diff --git a/llvm/lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp b/llvm/lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
index 34ae80669f2c..7a8835c3af60 100644
--- a/llvm/lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
+++ b/llvm/lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
@@ -101,12 +101,12 @@ class MSP430Operand : public MCParsedAsmOperand {
   } Kind;
 
   struct Memory {
-    unsigned Reg;
+    MCRegister Reg;
     const MCExpr *Offset;
   };
   union {
     const MCExpr *Imm;
-    unsigned      Reg;
+    MCRegister    Reg;
     StringRef     Tok;
     Memory        Mem;
   };
@@ -116,11 +116,11 @@ class MSP430Operand : public MCParsedAsmOperand {
 public:
   MSP430Operand(StringRef Tok, SMLoc const &S)
       : Kind(k_Tok), Tok(Tok), Start(S), End(S) {}
-  MSP430Operand(KindTy Kind, unsigned Reg, SMLoc const &S, SMLoc const &E)
+  MSP430Operand(KindTy Kind, MCRegister Reg, SMLoc const &S, SMLoc const &E)
       : Kind(Kind), Reg(Reg), Start(S), End(E) {}
   MSP430Operand(MCExpr const *Imm, SMLoc const &S, SMLoc const &E)
       : Kind(k_Imm), Imm(Imm), Start(S), End(E) {}
-  MSP430Operand(unsigned Reg, MCExpr const *Expr, SMLoc const &S,
+  MSP430Operand(MCRegister Reg, MCExpr const *Expr, SMLoc const &S,
                 SMLoc const &E)
       : Kind(k_Mem), Mem({Reg, Expr}), Start(S), End(E) {}
 
@@ -188,7 +188,7 @@ public:
     return Reg;
   }
 
-  void setReg(unsigned RegNo) {
+  void setReg(MCRegister RegNo) {
     assert(Kind == k_Reg && "Invalid access!");
     Reg = RegNo;
   }
@@ -197,9 +197,9 @@ public:
     return std::make_unique<MSP430Operand>(Str, S);
   }
 
-  static std::unique_ptr<MSP430Operand> CreateReg(unsigned RegNum, SMLoc S,
+  static std::unique_ptr<MSP430Operand> CreateReg(MCRegister Reg, SMLoc S,
                                                   SMLoc E) {
-    return std::make_unique<MSP430Operand>(k_Reg, RegNum, S, E);
+    return std::make_unique<MSP430Operand>(k_Reg, Reg, S, E);
   }
 
   static std::unique_ptr<MSP430Operand> CreateImm(const MCExpr *Val, SMLoc S,
@@ -207,20 +207,19 @@ public:
     return std::make_unique<MSP430Operand>(Val, S, E);
   }
 
-  static std::unique_ptr<MSP430Operand> CreateMem(unsigned RegNum,
-                                                  const MCExpr *Val,
-                                                  SMLoc S, SMLoc E) {
-    return std::make_unique<MSP430Operand>(RegNum, Val, S, E);
+  static std::unique_ptr<MSP430Operand>
+  CreateMem(MCRegister Reg, const MCExpr *Val, SMLoc S, SMLoc E) {
+    return std::make_unique<MSP430Operand>(Reg, Val, S, E);
   }
 
-  static std::unique_ptr<MSP430Operand> CreateIndReg(unsigned RegNum, SMLoc S,
-                                                  SMLoc E) {
-    return std::make_unique<MSP430Operand>(k_IndReg, RegNum, S, E);
+  static std::unique_ptr<MSP430Operand> CreateIndReg(MCRegister Reg, SMLoc S,
+                                                     SMLoc E) {
+    return std::make_unique<MSP430Operand>(k_IndReg, Reg, S, E);
   }
 
-  static std::unique_ptr<MSP430Operand> CreatePostIndReg(unsigned RegNum, SMLoc S,
-                                                  SMLoc E) {
-    return std::make_unique<MSP430Operand>(k_PostIndReg, RegNum, S, E);
+  static std::unique_ptr<MSP430Operand> CreatePostIndReg(MCRegister Reg,
+                                                         SMLoc S, SMLoc E) {
+    return std::make_unique<MSP430Operand>(k_PostIndReg, Reg, S, E);
   }
 
   SMLoc getStartLoc() const override { return Start; }
@@ -545,8 +544,8 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMSP430AsmParser() {
 #define GET_MATCHER_IMPLEMENTATION
 #include "MSP430GenAsmMatcher.inc"
 
-static unsigned convertGR16ToGR8(unsigned Reg) {
-  switch (Reg) {
+static MCRegister convertGR16ToGR8(MCRegister Reg) {
+  switch (Reg.id()) {
   default:
     llvm_unreachable("Unknown GR16 register");
   case MSP430::PC:  return MSP430::PCB;
@@ -575,7 +574,7 @@ unsigned MSP430AsmParser::validateTargetOperandClass(MCParsedAsmOperand &AsmOp,
   if (!Op.isReg())
     return Match_InvalidOperand;
 
-  unsigned Reg = Op.getReg();
+  MCRegister Reg = Op.getReg();
   bool isGR16 =
       MSP430MCRegisterClasses[MSP430::GR16RegClassID].contains(Reg);