+
+// Hide a GCC specific thing that breaks MSVC if left alone.
+# define __extension__
+
+#ifdef _M_IX86_FP
+# define FOLLY_SSE _M_IX86_FP
+# define FOLLY_SSE_MINOR 0
+#endif
+
+#endif
+
+#ifndef FOLLY_SSE
+# if defined(__SSE4_2__)
+# define FOLLY_SSE 4
+# define FOLLY_SSE_MINOR 2
+# elif defined(__SSE4_1__)
+# define FOLLY_SSE 4
+# define FOLLY_SSE_MINOR 1
+# elif defined(__SSE4__)
+# define FOLLY_SSE 4
+# define FOLLY_SSE_MINOR 0
+# elif defined(__SSE3__)
+# define FOLLY_SSE 3
+# define FOLLY_SSE_MINOR 0
+# elif defined(__SSE2__)
+# define FOLLY_SSE 2
+# define FOLLY_SSE_MINOR 0
+# elif defined(__SSE__)
+# define FOLLY_SSE 1
+# define FOLLY_SSE_MINOR 0
+# else
+# define FOLLY_SSE 0
+# define FOLLY_SSE_MINOR 0
+# endif