https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108356
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Andrew Macleod from comment #1) > From ccp2 : > > Simulating block 2 > > Visiting statement: > c.2_1 = c; > which is likely CONSTANT > Lattice value changed to VARYING. Adding SSA edges to worklist. > > > Whereas in GCC12 I see: > > Simulating block 2 > > Visiting statement: > c.2_1 = c; > which is likely CONSTANT > Lattice value changed to CONSTANT 3. Adding SSA edges to worklist. > marking stmt to be not simulated again > > > So we use to pick up that the memory load produces a 3 in CCP, but we no > longer do. I'm not sure how that specified ranger cache patch causes this? > ISTR some other PR where we aren't picking up a constant from a memory load > as well. The store c = 0 needs to be eliminated before IPA for that to work (and c promoted constant). Possibly some change in jump-threading?
