On Fri, Dec 5, 2014 at 6:15 PM, Eric Botcazou <ebotca...@adacore.com> wrote: >> --quote-- >> If we want to use this pass for x86, then for 4.8 we should also fix the >> discrepancy between the compare-elim canonical >> >> [(operate) >> (set-cc)] >> >> and the combine canonical >> >> [(set-cc) >> (operate)] >> >> (Because of the simplicity of the substitution in compare-elim, I prefer >> the former as the canonical canonical.) >> --/quote-- > > I agree with the above. > >> There were some patches flowing around [2], [3] that enhanced >> compare-elim pass for x86 needs, but the target never switched to new >> pass, mostly because compare-elim pass did not catch all cases that >> traditional RTX combine pass did. > > Does [2] really work with the mode mismatch? See the pending patch at > https://gcc.gnu.org/ml/gcc-patches/2014-11/msg03458.html > >> Due to the above, I would like to propose that existing RTX compare >> pass be updated to handle [(operate)(set-cc)] patterns (exclusively?). > > That's already what it does though, did you mean the opposite? Or did you > mean to write "combine" instead of "compare"?
The above should read "... that existing RTX *combine* pass be updated ...", thanks for pointing out! Uros.
