diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 950963ea187..21a0b984b64 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1027,11 +1027,15 @@ private:
   /// then they will be delete[]'d when the node is destroyed.
   uint16_t OperandsNeedDelete : 1;
 
+  /// HasDebugValue - This tracks whether this node has one or more dbg_value
+  /// nodes corresponding to it.
+  uint16_t HasDebugValue : 1;
+
 protected:
   /// SubclassData - This member is defined by this class, but is not used for
   /// anything.  Subclasses can use it to hold whatever state they find useful.
   /// This field is initialized to zero by the ctor.
-  uint16_t SubclassData : 15;
+  uint16_t SubclassData : 14;
 
 private:
   /// NodeId - Unique id per SDNode in the DAG.
@@ -1094,6 +1098,12 @@ public:
     return ~NodeType;
   }
 
+  /// getHasDebugValue - get this bit.
+  bool getHasDebugValue() const { return HasDebugValue; }
+
+  /// setHasDebugValue - set this bit.
+  void setHasDebugValue(bool b) { HasDebugValue = b; }
+
   /// use_empty - Return true if there are no uses of this node.
   ///
   bool use_empty() const { return UseList == NULL; }
@@ -1357,8 +1367,8 @@ protected:
 
   SDNode(unsigned Opc, const DebugLoc dl, SDVTList VTs, const SDValue *Ops,
          unsigned NumOps)
-    : NodeType(Opc), OperandsNeedDelete(true), SubclassData(0),
-      NodeId(-1),
+    : NodeType(Opc), OperandsNeedDelete(true), HasDebugValue(false),
+      SubclassData(0), NodeId(-1),
       OperandList(NumOps ? new SDUse[NumOps] : 0),
       ValueList(VTs.VTs), UseList(NULL),
       NumOperands(NumOps), NumValues(VTs.NumVTs),
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 02fe85dd996..625de114329 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -15,6 +15,7 @@
 
 #define DEBUG_TYPE "instr-emitter"
 #include "InstrEmitter.h"
+#include "SDDbgValue.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
@@ -497,6 +498,56 @@ InstrEmitter::EmitCopyToRegClassNode(SDNode *Node,
   assert(isNew && "Node emitted out of order - early");
 }
 
+/// EmitDbgValue - Generate any debug info that refers to this Node.  Constant
+/// dbg_value is not handled here.
+void
+InstrEmitter::EmitDbgValue(SDNode *Node,
+                           DenseMap<SDValue, unsigned> &VRBaseMap,
+                           SDDbgValue *sd) {
+  if (!Node->getHasDebugValue())
+    return;
+  if (!sd)
+    return;
+  unsigned VReg = getVR(SDValue(sd->getSDNode(), sd->getResNo()), VRBaseMap);
+  const TargetInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);
+  DebugLoc DL = sd->getDebugLoc();
+  MachineInstr *MI;
+  if (VReg) {
+    MI = BuildMI(*MF, DL, II).addReg(VReg, RegState::Debug).
+                              addImm(sd->getOffset()).
+                              addMetadata(sd->getMDPtr());
+  } else {
+    // Insert an Undef so we can see what we dropped.
+    MI = BuildMI(*MF, DL, II).addReg(0U).addImm(sd->getOffset()).
+                                    addMetadata(sd->getMDPtr());
+  }
+  MBB->insert(InsertPos, MI);
+}
+
+/// EmitDbgValue - Generate constant debug info.  No SDNode is involved.
+void
+InstrEmitter::EmitDbgValue(SDDbgValue *sd) {
+  if (!sd)
+    return;
+  const TargetInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);
+  DebugLoc DL = sd->getDebugLoc();
+  MachineInstr *MI;
+  Value *V = sd->getConst();
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+    MI = BuildMI(*MF, DL, II).addImm(CI->getZExtValue()).
+                                   addImm(sd->getOffset()).
+                                   addMetadata(sd->getMDPtr());
+  } else if (ConstantFP *CF = dyn_cast<ConstantFP>(V)) {
+    MI = BuildMI(*MF, DL, II).addFPImm(CF).addImm(sd->getOffset()).
+                                   addMetadata(sd->getMDPtr());
+  } else {
+    // Insert an Undef so we can see what we dropped.
+    MI = BuildMI(*MF, DL, II).addReg(0U).addImm(sd->getOffset()).
+                                    addMetadata(sd->getMDPtr());
+  }
+  MBB->insert(InsertPos, MI);
+}
+
 /// EmitNode - Generate machine code for a node and needed dependencies.
 ///
 void InstrEmitter::EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.h b/lib/CodeGen/SelectionDAG/InstrEmitter.h
index 91817e4d38a..4fe9f19cc90 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.h
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.h
@@ -23,6 +23,7 @@
 namespace llvm {
 
