diff --git a/llvm/include/llvm/ADT/StringRef.h b/llvm/include/llvm/ADT/StringRef.h
--- a/llvm/include/llvm/ADT/StringRef.h
+++ b/llvm/include/llvm/ADT/StringRef.h
@@ -240,6 +240,10 @@
     unsigned edit_distance(StringRef Other, bool AllowReplacements = true,
                            unsigned MaxEditDistance = 0) const;
 
+    LLVM_NODISCARD unsigned
+    edit_distance_insensitive(StringRef Other, bool AllowReplacements = true,
+                              unsigned MaxEditDistance = 0) const;
+
     /// str - Get the contents as an std::string.
     LLVM_NODISCARD
     std::string str() const {
diff --git a/llvm/include/llvm/ADT/edit_distance.h b/llvm/include/llvm/ADT/edit_distance.h
--- a/llvm/include/llvm/ADT/edit_distance.h
+++ b/llvm/include/llvm/ADT/edit_distance.h
@@ -28,6 +28,9 @@
 ///
 /// \param ToArray the second sequence to compare.
 ///
+/// \param Map A Functor to apply to each item of the sequences before
+/// comparison.
+///
 /// \param AllowReplacements whether to allow element replacements (change one
 /// element into another) as a single operation, rather than as two operations
 /// (an insertion and a removal).
@@ -39,10 +42,10 @@
 /// \returns the minimum number of element insertions, removals, or (if
 /// \p AllowReplacements is \c true) replacements needed to transform one of
 /// the given sequences into the other. If zero, the sequences are identical.
-template<typename T>
-unsigned ComputeEditDistance(ArrayRef<T> FromArray, ArrayRef<T> ToArray,
-                             bool AllowReplacements = true,
-                             unsigned MaxEditDistance = 0) {
+template <typename T, typename Functor>
+unsigned ComputeMappedEditDistance(ArrayRef<T> FromArray, ArrayRef<T> ToArray,
+                                   Functor Map, bool AllowReplacements = true,
+                                   unsigned MaxEditDistance = 0) {
   // The algorithm implemented below is the "classic"
   // dynamic-programming algorithm for computing the Levenshtein
   // distance, which is described here:
@@ -79,11 +82,12 @@
       int OldRow = Row[x];
       if (AllowReplacements) {
         Row[x] = std::min(
-            Previous + (FromArray[y-1] == ToArray[x-1] ? 0u : 1u),
-            std::min(Row[x-1], Row[x])+1);
+            Previous + (Map(FromArray[y - 1]) == Map(ToArray[x - 1]) ? 0u : 1u),
+            std::min(Row[x - 1], Row[x]) + 1);
       }
       else {
-        if (FromArray[y-1] == ToArray[x-1]) Row[x] = Previous;
+        if (Map(FromArray[y - 1]) == Map(ToArray[x - 1]))
+          Row[x] = Previous;
         else Row[x] = std::min(Row[x-1], Row[x]) + 1;
       }
       Previous = OldRow;
@@ -98,6 +102,15 @@
   return Result;
 }
 
+template <typename T>
+unsigned ComputeEditDistance(ArrayRef<T> FromArray, ArrayRef<T> ToArray,
+                             bool AllowReplacements = true,
+                             unsigned MaxEditDistance = 0) {
+  return ComputeMappedEditDistance(
+      FromArray, ToArray, [](const T &X) -> const T & { return X; },
+      AllowReplacements, MaxEditDistance);
+}
+
 } // End llvm namespace
 
 #endif
diff --git a/llvm/lib/Support/StringRef.cpp b/llvm/lib/Support/StringRef.cpp
--- a/llvm/lib/Support/StringRef.cpp
+++ b/llvm/lib/Support/StringRef.cpp
@@ -98,6 +98,13 @@
       AllowReplacements, MaxEditDistance);
 }
 
+unsigned llvm::StringRef::edit_distance_insensitive(
+    StringRef Other, bool AllowReplacements, unsigned MaxEditDistance) const {
+  return llvm::ComputeMappedEditDistance(
+      makeArrayRef(data(), size()), makeArrayRef(Other.data(), Other.size()),
+      llvm::toLower, AllowReplacements, MaxEditDistance);
+}
+
 //===----------------------------------------------------------------------===//
 // String Operations
 //===----------------------------------------------------------------------===//
diff --git a/llvm/unittests/ADT/StringRefTest.cpp b/llvm/unittests/ADT/StringRefTest.cpp
--- a/llvm/unittests/ADT/StringRefTest.cpp
+++ b/llvm/unittests/ADT/StringRefTest.cpp
@@ -584,6 +584,15 @@
                                        "people soiled our green "));
 }
 
+TEST(StringRefTest, EditDistanceInsensitive) {
+  StringRef Hello("HELLO");
+  EXPECT_EQ(2U, Hello.edit_distance_insensitive("hill"));
+  EXPECT_EQ(0U, Hello.edit_distance_insensitive("hello"));
+
+  StringRef Industry("InDuStRy");
+  EXPECT_EQ(6U, Industry.edit_distance_insensitive("iNtErEsT"));
+}
+
 TEST(StringRefTest, Misc) {
   std::string Storage;
   raw_string_ostream OS(Storage);