code: public static void ge_p1p1_to_p3(ge_p3 r, ge_p1p1 p) {
          fe_mul.fe_mul(r.X, p.X, p.T);
          fe_mul.fe_mul(r.Y, p.Y, p.Z);
          fe_mul.fe_mul(r.Z, p.Z, p.T);
          fe_mul.fe_mul(r.T, p.X, p.Y);
      }
docs: /*
  r = p