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

[fw at gcc dot gnu.org]

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

--- Comment #3 from Florian Weimer <fw at gcc dot gnu.org> ---
(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.