diff --git a/include/llvm/ADT/StringMap.h b/include/llvm/ADT/StringMap.h
index fd8643fab15..840f328db79 100644
--- a/include/llvm/ADT/StringMap.h
+++ b/include/llvm/ADT/StringMap.h
@@ -248,6 +248,26 @@ public:
     return count(MapEntry.getKey());
   }
 
+  /// equal - check whether both of the containers are equal.
+  bool operator==(const StringMap &RHS) const {
+    if (size() != RHS.size())
+      return false;
+
+    for (const auto &KeyValue : *this) {
+      auto FindInRHS = RHS.find(KeyValue.getKey());
+
+      if (FindInRHS == RHS.end())
+        return false;
+
+      if (!(KeyValue.getValue() == FindInRHS->getValue()))
+        return false;
+    }
+
+    return true;
+  }
+
+  bool operator!=(const StringMap &RHS) const { return !(*this == RHS); }
+
   /// insert - Insert the specified key/value pair into the map.  If the key
   /// already exists in the map, return false and ignore the request, otherwise
   /// insert it and return true.
diff --git a/unittests/ADT/StringMapTest.cpp b/unittests/ADT/StringMapTest.cpp
index 73c91f5fdd3..98fbd6e1df5 100644
--- a/unittests/ADT/StringMapTest.cpp
+++ b/unittests/ADT/StringMapTest.cpp
@@ -387,6 +387,70 @@ TEST_F(StringMapTest, MoveAssignment) {
   ASSERT_EQ(B.count("x"), 0u);
 }
 
+TEST_F(StringMapTest, EqualEmpty) {
+  StringMap<int> A;
+  StringMap<int> B;
+  ASSERT_TRUE(A == B);
+  ASSERT_FALSE(A != B);
+  ASSERT_TRUE(A == A); // self check
+}
+
+TEST_F(StringMapTest, EqualWithValues) {
+  StringMap<int> A;
+  A["A"] = 1;
+  A["B"] = 2;
+  A["C"] = 3;
+  A["D"] = 3;
+
+  StringMap<int> B;
+  B["A"] = 1;
+  B["B"] = 2;
+  B["C"] = 3;
+  B["D"] = 3;
+
+  ASSERT_TRUE(A == B);
+  ASSERT_TRUE(B == A);
+  ASSERT_FALSE(A != B);
+  ASSERT_FALSE(B != A);
+  ASSERT_TRUE(A == A); // self check
+}
+
+TEST_F(StringMapTest, NotEqualMissingKeys) {
+  StringMap<int> A;
+  A["A"] = 1;
+  A["B"] = 2;
+
+  StringMap<int> B;
+  B["A"] = 1;
+  B["B"] = 2;
+  B["C"] = 3;
+  B["D"] = 3;
+
+  ASSERT_FALSE(A == B);
+  ASSERT_FALSE(B == A);
+  ASSERT_TRUE(A != B);
+  ASSERT_TRUE(B != A);
+}
+
+TEST_F(StringMapTest, NotEqualWithDifferentValues) {
+  StringMap<int> A;
+  A["A"] = 1;
+  A["B"] = 2;
+  A["C"] = 100;
+  A["D"] = 3;
+
+  StringMap<int> B;
+  B["A"] = 1;
+  B["B"] = 2;
+  B["C"] = 3;
+  B["D"] = 3;
+
+  ASSERT_FALSE(A == B);
+  ASSERT_FALSE(B == A);
+  ASSERT_TRUE(A != B);
+  ASSERT_TRUE(B != A);
+}
+
 struct Countable {
   int &InstanceCount;
   int Number;