Re: Committed, MMIX: fix PR43889, missing earlyclobber exposed by r154688

[Bernd Schmidt <bernds at codesourcery dot com>]

On 04/27/2010 04:31 PM, Hans-Peter Nilsson wrote:
> I really see nothing wrong here and have to wonder where you're
> coming from, or what it is that I (and Bonzini, it seems) are
> missing.  Are you somehow not seeing the "=" on the clobber
> constraint?

I think I see your point now.  If the pseudo is live past the insn,
we'll choose a register for the pair of matching operands that doesn't
conflict with the pseudo.  That does seem to actually work.

Still, it's a baffling way to write the pattern, and I think it would be
somewhat cleaner to simply represent this with a "=r" constraint on the
scratch, with any necessary register moves handled in the pattern.


Bernd