V_cdg_exp_backoff_scale
V_cdg_exp_backoff_scale = 3;
backoff = (qtrend > ((MAXGRAD * V_cdg_exp_backoff_scale) << D_P_E));
if (V_cdg_exp_backoff_scale > 1)
idx = (qtrend + V_cdg_exp_backoff_scale / 2) /
V_cdg_exp_backoff_scale;