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Re: New insns for the s390 backend (3)
Hello Richard,
> I think you only need splitters here, not insn_and_split.
The additional insn definition is mandatory otherwise combine would never
create an AND rtx with such a high constant because s390 doesn't provide an
appropriate instruction. Therefore the splitter would never get a chance.
> Moreover, I don't see why reload_completed is relevant.
This is true. Omitting the reload_completed constraint would make no
difference. It was just included to make it explicit that this splitter is
one of the after-reload-kind. Not a good idea?
> It would probably be best if you arranged for the new
> insn to be generated immediately from anddi3 instead of
> waiting for combine to clean it up.
Unfortunately the patterns for AND and llgt differ a lot from each other.
Covering both instructions with the same pattern would probably lead to a
more complicated construction. I would not be very happy with a complex insn
for "anddi3" & co to cover the special case of llgt.
Andreas