(let* ((class (sb!xc:find-class (type-of instance)))
(layout (class-layout class)))
(if (zerop index)
(error "can't set %INSTANCE-REF FOO 0 in cross-compilation host")
(let* ((dd (layout-info layout))
(dsd (elt (dd-slots dd) (1- index)))
(let* ((class (sb!xc:find-class (type-of instance)))
(layout (class-layout class)))
(if (zerop index)
(error "can't set %INSTANCE-REF FOO 0 in cross-compilation host")
(let* ((dd (layout-info layout))
(dsd (elt (dd-slots dd) (1- index)))