IWI_EXP2
sc->wme[1].cwmin[ac] = IWI_EXP2(wmep->wmep_logcwmin);
sc->wme[1].cwmax[ac] = IWI_EXP2(wmep->wmep_logcwmax);
sc->wme[2].cwmin[ac] = IWI_EXP2(wmep->wmep_logcwmin);
sc->wme[2].cwmax[ac] = IWI_EXP2(wmep->wmep_logcwmax);
sc->wme[0].cwmin[ac] = IWI_EXP2(wmep->wmep_logcwmin);
sc->wme[0].cwmax[ac] = IWI_EXP2(wmep->wmep_logcwmax);