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Re: A plan for eliminating cc0
Richard Henderson <rth@redhat.com> writes:
> Note that there's no longer any insn that *sets* cc_reg. I think
> that's a bit dangerous.
Hmmm, good point.
> One solution to this is to convert the new setter to
>
> [(set (reg 1) (plus (reg 1) (reg 2)))
> (set (reg cc_reg) (unspec [(const_int 0)] cc_set))]
>
> I don't think it matters what we set cc_reg to, just that *some*
> set is visible in the instruction stream.
>
> This requires that we generate two patterns for clobbercc insns,
> but that shouldn't be a problem.
Makes sense.
Ian