https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99422
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I see the function is called before selecting a particular alternative, so perhaps it means to care only about constraints like "X" and "" and not say that mixed with other constraints etc. But, shouldn't the code at least skip the =, +, &, % and whitespace from the start? What about other modifiers (the various disparage slightly etc. chars)? And only consider as empty constraint if after those skips constraint is ""? Not really sure if ",,," constraint is valid... And, regarding of Eric's change to handle "X" that way, does that really apply just to MEM and not SUBREG of MEM too?
