V_icmplim_jitter
if (V_icmplim_jitter > 0)
arc4random_uniform(V_icmplim_jitter * 2 + 1) -
V_icmplim_jitter;
new = lim ? V_icmplim : V_icmplim_jitter;
if (new != 0 && new <= V_icmplim_jitter)
V_icmplim_jitter = new;
MPASS(V_icmplim == 0 || V_icmplim > V_icmplim_jitter);