The /ARCHITECTURE qualifier specifies which version of the architecture to
   generate instructions for.

   The format of the /ARCHITECTURE qualifier is as follows:

      /ARCHITECTURE={GENERIC }
                    {HOST    }
                    {MERCED  }
                    {ITANIUM2}

   where:

      GENERIC        generate  instructions  that  are  appropriate  for  all
                     processors.  This option is the default.

      HOST           generate  instructions  for  the  processor   that   the
                     compiler is running on.

   The default is /ARCHITECTURE=GENERIC.