https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95489
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2020-06-03
Keywords| |easyhack
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
phiopt1 sees
<bb 2> :
if (x_3(D) != 0)
goto <bb 3>; [INV]
else
goto <bb 4>; [INV]
<bb 3> :
_1 = x_3(D) & y_4(D);
if (_1 != 0)
goto <bb 5>; [INV]
else
goto <bb 4>; [INV]
<bb 4> :
<bb 5> :
# iftmp.0_2 = PHI <1(3), 0(4)>
return iftmp.0_2;
and ifcombine_ifandif fails to combine the conditions via
maybe_fold_and_comparisons. Via ifcombine we're looking also
at simplifying
_tem1 = _1 != 0;
_tem2 = x_3(D) != 0;
_tem1 & _tem2
and thus
(bit_and (ne (bit_and x_3 y_4) 0) (ne x_3 0))
where I'd say we miss
(bit_and (ne @0 integer_zerop) (ne @1 integer_zerop))
->
(ne (bit_and @0 @1) integer_zerop)
if @0 and @1 have compatible enough types. That would probably do the
trick here. Eventually works for generic equal values besides zero.
And also for bit_ior (but there only for special constants).
