+/* Useful for structures whose layout must much some binary specification
+ regardless of the alignment and padding qualities of the compiler. */
+#ifndef ATTRIBUTE_PACKED
+# define ATTRIBUTE_PACKED __attribute__ ((packed))
+#endif
+
+/* Attribute `hot' and `cold' was valid as of gcc 4.3. */
+#ifndef ATTRIBUTE_COLD
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_COLD __attribute__ ((__cold__))
+# else
+# define ATTRIBUTE_COLD
+# endif /* GNUC >= 4.3 */
+#endif /* ATTRIBUTE_COLD */
+#ifndef ATTRIBUTE_HOT
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_HOT __attribute__ ((__hot__))
+# else
+# define ATTRIBUTE_HOT
+# endif /* GNUC >= 4.3 */
+#endif /* ATTRIBUTE_HOT */
+