_MKLDNN: ON
     WITH_GPU: ON
     CUDA version: 8.0
     CUDNN version: v7
