anchor.diff:                      last-slot-aligned-offset
                       last-slot-machine-size
                       array-type)))
  -    ;; 9. If the member is a structure, the base alignment of the
  -    ;; structure is N , where N is the largest base alignment value of any
  -    ;; of its members, and rounded up to the base alignment of a vec4.
  -    ;; The structure may have padding at the end; the base offset of
  -    ;; the member following the sub-structure is rounded up to the
  -    ;; next multiple of the base alignment of the structure.
       ((v-typep type 'v-struct)
        (calc-struct-layout name
                            parent-type-aligned-offset
  
positive.code:     ;;    following the array is rounded up to the next multiple of the base
      ;;    alignment.
      ((v-typep type 'v-array)
       'TODO-PADDING
       (let* ((base-offset (calc-base-offset parent-type-aligned-offset
                                             last-slot-base-offset
                                             last-slot-aligned-offset
  
negative.code: ;; Common
  
  (defun machine-unit-size (type &optional stride)
    (if (typep type 'v-array)
        (progn
          (assert stride)
          (* (round-to-next-multiple (machine-unit-size (v-element-type type))
  