diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index aad5d6fde17f..5d966aac07d4 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -1221,9 +1221,11 @@ public:
     return DbgInfo->getSDDbgValues(SD);
   }
 
-  /// Transfer SDDbgValues.
+private:
+  /// Transfer SDDbgValues. Called via ReplaceAllUses{OfValue}?With
   void TransferDbgValues(SDValue From, SDValue To);
 
+public:
   /// Return true if there are any SDDbgValue nodes associated
   /// with this SelectionDAG.
   bool hasDebugValues() const { return !DbgInfo->empty(); }
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index e9e68b72fa6a..1da1f0acb392 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1333,8 +1333,6 @@ void DAGCombiner::Run(CombineLevel AtLevel) {
     DEBUG(dbgs() << " ... into: ";
           RV.getNode()->dump(&DAG));
 
-    // Transfer debug value.
-    DAG.TransferDbgValues(SDValue(N, 0), RV);
     if (N->getNumValues() == RV.getNode()->getNumValues())
       DAG.ReplaceAllUsesWith(N, RV.getNode());
     else {
diff --git a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 4448b0582ba2..a44b936ba923 100644
--- a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -320,7 +320,6 @@ InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB,
          "Chain and glue operands should occur at end of operand list!");
   // Get/emit the operand.
   unsigned VReg = getVR(Op, VRBaseMap);
-  assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
 
   const MCInstrDesc &MCID = MIB->getDesc();
   bool isOptDef = IIOpNum < MCID.getNumOperands() &&
@@ -334,6 +333,8 @@ InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB,
     const TargetRegisterClass *DstRC = nullptr;
     if (IIOpNum < II->getNumOperands())
       DstRC = TRI->getAllocatableClass(TII->getRegClass(*II,IIOpNum,TRI,*MF));
+    assert((!DstRC || TargetRegisterInfo::isVirtualRegister(VReg)) &&
+           "Expected VReg");
     if (DstRC && !MRI->constrainRegClass(VReg, DstRC, MinRCSize)) {
       unsigned NewVReg = MRI->createVirtualRegister(DstRC);
       BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 129765e8cd2a..ac68bcdb426a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -179,8 +179,6 @@ public:
            "Replacing one node with another that produces a different number "
            "of values!");
     DAG.ReplaceAllUsesWith(Old, New);
-    for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i)
-      DAG.TransferDbgValues(SDValue(Old, i), SDValue(New, i));
     if (UpdatedNodes)
       UpdatedNodes->insert(New);
     ReplacedNode(Old);
@@ -190,7 +188,6 @@ public:
           dbgs() << "     with:      "; New->dump(&DAG));
 
     DAG.ReplaceAllUsesWith(Old, New);
-    DAG.TransferDbgValues(Old, New);
     if (UpdatedNodes)
       UpdatedNodes->insert(New.getNode());
     ReplacedNode(Old.getNode());
@@ -203,7 +200,6 @@ public:
       DEBUG(dbgs() << (i == 0 ? "     with:      "
                               : "      and:      ");
             New[i]->dump(&DAG));
-      DAG.TransferDbgValues(SDValue(Old, i), New[i]);
       if (UpdatedNodes)
         UpdatedNodes->insert(New[i].getNode());
     }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 0f43fd483d3c..754e481f3036 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6333,6 +6333,9 @@ void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To) {
     AddModifiedNodeToCSEMaps(User);
   }
 
+  // Preserve Debug Values
+  TransferDbgValues(FromN, To);
+
   // If we just RAUW'd the root, take note.
   if (FromN == getRoot())
     setRoot(To);
@@ -6356,6 +6359,11 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To) {
   if (From == To)
     return;
 
+  // Preserve Debug Info. Only do this if there's a use.
+  for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
+    if (From->hasAnyUseOfValue(i))
+      TransferDbgValues(SDValue(From, i), SDValue(To, i));
+
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From->use_begin(), UE = From->use_end();
@@ -6395,6 +6403,10 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, const SDValue *To) {
   if (From->getNumValues() == 1)  // Handle the simple case efficiently.
     return ReplaceAllUsesWith(SDValue(From, 0), To[0]);
 
+  // Preserve Debug Info.
+  for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
+    TransferDbgValues(SDValue(From, i), *To);
+
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From->use_begin(), UE = From->use_end();
@@ -6439,6 +6451,9 @@ void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To){
     return;
   }
 
