diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp
index 3da201e..9fb2a45 100644
--- a/lib/CodeGen/LiveIntervalUnion.cpp
+++ b/lib/CodeGen/LiveIntervalUnion.cpp
@@ -156,7 +156,7 @@
 //
 // This design assumes only a fast mechanism for intersecting a single live
 // virtual register segment with a set of LiveIntervalUnion segments.  This may
-// be ok since most VIRTREGs have very few segments.  If we had a data
+// be ok since most virtual registers have very few segments.  If we had a data
 // structure that optimizd MxN intersection of segments, then we would bypass
 // the loop that advances within the LiveInterval.
 //