diff -r 000000000000 -r 6474c204b198 gfx/2d/SSEHelpers.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/2d/SSEHelpers.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+/* 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 <xmmintrin.h>
+#include <emmintrin.h>
+
+/* Before Nehalem _mm_loadu_si128 could be very slow, this trick is a little
+ * faster. Once enough people are on architectures where _mm_loadu_si128 is
+ * fast we can migrate to it.
+ */
+MOZ_ALWAYS_INLINE __m128i loadUnaligned128(const __m128i *aSource)
+{
+  // Yes! We use uninitialized memory here, we'll overwrite it though!
+  __m128 res = _mm_loadl_pi(_mm_set1_ps(0), (const __m64*)aSource);
+  return _mm_castps_si128(_mm_loadh_pi(res, ((const __m64*)(aSource)) + 1));
+}