rn_r
x = x->rn_r;
x = x->rn_r;
t = t->rn_r;
x = x->rn_r;
p->rn_r = t;
t->rn_r = x;
t->rn_r = tt;
x->rn_r = tt;
if (t->rn_r == saved_tt)
x = t->rn_r;
t->rn_r = x;
p->rn_r = x;
x->rn_r->rn_p = x;
x = t->rn_r;
if (p->rn_r == t)
p->rn_r = x;
t->rn_r->rn_p = t;
p->rn_r = t;
while (rn->rn_p->rn_r == rn && !(rn->rn_flags & RNF_ROOT))
for (rn = rn->rn_p->rn_r; rn->rn_b >= 0; )
t->rn_r = ttt;