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

[Steven Bosscher]

On Mon, Oct 15, 2012 at 7:45 PM, Eric Botcazou wrote:
> This extends the lifetime of the hard register up to the beginning of the
> function, causing reload to die on the complex division instruction.

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


> The attached patch prevents the invariant from being hoisted in this very
> particular case.  Any better idea?

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

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.

Ciao!
Steven