Optimization.cmake

include_guard()

# Enable Interprocedural Optimization (Link Time Optimization, LTO) in the release build
macro(enable_interprocedural_optimization _project_name)
  if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
    include(CheckIPOSupported)
    check_ipo_supported(RESULT result OUTPUT output)
    is_mingw(_is_mingw)
    if(result AND NOT ${_is_mingw})
      # If a static library of this project is used in another project that does not have `CMAKE_INTERPROCEDURAL_OPTIMIZATION` enabled, a linker error might happen.
      # TODO set this option in `package_project` function.
      message(
        STATUS
          "Interprocedural optimization is enabled. In other projects, linking with the compiled libraries of this project might require `set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)`"
      )
      set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
      set_target_properties(${_project_name} PROPERTIES INTERPROCEDURAL_OPTIMIZATION ON)
    else()
      message(
        WARNING
          "Interprocedural Optimization is not supported. Not using it. Here is the error log: ${output}"
      )
    endif()
  endif()
endmacro()

# Enable the optimizations specific to the build machine (e.g. SSE4_1, AVX2, etc.).
macro(enable_native_optimization _project_name)
  detect_architecture(_arch)
  if("${_arch}" STREQUAL "x64")
    message(
      STATUS "Enabling the optimizations specific to the current build machine (less portable)"
    )
    if(MSVC)
      # TODO It seems it only accepts the exact instruction set like AVX https://docs.microsoft.com/en-us/cpp/build/reference/arch-x64
      # target_compile_options(${_project_name} INTERFACE /arch:native)
    else()
      target_compile_options(${_project_name} INTERFACE -march=native)
    endif()
  endif()
endmacro()

# Disable C++ exceptions for the given project.
macro(disable_exceptions _project_name)
  target_compile_options(
    ${_project_name} INTERFACE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>:/EHs-c-
                               /D_HAS_EXCEPTIONS=0>
  )
  target_compile_options(
    ${_project_name}
    INTERFACE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<NOT:$<CXX_COMPILER_ID:MSVC>>>:-fno-exceptions
              -fno-unwind-tables>
  )
endmacro()

# Disable C++ RTTI (Run-Time Type Information) for the given project.
macro(disable_rtti _project_name)
  target_compile_options(
    ${_project_name} INTERFACE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>:/GR->
  )
  target_compile_options(
    ${_project_name}
    INTERFACE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<NOT:$<CXX_COMPILER_ID:MSVC>>>:-fno-rtti>
  )
endmacro()