https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99078
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2021-02-12
Known to work| |6.5.0
Summary|Optimizer moves struct |[8/9/10/11 Regression]
|initialization into loop |Optimizer moves struct
| |initialization into loop
Ever confirmed|0 |1
Component|c++ |tree-optimization
Keywords| |missed-optimization
Known to fail| |11.0, 7.5.0
Status|UNCONFIRMED |NEW
Priority|P3 |P2
CC| |jamborm at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Target Milestone|--- |8.5
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed. It is SRA that with total scalarization re-materializes 's' before
the aggregate use it cannot transform (*dest_106 = s). Looks like quite
pointless in any case (removing one set of inits just to re-emit them for
the single remat case), maybe there's no costing involved at all?
There isn't really sth like a pass that hoists stores so undoing this
is really hard which means better avoid total scalarization of sth
where rematerialization in a bigger loop depth is required?
--- t.C.117t.cplxlower1 2021-02-12 09:17:00.278704232 +0100
+++ t.C.118t.sra 2021-02-12 09:17:00.278704232 +0100
...
@@ -10,26 +58,46 @@
<bb 2> [local count: 118111600]:
s = {};
- s.c[1] = 1;
- s.c[2] = 2;
- s.c[3] = 3;
- s.c[4] = 4;
- s.c[5] = 5;
- s.c[6] = 6;
- s.c[8] = 8;
- s.c[9] = 9;
- s.c[10] = 10;
- s.c[11] = 11;
- s.c[12] = 12;
- s.c[13] = 13;
- s.c[14] = 14;
- s.c[16] = 16;
- s.c[17] = 17;
- s.c[18] = 18;
- s.c[19] = 19;
- s.c[20] = 20;
- s.c[21] = 21;
- s.c[22] = 22;
+ s$c$1_12 = 0;
+ s$c$2_5 = 0;
+ s$c$3_4 = 0;
+ s$c$4_101 = 0;
+ s$c$5_100 = 0;
+ s$c$6_99 = 0;
+ s$c$8_116 = 0;
+ s$c$9_119 = 0;
+ s$c$10_121 = 0;
+ s$c$11_124 = 0;
+ s$c$12_126 = 0;
+ s$c$13_129 = 0;
+ s$c$14_131 = 0;
+ s$c$16_64 = 0;
+ s$c$17_66 = 0;
+ s$c$18_69 = 0;
+ s$c$19_71 = 0;
+ s$c$20_74 = 0;
+ s$c$21_76 = 0;
+ s$c$22_79 = 0;
+ s$c$1_81 = 1;
+ s$c$2_84 = 2;
+ s$c$3_86 = 3;
+ s$c$4_89 = 4;
+ s$c$5_91 = 5;
+ s$c$6_94 = 6;
+ s$c$8_96 = 8;
+ s$c$9_29 = 9;
+ s$c$10_31 = 10;
+ s$c$11_34 = 11;
+ s$c$12_36 = 12;
+ s$c$13_39 = 13;
+ s$c$14_41 = 14;
+ s$c$16_44 = 16;
+ s$c$17_46 = 17;
+ s$c$18_49 = 18;
+ s$c$19_51 = 19;
+ s$c$20_54 = 20;
+ s$c$21_56 = 21;
+ s$c$22_59 = 22;
count_104 = count_20(D) + 4294967295;
if (count_20(D) != 0)
goto <bb 3>; [89.00%]
@@ -40,6 +108,26 @@
# dest_106 = PHI <dest_19(D)(2), dest_25(3)>
# count_114 = PHI <count_104(2), count_23(3)>
dest_25 = dest_106 + 24;
+ s.c[1] = s$c$1_81;
+ s.c[2] = s$c$2_84;
+ s.c[3] = s$c$3_86;
+ s.c[4] = s$c$4_89;
+ s.c[5] = s$c$5_91;
+ s.c[6] = s$c$6_94;
+ s.c[8] = s$c$8_96;
+ s.c[9] = s$c$9_29;
+ s.c[10] = s$c$10_31;
+ s.c[11] = s$c$11_34;
+ s.c[12] = s$c$12_36;
+ s.c[13] = s$c$13_39;
+ s.c[14] = s$c$14_41;
+ s.c[16] = s$c$16_44;
+ s.c[17] = s$c$17_46;
+ s.c[18] = s$c$18_49;
+ s.c[19] = s$c$19_51;
+ s.c[20] = s$c$20_54;
+ s.c[21] = s$c$21_56;
+ s.c[22] = s$c$22_59;
*dest_106 = s;
count_23 = count_114 + 4294967295;
if (count_114 != 0)
