} catch (ArithmeticException expected) {
        // do nothing
      }

      if (expectedDouble != null) {
        assertThat(LongMath.roundToDouble(candidate, UNNECESSARY)).isEqualTo(expectedDouble);
      } else {
        try {
          LongMath.roundToDouble(candidate, UNNECESSARY);

      } catch (ArithmeticException expected) {
        // do nothing
      }

      if (expectedDouble != null) {
        assertThat(LongMath.roundToDouble(candidate, UNNECESSARY)).isEqualTo(expectedDouble);
      } else {
        try {
          LongMath.roundToDouble(candidate, UNNECESSARY);

      if (!expectedValues.containsKey(UNNECESSARY)) {
        assertWithMessage("Expected roundUnnecessaryShouldThrow call")
            .that(unnecessaryShouldThrow)
            .isTrue();
        assertThrows(
            "Expected ArithmeticException for roundToDouble(" + input + ", UNNECESSARY)",
            ArithmeticException.class,
            () -> BigDecimalMath.roundToDouble(input, UNNECESSARY));
      }
    }
  }

      // every mode except UNNECESSARY
      BigDecimal expected = new BigDecimal(d).setScale(0, UNNECESSARY);
      boolean isInBounds =
          expected.compareTo(MAX_LONG_AS_BIG_DECIMAL) <= 0
              & expected.compareTo(MIN_LONG_AS_BIG_DECIMAL) >= 0;

      try {
        assertEquals(expected.longValue(), DoubleMath.roundToLong(d, UNNECESSARY));
        assertTrue(isInBounds);

      // every mode except UNNECESSARY
      BigDecimal expected = new BigDecimal(d).setScale(0, UNNECESSARY);
      boolean isInBounds =
          expected.compareTo(MAX_LONG_AS_BIG_DECIMAL) <= 0
              & expected.compareTo(MIN_LONG_AS_BIG_DECIMAL) >= 0;

      try {
        assertEquals(expected.longValue(), DoubleMath.roundToLong(d, UNNECESSARY));
        assertTrue(isInBounds);

      }

      if (!expectedValues.containsKey(UNNECESSARY)) {
        assertWithMessage("Expected roundUnnecessaryShouldThrow call")
            .that(unnecessaryShouldThrow)
            .isTrue();
        try {
          BigIntegerMath.roundToDouble(input, UNNECESSARY);
          fail("Expected ArithmeticException for roundToDouble(" + input + ", UNNECESSARY)");
        } catch (ArithmeticException expected) {

      }

      if (!expectedValues.containsKey(UNNECESSARY)) {
        assertWithMessage("Expected roundUnnecessaryShouldThrow call")
            .that(unnecessaryShouldThrow)
            .isTrue();
        try {
          BigIntegerMath.roundToDouble(input, UNNECESSARY);
          fail("Expected ArithmeticException for roundToDouble(" + input + ", UNNECESSARY)");
        } catch (ArithmeticException expected) {

        case UP:
          return roundArbitrarily;
        case UNNECESSARY:
          throw new ArithmeticException(x + " cannot be represented precisely as a double");
      }
    }
    X roundArbitrarilyAsX = toX(roundArbitrarily, RoundingMode.UNNECESSARY);
    int cmpXToRoundArbitrarily = x.compareTo(roundArbitrarilyAsX);
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(cmpXToRoundArbitrarily == 0);

   * @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
   *     is not a power of two
   */
  @SuppressWarnings("fallthrough")
  // TODO(kevinb): remove after this warning is disabled globally
  public static int log2(int x, RoundingMode mode) {
    checkPositive("x", x);
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(isPowerOfTwo(x));
        // fall through

  static double roundIntermediate(double x, RoundingMode mode) {
    if (!isFinite(x)) {
      throw new ArithmeticException("input is infinite or NaN");
    }
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(isMathematicalInteger(x));
        return x;

      case FLOOR:
        if (x >= 0.0 || isMathematicalInteger(x)) {
          return x;
        } else {