import java.math.BigInteger;

/**
 * Utilities for {@code double} primitives.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class DoubleUtils {
  private DoubleUtils() {}

  static double nextDown(double d) {
    return -Math.nextUp(-d);
  }

  // The mask for the significand, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.

import java.math.BigInteger;

/**
 * Utilities for {@code double} primitives.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class DoubleUtils {
  private DoubleUtils() {}

  static double nextDown(double d) {
    return -Math.nextUp(-d);
  }

  // The mask for the significand, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.

      assertThat(DoubleUtils.ensureNonNegative(positiveValue)).isEqualTo(positiveValue);
      assertThat(DoubleUtils.ensureNonNegative(-positiveValue)).isEqualTo(0.0);
    }
    assertThat(DoubleUtils.ensureNonNegative(Double.POSITIVE_INFINITY)).isPositiveInfinity();
    assertThat(DoubleUtils.ensureNonNegative(Double.NEGATIVE_INFINITY)).isEqualTo(0.0);
    assertThrows(IllegalArgumentException.class, () -> DoubleUtils.ensureNonNegative(Double.NaN));

      assertThat(DoubleUtils.ensureNonNegative(positiveValue)).isEqualTo(positiveValue);
      assertThat(DoubleUtils.ensureNonNegative(-positiveValue)).isEqualTo(0.0);
    }
    assertThat(DoubleUtils.ensureNonNegative(Double.POSITIVE_INFINITY)).isPositiveInfinity();
    assertThat(DoubleUtils.ensureNonNegative(Double.NEGATIVE_INFINITY)).isEqualTo(0.0);
    assertThrows(IllegalArgumentException.class, () -> DoubleUtils.ensureNonNegative(Double.NaN));

            ? roundArbitrarily
            : DoubleUtils.nextDown(roundArbitrarily);
      case CEILING:
        return (cmpXToRoundArbitrarily <= 0) ? roundArbitrarily : Math.nextUp(roundArbitrarily);
      case DOWN:
        if (sign(x) >= 0) {
          return (cmpXToRoundArbitrarily >= 0)
              ? roundArbitrarily
              : DoubleUtils.nextDown(roundArbitrarily);
        } else {

            ? roundArbitrarily
            : DoubleUtils.nextDown(roundArbitrarily);
      case CEILING:
        return (cmpXToRoundArbitrarily <= 0) ? roundArbitrarily : Math.nextUp(roundArbitrarily);
      case DOWN:
        if (sign(x) >= 0) {
          return (cmpXToRoundArbitrarily >= 0)
              ? roundArbitrarily
              : DoubleUtils.nextDown(roundArbitrarily);
        } else {

        .setExpectation(DoubleUtils.nextDown(-Math.pow(2, 54)), FLOOR, UP)
        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_negativeTwoToThe54MinusThree() {
    new RoundToDoubleTester(BigDecimal.valueOf((-1L << 54) - 3))
        .setExpectation(-Math.pow(2, 54), DOWN, CEILING)
        .setExpectation(

    throw new AssertionError();
  }

  @GwtIncompatible // TODO
  private static BigInteger sqrtFloor(BigInteger x) {
    /*
     * Adapted from Hacker's Delight, Figure 11-1.
     *
     * Using DoubleUtils.bigToDouble, getting a double approximation of x is extremely fast, and
     * then we can get a double approximation of the square root. Then, we iteratively improve this

            ? roundArbitrarily
            : DoubleUtils.nextDown(roundArbitrarily);
      case CEILING:
        return (cmpXToRoundArbitrarily <= 0) ? roundArbitrarily : Math.nextUp(roundArbitrarily);
      case DOWN:
        if (x >= 0) {
          return (cmpXToRoundArbitrarily >= 0)
              ? roundArbitrarily
              : DoubleUtils.nextDown(roundArbitrarily);
        } else {

            ? roundArbitrarily
            : DoubleUtils.nextDown(roundArbitrarily);
      case CEILING:
        return (cmpXToRoundArbitrarily <= 0) ? roundArbitrarily : Math.nextUp(roundArbitrarily);
      case DOWN:
        if (x >= 0) {
          return (cmpXToRoundArbitrarily >= 0)
              ? roundArbitrarily
              : DoubleUtils.nextDown(roundArbitrarily);
        } else {