anchor.diff:  
   (defun decode-group-7 (context info)
     (multiple-value-bind (reg r/m)
  -      (disassemble-ordinary-modr/m context info)
  +      (disassemble-modr/m context info)
       (let ((opcode (elt #(nil
                            nil
                            sys.lap-x86:lgdt
  
positive.code: 
  (defun decode-group-9 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-ordinary-modr/m context info)
      (case reg
        (1
         (if (rex-w info)
  
negative.code:            (if (eql (getf info :rep) #xF3)
                 (make-instruction 'sys.lap-x86:pause)
                 (make-instruction 'sys.lap-x86:nop)))
            (t
             (ecase (operand-size info)
               (64 (make-instruction 'sys.lap-x86:xchg64
                                     :rax
                                     (decode-gpr64 reg (rex-b info))))
               (32 (make-instruction 'sys.lap-x86:xchg32
                                     :eax
                                     (decode-gpr32 reg (rex-b info))))
               (16 (make-instruction 'sys.lap-x86:xchg16
                                     :ax
                                     (decode-gpr16 reg (rex-b info)))))))))
  
  (defun decode-pd-ed/q (context info opcode32 opcode64)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction (if (rex-w info)
                            opcode64
                            opcode32)
  