[Bug tree-optimization/118657] Missed optimization (unreachable branch could be pruned after taking into account the possible values of a constexpr lookup table)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118657

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andi Kleen from comment #6)
> The C test case needs to use constexpr too.


No it does not. Const variables which are initialized at compile time should be
enough for the optimization. We already do it if the index is optimized to a
constant and has done that for years now.