https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69983
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- So we fail analyzing the loop nest because a) the loop header check of the inner loop makes it conditionally executed, b) we have outer loop IV computes i+-1 guarded by that check. For a/b) it would be best if the outer loop were tail duplicated. Looking at the other reported fallout now.
