+#elif _MSC_VER < 1600
+
+// '_xgetbv()' was only available from VC10 onwards
+__declspec(noinline) static uint64_t
+_xgetbv (uint32_t xcr)
+{
+ return 0;
+
+ // N.B. The following would probably work for a pre-VC10 build,
+ // although it might suffer from optimization issues. We'd need
+ // to place this function into its own (unoptimized) source file.
+ __asm {
+ mov ecx, [xcr]
+ __asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0 /*xgetbv*/
+ }
+}