https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114346
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu.org
Status|UNCONFIRMED |NEW
Last reconfirmed| |2024-03-15
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I'll note the missing constant folding of
_72 = VIEW_CONVERT_EXPR<vector([2,2]) unsigned int>({ POLY_INT_CST [4, 4],
... });
(it's just a sign change)
Note the vectorizer generates
<bb 15> [local count: 94607391]:
vect_cst__44 = { POLY_INT_CST [4, 4], ... };
vect_cst__47 = { POLY_INT_CST [2, 2], ... };
_68 = niters.4_23 - POLY_INT_CST [4, 4];
<bb 3> [local count: 860067200]:
# res_17 = PHI <res_13(6), b_9(D)(15)>
# i_19 = PHI <i_14(6), 0(15)>
# vect_res_17.6_42 = PHI <vect_res_13.15_61(6), { 0.0, ... }(15)>
# vect_res_17.6_43 = PHI <vect_res_13.15_62(6), { 0.0, ... }(15)>
# vect_vec_iv_.7_45 = PHI <_49(6), { 0, 1, 2, ... }(15)>
# vectp_data.8_50 = PHI <vectp_data.8_51(6), data_12(D)(15)>
# ivtmp_69 = PHI <ivtmp_70(6), 0(15)>
_46 = vect_vec_iv_.7_45 + vect_cst__44;
_48 = vect_vec_iv_.7_45 + vect_cst__47;
_49 = _48 + vect_cst__47;
_1 = (long unsigned int) i_19;
_2 = _1 * 8;
_3 = data_12(D) + _2;
vect__4.10_52 = MEM <vector([2,2]) double> [(double *)vectp_data.8_50];
vectp_data.8_53 = vectp_data.8_50 + POLY_INT_CST [16, 16];
vect__4.11_54 = MEM <vector([2,2]) double> [(double *)vectp_data.8_53];
_4 = *_3;
vect__5.13_55 = (vector([2,2]) signed long) vect_vec_iv_.7_45;
vect__5.12_56 = (vector([2,2]) double) vect__5.13_55;
vect__5.13_57 = (vector([2,2]) signed long) _48;
vect__5.12_58 = (vector([2,2]) double) vect__5.13_57;
_5 = (double) i_19;
vect__6.14_59 = vect__4.10_52 * vect__5.12_56;
vect__6.14_60 = vect__4.11_54 * vect__5.12_58;
_6 = _4 * _5;
vect_res_13.15_61 = vect__6.14_59 + vect_res_17.6_42;
vect_res_13.15_62 = vect__6.14_60 + vect_res_17.6_43;
res_13 = _6 + res_17;
i_14 = i_19 + 1;
vectp_data.8_51 = vectp_data.8_53 + POLY_INT_CST [16, 16];
ivtmp_70 = ivtmp_69 + POLY_INT_CST [4, 4];
if (ivtmp_70 <= _68)
goto <bb 6>; [89.00%]
so there's just one IV here (the reduction needs two)
_46 = vect_vec_iv_.7_45 + vect_cst__44;
_48 = vect_vec_iv_.7_45 + vect_cst__47;
_49 = _48 + vect_cst__47;
looks somewhat redundant but the result you quote is from applying VN
and match.pd patterns. And in the original I can't
see the promotion to unsigned (possibly caused by some match.pd):
Value numbering stmt = _49 = _48 + vect_cst__47;
Setting value number of _49 to _49 (changed)
Matching expression match.pd:163, gimple-match-10.cc:57
Matching expression match.pd:163, gimple-match-10.cc:57
Matching expression match.pd:163, gimple-match-10.cc:57
Applying pattern match.pd:3561, gimple-match-8.cc:746
gimple_simplified to _71 = VIEW_CONVERT_EXPR<vector([2,2]) unsigned
int>(vect_vec_iv_.7_45);
_72 = VIEW_CONVERT_EXPR<vector([2,2]) unsigned int>({ POLY_INT_CST [4, 4], ...
});
_73 = _71 + _72;
_49 = VIEW_CONVERT_EXPR<vector([2,2]) int>(_73);
it seems we think that (x + POLY_INT_CST) + POLY_INT_CST cannot be
associated with signed. And we fail to value-number both increments
to the same value because of that. Also _46 is dead, so the first thing
is to see where we code-generate those initial stmts.
