diff --git a/llvm/include/llvm/CodeGen/MachinePipeliner.h b/llvm/include/llvm/CodeGen/MachinePipeliner.h
--- a/llvm/include/llvm/CodeGen/MachinePipeliner.h
+++ b/llvm/include/llvm/CodeGen/MachinePipeliner.h
@@ -304,7 +304,7 @@
   void checkValidNodeOrder(const NodeSetType &Circuits) const;
   bool schedulePipeline(SMSchedule &Schedule);
   bool computeDelta(MachineInstr &MI, unsigned &Delta);
-  MachineInstr *findDefInLoop(unsigned Reg);
+  MachineInstr *findDefInLoop(Register Reg);
   bool canUseLastOffsetValue(MachineInstr *MI, unsigned &BasePos,
                              unsigned &OffsetPos, unsigned &NewBase,
                              int64_t &NewOffset);
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -1632,7 +1632,8 @@
         if (Register::isVirtualRegister(Reg))
           Uses.insert(Reg);
         else if (MRI.isAllocatable(Reg))
-          for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
+          for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid();
+               ++Units)
             Uses.insert(*Units);
       }
   }
@@ -1645,7 +1646,8 @@
             LiveOutRegs.push_back(RegisterMaskPair(Reg,
                                                    LaneBitmask::getNone()));
         } else if (MRI.isAllocatable(Reg)) {
-          for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
+          for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid();
+               ++Units)
             if (!Uses.count(*Units))
               LiveOutRegs.push_back(RegisterMaskPair(*Units,
                                                      LaneBitmask::getNone()));
@@ -2270,7 +2272,7 @@
 /// Return the instruction in the loop that defines the register.
 /// If the definition is a Phi, then follow the Phi operand to
 /// the instruction in the loop.
-MachineInstr *SwingSchedulerDAG::findDefInLoop(unsigned Reg) {
+MachineInstr *SwingSchedulerDAG::findDefInLoop(Register Reg) {
   SmallPtrSet<MachineInstr *, 8> Visited;
   MachineInstr *Def = MRI.getVRegDef(Reg);
   while (Def->isPHI()) {
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -184,12 +184,12 @@
     /// to the copy source.
     void SalvageUnsunkDebugUsersOfCopy(MachineInstr &,
                                        MachineBasicBlock *TargetBlock);
-    bool AllUsesDominatedByBlock(unsigned Reg, MachineBasicBlock *MBB,
-                                 MachineBasicBlock *DefMBB,
-                                 bool &BreakPHIEdge, bool &LocalUse) const;
+    bool AllUsesDominatedByBlock(Register Reg, MachineBasicBlock *MBB,
+                                 MachineBasicBlock *DefMBB, bool &BreakPHIEdge,
+                                 bool &LocalUse) const;
     MachineBasicBlock *FindSuccToSinkTo(MachineInstr &MI, MachineBasicBlock *MBB,
                bool &BreakPHIEdge, AllSuccsCache &AllSuccessors);
-    bool isProfitableToSinkTo(unsigned Reg, MachineInstr &MI,
+    bool isProfitableToSinkTo(Register Reg, MachineInstr &MI,
                               MachineBasicBlock *MBB,
                               MachineBasicBlock *SuccToSinkTo,
                               AllSuccsCache &AllSuccessors);
@@ -253,12 +253,11 @@
 /// occur in blocks dominated by the specified block. If any use is in the
 /// definition block, then return false since it is never legal to move def
 /// after uses.
-bool
-MachineSinking::AllUsesDominatedByBlock(unsigned Reg,
-                                        MachineBasicBlock *MBB,
-                                        MachineBasicBlock *DefMBB,
-                                        bool &BreakPHIEdge,
-                                        bool &LocalUse) const {
+bool MachineSinking::AllUsesDominatedByBlock(Register Reg,
+                                             MachineBasicBlock *MBB,
+                                             MachineBasicBlock *DefMBB,
+                                             bool &BreakPHIEdge,
+                                             bool &LocalUse) const {
   assert(Register::isVirtualRegister(Reg) && "Only makes sense for vregs");
 
   // Ignore debug uses because debug info doesn't affect the code.
@@ -560,7 +559,7 @@
 }
 
 /// isProfitableToSinkTo - Return true if it is profitable to sink MI.
-bool MachineSinking::isProfitableToSinkTo(unsigned Reg, MachineInstr &MI,
+bool MachineSinking::isProfitableToSinkTo(Register Reg, MachineInstr &MI,
                                           MachineBasicBlock *MBB,
                                           MachineBasicBlock *SuccToSinkTo,
                                           AllSuccsCache &AllSuccessors) {
@@ -1312,9 +1311,9 @@
   return HasRegDependency;
 }
 
-static SmallSet<unsigned, 4> getRegUnits(unsigned Reg,
-                                         const TargetRegisterInfo *TRI) {
-  SmallSet<unsigned, 4> RegUnits;
+static SmallSet<MCRegister, 4> getRegUnits(MCRegister Reg,
+                                           const TargetRegisterInfo *TRI) {
+  SmallSet<MCRegister, 4> RegUnits;
   for (auto RI = MCRegUnitIterator(Reg, TRI); RI.isValid(); ++RI)
     RegUnits.insert(*RI);
   return RegUnits;
@@ -1364,8 +1363,8 @@
           continue;
 
         // Record debug use of each reg unit.
-        SmallSet<unsigned, 4> Units = getRegUnits(MO.getReg(), TRI);
-        for (unsigned Reg : Units)
+        SmallSet<MCRegister, 4> Units = getRegUnits(MO.getReg(), TRI);
+        for (MCRegister Reg : Units)
           SeenDbgInstrs[Reg].push_back(MI);
       }
       continue;
@@ -1414,8 +1413,8 @@
       if (!MO.isReg() || !MO.isDef())
         continue;
 
-      SmallSet<unsigned, 4> Units = getRegUnits(MO.getReg(), TRI);
-      for (unsigned Reg : Units)
+      SmallSet<MCRegister, 4> Units = getRegUnits(MO.getReg(), TRI);
+      for (MCRegister Reg : Units)
         for (auto *MI : SeenDbgInstrs.lookup(Reg))
           DbgValsToSinkSet.insert(MI);
     }