(SignExt8to(64|32|16) x) => (I64ShrS (I64Shl x (I64Const [56])) (I64Const [56]))
(ZeroExt32to64        x) => (I64And x (I64Const [0xffffffff]))
(ZeroExt16to(64|32)   x) => (I64And x (I64Const [0xffff]))
(ZeroExt8to(64|32|16) x) => (I64And x (I64Const [0xff]))

(Slicemask x) => (I64ShrS (I64Sub (I64Const [0]) x) (I64Const [63]))

// Lowering truncation
// Because we ignore the high parts, truncates are just copies.

	DNS_TYPE_TSIG    = 0x00fa
	DNS_TYPE_IXFR    = 0x00fb
	DNS_TYPE_AXFR    = 0x00fc
	DNS_TYPE_MAILB   = 0x00fd
	DNS_TYPE_MAILA   = 0x00fe
	DNS_TYPE_ALL     = 0x00ff
	DNS_TYPE_ANY     = 0x00ff
	DNS_TYPE_WINS    = 0xff01
	DNS_TYPE_WINSR   = 0xff02
	DNS_TYPE_NBSTAT  = 0xff01
)

const (
	DNS_INFO_NO_RECORDS = 0x251D
)

const (
	// flags inside DNSRecord.Dw
	DnsSectionQuestion   = 0x0000

		start := f.fset.Position(block.startByte)
		end := f.fset.Position(block.endByte)

		start, end = dedup(start, end)

		fmt.Fprintf(w, "\t\t%d, %d, %#x, // [%d]\n", start.Line, end.Line, (end.Column&0xFFFF)<<16|(start.Column&0xFFFF), i)
	}

	// Close the position array.
	fmt.Fprintf(w, "\t},\n")

	// Initialize the position array field.
	fmt.Fprintf(w, "\tNumStmt: [%d]uint16{\n", len(f.blocks))

	{0x00f0, "\xc3\xb0"},
	{0x00f8, "\xc3\xb8"},
	{0x00ff, "\xc3\xbf"},
	{0x0100, "\xc4\x80"},
	{0x07ff, "\xdf\xbf"},
	{0x0400, "\xd0\x80"},
	{0x0800, "\xe0\xa0\x80"},
	{0x0801, "\xe0\xa0\x81"},
	{0x1000, "\xe1\x80\x80"},
	{0xd000, "\xed\x80\x80"},
	{0xd7ff, "\xed\x9f\xbf"}, // last code point before surrogate half.
	{0xe000, "\xee\x80\x80"}, // first code point after surrogate half.
	{0xfffe, "\xef\xbf\xbe"},
	{0xffff, "\xef\xbf\xbf"},

	MOVD $2, R15      // Set up index

	// Set up masks for use with VSEL
	MOVD   $0xff, R21        // Set up mask 0xff000000ff000000...
	SLD    $24, R21
	MTVSRD R21, V10
	VSPLTW $1, V10, V29
	VSLDOI $2, V29, V29, V30 // Mask 0x0000ff000000ff00...
	MOVD   $0xffff, R21
	SLD    $16, R21
	MTVSRD R21, V10
	VSPLTW $1, V10, V31      // Mask 0xffff0000ffff0000...

	err := pipe2(&pp, flags)
	if err == nil {
		p[0] = int(pp[0])
		p[1] = int(pp[1])
	}
	return err
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr

	SOCK_CLOEXEC                     = 0x80000
	SOCK_DGRAM                       = 0x1
	SOCK_NONBLOCK                    = 0x80
	SOCK_STREAM                      = 0x2
	SOL_SOCKET                       = 0xffff
	SO_ACCEPTCONN                    = 0x1009
	SO_ATTACH_BPF                    = 0x32
	SO_ATTACH_REUSEPORT_CBPF         = 0x33
	SO_ATTACH_REUSEPORT_EBPF         = 0x34
	SO_BINDTODEVICE                  = 0x19

// symbols and ASCII space.
func IsPrint(r rune) bool {
	// Fast check for Latin-1
	if r <= 0xFF {
		if 0x20 <= r && r <= 0x7E {
			// All the ASCII is printable from space through DEL-1.
			return true
		}
		if 0xA1 <= r && r <= 0xFF {
			// Similarly for ¡ through ÿ...
			return r != 0xAD // ...except for the bizarre soft hyphen.
		}
		return false
	}

	SOCK_CLOEXEC                     = 0x80000
	SOCK_DGRAM                       = 0x1
	SOCK_NONBLOCK                    = 0x80
	SOCK_STREAM                      = 0x2
	SOL_SOCKET                       = 0xffff
	SO_ACCEPTCONN                    = 0x1009
	SO_ATTACH_BPF                    = 0x32
	SO_ATTACH_REUSEPORT_CBPF         = 0x33
	SO_ATTACH_REUSEPORT_EBPF         = 0x34
	SO_BINDTODEVICE                  = 0x19

	SOCK_CLOEXEC                     = 0x80000
	SOCK_DGRAM                       = 0x1
	SOCK_NONBLOCK                    = 0x80
	SOCK_STREAM                      = 0x2
	SOL_SOCKET                       = 0xffff
	SO_ACCEPTCONN                    = 0x1009
	SO_ATTACH_BPF                    = 0x32
	SO_ATTACH_REUSEPORT_CBPF         = 0x33
	SO_ATTACH_REUSEPORT_EBPF         = 0x34
	SO_BINDTODEVICE                  = 0x19