lines := strings.SplitAfter(string(data), "\n")
Diff:
	for _, line := range lines {
		lineno++

		// Ignore include of textflag.h.
		if strings.HasPrefix(line, "#include ") {
			continue
		}

		// Ignore GLOBL.
		if strings.HasPrefix(line, "GLOBL ") {
			continue
		}

		// The general form of a test input line is:
		//	// comment
		//	INST args [// printed form] [// hex encoding]

		copy(blk[:], b.Bytes())
		prefix := string(blk.toUSTAR().prefix())
		prefix, _, _ = strings.Cut(prefix, "\x00") // Truncate at the NUL terminator
		if blk.getFormat() == FormatGNU && len(prefix) > 0 && strings.HasPrefix(name, prefix) {
			t.Errorf("test %d, found prefix in GNU format: %s", i, prefix)
		}

		tr := NewReader(&b)
		hdr, err := tr.Next()
		if err != nil && err != ErrInsecurePath {

			var out Buffer
			if n < 0 {
				n = math.MaxInt
			}
			for i := 0; i < len(in); {
				if n == 0 {
					out.Write(in[i:])
					break
				}
				if HasPrefix(in[i:], old) {
					out.Write(new)
					i += len(old)
					n--
					if len(old) != 0 {
						continue
					}
					if i == len(in) {
						break
					}
				}