add CMake flag USE_NATIVE_CPU_ARCH for -march=native

Author: MartinPulec

CMakeLists.txt

@@ -8,6 +8,7 @@ set_property(CACHE BUILD_OPENGL PROPERTY STRINGS AUTO ON OFF)
 option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
 option(CMAKE_CUDA_ARCHITECTURES "CUDA architectures to build for (needs CMake 3.18)" OFF)
 option(ENABLE_FPNGE "Enable fpnge - requires c++ and sse4" OFF)
+option(USE_NATIVE_CPU_ARCH "Use -march=native for compilation (Linux only)" OFF)
 option(HUFFMAN_GPU_CONST_TABLES "Enable Huffman GPU decoder quick const tables" OFF)
 set(OPENGL_CONTEXT AUTO CACHE STRING "Use specifiedn OpenGL context creation, options are: AUTO GLX GLFW NONE")
 set_property(CACHE OPENGL_CONTEXT PROPERTY STRINGS AUTO GLX GLFW NONE)
@@ -78,6 +79,12 @@ if(ENABLE_FPNGE)
     file(GLOB_RECURSE CXX_FILES src/*.cc src/*.cpp)
 endif()
 
+if(USE_NATIVE_CPU_ARCH)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=native")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -march=native")
+    set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} -Xcompiler  -march=native")
+endif()
+
 # allow passing <PackageName>_ROOT to find_package()
 if(POLICY CMP0074)
     cmake_policy(SET CMP0074 NEW)

README.md

@@ -191,6 +191,9 @@ files are placed) and run `cmake` command:
     cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_CUDA_ARCHITECTURES=native -Bbuild .
     cmake --build build --config Release
 
+In Linux, you may also consider `-DUSE_NATIVE_CPU_ARCH=ON` for optimized
+CPU code build (`-march=native` added to compiler flags).
+
 In Linux, you can also use **autotools** to create a build recipe for
 the library and the application or a plain old _Makefile.bkp_. However,
 _cmake_ is recommended.