diff --git a/include/llvm/CodeGen/LiveVariables.h b/include/llvm/CodeGen/LiveVariables.h
index 6e7e23d495b..786a1fdc706 100644
--- a/include/llvm/CodeGen/LiveVariables.h
+++ b/include/llvm/CodeGen/LiveVariables.h
@@ -36,6 +36,7 @@
 namespace llvm {
 
 class MRegisterInfo;
+class BitVector;
 
 class LiveVariables : public MachineFunctionPass {
 public:
@@ -108,11 +109,11 @@ private:
   ///
   std::vector<VarInfo> VirtRegInfo;
 
-  /// AllocatablePhysicalRegisters - This vector keeps track of which registers
-  /// are actually register allocatable by the target machine.  We can not track
-  /// liveness for values that are not in this set.
+  /// ReservedRegisters - This vector keeps track of which registers
+  /// are reserved register which are not allocatable by the target machine.
+  /// We can not track liveness for values that are in this set.
   ///
-  BitVector AllocatablePhysicalRegisters;
+  BitVector ReservedRegisters;
 
 private:   // Intermediate data structures
   const MRegisterInfo *RegInfo;