+  // Preserve Debug Info.
+  TransferDbgValues(From, To);
+
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From.getNode()->use_begin(),
@@ -6513,6 +6528,8 @@ void SelectionDAG::ReplaceAllUsesOfValuesWith(const SDValue *From,
   if (Num == 1)
     return ReplaceAllUsesOfValueWith(*From, *To);
 
+  TransferDbgValues(*From, *To);
+
   // Read up all the uses and make records of them. This helps
   // processing new uses that are introduced during the
   // replacement process.
@@ -6661,7 +6678,7 @@ void SelectionDAG::AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter) {
   DbgInfo->add(DB, SD, isParameter);
 }
 
-/// TransferDbgValues - Transfer SDDbgValues.
+/// TransferDbgValues - Transfer SDDbgValues. Called in replace nodes.
 void SelectionDAG::TransferDbgValues(SDValue From, SDValue To) {
   if (From == To || !From.getNode()->getHasDebugValue())
     return;
diff --git a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
index 8552b3a22aed..277d9b1f7d2e 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
@@ -1308,8 +1308,6 @@ void HexagonDAGToDAGISel::SelectFrameIndex(SDNode *N) {
     R = CurDAG->getMachineNode(Hexagon::TFR_FIA, DL, MVT::i32, Ops);
   }
 
-  if (N->getHasDebugValue())
-    CurDAG->TransferDbgValues(SDValue(N, 0), SDValue(R, 0));
   ReplaceNode(N, R);
 }
 
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index 42feffc32015..1d23a74d9845 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -1057,8 +1057,8 @@ HexagonTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
   SDValue AC = DAG.getConstant(A, dl, MVT::i32);
   SDVTList VTs = DAG.getVTList(MVT::i32, MVT::Other);
   SDValue AA = DAG.getNode(HexagonISD::ALLOCA, dl, VTs, Chain, Size, AC);
-  if (Op.getNode()->getHasDebugValue())
-    DAG.TransferDbgValues(Op, AA);
+
+  DAG.ReplaceAllUsesOfValueWith(Op, AA);
   return AA;
 }
 
diff --git a/llvm/test/DebugInfo/X86/dbg-value-dag-combine.ll b/llvm/test/DebugInfo/X86/dbg-value-dag-combine.ll
index 663641edb837..62e53bb3f532 100644
--- a/llvm/test/DebugInfo/X86/dbg-value-dag-combine.ll
+++ b/llvm/test/DebugInfo/X86/dbg-value-dag-combine.ll
@@ -3,6 +3,13 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:32"
 target triple = "i686-apple-darwin"
 ; PR 9817
 
+; There should be a DEBUG_VALUE for each call to llvm.dbg.value
+
+; CHECK:  ##DEBUG_VALUE: __OpenCL_test_kernel:ip <- 
+; CHECK:  ##DEBUG_VALUE: xxx <- 0
+; CHECK:  ##DEBUG_VALUE: gid <- %E{{..$}}
+; CHECK:  ##DEBUG_VALUE: idx <- %E{{..$}}
+; CHECK-NOT:  ##DEBUG_VALUE:
 
 declare <4 x i32> @__amdil_get_global_id_int()
 declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
@@ -12,10 +19,9 @@ entry:
   %0 = call <4 x i32> @__amdil_get_global_id_int() nounwind
   %1 = extractelement <4 x i32> %0, i32 0
   call void @llvm.dbg.value(metadata i32 %1, i64 0, metadata !9, metadata !DIExpression()), !dbg !11
-  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !13, metadata !DIExpression()), !dbg !14
+  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !21, metadata !DIExpression()), !dbg !14
   %tmp2 = load i32, i32 addrspace(1)* %ip, align 4, !dbg !15
   %tmp3 = add i32 0, %tmp2, !dbg !15
-; CHECK:  ##DEBUG_VALUE: idx <- %E{{..$}}
   call void @llvm.dbg.value(metadata i32 %tmp3, i64 0, metadata !13, metadata !DIExpression()), !dbg !15
   %arrayidx = getelementptr i32, i32 addrspace(1)* %ip, i32 %1, !dbg !16
   store i32 %tmp3, i32 addrspace(1)* %arrayidx, align 4, !dbg !16
@@ -44,3 +50,4 @@ entry:
 !17 = !DILocation(line: 7, column: 1, scope: !0)
 !19 = !DIFile(filename: "OCL6368.tmp.cl", directory: "E:\5CUsers\5Cmvillmow.AMD\5CAppData\5CLocal\5CTemp")
 !20 = !{i32 1, !"Debug Info Version", i32 3}
+!21 = !DILocalVariable(name: "xxx", line: 4, scope: !10, file: !1, type: !6)