if (!zero)
bn_sqr_recursive(&(t[n2]), t, n, p);
else
if (!zero)
bn_sqr_recursive(&(t[n2]), t, n, p);
else
bn_sqr_recursive(r, a, n, p);
bn_sqr_recursive(&(r[n2]), &(a[n]), n, p);
bn_sqr_recursive(r, a, n, p);
bn_sqr_recursive(&(r[n2]), &(a[n]), n, p);