SPACE_CNT
resid = (int64_t)SPACE_CNT(bp->b_resid);
SPACE_CNT(sp_type), un->un_pos.eof, un->un_status);
if (((int64_t)SPACE_CNT(count) > 0x7fffff) ||
((int64_t)SPACE_CNT(count) < -(0x7fffff))) {
count = SPACE_CNT(bp->b_bcount);
count = SPACE_CNT(bp->b_bcount);