public static String s8(long v) {
    char[] result = new char[17];

    if (v < 0) {
      result[0] = '-';
      v = -v;
    } else {
      result[0] = '+';
    }

    for (int i = 0; i < 16; i++) {
      result[16 - i] = Character.forDigit((int) v & 0x0f, 16);
      v >>= 4;
    }

    return new String(result);
  }
Formats a {@code long} as an 8-byte signed hex value.

@param v value to format
@return {@code non-null;} formatted form
android/android_framework/dex-maker/src/main/java/com/android/dx/util/Hex.java