-/* (Optional) Efficiently swap the bytes of a 16-bit integer. */
-#if GCC_PREREQ(4, 8) || __has_builtin(__builtin_bswap16)
-# define compiler_bswap16 __builtin_bswap16
-#endif
-
-/* (Optional) Efficiently swap the bytes of a 32-bit integer. */
-#if GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap32)
-# define compiler_bswap32 __builtin_bswap32
-#endif
-
-/* (Optional) Efficiently swap the bytes of a 64-bit integer. */
-#if GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap64)
-# define compiler_bswap64 __builtin_bswap64
-#endif
-