Index: llvm/include/llvm/ADT/DenseSet.h
===================================================================
--- llvm/include/llvm/ADT/DenseSet.h
+++ llvm/include/llvm/ADT/DenseSet.h
@@ -15,6 +15,7 @@
 #define LLVM_ADT_DENSESET_H
 
 #include "llvm/ADT/DenseMap.h"
+#include <initializer_list>
 
 namespace llvm {
 
@@ -55,6 +56,11 @@
 
   explicit DenseSetImpl(unsigned InitialReserve = 0) : TheMap(InitialReserve) {}
 
+  DenseSetImpl(std::initializer_list<ValueT> Elems)
+      : DenseSetImpl(Elems.size()) {
+    insert(Elems.begin(), Elems.end());
+  }
+
   bool empty() const { return TheMap.empty(); }
   size_type size() const { return TheMap.size(); }
   size_t getMemorySize() const { return TheMap.getMemorySize(); }
Index: llvm/unittests/ADT/DenseSetTest.cpp
===================================================================
--- llvm/unittests/ADT/DenseSetTest.cpp
+++ llvm/unittests/ADT/DenseSetTest.cpp
@@ -64,6 +64,21 @@
     DenseSetTestTypes;
 TYPED_TEST_CASE(DenseSetTest, DenseSetTestTypes);
 
+TYPED_TEST(DenseSetTest, InitializerList) {
+  TypeParam set({1, 2, 1, 4});
+  EXPECT_EQ(3u, set.size());
+  EXPECT_EQ(1u, set.count(1));
+  EXPECT_EQ(1u, set.count(2));
+  EXPECT_EQ(1u, set.count(4));
+  EXPECT_EQ(0u, set.count(3));
+}
+
+TYPED_TEST(DenseSetTest, EmptyInitializerList) {
+  TypeParam set({});
+  EXPECT_EQ(0u, set.size());
+  EXPECT_EQ(0u, set.count(0));
+}
+
 TYPED_TEST(DenseSetTest, FindAsTest) {
   auto &set = this->Set;
   // Size tests