diff --git a/llvm/include/llvm/CodeGen/RegisterPressure.h b/llvm/include/llvm/CodeGen/RegisterPressure.h
--- a/llvm/include/llvm/CodeGen/RegisterPressure.h
+++ b/llvm/include/llvm/CodeGen/RegisterPressure.h
@@ -37,10 +37,10 @@
 class RegisterClassInfo;
 
 struct RegisterMaskPair {
-  unsigned RegUnit; ///< Virtual register or register unit.
+  Register RegUnit; ///< Virtual register or register unit.
   LaneBitmask LaneMask;
 
-  RegisterMaskPair(unsigned RegUnit, LaneBitmask LaneMask)
+  RegisterMaskPair(Register RegUnit, LaneBitmask LaneMask)
       : RegUnit(RegUnit), LaneMask(LaneMask) {}
 };
 
@@ -157,7 +157,7 @@
   const_iterator begin() const { return &PressureChanges[0]; }
   const_iterator end() const { return &PressureChanges[MaxPSets]; }
 
-  void addPressureChange(unsigned RegUnit, bool IsDec,
+  void addPressureChange(Register RegUnit, bool IsDec,
                          const MachineRegisterInfo *MRI);
 
   void dump(const TargetRegisterInfo &TRI) const;
@@ -275,7 +275,7 @@
   RegSet Regs;
   unsigned NumRegUnits;
 
-  unsigned getSparseIndexFromReg(unsigned Reg) const {
+  unsigned getSparseIndexFromReg(Register Reg) const {
     if (Register::isVirtualRegister(Reg))
       return Register::virtReg2Index(Reg) + NumRegUnits;
     assert(Reg < NumRegUnits);
@@ -292,7 +292,7 @@
   void clear();
   void init(const MachineRegisterInfo &MRI);
 
-  LaneBitmask contains(unsigned Reg) const {
+  LaneBitmask contains(Register Reg) const {
     unsigned SparseIndex = getSparseIndexFromReg(Reg);
     RegSet::const_iterator I = Regs.find(SparseIndex);
     if (I == Regs.end())
@@ -332,7 +332,7 @@
   template<typename ContainerT>
   void appendTo(ContainerT &To) const {
     for (const IndexMaskPair &P : Regs) {
-      unsigned Reg = getRegFromSparseIndex(P.Index);
+      Register Reg = getRegFromSparseIndex(P.Index);
       if (P.LaneMask.any())
         To.push_back(RegisterMaskPair(Reg, P.LaneMask));
     }
@@ -548,9 +548,9 @@
   /// after the current position.
   SlotIndex getCurrSlot() const;
 
-  void increaseRegPressure(unsigned RegUnit, LaneBitmask PreviousMask,
+  void increaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
                            LaneBitmask NewMask);
-  void decreaseRegPressure(unsigned RegUnit, LaneBitmask PreviousMask,
+  void decreaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
                            LaneBitmask NewMask);
 
   void bumpDeadDefs(ArrayRef<RegisterMaskPair> DeadDefs);
@@ -561,9 +561,9 @@
   void discoverLiveInOrOut(RegisterMaskPair Pair,
                            SmallVectorImpl<RegisterMaskPair> &LiveInOrOut);
 
-  LaneBitmask getLastUsedLanes(unsigned RegUnit, SlotIndex Pos) const;
-  LaneBitmask getLiveLanesAt(unsigned RegUnit, SlotIndex Pos) const;
-  LaneBitmask getLiveThroughAt(unsigned RegUnit, SlotIndex Pos) const;
+  LaneBitmask getLastUsedLanes(Register RegUnit, SlotIndex Pos) const;
+  LaneBitmask getLiveLanesAt(Register RegUnit, SlotIndex Pos) const;
+  LaneBitmask getLiveThroughAt(Register RegUnit, SlotIndex Pos) const;
 };
 
 void dumpRegSetPressure(ArrayRef<unsigned> SetPressure,
diff --git a/llvm/lib/CodeGen/RegisterPressure.cpp b/llvm/lib/CodeGen/RegisterPressure.cpp
--- a/llvm/lib/CodeGen/RegisterPressure.cpp
+++ b/llvm/lib/CodeGen/RegisterPressure.cpp
@@ -48,7 +48,7 @@
 
