http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51568
--- Comment #4 from Eugene <eugene at hutorny dot in.ua> 2011-12-16 10:48:59 UTC --- Enum can be packed to one byte with __attribute__((__packed__)) : enum en { v0, v1, v2, v3, v4, v5, v6, v7 } __attribute__((__packed__));