On Thu, Dec 12, 2019 at 07:43:58AM +0100, Stefan Franke wrote: > The problems are in the gcc implementation > > - the lra implementation is buggy
Patches welcome. Bug reports welcome. "It does not work" does not really help anyone -- you don't even say *what* doesn't work. > - the compare elimination can't handle parallel's containing a compare > - df-core considers parallel's containing a compare also as a USE > - some optimizations/mechanisms do only work if HAVE_CC0 is defined > - way more ... Patches welcome. Bug reports welcome. > And the current implementation is IMHO unusable for lra since it did not > introduce a CC register to track clobbering. So it's a dead end. I disagree. There *is* nothing to clobber, during LRA. There are no live values. Segher
