LTO only on release

CMakeLists.txt

@@ -9,6 +9,18 @@ set(CMAKE_POLICY_DEFAULT_CMP0063 NEW) 	# Set CMAKE visibility policy to NEW on p
 set(CMAKE_VISIBILITY_INLINES_HIDDEN ON) # Set C and C++ symbol visibility to hide inlined functions
 set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 
+# Check if link-time-optimization is supported and apply it if possible in release builds
+include(CheckIPOSupported)
+check_ipo_supported(RESULT supported OUTPUT error)
+
+if(supported)
+	message(STATUS "IPO / LTO enabled")
+	set(CMAKE_POLICY_DEFAULT_CMP0069 NEW)
+	set(CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE TRUE)
+else()
+	message(STATUS "IPO / LTO not supported: <${error}>")
+endif()
+
 # Read variables from file
 FILE(READ "${CMAKE_SOURCE_DIR}/CMakeVariables.txt" variables)