https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95034
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So after phiopt2 we end up with:
```
_1 = a_3(D) | b_4(D);
if (_1 != 0)
goto <bb 3>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 3> [local count: 536870912]:
_5 = a_3(D) & b_4(D);
_7 = ~_5;
<bb 4> [local count: 1073741824]:
# iftmp.0_2 = PHI <_7(3), 0(2)>
```
Phi-opt does not support more than one statement inside the middle BB so it
does nothing here.
But if we rewrite it such that the 2 statements were not inside the middle BB
by phiopt2, we get the xor as expected.
That is:
```
bool f(bool a, bool b)
{
bool c = a | b;
bool d = a & b;
d = !d;
return c ? d : false;
}
```
Will produce:
```
_8 = a_3(D) ^ b_4(D);
return _8;
```
>From the phiopt2 dump:
```
Folded into the sequence:
_8 = a_3(D) ^ b_4(D);
```
I wonder if we could support more than 1 statement in the middle BBs iff the
resulting simplifications only reference one SSA_NAME of the statements max ...
