Text() string
	// File reports the source file name of the token.
	File() string
	// Base reports the position base of the token.
	Base() *src.PosBase
	// SetBase sets the position base.
	SetBase(*src.PosBase)
	// Line reports the source line number of the token.
	Line() int
	// Col reports the source column number of the token.
	Col() int
	// Close does any teardown required.

				return nil, err
			}

			// Set the final guess at the format.
			if format.has(FormatUSTAR) && format.has(FormatPAX) {
				format.mayOnlyBe(FormatUSTAR)
			}
			hdr.Format = format
			return hdr, nil // This is a file, so stop
		}
	}
}

// handleRegularFile sets up the current file reader and padding such that it

	}

	// If seconds is negative, then perform correction.
	sign := ""
	if secs < 0 {
		sign = "-"             // Remember sign
		secs = -(secs + 1)     // Add a second to secs
		nsecs = -(nsecs - 1e9) // Take that second away from nsecs
	}
	return strings.TrimRight(fmt.Sprintf("%s%d.%09d", sign, secs, nsecs), "0")
}

// parsePAXRecord parses the input PAX record string into a key-value pair.

	p.get(')')
	p.setPseudoRegister(a, reg, isStatic, prefix)
}

// setPseudoRegister sets the NAME field of addr for a pseudo-register reference such as (SB).
func (p *Parser) setPseudoRegister(addr *obj.Addr, reg string, isStatic bool, prefix rune) {
	if addr.Reg != 0 {
		p.errorf("internal error: reg %s already set in pseudo", reg)
	}
	switch reg {
	case "FP":
		addr.Name = obj.NAME_PARAM
	case "PC":

				ts := int64(attrBuf.uint64()) // ModTime since Windows epoch
				secs := ts / ticksPerSecond
				nsecs := (1e9 / ticksPerSecond) * (ts % ticksPerSecond)
				epoch := time.Date(1601, time.January, 1, 0, 0, 0, 0, time.UTC)
				modified = time.Unix(epoch.Unix()+secs, nsecs)
			}
		case unixExtraID, infoZipUnixExtraID:
			if len(fieldBuf) < 8 {
				continue parseExtras
			}

	//      this is OK since r0 == $0, but the latter is preferred.
	ADD $0, R6, R5             	// 7ca60214

        //TODO: the assembler rewrites these into ADDIS $19, R5, Rx and ADD $-10617, Rx, Rx, but the test only sees the first ADDIS
	ADD $1234567, R5                // 3ca50013 or 0600001238a5d687
	ADD $1234567, R5, R6            // 3cc50013 or 0600001238c5d687

	ADDEX R3, R5, $3, R6            // 7cc32f54

The distinction rarely matters but
to avoid ambiguity, division or right shift where the right operand's
high bit is set is rejected.
</p>

<h3 id="symbols">Symbols</h3>

<p>
Some symbols, such as <code>R1</code> or <code>LR</code>,
are predefined and refer to registers.
The exact set depends on the architecture.
</p>

<p>
There are four predeclared symbols that refer to pseudo-registers.

	// This test compares byte slices that are almost identical, except one
	// difference that for some j, a[j]>b[j] and a[j+1]<b[j+1]. If the implementation
	// compares large chunks with wrong endianness, it gets wrong result.
	// no vector register is larger than 512 bytes for now
	const maxLength = 512
	a := make([]byte, maxLength)
	b := make([]byte, maxLength)
	// randomish but deterministic data. No 0 or 255.

		}

		// Canonicalize spacing in printed form.
		// First field is opcode, then tab, then arguments separated by spaces.
		// Canonicalize spaces after commas first.
		// Comma to separate argument gets a space; comma within does not.
		var buf []byte
		nest := 0
		for i := 0; i < len(printed); i++ {
			c := printed[i]
			switch c {
			case '{', '[':
				nest++
			case '}', ']':
				nest--