ring_subtract
(ring_subtract(ring, ring->mark, ring->consume) < count)) {
return ring_subtract(ring, ring->consume, ring->supply);
return ring_subtract(ring, ring->top, ring->supply);
return ring_subtract(ring, ring->consume, ring->supply);
return ring_subtract(ring, ring->supply, ring->consume);
return ring_subtract(ring, ring->mark, ring->consume);
return ring_subtract(ring, ring->top, ring->consume);
return ring_subtract(ring, ring->supply, ring->consume);
return ring_subtract(ring, ring->top, ring->consume);
return ring_subtract(ring, ring->mark, ring->consume);