anchor.diff:    (emit-xor out reg reg 2))
   
   (define (emit-push out reg)
  -  (emit out "push~A ~A" usual-size-suffix (value-sized reg)))
  +  (emit out "push~A ~A" value-insn-size-suffix (value-sized reg)))
   
   (define (emit-pop out reg)
  -  (emit out "pop~A ~A" usual-size-suffix (value-sized reg)))
  +  (emit out "pop~A ~A" value-insn-size-suffix (value-sized reg)))
   
   (define (emit-set out cc reg)
     (emit out "set~A ~A" cc (funcall reg 0)))
  
positive.code: 
  ;;; Instructions
  
  (defconstant insn-size-suffix '("b" "w" "l" "q"))
  (define usual-size-suffix (elt insn-size-suffix value-scale))
  
  (defmarco (define-insn-2 name insn)
    (quasiquote
  
negative.code: (define (emit-insn-1 out insn oper scale)
    (unless scale
      (set! scale value-scale))
    (emit out "~A~A ~A" insn (insn-size-suffix scale) (funcall oper scale)))
  
  (define-insn-1 emit-neg "neg")
  (define-insn-1 emit-idiv "idiv")
  