--- /dev/null
+
+#ifdef __GNUC__
+# define likely(x) __builtin_expect((x),1)
+# define unlikely(x) __builtin_expect((x),0)
+#else
+# define likely(x) (x)
+# define unlikely(x) (x)
+#endif
+
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#endif
+