Bug 877662 - Add AlignmentUtils.h r=padenot

MozReview-Commit-ID: E5peJVX2qFo

--HG--
extra : rebase_source : 5b54f30f4013dd03731b8332b773b7c06484d901

dom/media/webaudio/AlignmentUtils.h

@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#ifndef AlignmentUtils_h__
+#define AlignmentUtils_h__
+
+#define IS_ALIGNED16(ptr) ((((uintptr_t)ptr + 15) & ~0x0F) == (uintptr_t)ptr)
+
+#ifdef DEBUG
+  #define ASSERT_ALIGNED16(ptr)                                                  \
+            MOZ_ASSERT(IS_ALIGNED16(ptr), \
+                       #ptr " has to be aligned to a 16 byte boundary");
+#else
+  #define ASSERT_ALIGNED16(ptr)
+#endif
+
+#ifdef DEBUG
+  #define ASSERT_MULTIPLE16(v) \
+            MOZ_ASSERT(v % 16 == 0, #v " has to be a a multiple of 16");
+#else
+  #define ASSERT_MULTIPLE16(v)
+#endif
+
+#define ALIGNED16(ptr) (float*)(((uintptr_t)ptr + 15) & ~0x0F);
+
+#endif