https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110061
--- Comment #15 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to Wilco from comment #14)
> (In reply to Wilco from comment #13)
> > (In reply to Xi Ruoyao from comment #12)
> > > (In reply to Wilco from comment #11)
> > >
> > > > > Then the compiler (and the standard) is not what they consider. Such
> > > > > misunderstandings are everywhere and this has no difference.
> > > >
> > > > Where is int128 in "the standard"?
> > >
> > > Consider this:
> > >
> > > const _Atomic long double x = 0.1;
> > >
> > > int main()
> > > {
> > > double y = x;
> > > return y != 0.1;
> > > }
> > >
> > > If CAS is used here, the program will just segfault. Does the standard
> > > say
> > > this is ill-formed or not?
> >
> > I'd say this is ill formed yes. And it will crash on Atom laptops.
>
> Correction - it crashes on all AMD cpus too. Are you going to file
> bugreports for this?
PR95722.
