diff --git a/include/llvm/CodeGen/PBQP/ReductionRules.h b/include/llvm/CodeGen/PBQP/ReductionRules.h
index 8f54ec93dd2..d4a544bfe72 100644
--- a/include/llvm/CodeGen/PBQP/ReductionRules.h
+++ b/include/llvm/CodeGen/PBQP/ReductionRules.h
@@ -144,6 +144,7 @@ namespace PBQP {
     // TODO: Try to normalize newly added/modified edge.
   }
 
+#ifndef NDEBUG
   // Does this Cost vector have any register options ?
   template <typename VectorT>
   bool hasRegisterOptions(const VectorT &V) {
@@ -161,6 +162,7 @@ namespace PBQP {
 
     return false;
   }
+#endif
 
   // \brief Find a solution to a fully reduced graph by backpropagation.
   //
@@ -187,12 +189,14 @@ namespace PBQP {
 
       RawVector v = G.getNodeCosts(NId);
 
+#ifndef NDEBUG
       // Although a conservatively allocatable node can be allocated to a register,
       // spilling it may provide a lower cost solution. Assert here that spilling
       // is done by choice, not because there were no register available.
       if (G.getNodeMetadata(NId).wasConservativelyAllocatable())
         assert(hasRegisterOptions(v) && "A conservatively allocatable node "
                                         "must have available register options");
+#endif
 
       for (auto EId : G.adjEdgeIds(NId)) {
         const Matrix& edgeCosts = G.getEdgeCosts(EId);
diff --git a/include/llvm/CodeGen/RegAllocPBQP.h b/include/llvm/CodeGen/RegAllocPBQP.h
index a117eb070f0..827c4c90925 100644
--- a/include/llvm/CodeGen/RegAllocPBQP.h
+++ b/include/llvm/CodeGen/RegAllocPBQP.h
@@ -192,7 +192,11 @@ public:
 
   NodeMetadata()
     : RS(Unprocessed), NumOpts(0), DeniedOpts(0), OptUnsafeEdges(nullptr),
-      VReg(0), everConservativelyAllocatable(false) {}
+      VReg(0)
+#ifndef NDEBUG
+      , everConservativelyAllocatable(false)
+#endif
+      {}
 
   // FIXME: Re-implementing default behavior to work around MSVC. Remove once
   // MSVC synthesizes move constructors properly.
@@ -257,10 +261,12 @@ public:
     assert(RS >= this->RS && "A node's reduction state can not be downgraded");
     this->RS = RS;
 
+#ifndef NDEBUG
     // Remember this state to assert later that a non-infinite register
     // option was available.
     if (RS == ConservativelyAllocatable)
       everConservativelyAllocatable = true;
+#endif
   }
 
 
@@ -286,9 +292,11 @@ public:
        &OptUnsafeEdges[NumOpts]);
   }
 
+#ifndef NDEBUG
   bool wasConservativelyAllocatable() const {
     return everConservativelyAllocatable;
   }
+#endif
 
 private:
   ReductionState RS;
@@ -297,7 +305,10 @@ private:
   std::unique_ptr<unsigned[]> OptUnsafeEdges;
   unsigned VReg;
   GraphMetadata::AllowedRegVecRef AllowedRegs;
+
+#ifndef NDEBUG
   bool everConservativelyAllocatable;
+#endif
 };
 
 class RegAllocSolverImpl {