Index: llvm/include/llvm/CodeGen/SelectionDAG.h
===================================================================
--- llvm/include/llvm/CodeGen/SelectionDAG.h
+++ llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -276,7 +276,10 @@
 
   DenseMap<const SDNode *, CallSiteDbgInfo> SDCallSiteDbgInfo;
 
+#ifndef NDEBUG
+  // Used for debug printing.
   uint16_t NextPersistentId = 0;
+#endif
 
 public:
   /// Clients of various APIs that cause global effects on
Index: llvm/include/llvm/CodeGen/SelectionDAGNodes.h
===================================================================
--- llvm/include/llvm/CodeGen/SelectionDAGNodes.h
+++ llvm/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -613,9 +613,11 @@
   SDNodeFlags Flags;
 
 public:
+#ifndef NDEBUG
   /// Unique and persistent id per SDNode in the DAG.
   /// Used for debug printing.
   uint16_t PersistentId;
+#endif
 
   //===--------------------------------------------------------------------===//
   //  Accessors
@@ -1216,9 +1218,11 @@
 public:
   explicit HandleSDNode(SDValue X)
     : SDNode(ISD::HANDLENODE, 0, DebugLoc(), getSDVTList(MVT::Other)) {
+#ifndef NDEBUG
     // HandleSDNodes are never inserted into the DAG, so they won't be
     // auto-numbered. Use ID 65535 as a sentinel.
     PersistentId = 0xffff;
+#endif
 
     // Manually set up the operand list. This node type is special in that it's
     // always stack allocated and SelectionDAG does not manage its operands.