+(sb!disassem:define-instruction-format (x66-reg-reg/mem-dir 24
+ :default-printer
+ `(:name
+ :tab
+ ,(swap-if 'dir 'reg/mem ", " 'reg)))
+ (x66 :field (byte 8 0) :type 'x66 :value #x66)
+ (op :field (byte 6 10))
+ (dir :field (byte 1 9))
+ (width :field (byte 1 8) :type 'width)
+ (reg/mem :fields (list (byte 2 22) (byte 3 16))
+ :type 'reg/mem)
+ (reg :field (byte 3 19) :type 'reg))
+
+(sb!disassem:define-instruction-format (x66-rex-reg-reg/mem-dir 32
+ :default-printer
+ `(:name
+ :tab
+ ,(swap-if 'dir 'reg/mem ", " 'reg)))
+ (x66 :field (byte 8 0) :type 'x66 :value #x66)
+ (rex :field (byte 4 12) :value #b0100)
+ (wrxb :field (byte 4 8) :type 'wrxb)
+ (op :field (byte 6 18))
+ (dir :field (byte 1 17))
+ (width :field (byte 1 16) :type 'width)
+ (reg/mem :fields (list (byte 2 30) (byte 3 24))
+ :type 'reg/mem)
+ (reg :field (byte 3 27) :type 'reg))
+