https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112545
--- Comment #2 from Jeffrey A. Law <law at gcc dot gnu.org> ---
This looks like a missed case for singletons.
_1 = d.9_28 <= 0;
_2 = (signed short) _1;
_3 = (signed short) d.9_28;
c.a = 0;
if (_2 == _3)
goto <bb 4>; [0.00%]
else
goto <bb 5>; [100.00%]
Back substituting the condition is:
(d.9_28 <= 0) == d.9_28
d.9_28 <= 0 has a range [0,1]
The only value that can make that expression true is if d.9_28 has the value 0.
