--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/unittests/Support/DJBTest.cpp	Wed Aug 14 16:55:33 2019 +0900
@@ -0,0 +1,95 @@
+//===---------- llvm/unittest/Support/DJBTest.cpp -------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/DJB.h"
+#include "llvm/ADT/Twine.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(DJBTest, caseFolding) {
+  struct TestCase {
+    StringLiteral One;
+    StringLiteral Two;
+  };
+
+  static constexpr TestCase Tests[] = {
+      {{"ASDF"}, {"asdf"}},
+      {{"qWeR"}, {"QwEr"}},
+      {{"qqqqqqqqqqqqqqqqqqqq"}, {"QQQQQQQQQQQQQQQQQQQQ"}},
+
+      {{"I"}, {"i"}},
+      // Latin Small Letter Dotless I
+      {{u8"\u0130"}, {"i"}},
+      // Latin Capital Letter I With Dot Above
+      {{u8"\u0131"}, {"i"}},
+
+      // Latin Capital Letter A With Grave
+      {{u8"\u00c0"}, {u8"\u00e0"}},
+      // Latin Capital Letter A With Macron
+      {{u8"\u0100"}, {u8"\u0101"}},
+      // Latin Capital Letter L With Acute
+      {{u8"\u0139"}, {u8"\u013a"}},
+      // Cyrillic Capital Letter Ie
+      {{u8"\u0415"}, {u8"\u0435"}},
+      // Latin Capital Letter A With Circumflex And Grave
+      {{u8"\u1ea6"}, {u8"\u1ea7"}},
+      // Kelvin Sign
+      {{u8"\u212a"}, {u8"\u006b"}},
+      // Glagolitic Capital Letter Chrivi
+      {{u8"\u2c1d"}, {u8"\u2c4d"}},
+      // Fullwidth Latin Capital Letter M
+      {{u8"\uff2d"}, {u8"\uff4d"}},
+      // Old Hungarian Capital Letter Ej
+      {{u8"\U00010c92"}, {u8"\U00010cd2"}},
+  };
+
+  for (const TestCase &T : Tests) {
+    SCOPED_TRACE("Comparing '" + T.One + "' and '" + T.Two + "'");
+    EXPECT_EQ(caseFoldingDjbHash(T.One), caseFoldingDjbHash(T.Two));
+  }
+}
+
+TEST(DJBTest, knownValuesLowerCase) {
+  struct TestCase {
+    StringLiteral Text;
+    uint32_t Hash;
+  };
+  static constexpr TestCase Tests[] = {
+      {{""}, 5381u},
+      {{"f"}, 177675u},
+      {{"fo"}, 5863386u},
+      {{"foo"}, 193491849u},
+      {{"foob"}, 2090263819u},
+      {{"fooba"}, 259229388u},
+      {{"foobar"}, 4259602622u},
+      {{"pneumonoultramicroscopicsilicovolcanoconiosis"}, 3999417781u},
+  };
+
+  for (const TestCase &T : Tests) {
+    SCOPED_TRACE("Text: '" + T.Text + "'");
+    EXPECT_EQ(T.Hash, djbHash(T.Text));
+    EXPECT_EQ(T.Hash, caseFoldingDjbHash(T.Text));
+    EXPECT_EQ(T.Hash, caseFoldingDjbHash(T.Text.upper()));
+  }
+}
+
+TEST(DJBTest, knownValuesUnicode) {
+  EXPECT_EQ(5866553u, djbHash(u8"\u0130"));
+  EXPECT_EQ(177678u, caseFoldingDjbHash(u8"\u0130"));
+  EXPECT_EQ(
+      1302161417u,
+      djbHash(
+          u8"\u0130\u0131\u00c0\u00e0\u0100\u0101\u0139\u013a\u0415\u0435\u1ea6"
+          u8"\u1ea7\u212a\u006b\u2c1d\u2c4d\uff2d\uff4d\U00010c92\U00010cd2"));
+  EXPECT_EQ(
+      1145571043u,
+      caseFoldingDjbHash(
+          u8"\u0130\u0131\u00c0\u00e0\u0100\u0101\u0139\u013a\u0415\u0435\u1ea6"
+          u8"\u1ea7\u212a\u006b\u2c1d\u2c4d\uff2d\uff4d\U00010c92\U00010cd2"));
+}