[llvm] 873ab73 - [ValueLattice] Clarify that constant state can reached from undef.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2020-03-17T14:20:25Z
New Revision: 873ab73db47799cffd0f8ed1dac303df4beae3c4

URL: https://github.com/llvm/llvm-project/commit/873ab73db47799cffd0f8ed1dac303df4beae3c4
DIFF: https://github.com/llvm/llvm-project/commit/873ab73db47799cffd0f8ed1dac303df4beae3c4.diff

LOG: [ValueLattice] Clarify that constant state can reached from undef.

As suggested as post-commit comment in D75845.

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/ValueLattice.h

Removed: 
    


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diff  --git a/llvm/include/llvm/Analysis/ValueLattice.h b/llvm/include/llvm/Analysis/ValueLattice.h
index 225d5acb19d5..2810ba5a3fc3 100644
--- a/llvm/include/llvm/Analysis/ValueLattice.h
+++ b/llvm/include/llvm/Analysis/ValueLattice.h
@@ -43,7 +43,8 @@ class ValueLatticeElement {
 
     /// This Value has a specific constant value.  The constant cannot be undef.
     /// (For constant integers, constantrange is used instead. Integer typed
-    /// constantexprs can appear as constant.)
+    /// constantexprs can appear as constant.) Note that the constant state
+    /// can be reached by merging undef & constant states.
     /// Transition allowed to the following states:
     ///  overdefined
     constant,