diff --git a/lib/CodeGen/Collector.cpp b/lib/CodeGen/Collector.cpp
index 1064e59..fe5119e 100644
--- a/lib/CodeGen/Collector.cpp
+++ b/lib/CodeGen/Collector.cpp
@@ -337,7 +337,7 @@
 unsigned MachineCodeAnalysis::InsertLabel(MachineBasicBlock &MBB, 
                                      MachineBasicBlock::iterator MI) const {
   unsigned Label = MMI->NextLabelID();
-  BuildMI(MBB, MI, TII->get(TargetInstrInfo::LABEL)).addImm(Label);
+  BuildMI(MBB, MI, TII->get(TargetInstrInfo::LABEL)).addImm(Label).addImm(2);
   return Label;
 }
 
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 8aa854d..f40ac91 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -18,6 +18,7 @@
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/SelectionDAGNodes.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetInstrDesc.h"
 #include "llvm/Target/MRegisterInfo.h"
 #include "llvm/Support/LeakDetector.h"
@@ -512,6 +513,12 @@
 }
 
 
+/// isDebugLabel - Returns true if the MachineInstr represents a debug label.
+///
+bool MachineInstr::isDebugLabel() const {
+  return getOpcode() == TargetInstrInfo::LABEL && getOperand(1).getImm() == 0;
+}
+
 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of
 /// the specific register or -1 if it is not found. It further tightening
 /// the search criteria to a use that kills the register if isKill is true.
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 80bedd0..12680a0 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1914,7 +1914,7 @@
     // Iterate through instructions.
     for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
       // Is it a label.
-      if ((unsigned)I->getOpcode() == TargetInstrInfo::LABEL) {
+      if (I->isDebugLabel()) {
         // The label ID # is always operand #0, an immediate.
         unsigned NextLabel = I->getOperand(0).getImm();
         
diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index c990ba4..34cbb2b 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -253,7 +253,7 @@
   // entry block.
   MachineModuleInfo *MMI = FFI->getMachineModuleInfo();
   if (MMI && MMI->hasDebugInfo())
-    while (I != MBB->end() && I->getOpcode() == TargetInstrInfo::LABEL)
+    while (I != MBB->end() && I->isDebugLabel())
       ++I;
 
   if (!TII.spillCalleeSavedRegisters(*MBB, I, CSI)) {
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 1dbcf85..9a4bec2 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1060,7 +1060,8 @@
           unsigned Col = cast<ConstantSDNode>(ColOp)->getValue();
           unsigned ID = MMI->RecordLabel(Line, Col, SrcFile);
           Ops.push_back(DAG.getConstant(ID, MVT::i32));
-          Result = DAG.getNode(ISD::LABEL, MVT::Other,&Ops[0],Ops.size());
+          Ops.push_back(DAG.getConstant(0, MVT::i32)); // a debug label
+          Result = DAG.getNode(ISD::LABEL, MVT::Other, &Ops[0], Ops.size());
         }
       } else {
         Result = Tmp1;  // chain
@@ -1103,13 +1104,14 @@
     break;    
 
   case ISD::LABEL:
-    assert(Node->getNumOperands() == 2 && "Invalid LABEL node!");
+    assert(Node->getNumOperands() == 3 && "Invalid LABEL node!");
     switch (TLI.getOperationAction(ISD::LABEL, MVT::Other)) {
     default: assert(0 && "This action is not supported yet!");
     case TargetLowering::Legal:
       Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain.
       Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the label id.
-      Result = DAG.UpdateNodeOperands(Result, Tmp1, Tmp2);
+      Tmp3 = LegalizeOp(Node->getOperand(2));  // Legalize the "flavor" operand.
+      Result = DAG.UpdateNodeOperands(Result, Tmp1, Tmp2, Tmp3);
       break;
     case TargetLowering::Expand:
       Result = LegalizeOp(Node->getOperand(0));
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
index c9fc812..ac35b40 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -733,18 +733,16 @@
     }
 
