OpenMP

# For CMake < 3.9, we need to make the target ourselves
if(NOT TARGET OpenMP::OpenMP_CXX)
    find_package(Threads REQUIRED)
    set_property(TARGET OpenMP::OpenMP_CXX
                 PROPERTY INTERFACE_COMPILE_OPTIONS ${OpenMP_CXX_FLAGS})
    # Only works if the same flag is passed to the linker; use CMake 3.9+ otherwise (Intel, AppleClang)
                 PROPERTY INTERFACE_LINK_LIBRARIES ${OpenMP_CXX_FLAGS} Threads::Threads)
endif()