diff --git a/llvm/include/llvm/CodeGen/LiveIntervals.h b/llvm/include/llvm/CodeGen/LiveIntervals.h
--- a/llvm/include/llvm/CodeGen/LiveIntervals.h
+++ b/llvm/include/llvm/CodeGen/LiveIntervals.h
@@ -423,7 +423,7 @@
     /// Reg. Subsequent uses should rely on on-demand recomputation.  \note This
     /// method can result in inconsistent liveness tracking if multiple phyical
     /// registers share a regunit, and should be used cautiously.
-    void removeAllRegUnitsForPhysReg(unsigned Reg) {
+    void removeAllRegUnitsForPhysReg(MCRegister Reg) {
       for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
         removeRegUnit(*Units);
     }
diff --git a/llvm/include/llvm/CodeGen/TargetRegisterInfo.h b/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
--- a/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
@@ -386,12 +386,12 @@
   /// The registers may be virtual registers.
   bool regsOverlap(Register regA, Register regB) const {
     if (regA == regB) return true;
-    if (regA.isVirtual() || regB.isVirtual())
+    if (!regA.isPhysical() || !regB.isPhysical())
       return false;
 
     // Regunits are numerically ordered. Find a common unit.
-    MCRegUnitIterator RUA(regA, this);
-    MCRegUnitIterator RUB(regB, this);
+    MCRegUnitIterator RUA(regA.asMCReg(), this);
+    MCRegUnitIterator RUB(regB.asMCReg(), this);
     do {
       if (*RUA == *RUB) return true;
       if (*RUA < *RUB) ++RUA;
diff --git a/llvm/lib/CodeGen/BreakFalseDeps.cpp b/llvm/lib/CodeGen/BreakFalseDeps.cpp
--- a/llvm/lib/CodeGen/BreakFalseDeps.cpp
+++ b/llvm/lib/CodeGen/BreakFalseDeps.cpp
@@ -118,7 +118,7 @@
   if (!MO.isRenamable())
     return false;
 
-  Register OriginalReg = MO.getReg();
+  MCRegister OriginalReg = MO.getReg().asMCReg();
 
   // Update only undef operands that have reg units that are mapped to one root.
   for (MCRegUnitIterator Unit(OriginalReg, TRI); Unit.isValid(); ++Unit) {
diff --git a/llvm/lib/CodeGen/EarlyIfConversion.cpp b/llvm/lib/CodeGen/EarlyIfConversion.cpp
--- a/llvm/lib/CodeGen/EarlyIfConversion.cpp
+++ b/llvm/lib/CodeGen/EarlyIfConversion.cpp
@@ -265,7 +265,8 @@
 
     // Remember clobbered regunits.
     if (MO.isDef() && Register::isPhysicalRegister(Reg))
-      for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
+      for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid();
+           ++Units)
         ClobberedRegUnits.set(*Units);
 
     if (!MO.readsReg() || !Register::isVirtualRegister(Reg))
@@ -364,7 +365,7 @@
   // Keep track of live regunits before the current position.
   // Only track RegUnits that are also in ClobberedRegUnits.
   LiveRegUnits.clear();
-  SmallVector<unsigned, 8> Reads;
+  SmallVector<MCRegister, 8> Reads;
   MachineBasicBlock::iterator FirstTerm = Head->getFirstTerminator();
   MachineBasicBlock::iterator I = Head->end();
   MachineBasicBlock::iterator B = Head->begin();
@@ -386,11 +387,12 @@
         continue;
       // I clobbers Reg, so it isn't live before I.
       if (MO.isDef())
-        for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
+        for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid();
+             ++Units)
           LiveRegUnits.erase(*Units);
       // Unless I reads Reg.
       if (MO.readsReg())
-        Reads.push_back(Reg);
+        Reads.push_back(Reg.asMCReg());
     }
     // Anything read by I is live before I.
     while (!Reads.empty())