anchor.diff:  
   (defun decode-group-1a (context info)
     (multiple-value-bind (reg r/m)
  -      (disassemble-ordinary-modr/m context info)
  +      (disassemble-modr/m context info)
       (case reg
         (0
          (make-instruction 'sys.lap-x86:pop
  
positive.code:   (make-instruction opcode :al (consume-sb8 context)))
  
  (defun decode-ax-iz (context info opcode16 opcode32 opcode64)
    (declare (ignore opcode16))
    (let ((imm (consume-sb32/le context)))
      (if (rex-w info)
          (make-instruction opcode64 :rax imm)
          (make-instruction opcode32 :eax imm))))
  
  (defun decode-eb-ib (context info group-table)
    (multiple-value-bind (reg r/m)
        (disassemble-ordinary-modr/m context info)
      (let ((opcodes (aref (symbol-value group-table) reg)))
        (cond (opcodes
               (and (first opcodes)
  
negative.code:                     :al))
  
  (defun decode-ov-ax (context info opcode16 opcode32 opcode64)
    (multiple-value-bind (opcode reg)
        (ecase (operand-size info)
          (64 (values opcode64 :rax))
          (32 (values opcode32 :eax))
          (16 (values opcode16 :ax)))
      (make-instruction opcode
                        (make-instance 'effective-address
                                       :disp (consume-sb64/le context))
                        reg)))
  
  (defun decode-movzx8 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction 'sys.lap-x86:movzx8
                        (ecase (operand-size info)
                          (64 (decode-gpr64 reg (rex-r info)))
                          (32 (decode-gpr32 reg (rex-r info)))
                          (16 (decode-gpr16 reg (rex-r info))))
                        (decode-gpr8-or-mem r/m (rex-b info)))))
  
  (defun decode-movzx16 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction 'sys.lap-x86:movzx16
                        (ecase (operand-size info)
                          (64 (decode-gpr64 reg (rex-r info)))
                          (32 (decode-gpr32 reg (rex-r info)))
                          (16 (decode-gpr16 reg (rex-r info))))
                        (decode-gpr16-or-mem r/m (rex-b info)))))
  
  (defun decode-movsx8 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction 'sys.lap-x86:movsx8
                        (ecase (operand-size info)
                          (64 (decode-gpr64 reg (rex-r info)))
                          (32 (decode-gpr32 reg (rex-r info)))
                          (16 (decode-gpr16 reg (rex-r info))))
                        (decode-gpr8-or-mem r/m (rex-b info)))))
  
  (defun decode-movsx16 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction 'sys.lap-x86:movsx16
                        (ecase (operand-size info)
                          (64 (decode-gpr64 reg (rex-r info)))
                          (32 (decode-gpr32 reg (rex-r info)))
                          (16 (decode-gpr16 reg (rex-r info))))
                        (decode-gpr16-or-mem r/m (rex-b info)))))
  
  (defun decode-movsx32 (context info)
    (multiple-value-bind (reg r/m)
        (disassemble-modr/m context info)
      (make-instruction 'sys.lap-x86:movsx32
                        (ecase (operand-size info)
                          (64 (decode-gpr64 reg (rex-r info)))
                          (32 (decode-gpr32 reg (rex-r info)))
                          (16 (decode-gpr16 reg (rex-r info))))
                        (decode-gpr32-or-mem r/m (rex-b info)))))
  
  (defun decode-xchg+r (context info)
  