// float64 become -0, but Rat obviously cannot
			// preserve the sign from SetString("-0").
			switch {
			case math.Float32bits(e) == math.Float32bits(f):
				// Ok: bitwise equal.
			case f == 0 && r.Num().BitLen() == 0:
				// Ok: Rat(0) is equivalent to both +/- float64(0).
			default:
				t.Errorf("strconv.ParseFloat(%q) = %g (%b), want %g (%b); delta = %g", input, e, e, f, f, f-e)
			}
		}

		return makeRat(x)
	case *big.Float:
		return makeFloat(x)
	default:
		return unknownVal{}
	}
}

// BitLen returns the number of bits required to represent
// the absolute value x in binary representation; x must be an [Int] or an [Unknown].
// If x is [Unknown], the result is 0.
func BitLen(x Value) int {
	switch x := x.(type) {
	case int64Val:
		u := uint64(x)
		if x < 0 {
			u = uint64(-x)
		}

		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
	}

	n, i, ok := dtoi(mask)
	if !ok || i != len(mask) || n < 0 || n > ipAddr.BitLen() {
		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
	}
	m := CIDRMask(n, ipAddr.BitLen())
	addr16 := ipAddr.As16()
	return IP(addr16[:]), &IPNet{IP: IP(addr16[:]).Mask(m), Mask: m}, nil
}

func copyIP(x IP) IP {
	y := make(IP, len(x))

	}
	return z
}

func putNat(x *nat) {
	natPool.Put(x)
}

var natPool sync.Pool

// bitLen returns the length of x in bits.
// Unlike most methods, it works even if x is not normalized.
func (x nat) bitLen() int {
	// This function is used in cryptographic operations. It must not leak
	// anything but the Int's sign and bit size through side-channels. Any

func umagic(n uint, c int64) umagicData {
	// Convert from ConstX auxint values to the real uint64 constant they represent.
	d := uint64(c) << (64 - n) >> (64 - n)

	C := new(big.Int).SetUint64(d)
	s := C.BitLen()
	M := big.NewInt(1)
	M.Lsh(M, n+uint(s))     // 2^(n+s)
	M.Add(M, C)             // 2^(n+s)+c
	M.Sub(M, big.NewInt(1)) // 2^(n+s)+c-1
	M.Div(M, C)             // ⎡2^(n+s)/c⎤
	if M.Bit(int(n)) != 1 {

	x.abs.bytes(buf)
	return buf
}

// BitLen returns the length of the absolute value of x in bits.
// The bit length of 0 is 0.
func (x *Int) BitLen() int {
	// This function is used in cryptographic operations. It must not leak
	// anything but the Int's sign and bit size through side-channels. Any
	// changes must be reviewed by a security expert.
	return x.abs.bitLen()
}

		o &= 0x7f
		if i != 0 {
			o |= 0x80
		}
		dst = append(dst, o)
	}
	return dst
}

func base128BigIntLength(n *big.Int) int {
	if n.Cmp(big.NewInt(0)) == 0 {
		return 1
	}
	return (n.BitLen() + 6) / 7
}

func appendBase128BigInt(dst []byte, n *big.Int) []byte {
	if n.Cmp(big.NewInt(0)) == 0 {
		return append(dst, 0)
	}

	for i := base128BigIntLength(n) - 1; i >= 0; i-- {

// for ECDSA, use the GenerateKey function of the crypto/ecdsa package.
func GenerateKey(curve Curve, rand io.Reader) (priv []byte, x, y *big.Int, err error) {
	N := curve.Params().N
	bitSize := N.BitLen()
	byteLen := (bitSize + 7) / 8
	priv = make([]byte, byteLen)

	for x == nil {
		_, err = io.ReadFull(rand, priv)
		if err != nil {
			return
		}

		if z.Bit(i) == 0 {
			t.Errorf("bitset: bit %d of %s got 0 want 1", i, x)
		}
		if z.Cmp(z1) != 0 {
			t.Errorf("bitset: inconsistent value after SetBit 1, got %s want %s", z, z1)
		}
		z.SetBit(z, i, 0)
		altSetBit(z1, z1, i, 0)
		if z.Bit(i) != 0 {
			t.Errorf("bitset: bit %d of %s got 1 want 0", i, x)
		}
		if z.Cmp(z1) != 0 {

func TestKeyGeneration(t *testing.T) {
	for _, size := range []int{128, 1024, 2048, 3072} {
		priv, err := GenerateKey(rand.Reader, size)
		if err != nil {
			t.Errorf("GenerateKey(%d): %v", size, err)
		}
		if bits := priv.N.BitLen(); bits != size {
			t.Errorf("key too short (%d vs %d)", bits, size)
		}
		testKeyBasics(t, priv)
		if testing.Short() {
			break
		}
	}
}

func Test3PrimeKeyGeneration(t *testing.T) {
	size := 768