https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94567
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Jeffrey A. Law from comment #7) > I think it's trying to use smaller modes because the encodings can be > smaller. In other cases it changes the mode to avoid partial register > stalls. It's a bit of a mess. > > WRT the fragment you mentioned, I looked at that repeatedly trying to > ascertain the real motivation and whether or not that code needed > generalization to handle this case or was a misguided attempt to fix another > instance of this issue. > > The conclusion I came to was that hunk of code may well be working around > another instance of this same problem, but it was neither generalizable to > this BZ nor would my approach totally fix that instance. > > We may be able to remove the hack in the testqi_ext_3 pattern, but I think > the corresponding hack in testdi_1 would have to stay unless we found a way > to merge testdi_1 into the more general test<mode>_1 pattern. Neither of > those seems terribly appropriate right now. agreed
