https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121383
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- if-conversion does nothing to loops with multiple exits. One could think to sub-divide its work, but in this case there's a lack of PHIs and the expected if-conversion is on control dependences rather than data dependences. I would rather see this as an opportunity to look how to handle such cases in the vectorizer itself?