[Bug middle-end/112572] [14 regression] LLVM miscompiled since r14-5355-g3cd3a09b3f91a1

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112572

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-11-18
             Status|UNCONFIRMED                 |NEW

--- Comment #18 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This fixes the issue for me:
```
diff --git a/gcc/compare-elim.cc b/gcc/compare-elim.cc
index c59dc0cf5a5..50424bdfa09 100644
--- a/gcc/compare-elim.cc
+++ b/gcc/compare-elim.cc
@@ -908,6 +908,7 @@ static unsigned int
 execute_compare_elim_after_reload (void)
 {
   df_set_flags (DF_LR_RUN_DCE);
+  df_note_add_problem ();
   df_analyze ();

   gcc_checking_assert (!all_compares.exists ());

```

compare-elim.cc depends on up to date REG_UNUSED and between before vzeroupper
and cmpelim the note gets out of date.