https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103316
--- Comment #6 from Segher Boessenkool <segher at gcc dot gnu.org> --- Ah, now I see. Thanks! Power10 has some new 128-bit insns (and p9 and p8 did before, too). I still think it would be best if Gimple did *never* split data. It simply does not know enough about the machine and what the eventual machine code will be like to do so advantageously. This is the kind of thing that RTL can do much better, is much better positioned to do (and in fact it does do this, in all subregN passes).