https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119797
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- There is a patch which should improve/fix this situtation proposed for GCC 16 (it was actually submitted a few months ago but reviews on it has been slow). Basically because of optimization (jump threading) we know in some cases r will be out of bounds. In Bug, either add: if (r >= std::size(BUG)) std::unreachable (); // or //__builtin_unreachable(); or something similar at the begining of the function to signal that r being greater than the size of the BUG array is invalid.