 /// Increase pressure for each pressure set provided by TargetRegisterInfo.
 static void increaseSetPressure(std::vector<unsigned> &CurrSetPressure,
-                                const MachineRegisterInfo &MRI, unsigned Reg,
+                                const MachineRegisterInfo &MRI, Register Reg,
                                 LaneBitmask PrevMask, LaneBitmask NewMask) {
   assert((PrevMask & ~NewMask).none() && "Must not remove bits");
   if (PrevMask.any() || NewMask.none())
@@ -62,7 +62,7 @@
 
 /// Decrease pressure for each pressure set provided by TargetRegisterInfo.
 static void decreaseSetPressure(std::vector<unsigned> &CurrSetPressure,
-                                const MachineRegisterInfo &MRI, unsigned Reg,
+                                const MachineRegisterInfo &MRI, Register Reg,
                                 LaneBitmask PrevMask, LaneBitmask NewMask) {
   //assert((NewMask & !PrevMask) == 0 && "Must not add bits");
   if (NewMask.any() || PrevMask.none())
@@ -152,7 +152,7 @@
 
 #endif
 
-void RegPressureTracker::increaseRegPressure(unsigned RegUnit,
+void RegPressureTracker::increaseRegPressure(Register RegUnit,
                                              LaneBitmask PreviousMask,
                                              LaneBitmask NewMask) {
   if (PreviousMask.any() || NewMask.none())
@@ -167,7 +167,7 @@
   }
 }
 
-void RegPressureTracker::decreaseRegPressure(unsigned RegUnit,
+void RegPressureTracker::decreaseRegPressure(Register RegUnit,
                                              LaneBitmask PreviousMask,
                                              LaneBitmask NewMask) {
   decreaseSetPressure(CurrSetPressure, *MRI, RegUnit, PreviousMask, NewMask);
@@ -234,8 +234,8 @@
   Regs.clear();
 }
 
-static const LiveRange *getLiveRange(const LiveIntervals &LIS, unsigned Reg) {
-  if (Register::isVirtualRegister(Reg))
+static const LiveRange *getLiveRange(const LiveIntervals &LIS, Register Reg) {
+  if (Reg.isVirtual())
     return &LIS.getInterval(Reg);
   return LIS.getCachedRegUnit(Reg);
 }
@@ -360,16 +360,15 @@
   LiveThruPressure.assign(TRI->getNumRegPressureSets(), 0);
   assert(isBottomClosed() && "need bottom-up tracking to intialize.");
   for (const RegisterMaskPair &Pair : P.LiveOutRegs) {
-    unsigned RegUnit = Pair.RegUnit;
-    if (Register::isVirtualRegister(RegUnit)
-        && !RPTracker.hasUntiedDef(RegUnit))
+    Register RegUnit = Pair.RegUnit;
+    if (RegUnit.isVirtual() && !RPTracker.hasUntiedDef(RegUnit))
       increaseSetPressure(LiveThruPressure, *MRI, RegUnit,
                           LaneBitmask::getNone(), Pair.LaneMask);
   }
 }
 
 static LaneBitmask getRegLanes(ArrayRef<RegisterMaskPair> RegUnits,
-                               unsigned RegUnit) {
+                               Register RegUnit) {
   auto I = llvm::find_if(RegUnits, [RegUnit](const RegisterMaskPair Other) {
     return Other.RegUnit == RegUnit;
   });
@@ -380,7 +379,7 @@
 
 static void addRegLanes(SmallVectorImpl<RegisterMaskPair> &RegUnits,
                         RegisterMaskPair Pair) {
-  unsigned RegUnit = Pair.RegUnit;
+  Register RegUnit = Pair.RegUnit;
   assert(Pair.LaneMask.any());
   auto I = llvm::find_if(RegUnits, [RegUnit](const RegisterMaskPair Other) {
     return Other.RegUnit == RegUnit;
@@ -393,7 +392,7 @@
 }
 
 static void setRegZero(SmallVectorImpl<RegisterMaskPair> &RegUnits,
-                       unsigned RegUnit) {
+                       Register RegUnit) {
   auto I = llvm::find_if(RegUnits, [RegUnit](const RegisterMaskPair Other) {
     return Other.RegUnit == RegUnit;
   });
@@ -406,7 +405,7 @@
 
 static void removeRegLanes(SmallVectorImpl<RegisterMaskPair> &RegUnits,
                            RegisterMaskPair Pair) {
-  unsigned RegUnit = Pair.RegUnit;
+  Register RegUnit = Pair.RegUnit;
   assert(Pair.LaneMask.any());
   auto I = llvm::find_if(RegUnits, [RegUnit](const RegisterMaskPair Other) {
     return Other.RegUnit == RegUnit;
@@ -418,11 +417,12 @@
   }
 }
 
