# define AV_GCC_VERSION_AT_MOST(x,y) 0
#endif
+#ifdef __has_builtin
+# define AV_HAS_BUILTIN(x) __has_builtin(x)
+#else
+# define AV_HAS_BUILTIN(x) 0
+#endif
+
#ifndef av_always_inline
#if AV_GCC_VERSION_AT_LEAST(3,1)
# define av_always_inline __attribute__((always_inline)) inline