https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95717
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
The bogus def is set via
if (scalar_loop != loop)
{
/* If we copied from SCALAR_LOOP rather than LOOP, SSA_NAMEs from
SCALAR_LOOP will have current_def set to SSA_NAMEs in the new_loop,
but LOOP will not. slpeel_update_phi_nodes_for_guard{1,2} expects
the LOOP SSA_NAMEs (on the exit edge and edge from latch to
header) to have current_def set, so copy them over. */
slpeel_duplicate_current_defs_from_edges (single_exit (scalar_loop),
exit);
because that interferes with the renaming process. The if-conversion
applied the missed optimization to the to-be vectorized loop introducing
a LC PHI (required for the not if-converted copy) which has one invariant
and one non-invariant arg.
So we have to do that copying after renaming in the BBs. That seems to work,
testing patch.
