[Bug target/85939] -mstackrealign does not realign stack with local __m64 variable

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85939

--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Uroš Bizjak from comment #5)
> (In reply to Florian Weimer from comment #3)
> > (In reply to Uroš Bizjak from comment #1)
> > > Please also use -mincoming-stack-boundary=2 to tell the compiler about
> > > possible incoming stack (mis)alignment.
> > 
> > This does change the result; alignment is performed.  This is not
> > documented.  I'm not sure what the intent is here.
> > 
> > (In reply to Uroš Bizjak from comment #2)
> > > FYI, -mstackrealign applies only to main ().
> > 
> > I don't think this is true.  In the example, stack alignment is performed if
> > I use __m128 instead of __m64.
> 
> Let's add HJ to CC, maybe he can shed some light on this option.

I believe __m64 is 4-byte aligned.