 class TargetInstrDesc;
+class SDDbgValue;
 
 class InstrEmitter {
   MachineFunction *MF;
@@ -97,6 +98,16 @@ public:
   /// MachineInstr.
   static unsigned CountOperands(SDNode *Node);
 
+  /// EmitDbgValue - Generate any debug info that refers to this Node.  Constant
+  /// dbg_value is not handled here.
+  void EmitDbgValue(SDNode *Node,
+                    DenseMap<SDValue, unsigned> &VRBaseMap,
+                    SDDbgValue* sd);
+
+
+  /// EmitDbgValue - Generate a constant DBG_VALUE.  No node is involved.
+  void EmitDbgValue(SDDbgValue* sd);
+
   /// EmitNode - Generate machine code for a node and needed dependencies.
   ///
   void EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
diff --git a/lib/CodeGen/SelectionDAG/SDDbgValue.h b/lib/CodeGen/SelectionDAG/SDDbgValue.h
new file mode 100644
index 00000000000..9e15fc98bc4
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/SDDbgValue.h
@@ -0,0 +1,67 @@
+//===-- llvm/CodeGen/SDDbgValue.h - SD dbg_value handling--------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SDDbgValue class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SDDBGVALUE_H
+#define LLVM_CODEGEN_SDDBGVALUE_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/DebugLoc.h"
+
+namespace llvm {
+
+class MDNode;
+class SDNode;
+class Value;
+
+/// SDDbgValue - Holds the information from a dbg_value node through SDISel.
+/// Either Const or Node is nonzero, but not both.
+/// We do not use SDValue here to avoid including its header.
+
+class SDDbgValue {
+  SDNode *Node;           // valid for non-constants
+  unsigned ResNo;         // valid for non-constants
+  Value *Const;           // valid for constants
+  MDNode *mdPtr;
+  uint64_t Offset;
+  DebugLoc DL;
+public:
+  // Constructor for non-constants.
+  SDDbgValue(MDNode *mdP, SDNode *N, unsigned R, uint64_t off, DebugLoc dl) :
+    Node(N), ResNo(R), Const(0), mdPtr(mdP), Offset(off), DL(dl) {}
+
+  // Constructor for constants.
+  SDDbgValue(MDNode *mdP, Value *C, uint64_t off, DebugLoc dl) : Node(0),
+    ResNo(0), Const(C), mdPtr(mdP), Offset(off), DL(dl) {}
+
+  // Returns the MDNode pointer.
+  MDNode *getMDPtr() { return mdPtr; }
+
+  // Returns the SDNode* (valid for non-constants only).
+  SDNode *getSDNode() { assert (!Const); return Node; }
+
+  // Returns the ResNo (valid for non-constants only).
+  unsigned getResNo() { assert (!Const); return ResNo; }
+
+  // Returns the Value* for a constant (invalid for non-constants).
+  Value *getConst() { assert (!Node); return Const; }
+
+  // Returns the offset.
+  uint64_t getOffset() { return Offset; }
+
+  // Returns the DebugLoc.
+  DebugLoc getDebugLoc() { return DL; }
+};
+
+} // end llvm namespace
+
+#endif