[Bug libstdc++/114865] [13/14/15 Regression] std::atomic::compare_exchange_strong seems to hang under GCC 13 for C++11

[pdimov at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114865

--- Comment #13 from Peter Dimov <pdimov at gmail dot com> ---
(In reply to Andrew Pinski from comment #10)
> #if __cplusplus >= 201402L && __has_builtin(__builtin_clear_padding)
>         if _GLIBCXX17_CONSTEXPR (__atomic_impl::__maybe_has_padding<_Tp>())
>           __builtin_clear_padding(std::__addressof(_M_i));
> #endif
> 
> So yes it is definitely dependent on C++ level ...
> That is for C++14+ it is working correctly.

Oh, that's the constructor of `atomic`. I thought it was the compiler
initializing the padding in C++14 and above.

I wonder why `__cplusplus >= 201402L` is here.