https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105740
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- IIRC switch conversion was run early originally because it was supposed to improve inlining heuristics. One might view if-to-switch + switch-conversion as canonicalization which would mean running it before things like jump threading or loop opts (most don't like switches at least). Then one might view if-to-switch + switch-conversion as (target specific) code generation optimization (for that we also have pass_lower_switch, so one thing would be re-running if-to-switch before that again, supposed pass_lower_switch also performs the transforms switch-conversion does). I usually don't like running things again and again.
