https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121126
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
That means previously the
/* FORNOW: we currently don't support the case that these phis
2029 are not used in the outerloop (unless it is double
reduction,
2030 i.e., this phi is vect_reduction_def), cause this case
2031 requires to actually do something here. */
2032 if (STMT_VINFO_LIVE_P (stmt_info)
2033 && !vect_active_double_reduction_p (stmt_info))
2034 return opt_result::failure_at (phi,
2035 "Unsupported loop-closed
phi"
2036 " in outer-loop.\n");
2037
2038 /* If PHI is used in the outer loop, we check that its
operand
check might have avoided vectorization here. In particular the inner loop
has
# b_lsm... = PHI <_3>
defined outside of the loop - a missed propagation.
