Hint GCC on branch prediction

Declare and use the macros:

	#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

view raw branch_predict_decl.c hosted with ❤ by GitHub

	if (UNLIKELY(x != OK))
	{
	/* ... */
	}

view raw branch_predict_use.c hosted with ❤ by GitHub