On Thu, 2020-04-23 at 07:41 +0530, Senthil Kumar wrote: > On Wed, Apr 22, 2020 at 10:08 PM Jeff Law <l...@redhat.com> wrote: > > On Wed, 2020-04-22 at 22:01 +0530, Senthil Kumar via Gcc wrote: > > > Hi, > > > > > > I'm thinking about attempting to do the CC0 transition for the > > > AVR port in my spare time. I've read the CC0Transition gcc wiki > > > page, and as the AVR ISA does not have non-condition-code > > > clobbering arithmetic instructions, concluded that I'd have to > > > follow the steps outlined for case #2. > > > > > > Are there any other things I need to watch out for? > > Not offhand. You might want to look at how Bernd did the m68k though. I > > think a > > conceptually similar transition would be reasonable for AVR as well as the > > alternative would be dropping the AVR port. > > Hi Jeff, > > Thanks, I will take a look at Bernd's work. IIRC, he took a > different approach from what was suggested in the wiki, right? Right. Conceptually he brought the cc0-setter insn back into the cc0-user insn, but kept some ability to remove the cc0-setter when the previous insn had set the condition codes in a useful way.
Jeff >
