[PATCH] D104503: [SCEV] Don't require dominance ordering of add/mul/min/max expressions

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:754
         return 1;
-      else
-        assert(DT.dominates(RHead, LHead) &&
-               "No dominance between recurrences used by one SCEV?");
-      return -1;
+      else if (DT.dominates(RHead, LHead))
+        return -1;
----------------
reames wrote:
> efriedma wrote:
> > I'm not sure this produces a strict weak ordering suitable for sorting.  We've run into issues with other code that tries to sort on dominates().  The solution is usually to use domtree DFS numbering instead.
> I'm happy to make the change, but do you have an example?  I don't see how we'd end up with anything problematic here.  
For example, D103441


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104503/new/

https://reviews.llvm.org/D104503