Make the CPUSTRING and additional from default optimizations configureable

neo/CMakeLists.txt

@@ -36,6 +36,10 @@ option(USE_SYSTEM_LIBJPEG
 option(USE_SYSTEM_LIBGLEW
                 "Use the system libglew instead of the bundled one" OFF)
 
+set(CPU_TYPE "" CACHE STRING "When set, passes this string as CPU-ID and disables CPU specific optimizatin which are not default for the compiler")
+
+set(CPU_OPTIMIZATION "-mmmx -msse -msse2" CACHE STRING "Which CPU specific optimitations should be used beside the compiler's default?")
+
 if(UNIX)
 	set(OPENAL TRUE)
 endif()
@@ -61,7 +65,12 @@ if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
 	#add_definitions(-Wall)
 	add_definitions(-Werror=format-security)
 	add_definitions(-Werror=format)
-	add_definitions(-mmmx -msse -msse2)
+	if(CPU_TYPE)
+		add_definitions(-DCPUSTRING="${CPU_TYPE}")
+	endif()
+	if (CPU_OPTIMIZATION)
+		add_definitions(${CPU_OPTIMIZATION})
+	endif()
 	if(WIN32)
 		# require msvcr70.dll or newer for _aligned_malloc etc
 		# I think it is from Visual C++ .NET 2002, so it should be available on any remotely modern system.

neo/idlib/sys/sys_defines.h

@@ -104,10 +104,14 @@ If you have questions concerning this license or the applicable additional terms
 
 #elif defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__)
 
+#ifndef CPUSTRING
 #if defined(__i386__)
 #define	CPUSTRING						"x86"
 #elif defined(__x86_64__)
 #define CPUSTRING						"x86_86"
+#else
+#error unknown CPU
+#endif
 #endif
 
 #if defined(__FreeBSD__)

neo/idlib/sys/sys_intrinsics.h

@@ -29,7 +29,10 @@ If you have questions concerning this license or the applicable additional terms
 #ifndef __SYS_INTRIINSICS_H__
 #define __SYS_INTRIINSICS_H__
 
+#if defined(__x86_64__)
+// Enable this only on amd64
 #define USE_INTRINSICS
+#endif
 
 #if defined(USE_INTRINSICS)
 #include <emmintrin.h>