[PATCH] D14476: [LVI] Introduce an intersect operation on lattice values

[Sanjoy Das via llvm-commits]

sanjoy added inline comments.

================
Comment at: lib/Analysis/LazyValueInfo.cpp:1019
@@ +1018,3 @@
+    // TODO: Arbitrary choice, could be improved
+    return A;
+  }
----------------
I was suggesting putting the return inside the if -- the rule I was suggesting was that if one of the values is not a ConstantRange and the other one isn't then return the one that //is// a constantrange.  However, after re-reading the code it looks like you'll enter the `if` only with either two `nonconstant` s or one `nonconstant` and one `constantrange`.  With that in mind, I'm not sure if my suggestion is actually useful -- both a `constantrange` and `nonconstant` are equally "good" I think.

================
Comment at: lib/Analysis/LazyValueInfo.cpp:1041
@@ +1040,3 @@
+  LVILatticeVal LocalResult;
+  // Never new work to push, just fallthrough
+  (void) getEdgeValueLocal(Val, BBFrom, BBTo, LocalResult);
----------------
Fixing as a follow on change is fine.


http://reviews.llvm.org/D14476