GCC 4.4: Avoid range check on switch/case statement in gcc?

Question

This is only an issue on GCC versions prior to 4.4, this was fixed in GCC 4.5.

Is it possible to tell the compiler the variable used in a switch fits within the provided

Answer 1

I didn't try, but I'm not sure that gcc_unreachable does the same thing as __builtin_unreachable. Googling the two, gcc_unreachable appears to be designed as a as an assertion tool for development of GCC itself, perhaps with a branch prediction hint included, whereas __builtin_unreachable makes the program instantly undefined — which sounds like deleting the basic block, which is what you want.

http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#index-g_t_005f_005fbuiltin_005funreachable-3075