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Author: rangsimanketkaew

compile_tensorflow_cpp.md

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+# Compile TensorFlow C++ from source code
+
+Building TensorFlow C++ API is very tricky and can be a pain as there is not much information you can find about it even on TensorFlow's official documentation. Following you will find a step-by-step instruction showing how to build TensorFlow C++ v2 on Linux. It works well for my Ubuntu 20.04 running on AMD Ryzen processors.
+
+## Dependencies
+
+- Conda environment
+- Python 3.9.0
+- TensorFlow 2.7
+- Bazel 3.7.2
+- Protobuf 3.9.2 (must be compatible with the version of TensorFlow-built protobuf or protoc)
+
+## Environment setup & install Python
+```
+conda create -n tfcc
+conda activate tfcc
+conda install python
+conda update --all -y
+```
+
+## Install bazel
+```
+sudo apt install bazel-3.7.2
+```
+
+## Install TensorFlow CC
+```
+git clone https://github.com/tensorflow/tensorflow
+cd tensorflow
+git checkout r2.7
+```
+
+---
+
+## 1. Compile TF shared library (with optimization)
+```
+export CC=gcc
+export CXX=g++
+bazel build --jobs=4 --cxxopt="-D_GLIBCXX_USE_CXX11_ABI=0" -c opt \
+            //tensorflow:libtensorflow.so \
+            //tensorflow:libtensorflow_cc.so \
+            //tensorflow:libtensorflow_framework.so \
+            //tensorflow:install_headers \
+            //tensorflow/tools/pip_package:build_pip_package
+```
+
+Note:
+
+1. Building TF uses a lot of memory, I prefer a small number of CPUs (`--jobs`)
+2. The whole process can take several hours
+3. Add `-D_GLIBCXX_USE_CXX11_ABI=0` if you use GCC 5 or higher
+4. Flags for optimization: `--copt="-O3"`
+5. Flasg for both AMD and Intel chips: `--copt=-mfma --copt=-msse4.1 --copt=-msse4.2 --copt=-mfpmath=both`
+6. Flags for Intel: `--copt=-mavx --copt=-mavx2`
+7. Rebuild with `--config=monolithic` if you want compile all TF C++ code into a single shared object
+
+**optional**
+```
+bazel test --jobs=4 --cxxopt="-D_GLIBCXX_USE_CXX11_ABI=0" -c opt \
+           //tensorflow/tools/lib_package:libtensorflow_test
+```
+
+## 2. Install protobuf
+
+1. Check the version of protobuf that TF is built with
+   ```
+   bazel-bin/external/com_google_protobuf/protoc --version
+   libprotoc 3.9.2
+   ```
+2. Download protobuf source code from its GitHub release https://github.com/protocolbuffers/protobuf/tags
+3. Compile and link
+   ```
+   ./configure --prefix=/home/rangsiman/protobuf-3.9.2/
+   make
+   make check
+   make install
+   ```
+
+## 3. Copy required files into a single path for C++ linkage
+```
+sudo mkdir /usr/local/tensorflow
+sudo cp -r bazel-bin/tensorflow/include/ /usr/local/tensorflow/
+sudo cp -r /home/rangsiman/protobuf-3.9.2/include/google/ /usr/local/tensorflow/include/
+sudo mkdir /usr/local/tensorflow/lib
+sudo cp -r bazel-bin/tensorflow/*.so* /usr/local/tensorflow/lib
+sudo cp -r /home/rangsiman/protobuf-3.9.2/lib/*.so* /usr/local/tensorflow/lib
+```
+
+## 4. Compiling the op library and example code
+
+**Example-1**: Zero out
+
+Create `zero_out.cpp`
+```
+#include "tensorflow/core/framework/op.h"
+#include "tensorflow/core/framework/shape_inference.h"
+
+using namespace tensorflow;
+
+REGISTER_OP("ZeroOut")
+    .Input("to_zero: int32")
+    .Output("zeroed: int32")
+    .SetShapeFn([](::tensorflow::shape_inference::InferenceContext* c) {
+      c->set_output(0, c->input(0));
+      return Status::OK();
+    });
+```
+
+Run the following
+```
+g++ -Wall -fPIC -D_GLIBCXX_USE_CXX11_ABI=0 \
+    -shared zero_out.cpp -o zero_out.so \
+    -I/usr/local/tensorflow/include/ -L/usr/local/tensorflow/lib \
+    -ltensorflow_cc -ltensorflow_framework
+```
+
+**Example-2**: Call TF session
+
+Create `session.cpp`
+```
+#include <tensorflow/core/platform/env.h>
+#include <tensorflow/core/public/session.h>
+
+#include <iostream>
+
+using namespace std;
+using namespace tensorflow;
+
+int main()
+{
+    Session* session;
+    Status status = NewSession(SessionOptions(), &session);
+    if (!status.ok()) {
+        cout << status.ToString() << "\n";
+        return 1;
+    }
+    cout << "Session successfully created.\n";
+}
+```
+            
+Run the following
+```
+g++ -Wall -fPIC -D_GLIBCXX_USE_CXX11_ABI=0 \
+    session.cpp -o session \
+    -I/usr/local/tensorflow/include/ -L/usr/local/tensorflow/lib \
+    -ltensorflow_cc -ltensorflow_framework
+```
+
+To run the executable, you also need to add `/usr/local/tensorflow/lib/` into `LD_LIBRARY_PATH` env var.
+
+---
+
+## Optional: Compile TF via pip (wheel) builder
+```
+## create a wheel package
+./bazel-bin/tensorflow/tools/pip_package/build_pip_package /tmp/tensorflow_pkg
+
+## install TF using a created wheel
+pip install /tmp/tensorflow_pkg/tensorflow-*.whl
+```
+
+## References
+1. https://www.tensorflow.org/guide/create_op#compile_the_op_using_your_system_compiler_tensorflow_binary_installation
+2. https://www.tensorflow.org/install/source#bazel_build_options