anchor.diff:  (defmacro gen-lpc-predictor (n)
     "Generate FIR linear predictor of order N"
     `(flet ((lpc-predictor (subframe)
  -            (declare (optimize (speed 3)
  -                               (safety 0)))
               (let ((out-buf (subframe-out-buf subframe))
                     (shift (subframe-lpc-coeff-shift subframe))
                     (coeff (subframe-lpc-predictor-coeff subframe)))
  
positive.code: 
  (defmethod subframe-decode ((subframe subframe-fixed) frame)
    ;; Decodes subframe destructively modifiying it
    (declare (optimize (speed 3)
  		     (safety 0))
  	   (ignore frame))
    (let* ((out-buf (subframe-out-buf subframe))
  	 (order (subframe-order subframe))
  	 (len (length out-buf)))
  
negative.code: (defun frame-decode (frame)
    "Decode a frame destructively modifying (and garbaging) all subframes within.
  Returns list of decoded audio buffers (one buffer for each channel)."
    (let ((decoded-subframes
  	 (mapcar #'(lambda (subframe) (subframe-decode subframe frame))
  		 (frame-subframes frame)))
  