CC0 to CCmode conversion

[Denis Chertykov]

Bernardo Innocenti <bernie@develer.com> writes:

> Denis Chertykov wrote:
> 
> > I have converted the AVR port from CC0 to CCmode.
> 
> That's indeed very good news.  Incidentally, CC0
> conversion of the AVR target was being discussed
> in an off-list thread with Andy Hutchinson.
> 
> 
> > But may be I have converted the port in wrong way.
> > (It's because I was interested in *this* way.)
> 
> Uh?  That's very bad news.
> 
> 
> > I have used CCmode register and havn't added the
> > '(clobber (reg:QI CC_REGNUM))' to any insn that really clobber the
> > CC_REGNUM just because AVR is'n needed in scheduling.
> > I think that sequence of compare + cond-jump will exists in any
> > compiler pass.
> > The port was successfully tested without new regressions.
> 
> Did you notice any pessimization spots in the generated
> code?  IIRC, the converted H8 backend required some
> massaging before it was back on par with the old
> version.

I have a bit pessimization but compare/branch operations can be
optimized even more than CC0 version.

Denis.