REFCOUNT_SATURATED
if (__predict_false(REFCOUNT_SATURATED(old + 1)))
if (__predict_false(REFCOUNT_SATURATED(old)))
if (__predict_false(old < n || REFCOUNT_SATURATED(old))) {
if (__predict_false(REFCOUNT_SATURATED(old))) \
KASSERT(!REFCOUNT_SATURATED(value),
if (__predict_false(REFCOUNT_SATURATED(old)))
if (__predict_false(REFCOUNT_SATURATED(old)))