[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 --- Comment #7 from Andrew Macleod --- We probably do need to revisit some pass ordering. I hope to do even less propagation within the VRPs next release, so I would expect running copyprop afterwards would be worthwhile.
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 Andrew Pinski changed: What|Removed |Added Resolution|FIXED |WONTFIX --- Comment #6 from Andrew Pinski --- This bug was asking explictly for evpr to do that. So closing as won't fix then. The reasoning why I filed this bug is because between evrp and phiopt1 there is not a copy prop pass. The next copy prop pass is not until after inlining so we might not inline as much either. So either we need to reorder some passes around or add a copy prop pass sooner.
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 Andrew Macleod changed: What|Removed |Added Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #5 from Andrew Macleod --- We perform this optimization in appropriate places. EVRP uses ranges to remove the | -128 leaving the statement as a copy. Although we could then propagate the copy into the PHI node, I think we should leave that to the copy propagation and PHIOPT passes, as we could also make poor decisions since we are doing it with no context. EVRP is enabling the other passes to do their job, and GCC turns this into "return a" as expected.
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 Andrew Pinski changed: What|Removed |Added CC||rguenth at gcc dot gnu.org --- Comment #4 from Andrew Pinski --- *** Bug 77893 has been marked as a duplicate of this bug. ***
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 --- Comment #3 from Andrew Macleod --- And BTW, we do this optimization, just not completely in evrp. EVRP removes the extraneous | -128 since that is a range related action. Constant propagation handles the propagation of the copy into the PHI, I'm not sure we also need to do it in a VRP pass.
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 Andrew Macleod changed: What|Removed |Added CC||amacleod at redhat dot com --- Comment #2 from Andrew Macleod --- I can tweak it so that we do register the equivalence with ranger by reprocessing statements after a successful simplify or fold: === BB 3 a_2(D) signed char [-INF, -1] Equivalence set : [a_2(D), v_4] : v_4 = a_2(D); v_4 : signed char [-INF, -1] === BB 4 : # v_1 = PHI but it doesn't buy us much on its own. Later passes propagate a_2 into the PHI and then fold the PHI into a copy regardless. We could in theory do that in EVRP too, but it seems like something copy propagation or PHI-opt would handle more naturally. The arguments can come from an arbitrary list of equivalences and yet resolve to the same value... but we need to pick the right one. That said, its probably worth getting the equivalence added because that could be useful in other ways too.
[Bug tree-optimization/103221] evrp removes |SIGN but does not propagate the ssa name
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103221 Richard Biener changed: What|Removed |Added Last reconfirmed||2021-11-15 Status|UNCONFIRMED |NEW Ever confirmed|0 |1 --- Comment #1 from Richard Biener --- IIRC this is simplify_stmt_using_ranges not being applied during propagation and thus the copy not being recorded. At elimination time we are not recording new equivalences.
