https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111901
--- Comment #15 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Uroš Bizjak from comment #13)
> (In reply to Eric Botcazou from comment #12)
>
> > So what about just marking inline asms with memory clobber as having side
> > effects?
> I guess this would work, the compiler must preserve side effects when
> optimizing.
FTR, clobbers are already marked as having side effects:
side_effect_p ():
case CLOBBER:
/* Reject CLOBBER with a non-VOID mode. These are made by combine.cc
when some combination can't be done. If we see one, don't think
that we can simplify the expression. */
return (GET_MODE (x) != VOIDmode);
