// blocks (i.e. a multiple of 64 bytes) have been hashed.
	if d.nx != 0 {
		panic("d.nx != 0")
	}

	var digest [Size]byte
	byteorder.LePutUint32(digest[0:], d.s[0])
	byteorder.LePutUint32(digest[4:], d.s[1])
	byteorder.LePutUint32(digest[8:], d.s[2])
	byteorder.LePutUint32(digest[12:], d.s[3])
	return digest
}

// Sum returns the MD5 checksum of the data.
func Sum(data []byte) [Size]byte {
	var d digest

	)
}

func LeUint32(b []byte) uint32 {
	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}

func LePutUint32(b []byte, v uint32) {
	_ = b[3] // early bounds check to guarantee safety of writes below
	b[0] = byte(v)
	b[1] = byte(v >> 8)
	b[2] = byte(v >> 16)
	b[3] = byte(v >> 24)
}

	byteorder.LePutUint16(b, v)
	return b[2:]
}

// pbit32 copies the 32-bit number v to b in little-endian order and returns the remaining slice of b.
func pbit32(b []byte, v uint32) []byte {
	byteorder.LePutUint32(b, v)
	return b[4:]
}

// pbit64 copies the 64-bit number v to b in little-endian order and returns the remaining slice of b.
func pbit64(b []byte, v uint64) []byte {
	byteorder.LePutUint64(b, v)