AND	$-2, R1               // a517fffe
	AND	$-65536, R1           // c01bffff0000
	AND	$1, R1                // c0a100000001b980001a
	ANDW	R1, R2                // 1421
	ANDW	R1, R2, R3            // b9f42031
	ANDW	$1, R1                // c01b00000001
	ANDW	$131071, R1           // a5160001
	ANDW	$65536, R1            // c01b00010000
	ANDW	$-2, R1               // a517fffe
	OR	R1, R2                // b9810021

	BEQ	R1, 2(PC)
	JAL	0(R1)		// CALL (R1)	// 0020f809
	BEQ	R1, 2(PC)
	JAL	foo+0(SB)	// CALL foo(SB)	// 0c000021

//
// BEQ/BNE
//
//	LBRA rreg ',' rel
//	{
//		outcode(int($1), &$2, 0, &$4);
//	}
label1:
	BEQ	R1, 1(PC)	// BEQ R1, 1(PC)	// 10200001
	BEQ	R1, label1	// BEQ R1, 18		// 1020fffd

//	LBRA rreg ',' sreg ',' rel
//	{
//		outcode(int($1), &$2, 0, &$4);
//	}
label2:

// including forms involving multiple registers such as R1:R2.
func (p *Parser) register(name string, prefix rune) (r1, r2 int16, scale int8, ok bool) {
	// R1 or R(1) R1:R2 R1,R2 R1+R2, or R1*scale.
	r1, ok = p.registerReference(name)
	if !ok {
		return
	}
	if prefix != 0 && prefix != '*' { // *AX is OK.

	{"1024", "1024"},
	{"12(R(1))", "12(R1)"},
	{"12(R13)", "12(R13)"},
	{"R0", "R0"},
	{"R0->(32-1)", "R0->31"},
	{"R0<<R1", "R0<<R1"},
	{"R0>>R(1)", "R0>>R1"},
	{"R0@>(32-1)", "R0@>31"},
	{"R1", "R1"},
	{"R11", "R11"},
	{"R12", "R12"},
	{"R13", "R13"},
	{"R14", "R14"},
	{"R15", "R15"},
	{"R1<<2(R3)", "R1<<2(R3)"},
	{"R(1)<<2(R(3))", "R1<<2(R3)"},
	{"R2", "R2"},
	{"R3", "R3"},

		}
	}
	w.Flush()

	r := NewReader(byteBuf)
	// Read them back with ReadRune
	for r1 := rune(0); r1 < NRune; r1++ {
		size := utf8.EncodeRune(buf, r1)
		nr, nbytes, err := r.ReadRune()
		if nr != r1 || nbytes != size || err != nil {
			t.Fatalf("ReadRune(0x%x) got 0x%x,%d not 0x%x,%d (err=%s)", r1, nr, nbytes, r1, size, err)
		}
	}
}

func TestWriteInvalidRune(t *testing.T) {

	MOVF	R1, F2             // ERROR "illegal combination"
	MOVD	R1, F2             // ERROR "illegal combination"
	MOVF	R1, R1             // ERROR "illegal combination"
	MOVD	R1, R2             // ERROR "illegal combination"
	MOVFW	R1, R2             // ERROR "illegal combination"
	MOVDW	R1, R2             // ERROR "illegal combination"
	MOVWF	R1, R2             // ERROR "illegal combination"

	}

	// check not at EOF
	buf.Write(b)
	for r := rune(0); r < NRune; r++ {
		r1, size, _ := buf.ReadRune()
		if err := buf.UnreadRune(); err != nil {
			t.Fatalf("UnreadRune(%U) got error %q", r, err)
		}
		r2, nbytes, err := buf.ReadRune()
		if r1 != r2 || r1 != r || nbytes != size || err != nil {

	FLDPQ	(R0), (R1, R2)                                   // ERROR "invalid register pair"
	FLDPQ	(R1), (F2, F2)                                   // ERROR "constrained unpredictable behavior"
	FSTPQ	(R1, R2), (R0)                                   // ERROR "invalid register pair"
	FLDPD	(R0), (R1, R2)                                   // ERROR "invalid register pair"

	var __cgofn__cgo_be59f0f25121_Cfunc_puts byte
	var _cgo_be59f0f25121_Cfunc_puts = unsafe.Pointer(&__cgofn__cgo_be59f0f25121_Cfunc_puts)

	func _Cfunc_puts(p0 *_Ctype_char) (r1 _Ctype_int) {
		_cgo_runtime_cgocall(_cgo_be59f0f25121_Cfunc_puts, uintptr(unsafe.Pointer(&p0)))
		return
	}

The hexadecimal number is a hash of cgo's input, chosen to be

func IndexRune(s []byte, r rune) int {
	switch {
	case 0 <= r && r < utf8.RuneSelf:
		return IndexByte(s, byte(r))
	case r == utf8.RuneError:
		for i := 0; i < len(s); {
			r1, n := utf8.DecodeRune(s[i:])
			if r1 == utf8.RuneError {
				return i
			}
			i += n
		}
		return -1
	case !utf8.ValidRune(r):
		return -1
	default:
		var b [utf8.UTFMax]byte
		n := utf8.EncodeRune(b[:], r)