-static LaneBitmask getLanesWithProperty(const LiveIntervals &LIS,
-    const MachineRegisterInfo &MRI, bool TrackLaneMasks, unsigned RegUnit,
-    SlotIndex Pos, LaneBitmask SafeDefault,
-    bool(*Property)(const LiveRange &LR, SlotIndex Pos)) {
-  if (Register::isVirtualRegister(RegUnit)) {
+static LaneBitmask
+getLanesWithProperty(const LiveIntervals &LIS, const MachineRegisterInfo &MRI,
+                     bool TrackLaneMasks, Register RegUnit, SlotIndex Pos,
+                     LaneBitmask SafeDefault,
+                     bool (*Property)(const LiveRange &LR, SlotIndex Pos)) {
+  if (RegUnit.isVirtual()) {
     const LiveInterval &LI = LIS.getInterval(RegUnit);
     LaneBitmask Result;
     if (TrackLaneMasks && LI.hasSubRanges()) {
@@ -448,7 +448,7 @@
 
 static LaneBitmask getLiveLanesAt(const LiveIntervals &LIS,
                                   const MachineRegisterInfo &MRI,
-                                  bool TrackLaneMasks, unsigned RegUnit,
+                                  bool TrackLaneMasks, Register RegUnit,
                                   SlotIndex Pos) {
   return getLanesWithProperty(LIS, MRI, TrackLaneMasks, RegUnit, Pos,
                               LaneBitmask::getAll(),
@@ -457,7 +457,6 @@
                               });
 }
 
-
 namespace {
 
 /// Collect this instruction's unique uses and defs into SmallVectors for
@@ -517,9 +516,9 @@
     }
   }
 
-  void pushReg(unsigned Reg,
+  void pushReg(Register Reg,
                SmallVectorImpl<RegisterMaskPair> &RegUnits) const {
-    if (Register::isVirtualRegister(Reg)) {
+    if (Reg.isVirtual()) {
       addRegLanes(RegUnits, RegisterMaskPair(Reg, LaneBitmask::getAll()));
     } else if (MRI.isAllocatable(Reg)) {
       for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units)
@@ -549,9 +548,9 @@
     }
   }
 
-  void pushRegLanes(unsigned Reg, unsigned SubRegIdx,
+  void pushRegLanes(Register Reg, unsigned SubRegIdx,
                     SmallVectorImpl<RegisterMaskPair> &RegUnits) const {
-    if (Register::isVirtualRegister(Reg)) {
+    if (Reg.isVirtual()) {
       LaneBitmask LaneMask = SubRegIdx != 0
                              ? TRI.getSubRegIndexLaneMask(SubRegIdx)
                              : MRI.getMaxLaneMaskForVReg(Reg);
@@ -580,7 +579,7 @@
                                       const LiveIntervals &LIS) {
   SlotIndex SlotIdx = LIS.getInstructionIndex(MI);
   for (auto RI = Defs.begin(); RI != Defs.end(); /*empty*/) {
-    unsigned Reg = RI->RegUnit;
+    Register Reg = RI->RegUnit;
     const LiveRange *LR = getLiveRange(LIS, Reg);
     if (LR != nullptr) {
       LiveQueryResult LRQ = LR->Query(SlotIdx);
@@ -605,9 +604,9 @@
                                            Pos.getDeadSlot());
     // If the def is all that is live after the instruction, then in case
     // of a subregister def we need a read-undef flag.
-    unsigned RegUnit = I->RegUnit;
-    if (Register::isVirtualRegister(RegUnit) &&
-        AddFlagsMI != nullptr && (LiveAfter & ~I->LaneMask).none())
+    Register RegUnit = I->RegUnit;
+    if (RegUnit.isVirtual() && AddFlagsMI != nullptr &&
+        (LiveAfter & ~I->LaneMask).none())
       AddFlagsMI->setRegisterDefReadUndef(RegUnit);
 
