https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107196
--- Comment #8 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
I confirm that today's master does not exhibit the failure. Bisecting to the
fix ends up at this fix:
commit c9b840db504d15db01f06fe1fec38282dbafee07
Author: Aldy Hernandez <al...@redhat.com>
Date: Mon Oct 17 18:56:24 2022 +0200
Make sure exported range for SSA post-dominates the DEF in
set_global_ranges_from_unreachable_edges.
The problem here is that we're exporting a range for an SSA range that
happens on the other side of a __builtin_unreachable, but the SSA does
not post-dominate the definition point. This is causing ivcanon to
unroll things incorrectly.
This was a snafu when converting the code from evrp.
PR tree-optimization/107293
Looks plausible?
