if rn.Intn(8) == 0 && cap(b) > 0 {
			b = b[1:1:cap(b)]
		}

		// Append a random integer of varying width.
		n := int64(rn.Intn(1 << rn.Intn(30)))
		want = append(strconv.AppendInt(want, n, 10), ' ')
		b = append(strconv.AppendInt(b, n, 10), ' ')
		w.Write(b)
	}
	w.Flush()

	if !bytes.Equal(got.Bytes(), want) {
		t.Errorf("output mismatch:\ngot  %s\nwant %s", got.Bytes(), want)
	}
}

			if n, err := strconv.Atoi(s[len("__cgodebug_str__"):]); err == nil {
				return n
			}
		}
		return -1
	}
	indexOfDebugStrlen := func(s string) int {
		// Some systems use leading _ to denote non-assembly symbols.
		if strings.HasPrefix(s, "___") {
			s = s[1:]
		}
		if strings.HasPrefix(s, "__cgodebug_strlen__") {

				ToValidUTF8(test.input, replacement)
			}
		})
	}
}

func makeBenchInputHard() []byte {
	tokens := [...]string{
		"<a>", "<p>", "<b>", "<strong>",
		"</a>", "</p>", "</b>", "</strong>",
		"hello", "world",
	}
	x := make([]byte, 0, 1<<20)
	for {
		i := rand.Intn(len(tokens))
		if len(x)+len(tokens[i]) >= 1<<20 {
			break
		}