Version uint8
	Type    uint8
	Addrs   int32
	Flags   int32
	Index   uint16
	Addrlen uint8
	_       [1]byte
}

type FdSet struct {
	Bits [2048]int32
}

type Utsname struct {
	Sysname  [32]byte
	Nodename [32]byte
	Release  [32]byte
	Version  [32]byte
	Machine  [32]byte
}

type Ustat_t struct{}

type Sigset_t struct {
	Losigs uint32
	Hisigs uint32
}

	packUint32(hdr[7:11], uint32(nsec))

	// TODO(hakim):  hdr[1:2] = gettid?

	return 11 + len(writeHeader)
}

func packUint32(b []byte, v uint32) {
	// little-endian.
	b[0] = byte(v)
	b[1] = byte(v >> 8)
	b[2] = byte(v >> 16)
	b[3] = byte(v >> 24)

//go:noescape
func chacha20Poly1305Open(dst []byte, key []uint32, src, ad []byte) bool

//go:noescape
func chacha20Poly1305Seal(dst []byte, key []uint32, src, ad []byte)

var (
	useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI2
)

// setupState writes a ChaCha20 input matrix to state. See
// https://tools.ietf.org/html/rfc7539#section-2.3.
func setupState(state *[16]uint32, key *[32]byte, nonce []byte) {
	state[0] = 0x61707865

func (d *digest) Sum(in []byte) []byte {
	s := d.Sum64()
	return append(in, byte(s>>56), byte(s>>48), byte(s>>40), byte(s>>32), byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
}

// Checksum returns the CRC-64 checksum of data
// using the polynomial represented by the [Table].
func Checksum(data []byte, tab *Table) uint64 { return update(0, tab, data) }

}

// StripVersion strips the version fields of a YAML content.
func StripVersion(yaml []byte) []byte {
	return statusPattern.ReplaceAllLiteral(yaml, []byte(statusReplacement))
}

// RefreshGoldenFile updates the golden file with the given content
func RefreshGoldenFile(t test.Failer, content []byte, goldenFile string) {
	if Refresh() {
		t.Logf("Refreshing golden file %s", goldenFile)

	F_asyncwrites uint64
	F_asyncreads  uint64
	F_fsid        Fsid
	F_namemax     uint32
	F_owner       uint32
	F_ctime       uint64
	F_fstypename  [16]byte
	F_mntonname   [90]byte
	F_mntfromname [90]byte
	F_mntfromspec [90]byte
	_             [2]byte
	Mount_info    [160]byte
}

type Flock_t struct {
	Start  int64
	Len    int64
	Pid    int32
	Type   int16
	Whence int16
}

type Dirent struct {

	b, d.s[3] = consumeUint32(b)
	b = b[copy(d.x[:], b):]
	b, d.len = consumeUint64(b)
	d.nx = int(d.len % BlockSize)
	return nil
}

func consumeUint64(b []byte) ([]byte, uint64) {
	return b[8:], byteorder.BeUint64(b[0:8])
}

func consumeUint32(b []byte) ([]byte, uint32) {
	return b[4:], byteorder.BeUint32(b[0:4])
}

// New returns a new hash.Hash computing the MD5 checksum. The Hash also

	// R3 = byte array pointer
	// R4 = length
	// R6 = byte to count
	MTVRD	R6, V1		// move compare byte
	MOVD	R6, R5
	VSPLTB	$7, V1, V1	// replicate byte across V1
	BR	countbytebody<>(SB)

TEXT ·CountString<ABIInternal>(SB), NOSPLIT|NOFRAME, $0-32
	// R3 = byte array pointer
	// R4 = length
	// R5 = byte to count
	MTVRD	R5, V1		// move compare byte
	VSPLTB	$7, V1, V1	// replicate byte across V1

	name        string
	newPoint    func() Point
	scalarOrder []byte
}

// nistPoint is a generic constraint for the nistec Point types.
type nistPoint[T any] interface {
	Bytes() []byte
	BytesX() ([]byte, error)
	SetBytes([]byte) (T, error)
	ScalarMult(T, []byte) (T, error)
	ScalarBaseMult([]byte) (T, error)
}

func (c *nistCurve[Point]) String() string {
	return c.name
}

}

func (d *digest) Sum32() uint32 { return d.crc }

func (d *digest) Sum(in []byte) []byte {
	s := d.Sum32()
	return append(in, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
}

// Checksum returns the CRC-32 checksum of data
// using the polynomial represented by the [Table].
func Checksum(data []byte, tab *Table) uint32 { return Update(0, tab, data) }

// ChecksumIEEE returns the CRC-32 checksum of data