}

// uint128 holds a 128-bit number as two 64-bit limbs, for use with the
// bits.Mul64 and bits.Add64 intrinsics.
type uint128 struct {
	lo, hi uint64
}

func mul64(a, b uint64) uint128 {
	hi, lo := bits.Mul64(a, b)
	return uint128{lo, hi}
}

func add128(a, b uint128) uint128 {
	lo, c := bits.Add64(a.lo, b.lo, 0)
	hi, c := bits.Add64(a.hi, b.hi, c)
	if c != 0 {
		panic("poly1305: unexpected overflow")
	}

			v1 := w[i-2]
			t1 := bits.RotateLeft64(v1, -19) ^ bits.RotateLeft64(v1, -61) ^ (v1 >> 6)
			v2 := w[i-15]
			t2 := bits.RotateLeft64(v2, -1) ^ bits.RotateLeft64(v2, -8) ^ (v2 >> 7)

			w[i] = t1 + w[i-7] + t2 + w[i-16]
		}

		a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7

		for i := 0; i < 80; i++ {

// Prime will return error for any error returned by [rand.Read] or if bits < 2.
func Prime(rand io.Reader, bits int) (*big.Int, error) {
	if bits < 2 {
		return nil, errors.New("crypto/rand: prime size must be at least 2-bit")
	}

	randutil.MaybeReadByte(rand)

	b := uint(bits % 8)
	if b == 0 {
		b = 8
	}

	bytes := make([]byte, (bits+7)/8)
	p := new(big.Int)

	for {

			v1 := w[i-2]
			t1 := (bits.RotateLeft32(v1, -17)) ^ (bits.RotateLeft32(v1, -19)) ^ (v1 >> 10)
			v2 := w[i-15]
			t2 := (bits.RotateLeft32(v2, -7)) ^ (bits.RotateLeft32(v2, -18)) ^ (v2 >> 3)
			w[i] = t1 + w[i-7] + t2 + w[i-16]
		}

		a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7

		for i := 0; i < 64; i++ {

  private final int bits;
  private final String toString;

  ChecksumHashFunction(
      ImmutableSupplier<? extends Checksum> checksumSupplier, int bits, String toString) {
    this.checksumSupplier = checkNotNull(checksumSupplier);
    checkArgument(bits == 32 || bits == 64, "bits (%s) must be either 32 or 64", bits);
    this.bits = bits;
    this.toString = checkNotNull(toString);
  }

	code := uint16(0)
	for n, bits := range bitCount {
		code <<= 1
		if n == 0 || bits == 0 {
			continue
		}
		// The literals list[len(list)-bits] .. list[len(list)-bits]
		// are encoded using "bits" bits, and get the values
		// code, code + 1, ....  The code values are
		// assigned in literal order (not frequency order).
		chunk := list[len(list)-int(bits):]

		h.lns.sort(chunk)

// So RotRight(x, k) == ⎣x/(2^k)⎦ <= ⎣a/(2^k)⎦
//
// If x does not end in k zero bits, then RotRight(x, k)
// has some non-zero bits in the k highest bits.
// ⎣x/(2^k)⎦ has all zeroes in the k highest bits,
// so RotRight(x, k) > ⎣x/(2^k)⎦
//
// Finally, if x > a and has k trailing zero bits, then RotRight(x, k) == ⎣x/(2^k)⎦

// Set adds fd to the set fds.
func (fds *FdSet) Set(fd int) {
	fds.Bits[fd/NFDBITS] |= (1 << (uintptr(fd) % NFDBITS))
}

// Clear removes fd from the set fds.
func (fds *FdSet) Clear(fd int) {
	fds.Bits[fd/NFDBITS] &^= (1 << (uintptr(fd) % NFDBITS))
}

// IsSet returns whether fd is in the set fds.
func (fds *FdSet) IsSet(fd int) bool {
	return fds.Bits[fd/NFDBITS]&(1<<(uintptr(fd)%NFDBITS)) != 0
}

package zstd

import (
	"io"
	"math/bits"
)

// maxHuffmanBits is the largest possible Huffman table bits.
const maxHuffmanBits = 11

// readHuff reads Huffman table from data starting at off into table.
// Each entry in a Huffman table is a pair of bytes.
// The high byte is the encoded value. The low byte is the number
// of bits used to encode that value. We index into the table

		b.set(i)
		return
	}
	// Set bits [i, j].
	j := i + n - 1
	if i/64 == j/64 {
		b[i/64] |= ((uint64(1) << n) - 1) << (i % 64)
		return
	}
	_ = b[j/64]
	// Set leading bits.
	b[i/64] |= ^uint64(0) << (i % 64)
	for k := i/64 + 1; k < j/64; k++ {
		b[k] = ^uint64(0)
	}
	// Set trailing bits.
	b[j/64] |= (uint64(1) << (j%64 + 1)) - 1
}

// setAll sets all the bits of b.
func (b *pageBits) setAll() {