diff --git a/llvm/utils/TableGen/OptParserEmitter.cpp b/llvm/utils/TableGen/OptParserEmitter.cpp
--- a/llvm/utils/TableGen/OptParserEmitter.cpp
+++ b/llvm/utils/TableGen/OptParserEmitter.cpp
@@ -219,9 +219,8 @@
   PrefixesT Prefixes;
   Prefixes.insert(std::make_pair(PrefixKeyT(), "prefix_0"));
   unsigned CurPrefix = 0;
-  for (unsigned i = 0, e = Opts.size(); i != e; ++i) {
-    const Record &R = *Opts[i];
-    std::vector<StringRef> prf = R.getValueAsListOfStrings("Prefixes");
+  for (const Record *R : Opts) {
+    std::vector<StringRef> prf = R->getValueAsListOfStrings("Prefixes");
     PrefixKeyT prfkey(prf.begin(), prf.end());
     unsigned NewPrefix = CurPrefix + 1;
     if (Prefixes.insert(std::make_pair(prfkey, (Twine("prefix_") +
@@ -235,18 +234,16 @@
   OS << "// Prefixes\n\n";
   OS << "#ifdef PREFIX\n";
   OS << "#define COMMA ,\n";
-  for (PrefixesT::const_iterator I = Prefixes.begin(), E = Prefixes.end();
-                                  I != E; ++I) {
+  for (auto PrefixIt : Prefixes) {
     OS << "PREFIX(";
 
     // Prefix name.
-    OS << I->second;
+    OS << PrefixIt.second;
 
     // Prefix values.
     OS << ", {";
-    for (PrefixKeyT::const_iterator PI = I->first.begin(),
-                                    PE = I->first.end(); PI != PE; ++PI) {
-      OS << "\"" << *PI << "\" COMMA ";
+    for (const SmallString<2> &PrefixKey : PrefixIt.first) {
+      OS << "\"" << PrefixKey << "\" COMMA ";
     }
     OS << "nullptr})\n";
   }
@@ -256,9 +253,7 @@
   OS << "/////////\n";
   OS << "// Groups\n\n";
   OS << "#ifdef OPTION\n";
-  for (unsigned i = 0, e = Groups.size(); i != e; ++i) {
-    const Record &R = *Groups[i];
-
+  for (const Record *R : Groups) {
     // Start a single option entry.
     OS << "OPTION(";
 
@@ -266,17 +261,17 @@
     OS << "nullptr";
 
     // The option string.
-    OS << ", \"" << R.getValueAsString("Name") << '"';
+    OS << ", \"" << R->getValueAsString("Name") << '"';
 
     // The option identifier name.
-    OS << ", " << getOptionName(R);
+    OS << ", " << getOptionName(*R);
 
     // The option kind.
     OS << ", Group";
 
     // The containing option group (if any).
     OS << ", ";
-    if (const DefInit *DI = dyn_cast<DefInit>(R.getValueInit("Group")))
+    if (const DefInit *DI = dyn_cast<DefInit>(R->getValueInit("Group")))
       OS << getOptionName(*DI->getDef());
     else
       OS << "INVALID";
@@ -285,10 +280,10 @@
     OS << ", INVALID, nullptr, 0, 0";
 
     // The option help text.
-    if (!isa<UnsetInit>(R.getValueInit("HelpText"))) {
+    if (!isa<UnsetInit>(R->getValueInit("HelpText"))) {
       OS << ",\n";
       OS << "       ";
-      write_cstring(OS, R.getValueAsString("HelpText"));
+      write_cstring(OS, R->getValueAsString("HelpText"));
     } else
       OS << ", nullptr";
 
@@ -343,8 +338,8 @@
       OS << "nullptr";
     } else {
       OS << "\"";
-      for (size_t i = 0, e = AliasArgs.size(); i != e; ++i)
-        OS << AliasArgs[i] << "\\0";
+      for (const StringRef &AliasArg : AliasArgs)
+        OS << AliasArg << "\\0";
       OS << "\"";
     }
 
@@ -394,15 +389,13 @@
   };
 
   std::vector<const Record *> OptsWithMarshalling;
-  for (unsigned I = 0, E = Opts.size(); I != E; ++I) {
-    const Record &R = *Opts[I];
-
+  for (const Record *R : Opts) {
     // Start a single option entry.
     OS << "OPTION(";
-    WriteOptRecordFields(OS, R);
+    WriteOptRecordFields(OS, *R);
     OS << ")\n";
-    if (IsMarshallingOption(R))
-      OptsWithMarshalling.push_back(&R);
+    if (IsMarshallingOption(*R))
+      OptsWithMarshalling.push_back(R);
   }
   OS << "#endif // OPTION\n";
 
@@ -462,18 +455,17 @@
   OS << "#ifdef OPTTABLE_ARG_INIT\n";
   OS << "//////////\n";
   OS << "// Option Values\n\n";
-  for (unsigned I = 0, E = Opts.size(); I != E; ++I) {
-    const Record &R = *Opts[I];
-    if (isa<UnsetInit>(R.getValueInit("ValuesCode")))
+  for (const Record *R : Opts) {
+    if (isa<UnsetInit>(R->getValueInit("ValuesCode")))
       continue;
     OS << "{\n";
     OS << "bool ValuesWereAdded;\n";
-    OS << R.getValueAsString("ValuesCode");
+    OS << R->getValueAsString("ValuesCode");
     OS << "\n";
-    for (StringRef Prefix : R.getValueAsListOfStrings("Prefixes")) {
+    for (StringRef Prefix : R->getValueAsListOfStrings("Prefixes")) {
       OS << "ValuesWereAdded = Opt.addValues(";
       std::string S(Prefix);
-      S += R.getValueAsString("Name");
+      S += R->getValueAsString("Name");
       write_cstring(OS, S);
       OS << ", Values);\n";
       OS << "(void)ValuesWereAdded;\n";