anchor.diff:  
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  +;;; Instruction SIMPLE-SHORT-FLOAT-AREF-INSTRUCTION.
  +;;;
  +;;; This instruction takes two inputs.  The first input is assumed to
  +;;; be a simple array specialized to SHORT-FLOAT.  The second is
  +;;; assumed to be a FIXNUM and represents the index in the instance of
  +;;; the element to be read.  This instruction produces a single
  +;;; output, the element read, which is an unboxed SHORT-FLOAT.
  +
  +(defclass simple-short-float-aref-instruction (instruction one-successor-mixin)
  +  ())
  +
  +(defun make-simple-short-float-aref-instruction (input1 input2 output successor)
  +  (make-instance 'simple-short-float-aref-instruction
  +    :inputs (list input1 input2)
  +    :outputs (list output)
  +    :successors (list successor)))
  +
  +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  +;;;
   ;;; Instruction SIMPLE-SHORT-FLOAT-ASET-INSTRUCTION.
   ;;;
   ;;; This instruction takes three inputs.  The first input is assumed
  
positive.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Instruction BIT-ASET-INSTRUCTION.
  ;;;
  ;;; This instruction takes three inputs.  The first input is assumed
  
negative.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Instruction DOUBLE-FLOAT-AREF-INSTRUCTION.
  ;;;
  ;;; This instruction takes two inputs.  The first input is assumed
  ;;; to be an array specialized to DOUBLE-FLOAT.  The second is assumed
  ;;; to be a FIXNUM and represents the index in the instance of the
  ;;; element to be read.  This instruction produces a single output,
  ;;; the element read, which is an unboxed DOUBLE-FLOAT.
  
  (defclass double-float-aref-instruction (instruction one-successor-mixin)
    ())
  
  (defun make-double-float-aref-instruction (input1 input2 output successor)
    (make-instance 'double-float-aref-instruction
      :inputs (list input1 input2)
      :outputs (list output)
      :successors (list successor)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Instruction DOUBLE-FLOAT-ASET-INSTRUCTION.
  ;;;
  ;;; This instruction takes three inputs.  The first input is assumed
  