}
	M.SetBit(M, int(n), 0)
	m := M.Uint64()
	return umagicData{s: int64(s), m: m}
}

func umagic8(c int8) umagicData   { return umagic(8, int64(c)) }
func umagic16(c int16) umagicData { return umagic(16, int64(c)) }
func umagic32(c int32) umagicData { return umagic(32, int64(c)) }
func umagic64(c int64) umagicData { return umagic(64, c) }

// For signed division, we use a similar strategy.
// First, we enforce a positive c.

	trailer := string(b.toSTAR().trailer())
	switch {
	case magic == magicUSTAR && trailer == trailerSTAR:
		return formatSTAR
	case magic == magicUSTAR:
		return FormatUSTAR | FormatPAX
	case magic == magicGNU && version == versionGNU:
		return FormatGNU
	default:
		return formatV7
	}
}

// setFormat writes the magic values necessary for specified format
// and then updates the checksum accordingly.

	case beMagic == go12magic:
		t.binary, possibleVersion = binary.BigEndian, ver12
	case leMagic == go116magic:
		t.binary, possibleVersion = binary.LittleEndian, ver116
	case beMagic == go116magic:
		t.binary, possibleVersion = binary.BigEndian, ver116
	case leMagic == go118magic:
		t.binary, possibleVersion = binary.LittleEndian, ver118
	case beMagic == go118magic:

// meta-data blobs/sections (one per instrumented package), and an offsets
// area storing the offsets of each section. Format of the meta-data
// file looks like:
//
// --header----------
//  | magic: [4]byte magic string
//  | version
//  | total length of meta-data file in bytes
//  | numPkgs: number of package entries in file
//  | hash: [16]byte hash of entire meta-data payload
//  | offset to string table section

retry:
	relativeOffset := 0

	// Read magic number. RFC 3.1.1.
	if _, err := io.ReadFull(r.r, r.scratch[:4]); err != nil {
		// We require that the stream contains at least one frame.
		if err == io.EOF && !r.readOneFrame {
			err = io.ErrUnexpectedEOF
		}
		return r.wrapError(relativeOffset, err)
	}

	if magic := binary.LittleEndian.Uint32(r.scratch[:4]); magic != 0xfd2fb528 {

const bzip2FinalMagic = 0x177245385090

// setup parses the bzip2 header.
func (bz2 *reader) setup(needMagic bool) error {
	br := &bz2.br

	if needMagic {
		magic := br.ReadBits(16)
		if magic != bzip2FileMagic {
			return StructuralError("bad magic value")
		}
	}

	t := br.ReadBits(8)
	if t != 'h' {
		return StructuralError("non-Huffman entropy encoding")
	}

	level := br.ReadBits(8)

func (h *Header) Read(r *Reader) error {
	b := r.BytesAt(0, len(Magic))
	h.Magic = string(b)
	if h.Magic != Magic {
		return errors.New("wrong magic, not a Go object file")
	}
	off := uint32(len(h.Magic))
	copy(h.Fingerprint[:], r.BytesAt(off, len(h.Fingerprint)))
	off += 8
	h.Flags = r.uint32At(off)
	off += 4
	for i := range h.Offsets {
		h.Offsets[i] = r.uint32At(off)
		off += 4
	}
	return nil
}

        then:
        ReadelfBinaryInfo.readArch(inputLines).isI386() == true

        where:
        [language, input] << [
            ["English", """
ELF Header:
 Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
 Class:                             ELF32
 Data:                              2's complement, little endian
 Version:                           1 (current)

	sr := io.NewSectionReader(r, 0, 1<<63-1)
	// Read XCOFF target machine
	var magic uint16
	if err := binary.Read(sr, binary.BigEndian, &magic); err != nil {
		return nil, err
	}
	if magic != U802TOCMAGIC && magic != U64_TOCMAGIC {
		return nil, fmt.Errorf("unrecognised XCOFF magic: 0x%x", magic)
	}

	f := new(File)
	f.TargetMachine = magic

	// Read XCOFF file header

		// We need to read them first to determine the type and
		// validity of optional header.
		ohMagic   uint16
		ohMagicSz = binary.Size(ohMagic)
	)

	// If optional header size is greater than 0 but less than its magic size, return error.
	if sz < uint16(ohMagicSz) {
		return nil, fmt.Errorf("optional header size is less than optional header magic size")
	}

	// read reads from io.ReadSeeke, r, into data.
	var err error