diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp index 8a3e4fc5536c..98136b86435b 100644 --- a/llvm/lib/Analysis/LazyValueInfo.cpp +++ b/llvm/lib/Analysis/LazyValueInfo.cpp @@ -63,19 +63,24 @@ namespace llvm { namespace { class LVILatticeVal { enum LatticeValueTy { - /// This Value has no known value yet. + /// This Value has no known value yet. As a result, this implies the + /// producing instruction is dead. Caution: We use this as the starting + /// state in our local meet rules. In this usage, it's taken to mean + /// "nothing known yet". undefined, - /// This Value has a specific constant value. + /// This Value has a specific constant value. (For integers, constantrange + /// is used instead.) constant, - /// This Value is known to not have the specified value. + /// This Value is known to not have the specified value. (For integers, + /// constantrange is used instead.) notconstant, - /// The Value falls within this range. + /// The Value falls within this range. (Used only for integer typed values.) constantrange, - /// This value is not known to be constant, and we know that it has a value. + /// We can not precisely model the dynamic values this value might take. overdefined };