https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99504
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Keywords| |missed-optimization
Last reconfirmed| |2021-03-10
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is that in the pixel case we have an aggregate assignment:
<bb 3> [local count: 955630225]:
# p_17 = PHI <p_10(6), p_5(D)(5)>
# q_18 = PHI <q_9(6), q_6(D)(5)>
# i_19 = PHI <i_12(6), 0(5)>
q_9 = q_18 + 4;
p_10 = p_17 + 4;
*p_17 = *q_18;
i_12 = i_19 + 1;
if (n_8(D) != i_12)
goto <bb 6>; [89.00%]
else
goto <bb 4>; [11.00%]
and that's not handled by vectorization or dependence analysis.
We might want to consider applying the same folding to this as we do for
memcpy folding and turn it into
_42 = MEM<unsigned int> [q_18, (pixel *)0];
MEM<unsigned int> [q_17, (pixel *)0] = _42;
