fe64_sqr
fe64_sqr(t0, z);
fe64_sqr(t1, t0);
fe64_sqr(t1, t1);
fe64_sqr(t2, t0);
fe64_sqr(t2, t1);
fe64_sqr(t2, t2);
fe64_sqr(t2, t1);
fe64_sqr(t2, t2);
fe64_sqr(t3, t2);
fe64_sqr(t3, t3);
fe64_sqr(t2, t2);
fe64_sqr(t2, t1);
fe64_sqr(t2, t2);
fe64_sqr(t3, t2);
fe64_sqr(t3, t3);
fe64_sqr(t2, t2);
fe64_sqr(t1, t1);
fe64_sqr(tmp0, tmp1);
fe64_sqr(tmp1, x2);
fe64_sqr(z2, z2);
fe64_sqr(x3, x3);