diff --git a/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp b/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
index 0ec437e2c002..c3b1e4d5b271 100644
--- a/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
@@ -496,7 +496,7 @@ void MarkupFilter::printValue(Twine Value) {
 #define ASSIGN_OR_RETURN_NONE(TYPE, NAME, EXPR)                                \
   auto NAME##Opt = (EXPR);                                                     \
   if (!NAME##Opt)                                                              \
-    return None;                                                               \
+    return std::nullopt;                                                       \
   TYPE NAME = std::move(*NAME##Opt)
 
 Optional<MarkupFilter::Module>
diff --git a/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp b/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
index 575a2b2f82f2..0667ca59830c 100644
--- a/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
+++ b/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
@@ -31,7 +31,7 @@ using namespace llvm;
       TY res = *NAME##View;                                                    \
       return res;                                                              \
     }                                                                          \
-    return None;                                                               \
+    return std::nullopt;                                                       \
   }
 
 MCOPT_EXP(bool, RelaxAll)
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index e6370a079b36..c13e5b5deff6 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -3947,7 +3947,7 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
     OS << "        MII.getDeprecatedInfo(Inst, getSTI(), Info)) {\n";
     OS << "      SMLoc Loc = ((" << Target.getName()
        << "Operand &)*Operands[0]).getStartLoc();\n";
-    OS << "      getParser().Warning(Loc, Info, None);\n";
+    OS << "      getParser().Warning(Loc, Info, std::nullopt);\n";
     OS << "    }\n";
   }
 
diff --git a/llvm/utils/TableGen/GICombinerEmitter.cpp b/llvm/utils/TableGen/GICombinerEmitter.cpp
index 14f24654c7ad..6890bbfbd137 100644
--- a/llvm/utils/TableGen/GICombinerEmitter.cpp
+++ b/llvm/utils/TableGen/GICombinerEmitter.cpp
@@ -647,7 +647,7 @@ void GICombinerEmitter::emitNameMatcher(raw_ostream &OS) const {
   StringMatcher Matcher("RuleIdentifier", Cases, OS);
   Matcher.Emit();
   OS << "#endif // ifndef NDEBUG\n\n"
-     << "  return None;\n"
+     << "  return std::nullopt;\n"
      << "}\n";
 }
 
@@ -960,7 +960,7 @@ void GICombinerEmitter::run(raw_ostream &OS) {
      << "    const auto Last = "
         "getRuleIdxForIdentifier(RangePair.second);\n"
      << "    if (!First || !Last)\n"
-     << "      return None;\n"
+     << "      return std::nullopt;\n"
      << "    if (First >= Last)\n"
      << "      report_fatal_error(\"Beginning of range should be before "
         "end of range\");\n"
@@ -971,7 +971,7 @@ void GICombinerEmitter::run(raw_ostream &OS) {
      << "  }\n"
      << "  const auto I = getRuleIdxForIdentifier(RangePair.first);\n"
      << "  if (!I)\n"
-     << "    return None;\n"
+     << "    return std::nullopt;\n"
      << "  return {{*I, *I + 1}};\n"
      << "}\n\n";
 
diff --git a/llvm/utils/TableGen/RegisterInfoEmitter.cpp b/llvm/utils/TableGen/RegisterInfoEmitter.cpp
index 4d75d3020383..1707574cac98 100644
--- a/llvm/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/llvm/utils/TableGen/RegisterInfoEmitter.cpp
@@ -1690,7 +1690,7 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
     OS << "  };\n";
     OS << "  return makeArrayRef(Masks);\n";
   } else {
-    OS << "  return None;\n";
+    OS << "  return std::nullopt;\n";
   }
   OS << "}\n\n";
 
@@ -1756,7 +1756,7 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
     OS << "  };\n";
     OS << "  return makeArrayRef(Names);\n";
   } else {
-    OS << "  return None;\n";
+    OS << "  return std::nullopt;\n";
   }
   OS << "}\n\n";
 
diff --git a/llvm/utils/TableGen/SubtargetEmitter.cpp b/llvm/utils/TableGen/SubtargetEmitter.cpp
index 0509f8540117..8352c22ac478 100644
--- a/llvm/utils/TableGen/SubtargetEmitter.cpp
+++ b/llvm/utils/TableGen/SubtargetEmitter.cpp
@@ -1862,7 +1862,7 @@ void SubtargetEmitter::run(raw_ostream &OS) {
   if (NumFeatures)
     OS << Target << "FeatureKV, ";
   else
-    OS << "None, ";
+    OS << "std::nullopt, ";
   if (NumProcs)
     OS << Target << "SubTypeKV, ";
   else
@@ -1955,7 +1955,7 @@ void SubtargetEmitter::run(raw_ostream &OS) {
   if (NumFeatures)
     OS << "makeArrayRef(" << Target << "FeatureKV, " << NumFeatures << "), ";
   else
-    OS << "None, ";
+    OS << "std::nullopt, ";
   if (NumProcs)
     OS << "makeArrayRef(" << Target << "SubTypeKV, " << NumProcs << "), ";
   else