unlikely
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
# define unlikely(x) __builtin_expect(!!(x), 0)
#define unlikely(cond) (cond)
#define unlikely(x) __builtin_expect(!!(x), 0)
# define unlikely(x) __builtin_expect(!!(x), 0)
#define unlikely(x) (__builtin_expect(!!(x), 0))
#define unlikely(x) __builtin_expect(!!(x), 0)
#define unlikely(cond) (cond)
#define unlikely(x) __builtin_expect(!!(x), 0)
#define unlikely
#define unlikely(x) __builtin_expect(!!(x), 0)
# define unlikely(x) (__builtin_expect(!!(x), 0))
#define unlikely(x) (__builtin_expect(!!(x), 0))