https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105740
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The problem with switch-conversion done multiple times is that when it is done early, it can do worse job than when it is done late, e.g. we can have better range information later which allows (unfortunately switch-conversion doesn't use that yet, there is a PR about it) to ignore some never reachable values etc. So ideally we either need to be able to undo switch-conversion and redo it if things have changed, or do it only late and for e.g. inlining costs perform it only in analysis mode and record somewhere what kind of lowering would be done and how much it would cost. With multiple if-to-switch, don't we risk that we turn some ifs into switch, then switch-conversion lowers it back to ifs and then another if-to-switch matches it again and again lowers it?
