// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build unix || js || wasip1

package net

import (
	"context"
	"internal/bytealg"
	"sync"
)

var onceReadProtocols sync.Once

// readProtocols loads contents of /etc/protocols into protocols map
// for quick access.
func readProtocols() {
	file, err := open("/etc/protocols")

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package bytealg

// Equal reports whether a and b
// are the same length and contain the same bytes.
// A nil argument is equivalent to an empty slice.
//
// Equal is equivalent to bytes.Equal.
// It is provided here for convenience,
// because some packages cannot depend on bytes.

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package bytealg

import "internal/cpu"

const MaxBruteForce = 64

func init() {
	if cpu.X86.HasAVX2 {
		MaxLen = 63
	} else {
		MaxLen = 31
	}
}

// Cutover reports the number of failures of IndexByte we should tolerate
// before switching over to Index.

// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build ppc64 || ppc64le

package bytealg

import "internal/cpu"

const MaxBruteForce = 16

var SupportsPower9 = cpu.PPC64.IsPOWER9

func init() {
	MaxLen = 32
}

// Cutover reports the number of failures of IndexByte we should tolerate

		return p, errors.New("overflowing coordinate")
	}
	// Encode the coordinates and let SetBytes reject invalid points.
	byteLen := (bitSize + 7) / 8
	buf := make([]byte, 1+2*byteLen)
	buf[0] = 4 // uncompressed point
	x.FillBytes(buf[1 : 1+byteLen])
	y.FillBytes(buf[1+byteLen : 1+2*byteLen])
	return curve.newPoint().SetBytes(buf)
}

// pointToAffine is used to convert a nistec Point to a PublicKey.

	BitFields
}

// Parse parses the Arg out from the given binary instruction i.
func (a argField) Parse(i [2]uint32) Arg {
	switch a.Type {
	default:
		return nil
	case TypeUnknown:
		return nil
	case TypeReg:
		return R0 + Reg(a.BitFields.Parse(i))
	case TypeCondRegBit:
		return Cond0LT + CondReg(a.BitFields.Parse(i))
	case TypeCondRegField:
		return CR0 + CondReg(a.BitFields.Parse(i))
	case TypeFPReg:

// newBitReader returns a new bitReader reading from r. If r is not
// already an io.ByteReader, it will be converted via a bufio.Reader.
func newBitReader(r io.Reader) bitReader {
	byter, ok := r.(io.ByteReader)
	if !ok {
		byter = bufio.NewReader(r)
	}
	return bitReader{r: byter}
}

// ReadBits64 reads the given number of bits and returns them in the
// least-significant part of a uint64. In the event of an error, it returns 0

// considered to be equal.
func (ip IP) Equal(x IP) bool {
	if len(ip) == len(x) {
		return bytealg.Equal(ip, x)
	}
	if len(ip) == IPv4len && len(x) == IPv6len {
		return bytealg.Equal(x[0:12], v4InV6Prefix) && bytealg.Equal(ip, x[12:])
	}
	if len(ip) == IPv6len && len(x) == IPv4len {
		return bytealg.Equal(ip[0:12], v4InV6Prefix) && bytealg.Equal(ip[12:], x)
	}
	return false
}

func (ip IP) matchAddrFamily(x IP) bool {

// license that can be found in the LICENSE file.

//go:build 386 || amd64 || s390x || arm || arm64 || loong64 || ppc64 || ppc64le || mips || mipsle || wasm || mips64 || mips64le || riscv64

package bytealg

import _ "unsafe" // For go:linkname

//go:noescape
func Compare(a, b []byte) int

func CompareString(a, b string) int {
	return abigen_runtime_cmpstring(a, b)
}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build !amd64 && !arm && !arm64 && !ppc64le && !ppc64 && !riscv64 && !s390x

package bytealg

func Count(b []byte, c byte) int {
	n := 0
	for _, x := range b {
		if x == c {
			n++
		}
	}
	return n
}

func CountString(s string, c byte) int {
	n := 0
	for i := 0; i < len(s); i++ {