return v } // mul51 returns lo + hi * 2⁵¹ = a * b. func mul51(a uint64, b uint32) (lo uint64, hi uint64) { mh, ml := bits.Mul64(a, uint64(b)) lo = ml & maskLow51Bits hi = (mh << 13) | (ml >> 51) return } // Pow22523 set v = x^((p-5)/8), and returns v. (p-5)/8 is 2^252-3. func (v *Element) Pow22523(x *Element) *Element { var t0, t1, t2 Element t0.Square(x) // x^2 t1.Square(&t0) // x^4 t1.Square(&t1) // x^8 t1.Multiply(x, &t1) // x^9 t0.Multiply(&t0, &t1) // x^11 t0.Square(&t0) // x^22 t0.Multiply(&t1,...