RE: Ping: [PATCH GCC/ARM] Fix problem that hardreg_cprop opportunities are missed on thumb1

[Bin Cheng]

> >
> > Yes, it may be feasible to rewrite the instruction in machine reorg
> > pass, rather than peephole2. But that need bigger change in ARM back
end.
> > Hi Ramana, Richard, what's your opinion on this?
> >
> > Thanks very much.
> >
> >
> 
> I side with Richard on this one.  The mid-end should only have to deal
with
> RTL that's in canonical form.
> 
So how about rewrite mov insn into sub in machine reorg pass and remove the
current peeophole2 codes?

Thanks