[Bug tree-optimization/107467] [12/13 Regression] Miscompilation involing -Os , -flto and -fno-strict-aliasing since r12-656-ga564da506f52be66

[hubicka at ucw dot cz via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107467

--- Comment #9 from Jan Hubicka  ---
> 
> so it's ICFed compare_pairs having modref TBAA info that makes the
> stores dead.  I suppose ICF needs to reset / alter the modref summaries?

Well, matching that ICF does should be enough to verify that modref
sumaries are same.  Modref only does what would happen after inlining
and ICF should be safe WRT both modref and inlining.

[Bug tree-optimization/107467] [12/13 Regression] Miscompilation involing -Os , -flto and -fno-strict-aliasing since r12-656-ga564da506f52be66

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107467

Richard Biener  changed:

   What|Removed |Added

   Last reconfirmed|2022-10-30 00:00:00 |2023-1-13
   Priority|P3  |P2

--- Comment #8 from Richard Biener  ---
> diff -u a.ltrans0.ltrans.115t.vrp1 a.ltrans0.ltrans.116t.dse2
...
 __attribute__((noinline, optimize ("strict-aliasing")))
 bool clashy.isra ()
 {
@@ -90,8 +64,6 @@
   bool _1;

[local count: 1073741824]:
-  D.5191 = get_const.isra ();
-  D.5190 = get_const.isra ();
   _1 = compare_pairs (&D.5190, &D.5191);

so it's ICFed compare_pairs having modref TBAA info that makes the
stores dead.  I suppose ICF needs to reset / alter the modref summaries?

[Bug tree-optimization/107467] [12/13 Regression] Miscompilation involing -Os , -flto and -fno-strict-aliasing since r12-656-ga564da506f52be66

[hubicka at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107467

Jan Hubicka  changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
   Assignee|unassigned at gcc dot gnu.org  |hubicka at gcc dot 
gnu.org

--- Comment #7 from Jan Hubicka  ---
mine.