https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107114
--- Comment #2 from Jeffrey A. Law <law at gcc dot gnu.org> --- Which is just uber-weird. The change in question removes a little subloop which becomes unreachable. Why that would cause us to be unable to analyze the remaining key loop for the IV's range is a complete mystery. Though I guess I'll have to sit down and debug that a bit. VRP is just calling into the loop optimizer to to the IV analysis, right? WRT the new blocks -- I strongly suspect they're part of normalization of the loop and putting it into LCSSA form. I'm not terribly worried about them. Typically they're just going to be creating empty loop latches.
