> 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