     LaneBitmask ActualDef = I->LaneMask & LiveAfter;
@@ -631,8 +630,8 @@
   }
   if (AddFlagsMI != nullptr) {
     for (const RegisterMaskPair &P : DeadDefs) {
-      unsigned RegUnit = P.RegUnit;
-      if (!Register::isVirtualRegister(RegUnit))
+      Register RegUnit = P.RegUnit;
+      if (!RegUnit.isVirtual())
         continue;
       LaneBitmask LiveAfter = getLiveLanesAt(LIS, MRI, true, RegUnit,
                                              Pos.getDeadSlot());
@@ -667,7 +666,7 @@
 }
 
 /// Add a change in pressure to the pressure diff of a given instruction.
-void PressureDiff::addPressureChange(unsigned RegUnit, bool IsDec,
+void PressureDiff::addPressureChange(Register RegUnit, bool IsDec,
                                      const MachineRegisterInfo *MRI) {
   PSetIterator PSetI = MRI->getPressureSets(RegUnit);
   int Weight = IsDec ? -PSetI.getWeight() : PSetI.getWeight();
@@ -714,7 +713,7 @@
     SmallVectorImpl<RegisterMaskPair> &LiveInOrOut) {
   assert(Pair.LaneMask.any());
 
-  unsigned RegUnit = Pair.RegUnit;
+  Register RegUnit = Pair.RegUnit;
   auto I = llvm::find_if(LiveInOrOut, [RegUnit](const RegisterMaskPair &Other) {
     return Other.RegUnit == RegUnit;
   });
@@ -742,13 +741,13 @@
 
 void RegPressureTracker::bumpDeadDefs(ArrayRef<RegisterMaskPair> DeadDefs) {
   for (const RegisterMaskPair &P : DeadDefs) {
-    unsigned Reg = P.RegUnit;
+    Register Reg = P.RegUnit;
     LaneBitmask LiveMask = LiveRegs.contains(Reg);
     LaneBitmask BumpedMask = LiveMask | P.LaneMask;
     increaseRegPressure(Reg, LiveMask, BumpedMask);
   }
   for (const RegisterMaskPair &P : DeadDefs) {
-    unsigned Reg = P.RegUnit;
+    Register Reg = P.RegUnit;
     LaneBitmask LiveMask = LiveRegs.contains(Reg);
     LaneBitmask BumpedMask = LiveMask | P.LaneMask;
     decreaseRegPressure(Reg, BumpedMask, LiveMask);
@@ -770,7 +769,7 @@
   // Kill liveness at live defs.
   // TODO: consider earlyclobbers?
   for (const RegisterMaskPair &Def : RegOpers.Defs) {
-    unsigned Reg = Def.RegUnit;
+    Register Reg = Def.RegUnit;
 
     LaneBitmask PreviousMask = LiveRegs.erase(Def);
     LaneBitmask NewMask = PreviousMask & ~Def.LaneMask;
@@ -800,7 +799,7 @@
 
   // Generate liveness for uses.
   for (const RegisterMaskPair &Use : RegOpers.Uses) {
-    unsigned Reg = Use.RegUnit;
+    Register Reg = Use.RegUnit;
     assert(Use.LaneMask.any());
     LaneBitmask PreviousMask = LiveRegs.insert(Use);
     LaneBitmask NewMask = PreviousMask | Use.LaneMask;
@@ -840,8 +839,8 @@
   }
   if (TrackUntiedDefs) {
     for (const RegisterMaskPair &Def : RegOpers.Defs) {
-      unsigned RegUnit = Def.RegUnit;
-      if (Register::isVirtualRegister(RegUnit) &&
+      Register RegUnit = Def.RegUnit;
+      if (RegUnit.isVirtual() &&
           (LiveRegs.contains(RegUnit) & Def.LaneMask).none())
         UntiedDefs.insert(RegUnit);
     }
@@ -911,7 +910,7 @@
   }
 
   for (const RegisterMaskPair &Use : RegOpers.Uses) {
-    unsigned Reg = Use.RegUnit;
+    Register Reg = Use.RegUnit;
     LaneBitmask LiveMask = LiveRegs.contains(Reg);
     LaneBitmask LiveIn = Use.LaneMask & ~LiveMask;
     if (LiveIn.any()) {
@@ -1060,7 +1059,7 @@
 
