anchor.diff:  (define-u-b-object-ref sys.int::%%object-ref-unsigned-byte-32 4 sys.lap-x86:mov32   sys.lap-x86:mov32 :eax)
   
   (defbuiltin sys.int::%object-ref-unsigned-byte-64 (object offset) ()
  -  (let ((constant-offset (and (constant-type-p offset `(signed-byte ,(- 64 sys.int::+n-fixnum-bits+)))
  +  (let ((constant-offset (and (constant-type-p offset `(signed-byte ,(- 32 sys.int::+n-fixnum-bits+)))
                                 (second offset))))
       (unless constant-offset
         (load-in-reg :rdi offset t)
  
positive.code:     *r8-value*))
  
  (defbuiltin sys.int::%object-ref-unsigned-byte-64-unscaled (object offset) ()
    (let ((constant-offset (and (constant-type-p offset `(signed-byte ,(- 64 sys.int::+n-fixnum-bits+)))
                                (second offset))))
      (unless constant-offset
        (load-in-reg :rdi offset t)
  
negative.code:          (emit '(sys.lap-x86:lea64 :r8 ((:rax ,(ash 1 sys.int::+n-fixnum-bits+)))))
           (setf *r8-value* (list (gensym)))))
       (defbuiltin (setf ,name) (new-value object offset) ()
         (let ((constant-offset (and (constant-type-p offset `(signed-byte ,(- 32 sys.int::+n-fixnum-bits+)))
                                     (second offset))))
           (unless constant-offset
             (load-in-reg :rdi offset t)
  