BN_mod_lshift_quick
ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m));
|| !BN_mod_lshift_quick(t5, t5, 3, group->field)
|| !BN_mod_lshift_quick(r->Z, t2, 2, group->field))
|| !BN_mod_lshift_quick(t2, group->b, 2, group->field)
if (!BN_mod_lshift_quick(n2, n2, 2, p))
if (!BN_mod_lshift_quick(n3, n0, 3, p))
int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m);