diff --git a/llvm/include/llvm/MC/MCRegisterInfo.h b/llvm/include/llvm/MC/MCRegisterInfo.h
index f1caa077a6d7b..6d4c2d12e2e51 100644
--- a/llvm/include/llvm/MC/MCRegisterInfo.h
+++ b/llvm/include/llvm/MC/MCRegisterInfo.h
@@ -438,7 +438,7 @@ class LLVM_ABI MCRegisterInfo {
   /// number.  Returns -1 if there is no equivalent value.  The second
   /// parameter allows targets to use different numberings for EH info and
   /// debugging info.
-  virtual int64_t getDwarfRegNum(MCRegister RegNum, bool isEH) const;
+  virtual int64_t getDwarfRegNum(MCRegister Reg, bool isEH) const;
 
   /// Map a dwarf register back to a target register. Returns std::nullopt if
   /// there is no mapping.
@@ -450,11 +450,11 @@ class LLVM_ABI MCRegisterInfo {
 
   /// Map a target register to an equivalent SEH register
   /// number.  Returns LLVM register number if there is no equivalent value.
-  int getSEHRegNum(MCRegister RegNum) const;
+  int getSEHRegNum(MCRegister Reg) const;
 
   /// Map a target register to an equivalent CodeView register
   /// number.
-  int getCodeViewRegNum(MCRegister RegNum) const;
+  int getCodeViewRegNum(MCRegister Reg) const;
 
   regclass_iterator regclass_begin() const { return Classes; }
   regclass_iterator regclass_end() const { return Classes+NumClasses; }
diff --git a/llvm/lib/MC/MCInst.cpp b/llvm/lib/MC/MCInst.cpp
index 46a6a18e15963..61eeb5e5a5c71 100644
--- a/llvm/lib/MC/MCInst.cpp
+++ b/llvm/lib/MC/MCInst.cpp
@@ -29,7 +29,7 @@ void MCOperand::print(raw_ostream &OS, const MCContext *Ctx) const {
     if (Ctx && Ctx->getRegisterInfo())
       OS << Ctx->getRegisterInfo()->getName(getReg());
     else
-      OS << getReg();
+      OS << getReg().id();
   } else if (isImm())
     OS << "Imm:" << getImm();
   else if (isSFPImm())
diff --git a/llvm/lib/MC/MCRegisterInfo.cpp b/llvm/lib/MC/MCRegisterInfo.cpp
index 7fd92bf974b95..77fb7332619cd 100644
--- a/llvm/lib/MC/MCRegisterInfo.cpp
+++ b/llvm/lib/MC/MCRegisterInfo.cpp
@@ -89,7 +89,7 @@ ArrayRef<MCPhysReg> MCRegisterInfo::getCachedAliasesOf(MCRegister R) const {
     return Aliases;
 
   for (MCRegAliasIteratorImpl It(R, this); It.isValid(); ++It)
-    Aliases.push_back(*It);
+    Aliases.push_back((*It).id());
 
   sort(Aliases);
   Aliases.erase(unique(Aliases), Aliases.end());
@@ -141,15 +141,15 @@ unsigned MCRegisterInfo::getSubRegIndex(MCRegister Reg,
   return 0;
 }
 
-int64_t MCRegisterInfo::getDwarfRegNum(MCRegister RegNum, bool isEH) const {
+int64_t MCRegisterInfo::getDwarfRegNum(MCRegister Reg, bool isEH) const {
   const DwarfLLVMRegPair *M = isEH ? EHL2DwarfRegs : L2DwarfRegs;
   unsigned Size = isEH ? EHL2DwarfRegsSize : L2DwarfRegsSize;
 
   if (!M)
     return -1;
-  DwarfLLVMRegPair Key = { RegNum, 0 };
+  DwarfLLVMRegPair Key = {Reg.id(), 0};
   const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, Key);
-  if (I == M+Size || I->FromReg != RegNum)
+  if (I == M + Size || I->FromReg != Reg)
     return -1;
   // Consumers need to be able to detect -1 and -2, but at various points
   // the numbers move between unsigned and signed representations, as well as
@@ -191,20 +191,21 @@ int64_t MCRegisterInfo::getDwarfRegNumFromDwarfEHRegNum(uint64_t RegNum) const {
   return RegNum;
 }
 
-int MCRegisterInfo::getSEHRegNum(MCRegister RegNum) const {
-  const DenseMap<MCRegister, int>::const_iterator I = L2SEHRegs.find(RegNum);
-  if (I == L2SEHRegs.end()) return (int)RegNum;
+int MCRegisterInfo::getSEHRegNum(MCRegister Reg) const {
+  const DenseMap<MCRegister, int>::const_iterator I = L2SEHRegs.find(Reg);
+  if (I == L2SEHRegs.end())
+    return (int)Reg.id();
   return I->second;
 }
 
-int MCRegisterInfo::getCodeViewRegNum(MCRegister RegNum) const {
+int MCRegisterInfo::getCodeViewRegNum(MCRegister Reg) const {
   if (L2CVRegs.empty())
     report_fatal_error("target does not implement codeview register mapping");
-  const DenseMap<MCRegister, int>::const_iterator I = L2CVRegs.find(RegNum);
+  const DenseMap<MCRegister, int>::const_iterator I = L2CVRegs.find(Reg);
   if (I == L2CVRegs.end())
-    report_fatal_error("unknown codeview register " + (RegNum < getNumRegs()
-                                                           ? getName(RegNum)
-                                                           : Twine(RegNum)));
+    report_fatal_error("unknown codeview register " + (Reg.id() < getNumRegs()
+                                                           ? getName(Reg)
+                                                           : Twine(Reg.id())));
   return I->second;
 }