diff -r 000000000000 -r 6474c204b198 mfbt/tests/TestCountPopulation.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mfbt/tests/TestCountPopulation.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/MathAlgorithms.h"
+
+using mozilla::CountPopulation32;
+
+static void
+TestCountPopulation32()
+{
+  MOZ_RELEASE_ASSERT(CountPopulation32(0xFFFFFFFF) == 32);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0xF0FF1000) == 13);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x7F8F0001) == 13);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x3FFF0100) == 15);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x1FF50010) == 12);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00800000) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00400000) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00008000) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00004000) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00000080) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00000040) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00000001) == 1);
+  MOZ_RELEASE_ASSERT(CountPopulation32(0x00000000) == 0);
+}
+
+int main()
+{
+  TestCountPopulation32();
+  return 0;
+}