https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106895
--- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> --- (In reply to Nicholas Piggin from comment #9) > I don't know why constraint is wrong and mode is right Simple: you would need O(2**T*N) constraints for our existing N register constraints, together with T features like this. But only O(2**T) modes at most. > or why TI doesn't work but PTI apparently would, Because this is exactly what PTImode is *for*! > but I'll take anything that works. Could we > get PTI implemented? Does it need a new issue opened? It was implemented in 2013. The restriction to only even pairs was a bugfix, also from 2013. If you have code like typedef __int128 __attribute__((mode(PTI))) even; you get an error like error: no data type for mode 'PTI' This needs fixing. You can keep it in this PR?
