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Re: [RFC] Fix spill failure at -O on 64-bit Windows


> Does this still happen after my patch from yesterday to use DF_LIVE in IRA?

Yes, it even fails at -O2.

> Maybe add a cost-free dependency on the clobber, so that it's moved
> with the insn?

Maybe.  But I'm a little worried about (1) extending the lifetime of the hard 
register and (2) simply moving around a clobber of a hard register.

> And/or maybe punt on all likely_spilled hard registers if
> -fira-loop-pressure is not in effect, it's unlikely to be a win in any
> case.

I'd like to keep the change minimal, in particular restricted to uninitialized 
hard registers.  The failure mode is very specific (and might be unique to the 
64-bit ABI on Windows) so I'm not sure it's worth generalizing.

-- 
Eric Botcazou


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