*(*uint8)(f) &^= mask
	}
}

func (f bitset8) get2(shift uint8) uint8 {
	return uint8(f>>shift) & 3
}

// set2 sets two bits in f using the bottom two bits of b.
func (f *bitset8) set2(shift uint8, b uint8) {
	// Clear old bits.
	*(*uint8)(f) &^= 3 << shift
	// Set new bits.
	*(*uint8)(f) |= uint8(b&3) << shift
}

type bitset16 uint16

func (f *bitset16) set(mask uint16, b bool) {
	if b {

	// Only small positive powers of 10 are exact (5^28 has 66 bits).
	exact := q <= 27 && q >= 0

	di, dexp2, d0 := mult64bitPow10(mant, e2, q)
	if dexp2 >= 0 {
		panic("not enough significant bits after mult64bitPow10")
	}
	// As a special case, computation might still be exact, if exponent
	// was negative and if it amounts to computing an exact division.
	// In that case, we ignore all lower bits.

  TF_BFLOAT16 = 14,  // Float32 truncated to 16 bits.
  TF_QINT16 = 15,    // Quantized int16
  TF_QUINT16 = 16,   // Quantized uint16
  TF_UINT16 = 17,
  TF_COMPLEX128 = 18,  // Double-precision complex
  TF_HALF = 19,
  TF_RESOURCE = 20,
  TF_VARIANT = 21,
  TF_UINT32 = 22,
  TF_UINT64 = 23,
  TF_FLOAT8_E5M2 = 24,    // 5 exponent bits, 2 mantissa bits.
  TF_FLOAT8_E4M3FN = 25,  // 4 exponent bits, 3 mantissa bits, finite-only, with

// call. Bits are numbered in big endian order so the
// leftmost bit (the MSB) is at index 0.
type queryResult struct {
	bits [2]uint64
}

// Has reports whether the given functions are present.
func (q *queryResult) Has(fns ...function) bool {
	if len(fns) == 0 {
		panic("no function codes provided")
	}
	for _, f := range fns {
		if !bitIsSet(q.bits[:], uint(f)) {
			return false
		}
	}

	"PAIR",
	"SHIFT",
	"EXTREG",
	"SPR",
	"SPOP",
	"COND",
	"ARNG",
	"ELEM",
	"LIST",
	"ZCON",
	"ABCON0",
	"ADDCON0",
	"ABCON",
	"AMCON",
	"ADDCON",
	"MBCON",
	"MOVCON",
	"BITCON",
	"ADDCON2",
	"LCON",
	"MOVCON2",
	"MOVCON3",
	"VCON",
	"FCON",
	"VCONADDR",
	"AACON",
	"AACON2",
	"LACON",
	"AECON",
	"SBRA",
	"LBRA",
	"ZAUTO",
	"NSAUTO_16",
	"NSAUTO_8",

// It does not allocate. Unlike [Addr.Prefix], [PrefixFrom] does not mask
// off the host bits of ip.
//
// If bits is less than zero or greater than ip.BitLen, [Prefix.Bits]
// will return an invalid value -1.
func PrefixFrom(ip Addr, bits int) Prefix {
	var bitsPlusOne uint8
	if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
		bitsPlusOne = uint8(bits) + 1
	}
	return Prefix{
		ip:          ip.withoutZone(),

const m1 = 0x3333333333333333 // 00110011 ...
const m2 = 0x0f0f0f0f0f0f0f0f // 00001111 ...

// OnesCount64 returns the number of one bits ("population count") in x.
func OnesCount64(x uint64) int {
	// Implementation: Parallel summing of adjacent bits.
	// See "Hacker's Delight", Chap. 5: Counting Bits.
	// The following pattern shows the general approach:
	//
	//   x = x>>1&(m0&m) + x&(m0&m)
	//   x = x>>2&(m1&m) + x&(m1&m)

// Bits are numbered in big endian order so the
// leftmost bit (the MSB) is at index 0.
type facilityList struct {
	bits [4]uint64
}

// Has reports whether the given facilities are present.
func (s *facilityList) Has(fs ...facility) bool {
	if len(fs) == 0 {
		panic("no facility bits provided")
	}
	for _, f := range fs {
		if !bitIsSet(s.bits[:], uint(f)) {
			return false
		}
	}

	fixedOnce.Do(func() {
		// These come from the RFC section 3.2.6.
		var bits [288]int
		for i := 0; i < 144; i++ {
			bits[i] = 8
		}
		for i := 144; i < 256; i++ {
			bits[i] = 9
		}
		for i := 256; i < 280; i++ {
			bits[i] = 7
		}
		for i := 280; i < 288; i++ {
			bits[i] = 8
		}
		fixedHuffmanDecoder.init(bits[:])
	})
}

func (f *decompressor) Reset(r io.Reader, dict []byte) error {

	return p
}

// CIDRMask returns an [IPMask] consisting of 'ones' 1 bits
// followed by 0s up to a total length of 'bits' bits.
// For a mask of this form, CIDRMask is the inverse of [IPMask.Size].
func CIDRMask(ones, bits int) IPMask {
	if bits != 8*IPv4len && bits != 8*IPv6len {
		return nil
	}
	if ones < 0 || ones > bits {
		return nil
	}
	l := bits / 8
	m := make(IPMask, l)
	n := uint(ones)
	for i := 0; i < l; i++ {