diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -540,6 +540,42 @@
     return MutableArrayRef<T>(data, length);
   }
 
+  /// Construct a MutableArrayRef from a SmallVector.
+  template <typename T>
+  MutableArrayRef<T> makeMutableArrayRef(SmallVectorImpl<T> &Vec) {
+    return Vec;
+  }
+
+  /// Construct a MutableArrayRef from a SmallVector.
+  template <typename T, unsigned N>
+  MutableArrayRef<T> makeMutableArrayRef(SmallVector<T, N> &Vec) {
+    return Vec;
+  }
+
+  /// Construct a MutableArrayRef from a std::vector.
+  template<typename T>
+  MutableArrayRef<T> makeMutableArrayRef(std::vector<T> &Vec) {
+    return Vec;
+  }
+
+  /// Construct a MutableArrayRef from a std::array.
+  template <typename T, std::size_t N>
+  MutableArrayRef<T> makeMutableArrayRef(std::array<T, N> &Arr) {
+    return Arr;
+  }
+
+  /// Construct a MutableArrayRef from a MutableArrayRef (no-op) (const)
+  template <typename T>
+  MutableArrayRef<T> makeMutableArrayRef(const MutableArrayRef<T> &Vec) {
+    return Vec;
+  }
+
+  /// Construct a MutableArrayRef from a C array.
+  template<typename T, size_t N>
+  MutableArrayRef<T> makeMutableArrayRef(T (&Arr)[N]) {
+    return MutableArrayRef<T>(Arr);
+  }
+
   /// @}
   /// @name ArrayRef Comparison Operators
   /// @{
diff --git a/llvm/unittests/ADT/ArrayRefTest.cpp b/llvm/unittests/ADT/ArrayRefTest.cpp
--- a/llvm/unittests/ADT/ArrayRefTest.cpp
+++ b/llvm/unittests/ADT/ArrayRefTest.cpp
@@ -229,7 +229,6 @@
   EXPECT_TRUE(A.empty());
 }
 
-// Test that makeArrayRef works on ArrayRef (no-op)
 TEST(ArrayRefTest, makeArrayRef) {
   static const int A1[] = {1, 2, 3, 4, 5, 6, 7, 8};
 
@@ -265,4 +264,43 @@
 static_assert(std::is_trivially_copyable<ArrayRef<int>>::value,
               "trivially copyable");
 
+TEST(ArrayRefTest, makeMutableArrayRef) {
+  int A = 0;
+  auto AR = makeMutableArrayRef(A);
+  EXPECT_EQ(AR.data(), &A);
+  EXPECT_EQ(AR.size(), (size_t)1);
+
+  AR[0] = 1;
+  EXPECT_EQ(A, 1);
+
+  int B[] = {0, 1, 2, 3};
+  auto BR1 = makeMutableArrayRef(&B[0], 4);
+  auto BR2 = makeMutableArrayRef(B);
+  EXPECT_EQ(BR1.data(), &B[0]);
+  EXPECT_EQ(BR1.size(), (size_t)4);
+  EXPECT_EQ(BR2.data(), &B[0]);
+  EXPECT_EQ(BR2.size(), (size_t)4);
+
+  SmallVector<int> C1;
+  SmallVectorImpl<int> &C2 = C1;
+  C1.resize(5);
+  auto CR1 = makeMutableArrayRef(C1);
+  auto CR2 = makeMutableArrayRef(C2);
+  EXPECT_EQ(CR1.data(), C1.data());
+  EXPECT_EQ(CR1.size(), C1.size());
+  EXPECT_EQ(CR2.data(), C2.data());
+  EXPECT_EQ(CR2.size(), C2.size());
+
+  std::vector<int> D;
+  D.resize(5);
+  auto DR = makeMutableArrayRef(D);
+  EXPECT_EQ(DR.data(), D.data());
+  EXPECT_EQ(DR.size(), D.size());
+
+  std::array<int, 5> E;
+  auto ER = makeMutableArrayRef(E);
+  EXPECT_EQ(ER.data(), E.data());
+  EXPECT_EQ(ER.size(), E.size());
+}
+
 } // end anonymous namespace