https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118241
--- Comment #7 from Jeffrey A. Law <law at gcc dot gnu.org> --- Ah nuts! My mistake, I conflated this issue which is "prefetch" with the other issue in the "prefetchi" space. "prefetchi" is broken and likely requires a deeper fix than what we need here. I don't see a good path for Andrew's suggestion. The "prefetch" pattern name is special and does not include a mode. So there's can be one and only one. That in turn means that there's no way to support different mode operands, which is important as a pointer might be SI or DI. So while we could have a prefetch expander, its operands would continue to be modeless and would then match a X mode on their associated insn. I'm not sure that's an improvement over what we've currently got. The most straightforward path here is to tighten up the operands which probably needs to be done anyway. I think the biggest question is whether or not we try to support offsets. They don't seem difficult, we just need to reject those where the bottom 4 bits are nonzero. I'll play a bit with that to see if there are any surprises.