   // Kill liveness at live defs.
   for (const RegisterMaskPair &P : RegOpers.Defs) {
-    unsigned Reg = P.RegUnit;
+    Register Reg = P.RegUnit;
     LaneBitmask LiveLanes = LiveRegs.contains(Reg);
     LaneBitmask UseLanes = getRegLanes(RegOpers.Uses, Reg);
     LaneBitmask DefLanes = P.LaneMask;
@@ -1069,7 +1068,7 @@
   }
   // Generate liveness for uses.
   for (const RegisterMaskPair &P : RegOpers.Uses) {
-    unsigned Reg = P.RegUnit;
+    Register Reg = P.RegUnit;
     LaneBitmask LiveLanes = LiveRegs.contains(Reg);
     LaneBitmask LiveAfter = LiveLanes | P.LaneMask;
     increaseRegPressure(Reg, LiveLanes, LiveAfter);
@@ -1219,7 +1218,7 @@
 /// Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx).
 /// The query starts with a lane bitmask which gets lanes/bits removed for every
 /// use we find.
-static LaneBitmask findUseBetween(unsigned Reg, LaneBitmask LastUseMask,
+static LaneBitmask findUseBetween(Register Reg, LaneBitmask LastUseMask,
                                   SlotIndex PriorUseIdx, SlotIndex NextUseIdx,
                                   const MachineRegisterInfo &MRI,
                                   const LiveIntervals *LIS) {
@@ -1240,7 +1239,7 @@
   return LastUseMask;
 }
 
-LaneBitmask RegPressureTracker::getLiveLanesAt(unsigned RegUnit,
+LaneBitmask RegPressureTracker::getLiveLanesAt(Register RegUnit,
                                                SlotIndex Pos) const {
   assert(RequireIntervals);
   return getLanesWithProperty(*LIS, *MRI, TrackLaneMasks, RegUnit, Pos,
@@ -1250,7 +1249,7 @@
       });
 }
 
-LaneBitmask RegPressureTracker::getLastUsedLanes(unsigned RegUnit,
+LaneBitmask RegPressureTracker::getLastUsedLanes(Register RegUnit,
                                                  SlotIndex Pos) const {
   assert(RequireIntervals);
   return getLanesWithProperty(*LIS, *MRI, TrackLaneMasks, RegUnit,
@@ -1261,7 +1260,7 @@
       });
 }
 
-LaneBitmask RegPressureTracker::getLiveThroughAt(unsigned RegUnit,
+LaneBitmask RegPressureTracker::getLiveThroughAt(Register RegUnit,
                                                  SlotIndex Pos) const {
   assert(RequireIntervals);
   return getLanesWithProperty(*LIS, *MRI, TrackLaneMasks, RegUnit, Pos,
@@ -1294,7 +1293,7 @@
 
   if (RequireIntervals) {
     for (const RegisterMaskPair &Use : RegOpers.Uses) {
-      unsigned Reg = Use.RegUnit;
+      Register Reg = Use.RegUnit;
       LaneBitmask LastUseMask = getLastUsedLanes(Reg, SlotIdx);
       if (LastUseMask.none())
         continue;
@@ -1317,7 +1316,7 @@
 
   // Generate liveness for defs.
   for (const RegisterMaskPair &Def : RegOpers.Defs) {
-    unsigned Reg = Def.RegUnit;
+    Register Reg = Def.RegUnit;
     LaneBitmask LiveMask = LiveRegs.contains(Reg);
     LaneBitmask NewMask = LiveMask | Def.LaneMask;
     increaseRegPressure(Reg, LiveMask, NewMask);
diff --git a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
--- a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
@@ -348,7 +348,7 @@
 
   // Do not Track Physical Registers, because it messes up.
   for (const auto &RegMaskPair : RPTracker.getPressure().LiveInRegs) {
-    if (Register::isVirtualRegister(RegMaskPair.RegUnit))
+    if (RegMaskPair.RegUnit.isVirtual())
       LiveInRegs.insert(RegMaskPair.RegUnit);
   }
   LiveOutRegs.clear();