// (and in that mode the real sha256 uses cgo).
package notsha256

import (
	"encoding/binary"
	"hash"
)

// The size of a checksum in bytes.
const Size = 32

// The blocksize in bytes.
const BlockSize = 64

const (
	chunk = 64
	init0 = 0x6A09E667
	init1 = 0xBB67AE85
	init2 = 0x3C6EF372
	init3 = 0xA54FF53A
	init4 = 0x510E527F
	init5 = 0x9B05688C
	init6 = 0x1F83D9AB
	init7 = 0x5BE0CD19

	}
}

func stable_func(data lessSwap, n int) {
	blockSize := 20 // must be > 0
	a, b := 0, blockSize
	for b <= n {
		insertionSort_func(data, a, b)
		a = b
		b += blockSize
	}
	insertionSort_func(data, a, n)

	for blockSize < n {
		a, b = 0, 2*blockSize
		for b <= n {
			symMerge_func(data, a, a+blockSize, b)
			a = b
			b += 2 * blockSize
		}
		if m := a + blockSize; m < n {

// column and first row.
var zigzag = [blockSize]int{
	0, 1, 5, 6, 14, 15, 27, 28,
	2, 4, 7, 13, 16, 26, 29, 42,
	3, 8, 12, 17, 25, 30, 41, 43,
	9, 11, 18, 24, 31, 40, 44, 53,
	10, 19, 23, 32, 39, 45, 52, 54,
	20, 22, 33, 38, 46, 51, 55, 60,
	21, 34, 37, 47, 50, 56, 59, 61,
	35, 36, 48, 49, 57, 58, 62, 63,
}

func TestZigUnzig(t *testing.T) {
	for i := 0; i < blockSize; i++ {
		if unzig[zigzag[i]] != i {

	fd := f.Fd()
	_, err := unix.FcntlInt(fd, unix.F_NOCACHE, 0)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {
	return directio.AlignedBlock(blockSize)

	}
	flag &= ^(syscall.O_DIRECT)
	_, err = unix.FcntlInt(fd, unix.F_SETFL, flag)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {
	return directio.AlignedBlock(blockSize)

			Optional:    true,
		},
		config.HelpKV{
			Key:         BlockSize,
			Type:        "string",
			Description: "cache all objects below the specified block size" + defaultHelpPostfix(BlockSize),
			Optional:    true,
		},
	}

)

// blockPadding computes the number of bytes needed to pad offset up to the
// nearest block edge where 0 <= n < blockSize.
func blockPadding(offset int64) (n int64) {
	return -offset & (blockSize - 1)
}

var zeroBlock block

type block [blockSize]byte

// Convert block to any number of formats.
func (b *block) toV7() *headerV7       { return (*headerV7)(b) }

}

// NewCTR returns a Stream which encrypts/decrypts using the AES block
// cipher in counter mode. The length of iv must be the same as [BlockSize].
func (c *aesCipherAsm) NewCTR(iv []byte) cipher.Stream {
	if len(iv) != BlockSize {
		panic("cipher.NewCTR: IV length must equal block size")
	}
	var ac aesctr
	ac.block = c
	ac.ctr[0] = byteorder.BeUint64(iv[0:]) // high bits

func (s *sum128) Size() int  { return 16 }
func (s *sum128a) Size() int { return 16 }

func (s *sum32) BlockSize() int   { return 1 }
func (s *sum32a) BlockSize() int  { return 1 }
func (s *sum64) BlockSize() int   { return 1 }
func (s *sum64a) BlockSize() int  { return 1 }
func (s *sum128) BlockSize() int  { return 1 }
func (s *sum128a) BlockSize() int { return 1 }

func (s *sum32) Sum(in []byte) []byte {
	v := uint32(*s)

func stableOrdered[E cmp.Ordered](data []E, n int) {
	blockSize := 20 // must be > 0
	a, b := 0, blockSize
	for b <= n {
		insertionSortOrdered(data, a, b)
		a = b
		b += blockSize
	}
	insertionSortOrdered(data, a, n)

	for blockSize < n {
		a, b = 0, 2*blockSize
		for b <= n {
			symMergeOrdered(data, a, a+blockSize, b)
			a = b
			b += 2 * blockSize
		}
		if m := a + blockSize; m < n {