func (z *Int) modSqrt3Mod4Prime(x, p *Int) *Int {
	e := new(Int).Add(p, intOne) // e = p + 1
	e.Rsh(e, 2)                  // e = (p + 1) / 4
	z.Exp(x, e, p)               // z = x^e mod p
	return z
}

// modSqrt5Mod8Prime uses Atkin's observation that 2 is not a square mod p
//
//	alpha ==  (2*a)^((p-5)/8)    mod p
//	beta  ==  2*a*alpha^2        mod p  is a square root of -1

	p := tri(231)
	p.Sub(p, intOne)
	p.Sub(p, intOne) // tri(231) - 2 is a prime == 5 mod 8
	x := new(Int).SetUint64(7)
	for i := 0; i < b.N; i++ {
		x.SetUint64(7)
		x.modSqrt5Mod8Prime(x, p)
	}
}

func TestBitwise(t *testing.T) {
	x := new(Int)
	y := new(Int)
	for _, test := range bitwiseTests {
		x.SetString(test.x, 0)
		y.SetString(test.y, 0)