     // Now that we have emitted all operands, emit this instruction itself.
-    if (Opc == TargetInstrInfo::LABEL &&
+    if (ISD::isDebugLabel(Node) &&
         !BB->empty() && &MF->front() == BB) {
-      // If we are inserting a LABEL and this happens to be the first label in
-      // the entry block, it is the "function start" label. Make sure there are
-      // no other instructions before it.
+      // If we are inserting a debug label and this happens to be the first
+      // debug label in the entry block, it is the "function start" label.
+      // Make sure there are no other instructions before it.
       unsigned NumLabels = 0;
       MachineBasicBlock::iterator MBBI = BB->begin();
       while (MBBI != BB->end()) {
-        if (MBBI->getOpcode() == TargetInstrInfo::LABEL) {
-          if (++NumLabels > 1)
-            break;
-        }
+        if (!MBBI->isDebugLabel() || ++NumLabels > 1)
+          break;
         ++MBBI;
       }
       if (NumLabels <= 1)
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 118f980..28d7006 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -173,6 +173,22 @@
   return true;
 }
 
+/// isDebugLabel - Return true if the specified node represents a debug
+/// label (i.e. ISD::LABEL or TargetInstrInfo::LANEL node and third operand
+/// is 0).
+bool ISD::isDebugLabel(const SDNode *N) {
+  SDOperand Zero;
+  if (N->getOpcode() == ISD::LABEL)
+    Zero = N->getOperand(2);
+  else if (N->isTargetOpcode() &&
+           N->getTargetOpcode() == TargetInstrInfo::LABEL)
+    // Chain moved to last operand.
+    Zero = N->getOperand(1);
+  else
+    return false;
+  return isa<ConstantSDNode>(Zero) && cast<ConstantSDNode>(Zero)->isNullValue();
+}
+
 /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
 /// when given the operation for (X op Y).
 ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) {
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 04c4e01..4d1e7eb 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2621,7 +2621,8 @@
     if (MMI && RSI.getContext() && MMI->Verify(RSI.getContext())) {
       unsigned LabelID = MMI->RecordRegionStart(RSI.getContext());
       DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, getRoot(),
-                              DAG.getConstant(LabelID, MVT::i32)));
+                              DAG.getConstant(LabelID, MVT::i32),
+                              DAG.getConstant(0, MVT::i32)));
     }
 
     return 0;
@@ -2631,8 +2632,9 @@
     DbgRegionEndInst &REI = cast<DbgRegionEndInst>(I);
     if (MMI && REI.getContext() && MMI->Verify(REI.getContext())) {
       unsigned LabelID = MMI->RecordRegionEnd(REI.getContext());
-      DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other,
-                              getRoot(), DAG.getConstant(LabelID, MVT::i32)));
+      DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, getRoot(),
+                              DAG.getConstant(LabelID, MVT::i32),
+                              DAG.getConstant(0, MVT::i32)));
     }
 
     return 0;
@@ -2643,8 +2645,9 @@
     if (MMI && FSI.getSubprogram() &&
         MMI->Verify(FSI.getSubprogram())) {
       unsigned LabelID = MMI->RecordRegionStart(FSI.getSubprogram());
-      DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other,
-                  getRoot(), DAG.getConstant(LabelID, MVT::i32)));
+      DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, getRoot(),
+                              DAG.getConstant(LabelID, MVT::i32),
+                              DAG.getConstant(0, MVT::i32)));
     }
 
     return 0;
@@ -2972,7 +2975,8 @@
     // used to detect deletion of the invoke via the MachineModuleInfo.
     BeginLabel = MMI->NextLabelID();
     DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, getRoot(),
-                            DAG.getConstant(BeginLabel, MVT::i32)));
+                            DAG.getConstant(BeginLabel, MVT::i32),
+                            DAG.getConstant(1, MVT::i32)));
   }
 
   std::pair<SDOperand,SDOperand> Result =
@@ -2989,7 +2993,8 @@
     // can be used to detect deletion of the invoke via the MachineModuleInfo.
     EndLabel = MMI->NextLabelID();
     DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, getRoot(),
-                            DAG.getConstant(EndLabel, MVT::i32)));
+                            DAG.getConstant(EndLabel, MVT::i32),
+                            DAG.getConstant(1, MVT::i32)));
 
     // Inform MachineModuleInfo of range.
     MMI->addInvoke(LandingPad, BeginLabel, EndLabel);
@@ -4573,7 +4578,8 @@
     // landing pad can thus be detected via the MachineModuleInfo.
     unsigned LabelID = MMI->addLandingPad(BB);
     DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, DAG.getEntryNode(),
-                            DAG.getConstant(LabelID, MVT::i32)));
+                            DAG.getConstant(LabelID, MVT::i32),
+                            DAG.getConstant(1, MVT::i32)));
 
     // Mark exception register as live in.
     unsigned Reg = TLI.getExceptionAddressRegister();