Merge "Add base/memory.h."

base/include/base/memory.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_MEMORY_H
+#define BASE_MEMORY_H
+
+namespace android {
+namespace base {
+
+// Use packed structures for access to unaligned data on targets with alignment
+// restrictions.  The compiler will generate appropriate code to access these
+// structures without generating alignment exceptions.
+template <typename T>
+static inline T get_unaligned(const T* address) {
+  struct unaligned {
+    T v;
+  } __attribute__((packed));
+  const unaligned* p = reinterpret_cast<const unaligned*>(address);
+  return p->v;
+}
+
+template <typename T>
+static inline void put_unaligned(T* address, T v) {
+  struct unaligned {
+    T v;
+  } __attribute__((packed));
+  unaligned* p = reinterpret_cast<unaligned*>(address);
+  p->v = v;
+}
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_MEMORY_H