[PATCH] D18905: [ValueTracking] Improve isImpliedCondition for conditions with matching operands.

[Chad Rosier via llvm-commits]

mcrosier marked 5 inline comments as done.

================
Comment at: lib/Analysis/ValueTracking.cpp:3834
@@ +3833,3 @@
+  CmpInst::Predicate UnsignedBPred = ICmpInst::getUnsignedPredicate(BPred);
+  switch (UnsignedAPred) {
+  default:
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sanjoy wrote:
> This does not need to happen in this change, but it really looks like this logic is general enough to live in `CmpInst` along with things like `isTrueWhenEqual` as `CmpInst::isImpliedPredicate`.
I'll need to investigate.  Thanks for the suggestion, Sanjoy.

================
Comment at: lib/Analysis/ValueTracking.cpp:3900-3903
@@ -3799,3 +3899,6 @@
   // LHS ==> RHS by definition
-  if (LHS == RHS) return true;
+  if (LHS == RHS) {
+    ImpliedTrue = true;
+    return true;
+  }
 
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sanjoy wrote:
> This is why I'd have liked an `Optional<bool>` return value. :)  Avoids mistakes like these.
:/  I'll address this in a follow up commit.


http://reviews.llvm.org/D18905