anchor.diff:  
   (define (emit-insn-1 out insn oper scale)
     (unless scale
  -    (setq scale value-scale))
  +    (set! scale value-scale))
     (emit out "~A~A ~A" insn (elt insn-size-suffix scale) (funcall oper scale)))
   
   (define-insn-1 emit-neg "neg")
  
positive.code: 
  (define (emit-insn-2 out insn src dest scale)
    (unless scale
      (setq scale value-scale))
    (emit out "~A~A ~A, ~A" insn (elt insn-size-suffix scale)
          (funcall src scale) (funcall dest scale)))
  
  
negative.code: (define-insn-2 emit-sar "sar")
  
  (define (emit-movzx out src dest src-scale . dest-scale)
    (set! dest-scale (if (null dest-scale) value-scale (car dest-scale)))
    (labels ((movzx (src-scale dest-scale)
               (emit out "mov~A ~A,~A"
                     (elt (elt '(("b")
  