DRF_LW_IDX
(o)[DRF_LW_IDX((o),drf)] = DRF_LW_SET((o),drf,(v)); \
#define DRF_MW_SPANS(o,drf) (DRF_LW_IDX((o),drf) != DRF_HW_IDX((o),drf))
#define DRF_LW_GET(o,drf) (((o)[DRF_LW_IDX((o),drf)] >> DRF_LW_LO((o),drf)) & DRF_LW_MASK((o),drf))
#define DRF_LW_CLR(o,drf) ((o)[DRF_LW_IDX((o),drf)] & ~DRF_LW_SMASK((o),drf))