https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125444
Drea Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2026-05-25
CC| |aoliva at gcc dot gnu.org
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> ---
ifcombine causes the issue.
Before ifcombine we have:
```
_5 = b.1_1 ^ 65533;
b = _5;
_2 = (unsigned char) _5;
_13 = _5 & 240;
if (_13 != 0)
goto <bb 6>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 4> [local count: 488069348]:
if (_2 != 0)
goto <bb 6>; [67.00%]
else
goto <bb 5>; [33.00%]
<bb 5> [local count: 161062884]:
marker_171 ();
```
So this is basically
if ((_5&0xf0 == 0) & (_5&0xff == 0))
marker_171 ();
Which should be optimized to:
if (_5&0xff == 0)
marker_171 ();
But rather we are converting changing the conditional to 0; the ^ -3 seems to
be getting in the way.
