102 #define prefbit(pref) has_##pref = 1 << idx_##pref  macro
103     prefbit (rex_b),  enumerator
104     prefbit (rex_x),  enumerator
105     prefbit (rex_r),  enumerator
106     prefbit (rex_w),  enumerator
107     prefbit (rex),  enumerator
108     prefbit (cs),  enumerator
109     prefbit (ds),  enumerator
110     prefbit (es),  enumerator
111     prefbit (fs),  enumerator
112     prefbit (gs),  enumerator
113     prefbit (ss),  enumerator
114     prefbit (data16),  enumerator
115     prefbit (addr16),  enumerator
116     prefbit (rep),  enumerator
117     prefbit (repne),  enumerator
118     prefbit (lock)  enumerator