[Bug c++/110304] __builtin_adcs missing and jakub you miss the point of builtin_adcb

[unlvsur at live dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110304

--- Comment #11 from cqwrteur <unlvsur at live dot com> ---
Actually mine 

template<::std::unsigned_integral T>
inline constexpr T add_carry(T a,T b,T carryin,T& carryout) noexcept
{
    [[assume(carryin==0||carryin==1)]];
    a+=b;
    carryout=a<b;
    a+=carryin;
    carryout+=a<carryin;
    return a;
}

can be pattern-matching without builtins. This might be more universal and be
optimized very early on.