diff --git a/hpvm/include/SupportVISC/DFGraph.h b/hpvm/include/SupportVISC/DFGraph.h
index b74aee83797291d2b75100f10a82b430f72743b6..160e65928463d59ae51461959b473175cdb4a090 100644
--- a/hpvm/include/SupportVISC/DFGraph.h
+++ b/hpvm/include/SupportVISC/DFGraph.h
@@ -230,9 +230,9 @@ private:
                                   ///< successor DFNodes
   PropertyListType PropertyList;  ///< List of Properties
   StructType* OutputType;         ///< Output Type
-  int Level;                      ///< Distance to the top-level DFNode in the
+  unsigned Level;                 ///< Distance to the top-level DFNode in the
                                   ///< hierarchy
-  int Rank;                       ///< Ordering based on toplogical sort
+  unsigned Rank;                  ///< Ordering based on toplogical sort
   const DFNodeKind Kind;          ///< Kind of Node Internal/Leaf
   visc::Target Tag;               ///< Code Generated for which backend
   visc::Target Hint;              ///< To store preferred backend
@@ -364,11 +364,11 @@ public:
     return DimLimits;
   }
 
-  int getLevel() const {
+  unsigned getLevel() const {
     return Level;
   }
 
-  int getRank() const {
+  unsigned getRank() const {
     return Rank;
   }
 
@@ -584,7 +584,7 @@ public:
     // If Allocation Property is defined then it is not an allocation node
     return PropertyList.count(Allocation) != 0;
   }
-  void setRank(int r);
+  void setRank(unsigned r);
   bool isEntryNode();
   bool isExitNode();
   DFEdge* getInDFEdgeAt(unsigned inPort);
@@ -853,7 +853,7 @@ DFNode::DFNode(IntrinsicInst* _II, Function* _FuncPointer, visc::Target _Hint,
   GenFuncInfo.cudnn_hasX86Func = false;
 }
 
-void DFNode::setRank(int r) {
+void DFNode::setRank(unsigned r) {
   Rank = r;
   // Update rank of successors
   for(outdfedge_iterator i = outdfedge_begin(),