cmake: add option for pollyhedral optimization.

CMakeLists.txt

@@ -46,6 +46,7 @@ option(USE_NOVGUI_SCOREBOARD "Prefer non-VGUI Scoreboard when USE_VGUI is enable
 option(USE_VOICEMGR "Enable VOICE MANAGER." OFF)
 option(BUILD_CLIENT "Build client dll" ON)
 option(BUILD_SERVER "Build server dll" ON)
+option(POLLY "Enable pollyhedral optimization" OFF)
 
 if(CMAKE_SIZEOF_VOID_P EQUAL 4 OR
 	((WIN32 OR ${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
@@ -177,3 +178,11 @@ endif()
 if(NOT BUILD_SERVER AND NOT BUILD_CLIENT)
 	message(FATAL_ERROR "Nothing to build")
 endif()
+
+if(POLLY)
+	if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+		add_compile_options(-mllvm -polly)
+	elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+		add_compile_options(-fgraphite-identity -floop-interchange -floop-block)
+	endif()
+endif()