//    archAvailableCastagnoli() bool
//
//    // archInitCastagnoli initializes the architecture-specific CRC32-C
//    // algorithm. It can only be called if archAvailableCastagnoli() returns
//    // true.
//    archInitCastagnoli()
//
//    // archUpdateCastagnoli updates the given CRC32-C. It can only be called
//    // if archInitCastagnoli() was previously called.
//    archUpdateCastagnoli(crc uint32, p []byte) uint32

func archUpdateIEEE(crc uint32, p []byte) uint32 { panic("not available") }

func archAvailableCastagnoli() bool                    { return false }
func archInitCastagnoli()                              { panic("not available") }

import "internal/cpu"

func castagnoliUpdate(crc uint32, p []byte) uint32
func ieeeUpdate(crc uint32, p []byte) uint32

func archAvailableCastagnoli() bool {
	return cpu.ARM64.HasCRC32
}

func archInitCastagnoli() {
	if !cpu.ARM64.HasCRC32 {
		panic("arch-specific crc32 instruction for Castagnoli not available")
	}
}

func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
	if !cpu.ARM64.HasCRC32 {

//
//go:noescape
func vectorizedIEEE(crc uint32, p []byte) uint32

func archAvailableCastagnoli() bool {
	return hasVX
}

var archCastagnoliTable8 *slicing8Table

func archInitCastagnoli() {
	if !hasVX {
		panic("not available")
	}
	// We still use slicing-by-8 for small buffers.
	archCastagnoliTable8 = slicingMakeTable(Castagnoli)
}

// this function requires the buffer to be 16 byte aligned and > 16 bytes long.
//
//go:noescape
func vectorCrc32(crc uint32, poly uint32, p []byte) uint32

var archCastagnoliTable8 *slicing8Table

func archInitCastagnoli() {
	archCastagnoliTable8 = slicingMakeTable(Castagnoli)
}

func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
	if len(p) >= 4*vecMinLen {
		// If not aligned then process the initial unaligned bytes

type sse42Table [4]Table

var castagnoliSSE42TableK1 *sse42Table
var castagnoliSSE42TableK2 *sse42Table

func archAvailableCastagnoli() bool {
	return cpu.X86.HasSSE42
}

func archInitCastagnoli() {
	if !cpu.X86.HasSSE42 {
		panic("arch-specific Castagnoli not available")
	}
	castagnoliSSE42TableK1 = new(sse42Table)
	castagnoliSSE42TableK2 = new(sse42Table)
	// See description in updateCastagnoli.

		return slicingUpdate(crc, slicingTable, b)
	})
}

func TestArchCastagnoli(t *testing.T) {
	if !archAvailableCastagnoli() {
		t.Skip("Arch-specific Castagnoli not available.")
	}
	archInitCastagnoli()
	slicingTable := slicingMakeTable(Castagnoli)
	testCrossCheck(t, archUpdateCastagnoli, func(crc uint32, b []byte) uint32 {
		return slicingUpdate(crc, slicingTable, b)
	})
}