https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82828
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
This testcase is invalid, it is accessing uninitialized value (x).
XFtype ac, bd, ad, bc, x, y;
ac = a * c;
__asm__ ("": "=m" (ac):"m" (ac));
if (x != x)