Fix the comment for LegalizeOp to more accurately reflect what it does.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39827 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 63f58c2..a5146bd 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -551,9 +551,10 @@
 }
 
 
-/// LegalizeOp - We know that the specified value has a legal type.
-/// Recursively ensure that the operands have legal types, then return the
-/// result.
+/// LegalizeOp - We know that the specified value has a legal type, and
+/// that its operands are legal.  Now ensure that the operation itself
+/// is legal, recursively ensuring that the operands' operations remain
+/// legal.
 SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
   assert(isTypeLegal(Op.getValueType()) &&
          "Caller should expand or promote operands that are not legal!");