[Bug c/121479] The return value of __builtin_constant_p() is inconsistent at different optimization levels

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121479

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
If you want a constant expression in C, use constexpr keyword in C23 or an
enumerator.