RX_DESC
prefetch(&RX_DESC(rx, n));
macrx = RX_DESC(rx, n);
prefetch(&RX_DESC(rx, n+4));
eval = (RX_DESC(rx, n+1) & XCT_RXRES_8B_EVAL_M) >>
dma = (RX_DESC(rx, n+2) & XCT_PTR_ADDR_M);
RX_DESC(rx, n) = 0;
RX_DESC(rx, n+1) = 0;