diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index ed4f01f176c2f..b1e688788c333 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -45,7 +45,6 @@
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdlib>
-#include <map>
 #include <string>
 using namespace llvm;
 using namespace cl;
@@ -2339,7 +2338,7 @@ class CategorizedHelpPrinter : public HelpPrinter {
 protected:
   void printOptions(StrOptionPairVector &Opts, size_t MaxArgLen) override {
     std::vector<OptionCategory *> SortedCategories;
-    std::map<OptionCategory *, std::vector<Option *>> CategorizedOptions;
+    DenseMap<OptionCategory *, std::vector<Option *>> CategorizedOptions;
 
     // Collect registered option categories into vector in preparation for
     // sorting.
@@ -2351,17 +2350,13 @@ class CategorizedHelpPrinter : public HelpPrinter {
     array_pod_sort(SortedCategories.begin(), SortedCategories.end(),
                    OptionCategoryCompare);
 
-    // Create map to empty vectors.
-    for (OptionCategory *Category : SortedCategories)
-      CategorizedOptions[Category] = std::vector<Option *>();
-
     // Walk through pre-sorted options and assign into categories.
     // Because the options are already alphabetically sorted the
     // options within categories will also be alphabetically sorted.
     for (size_t I = 0, E = Opts.size(); I != E; ++I) {
       Option *Opt = Opts[I].second;
       for (auto &Cat : Opt->Categories) {
-        assert(CategorizedOptions.count(Cat) > 0 &&
+        assert(std::binary_search(SortedCategories.begin(), SortedCategories.end(), Cat, [](OptionCategory* A, OptionCategory* B) { return OptionCategoryCompare(&A, &B);}) &&
                "Option has an unregistered category");
         CategorizedOptions[Cat].push_back(Opt);
       }