https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91425
--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- There are quite many different cases to test, and many *more* do not currently generate the wanted code because it isn't optimised properly on gimple level, and that makes it hard to test the RTL / target problems. That is all. After expand we still have multiple basic blocks for what should just be one comparison, and most RTL optimisations do not look in more than one BB at once.
