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

[njuwy at smail dot nju.edu.cn via Gcc-bugs]

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

--- Comment #5 from Anonymous <njuwy at smail dot nju.edu.cn> ---
(In reply to Jakub Jelinek from comment #4)
> If you want a constant expression in C, use constexpr keyword in C23 or an
> enumerator.

Got it, thanks again.