> Hi, > > # define likely(x) __builtin_expect(!!(x), 1) > # define unlikely(x) __builtin_expect(!!(x), 0) > > I see these !! in the above expressions. Please explain me the > meaning of those double exclamations. What is their significance ? > This is a kind of cast to a "bool". After applying !!(x), the value will be either 0 or 1. It's roughly equivalent to (((x) != 0) ? 1 : 0) Regards. -- Yann Droneaud OPTEYA _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
