This should be a post-reload (i.e. predicated on reload_completed) split, I think.Actually, with the relatively recent lower-subreg work, it is desirable to split this sort of instruction before reload. That is, do an unconditional split.
Right. Combine cannot cope with the resulting 4-insn sequence and merge it back with the multiplication, but split is ran after combine and before the second lower-subreg pass.
So, making this an unconditional split should be the best of both worlds.
Paolo
