anchor.diff:      nil
       nil
       nil
  -    nil ; C0
  -    nil
  +    (decode-eb-gb sys.lap-x86:xadd8) ; C0
  +    (decode-ev-gv sys.lap-x86:xadd16 sys.lap-x86:xadd32 sys.lap-x86:xadd64)
       nil
       nil
       nil
  
positive.code:       (0
         (let ((imm (consume-sb32/le context)))
           (if (rex-w rex)
               `(sys.lap-x86:test64 ,(decode-gpr64-or-mem r/m (rex-b rex)) ,imm)
               `(sys.lap-x86:test32 ,(decode-gpr32-or-mem r/m (rex-b rex)) ,imm))))
        (t nil))))
  
  (defun decode-mov+r-iv (context opcode-byte rex)
    (let ((reg (ldb (byte 3 0) opcode-byte)))
      (cond ((rex-w rex)
             (let ((imm (consume-sb64/le context)))
               `(sys.lap-x86:mov64 ,(decode-gpr64 reg (rex-b rex))
                                   ,imm)))
            (t
             (let ((imm (consume-sb32/le context)))
               `(sys.lap-x86:mov32 ,(decode-gpr32 reg (rex-b rex))
                                   ,imm))))))
  
  (defun decode-simple (context opcode-byte rex opcode)
    (declare (ignore context opcode-byte rex))
    `(,opcode))
  
  (defun disassemble-one-instruction-1 (context)
    (let* ((byte (consume-ub8 context))
  
negative.code: (defconstant +sib-base+ (byte 3 0))
  
  (defclass instruction ()
    ((%offset :reader inst-offset)
     (%size :reader inst-size)
     (%opcode :initarg :opcode :reader inst-opcode)
     (%operands :initarg :operands :reader inst-operands)))
  
  (defun make-instruction (opcode &rest operands)
  