https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116307
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Keywords| |missed-optimization
Last reconfirmed| |2024-08-19
Ever confirmed|0 |1
CC| |hubicka at gcc dot gnu.org
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is that get_val() might not return so that function can be called
three times without a->a[2] then invoking undefined behavior. The unroller
lacks placing of gcc_unreachable () before such references. That's a
missed optimization that in turn causes these kind of issues.
I think we have plenty of duplicates of this underlying issue.
Honza might know if it is possible to place additional unreachables for the
recorded bounds in the last copied iteration.
