+/*
+ * The __hp() macro casts the void pointer @x to a pointer to a structure
+ * containing an array of char of the specified size. This allows passing the
+ * @addr arguments of the following inline functions as "m" and "+m" operands
+ * to the assembly. The @size parameter should be a constant to support
+ * compilers such as clang which do not support VLA.
+ */
+
+#define __hp(size, x) ((struct { char v[size]; } *)(x))