This data-type qualifier is used in pointer definitions, indicating
  to the compiler that the data pointed to is not properly aligned on
  a correct address.  (To be properly aligned, the address of an
  object must be a multiple of the size of the type.  For example,
  two-byte objects must be aligned on even addresses.) When data is
  accessed through a pointer declared __unaligned, the compiler
  generates the additional code necessary to copy or store the data
  without causing alignment errors.  It is best to avoid use of
  misaligned data altogether, but in some cases the usage may be
  justified by the need to access packed structures, or by other
  considerations.