------- Comment #16 from hjl dot tools at gmail dot com 2010-09-16 13:59
(In reply to comment #13)
> With that patch the assignment generated from memcpy doesn't need more
> that int alignment, but still cfgexpand.c sets DECL_ALIGN of the
> decl to 128 so expand uses aligned instructions.
> cfgexpand.c should not increase alignment and not set 'needs stack
> alignment' then, based on your comment #10. So this _is_ about
> stack alignment (but maybe not exclusively).
When we do
__m128 *p = (__m128 *) &d;
all bets are off.