anchor.diff:                (setf z4 (mul z4 (- +fix-0-390180644+)))
                 (incf z3 z5)
                 (incf z4 z5)
  -              (setf (svref dptr 7) (descale (plus3 tmp4 z1 z3) +shift-1+))
  -              (setf (svref dptr 5) (descale (plus3 tmp5 z2 z4) +shift-1+))
  -              (setf (svref dptr 3) (descale (plus3 tmp6 z2 z3) +shift-1+))
  -              (setf (svref dptr 1) (descale (plus3 tmp7 z1 z4) +shift-1+)))
  +              (setf (aref dptr 7) (descale (plus3 tmp4 z1 z3) +shift-1+))
  +              (setf (aref dptr 5) (descale (plus3 tmp5 z2 z4) +shift-1+))
  +              (setf (aref dptr 3) (descale (plus3 tmp6 z2 z3) +shift-1+))
  +              (setf (aref dptr 1) (descale (plus3 tmp7 z1 z4) +shift-1+)))
           (loop for cnt fixnum from 7 downto 0 do ; second pass: on columns
  -              (setf tmp0 (plus (dbref data cnt 0) (dbref data cnt 7)))
  -              (setf tmp7 (minus (dbref data cnt 0) (dbref data cnt 7)))
  -              (setf tmp1 (plus (dbref data cnt 1) (dbref data cnt 6)))
  -              (setf tmp6 (minus (dbref data cnt 1) (dbref data cnt 6)))
  -              (setf tmp2 (plus (dbref data cnt 2) (dbref data cnt 5)))
  -              (setf tmp5 (minus (dbref data cnt 2) (dbref data cnt 5)))
  -              (setf tmp3 (plus (dbref data cnt 3) (dbref data cnt 4)))
  -              (setf tmp4 (minus (dbref data cnt 3) (dbref data cnt 4)))
  +              (setf tmp0 (plus (fixref data cnt 0) (fixref data cnt 7)))
  +              (setf tmp7 (minus (fixref data cnt 0) (fixref data cnt 7)))
  +              (setf tmp1 (plus (fixref data cnt 1) (fixref data cnt 6)))
  +              (setf tmp6 (minus (fixref data cnt 1) (fixref data cnt 6)))
  +              (setf tmp2 (plus (fixref data cnt 2) (fixref data cnt 5)))
  +              (setf tmp5 (minus (fixref data cnt 2) (fixref data cnt 5)))
  +              (setf tmp3 (plus (fixref data cnt 3) (fixref data cnt 4)))
  +              (setf tmp4 (minus (fixref data cnt 3) (fixref data cnt 4)))
                 (setf tmp10 (plus tmp0 tmp3))
                 (setf tmp13 (minus tmp0 tmp3))
                 (setf tmp11 (plus tmp1 tmp2))
                 (setf tmp12 (minus tmp1 tmp2))
  -              (setf (dbref data cnt 0) (descale (plus tmp10 tmp11) 1))
  -              (setf (dbref data cnt 4) (descale (minus tmp10 tmp11) 1))
  +              (setf (fixref data cnt 0) (descale (plus tmp10 tmp11) 1))
  +              (setf (fixref data cnt 4) (descale (minus tmp10 tmp11) 1))
                 (setf z1 (mul (plus tmp12 tmp13) +fix-0-541196100+))
  -              (setf (dbref data cnt 2) (descale (plus z1 (mul tmp13 +fix-0-765366865+)) +shift+1+))
  -              (setf (dbref data cnt 6) (descale (plus z1 (mul tmp12 (- +fix-1-847759065+))) +shift+1+))
  +              (setf (fixref data cnt 2) (descale (plus z1 (mul tmp13 +fix-0-765366865+)) +shift+1+))
  +              (setf (fixref data cnt 6) (descale (plus z1 (mul tmp12 (- +fix-1-847759065+))) +shift+1+))
                 (setf z1 (plus tmp4 tmp7))
                 (setf z2 (plus tmp5 tmp6))
                 (setf z3 (plus tmp4 tmp6))
  
positive.code: ;;  -*- Mode: LISP; Package: (JPEG :use (common-lisp)) -*-
  ;;; Generic Common Lisp JPEG encoder/decoder implementation
  ;;; $Id: jpeg.lisp,v 1.6 2011-03-14 22:49:00 charmon Exp $
  ;;; Version 1.3, August 2015
  ;;; Written by Eugene Zaikonnikov [eugene@funcall.org]
  ;;; Copyright [c] 1999,2015, Eugene Zaikonnikov <eugene@funcall.org>
  ;;;               
  ;;; This software is distributed under the terms of BSD-like license
  
negative.code: (declaim (inline csize write-stuffed quantize get-average zigzag encode-block
                   llm-dct descale crunch colorspace-convert subsample inverse-llm-dct
                   dequantize upsample extend recieve decode-ac decode-dc decode-block
                   izigzag write-bits)
  	 )
  
  (deftype uint8 () '(unsigned-byte 8))
  
  (deftype uint8-array () '(simple-array uint8 (*)))
  (deftype uint8-2d-array () '(simple-array uint8-array (*)))
  
  (deftype fixnum-array () '(simple-array fixnum (*)))
  (deftype fixnum-2d-array () '(simple-array fixnum-array (*)))
  
  (eval-when (:compile-toplevel :load-toplevel :execute)
    (defparameter *optimize* '(optimize (safety 0) (space 0) (debug 0) (speed 3))))
  