[PATCH] D144050: [SCEV] Strengthen nowrap flags via ranges for ARs on construction.

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:5739
+                   (SCEV::NoWrapFlags)(AR->getNoWrapFlags() |
+                                       proveNoWrapViaConstantRanges(AR)));
+  }
----------------
fhahn wrote:
> mkazantsev wrote:
> > Should we update `Flags` here to have more optimistic flags for `BEInst`?
> I tried to do that in D144197, but it seems the only change is a single regression; I've not looked into it in detail so far though.
It's not exactly what I mean, I mean smth like
```
  if (auto *AR = dyn_cast<SCEVAddRecExpr>(PHISCEV)) {
    Flags = Flags | proveNoWrapViaConstantRanges(AR);
   setNoWrapFlags(const_cast<SCEVAddRecExpr *>(AR), Flags);
  }
  // further on, updated Flags is used, see line 5749.
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D144050/new/

https://reviews.llvm.org/D144050