diff --git a/llvm/include/llvm/CodeGen/MachineRegisterInfo.h b/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
--- a/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -77,6 +77,7 @@
     virtual void MRI_NoteNewVirtualRegister(Register Reg) = 0;
     virtual void MRI_NotecloneVirtualRegister(Register ClonedReg,
                                               Register Reg) {}
+    virtual void MRI_NoteVirtualRegisterSpill(Register Reg) {}
   };
 
 private:
@@ -196,6 +197,9 @@
     TheDelegates[DR] = delegate;
   }
 
+  /// Callback to notify a virtual register spill/reload.
+  void noteVirtualRegisterSpill(Register Reg);
+
   //===--------------------------------------------------------------------===//
   // Function State
   //===--------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/LiveIntervals.cpp b/llvm/lib/CodeGen/LiveIntervals.cpp
--- a/llvm/lib/CodeGen/LiveIntervals.cpp
+++ b/llvm/lib/CodeGen/LiveIntervals.cpp
@@ -1743,9 +1743,8 @@
     return;
   LLVM_DEBUG(dbgs() << "  Split " << NumComp << " components: " << LI << '\n');
   Register Reg = LI.reg();
-  const TargetRegisterClass *RegClass = MRI->getRegClass(Reg);
   for (unsigned I = 1; I < NumComp; ++I) {
-    Register NewVReg = MRI->createVirtualRegister(RegClass);
+    Register NewVReg = MRI->cloneVirtualRegister(Reg);
     LiveInterval &NewLI = createEmptyInterval(NewVReg);
     SplitLIs.push_back(&NewLI);
   }
diff --git a/llvm/lib/CodeGen/LiveRangeEdit.cpp b/llvm/lib/CodeGen/LiveRangeEdit.cpp
--- a/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ b/llvm/lib/CodeGen/LiveRangeEdit.cpp
@@ -33,7 +33,7 @@
 
 LiveInterval &LiveRangeEdit::createEmptyIntervalFrom(Register OldReg,
                                                      bool createSubRanges) {
-  Register VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
+  Register VReg = MRI.cloneVirtualRegister(OldReg);
   if (VRM)
     VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
 
@@ -53,7 +53,7 @@
 }
 
 Register LiveRangeEdit::createFrom(Register OldReg) {
-  Register VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
+  Register VReg = MRI.cloneVirtualRegister(OldReg);
   if (VRM) {
     VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
   }
diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -213,6 +213,12 @@
     I.second = 0;
 }
 
+void MachineRegisterInfo::noteVirtualRegisterSpill(Register Reg) {
+  Delegate *TheDelegate = getDelegate(DelegateReceiver::RESERVED);
+  if (TheDelegate)
+    TheDelegate->MRI_NoteVirtualRegisterSpill(Reg);
+}
+
 void MachineRegisterInfo::verifyUseList(Register Reg) const {
 #ifndef NDEBUG
   bool Valid = true;
diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -434,6 +434,7 @@
   int FI = getStackSpaceFor(VirtReg);
   LLVM_DEBUG(dbgs() << " to stack slot #" << FI << '\n');
 
+  MRI->noteVirtualRegisterSpill(VirtReg);
   const TargetRegisterClass &RC = *MRI->getRegClass(VirtReg);
   TII->storeRegToStackSlot(*MBB, Before, AssignedReg, Kill, FI, &RC, TRI);
   ++NumStores;
@@ -488,6 +489,7 @@
   LLVM_DEBUG(dbgs() << "Reloading " << printReg(VirtReg, TRI) << " into "
                     << printReg(PhysReg, TRI) << '\n');
   int FI = getStackSpaceFor(VirtReg);
+  MRI->noteVirtualRegisterSpill(VirtReg);
   const TargetRegisterClass &RC = *MRI->getRegClass(VirtReg);
   TII->loadRegFromStackSlot(*MBB, Before, PhysReg, FI, &RC, TRI);
   ++NumLoads;