diff --git a/llvm/include/llvm/CodeGen/MIRParser/MIParser.h b/llvm/include/llvm/CodeGen/MIRParser/MIParser.h
index 4d93213de5e07..0f2898d3554d0 100644
--- a/llvm/include/llvm/CodeGen/MIRParser/MIParser.h
+++ b/llvm/include/llvm/CodeGen/MIRParser/MIParser.h
@@ -45,7 +45,7 @@ struct VRegInfo {
   } D;
   Register VReg;
   Register PreferredReg;
-  std::vector<uint8_t> Flags;
+  uint8_t Flags = 0;
 };
 
 using Name2RegClassMap = StringMap<const TargetRegisterClass *>;
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 10d3cdcf0c1ce..c0c61b3fdd167 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -703,7 +703,7 @@ bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
         return error(FlagStringValue.SourceRange.Start,
                      Twine("use of undefined register flag '") +
                          FlagStringValue.Value + "'");
-      Info.Flags.push_back(FlagValue);
+      Info.Flags |= FlagValue;
     }
     RegInfo.noteNewVirtualRegister(Info.VReg);
   }