for _, c := range s {
		if c >= 0x80 || c == 0x00 {
			return false
		}
	}
	return true
}

// toASCII converts the input to an ASCII C-style string.
// This is a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
	if isASCII(s) {
		return s
	}
	b := make([]byte, 0, len(s))
	for _, c := range s {
		if c < 0x80 && c != 0x00 {
			b = append(b, byte(c))
		}
	}

		0x07, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00,
		0x50, 0x4b, 0x01, 0x02, 0x14, 0x03, 0x14, 0x00,
		0x08, 0x00, 0x00, 0x00, 0x6b, 0xb4, 0xba, 0x46,
		0x1d, 0x88, 0x77, 0xb0, 0x07, 0x00, 0x00, 0x00,
		0x07, 0x00, 0x00, 0x00, 0x03, 0x00, 0x18, 0x00,
		0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0xa0, 0x81, 0x00, 0x00, 0x00, 0x00, 0xca, 0x64,
		0x55, 0x75, 0x78, 0x0b, 0x00, 0x50, 0x4b, 0x05,

	LDAXRB (R19), R16                          // 70fe5f08
	LDAXRH (R5), R8                            // a8fc5f48
	//TODO LDNP 0xcc(RSP), ZR, R12             // ecff5928
	//TODO LDNP 0x40(R28), R9, R5              // 852744a8
	//TODO LDPSW -0xd0(R2), R0, R12            // 4c00e668
	//TODO LDPSW 0x5c(R4), R8, R5              // 85a0cb69
	//TODO LDPSW 0x6c(R12), R2, R27            // 9b894d69

			prefix = p.parseString(ustar.prefix())

			// For Format detection, check if block is properly formatted since
			// the parser is more liberal than what USTAR actually permits.
			notASCII := func(r rune) bool { return r >= 0x80 }
			if bytes.IndexFunc(tr.blk[:], notASCII) >= 0 {
				hdr.Format = FormatUnknown // Non-ASCII characters in block.
			}
			nul := func(b []byte) bool { return int(b[len(b)-1]) == 0 }

	MOVHU	R3, 0x20(R4)         // MOVHU R3, 32(R4)          // b032c4e1
	MOVHU.W	R3, 0x20(R4)         // MOVHU.W R3, 32(R4)        // b032e4e1
	MOVHU.P	R3, 0x20(R4)         // MOVHU.P R3, 32(R4)        // b032c4e0
	MOVH	R3, -0x20(R4)        // MOVH R3, -32(R4)          // b03244e1
	MOVH.W	R3, -0x20(R4)        // MOVH.W R3, -32(R4)        // b03264e1
	MOVH.P	R3, -0x20(R4)        // MOVH.P R3, -32(R4)        // b03244e0

	MOVD	$0xffffff(R7), R1             // MOVD	$16777215(R7), R1           // e1fc7f9121fc3f91
	MOVD	$-0x1(R7), R1                 // MOVD	$-1(R7), R1                 // e10400d1
	MOVD	$-0x30(R7), R1                // MOVD	$-48(R7), R1                // e1c000d1
	MOVD	$-0x708(R7), R1               // MOVD	$-1800(R7), R1              // e1201cd1

	utf8Valid1, utf8Require1 := detectUTF8(fh.Name)
	utf8Valid2, utf8Require2 := detectUTF8(fh.Comment)
	switch {
	case fh.NonUTF8:
		fh.Flags &^= 0x800
	case (utf8Require1 || utf8Require2) && (utf8Valid1 && utf8Valid2):
		fh.Flags |= 0x800
	}

	fh.CreatorVersion = fh.CreatorVersion&0xff00 | zipVersion20 // preserve compatibility byte
	fh.ReaderVersion = zipVersion20

		tw := NewWriter(new(bytes.Buffer))
		hdr := &Header{Name: "dir/", Typeflag: TypeDir}
		if err := tw.WriteHeader(hdr); err != nil {
			t.Fatalf("WriteHeader() = %v, want nil", err)
		}
		if _, err := tw.Write([]byte{0x00}); err != ErrWriteTooLong {
			t.Fatalf("Write() = %v, want %v", err, ErrWriteTooLong)
		}
	})

	t.Run("NegativeSize", func(t *testing.T) {
		tw := NewWriter(new(bytes.Buffer))

			// Argsize set below.
		},
	}
	nameAddr.Sym.Func().Text = prog
	prog.To.Val = int32(argSize)
	p.append(prog, "", true)
}

// asmData assembles a DATA pseudo-op.
// DATA masks<>+0x00(SB)/4, $0x00000000
func (p *Parser) asmData(operands [][]lex.Token) {
	if len(operands) != 2 {
		p.errorf("expect two operands for DATA")
		return
	}

	// Operand 0 has the general form foo<>+0x04(SB)/4.