http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61082
--- Comment #10 from David Greene <greened at obbligato dot org> ---
(In reply to H.J. Lu from comment #9)
> Y is returned as {NO_CLASS, INTEGER} in register. psABI doesn't
> explicitly say how NO_CLASS should be handled in this case. GCC
> simply skips NO_CLASS when assigning it to a register.
Except section 3.2.3 when talking about classifying aggregates says under point
4 (b):
If one of the classes is NO_CLASS, the resulting class is the other class.
So Y should be classified as INTEGER and returned in (RAX, RDX).
