Re: RFA: Fix rtl-optimization/22258

[Dale Johannesen <dalej at apple dot com>]

On Jun 30, 2005, at 1:37 PM, Joern RENNECKE wrote:
> Bernd Schmidt wrote:
>
> >    Ok, I see.  I must say I'm not very fond of introducing hard reg 
> > references into complex insns during combine; I'd prefer 
> > cant_combine_insn_p to just reject any moves involving hardregs.  My 
> > initial version of that function did that, but in
> >    http://gcc.gnu.org/ml/gcc-patches/2002-05/msg01216.html
> > Dale Johannesen claims that restricting the test to 
> > CLASS_LIKELY_SPILLED_P is a win on PPC.  I'm curious why.
>
> It is also a win on the SH, because arguments that are passed in 
> registers can be put directly into the right register.

I'm fairly sure this was the reason on ppc also.  I'm entirely sure it 
was a win experimentally.