@VisibleForTesting static final int MAX_SIGNED_POWER_OF_TWO = 1 << (Integer.SIZE - 2);

  /**
   * Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
   * {@code checkedPow(2, log2(x, CEILING))}.
   *
   * @throws IllegalArgumentException if {@code x <= 0}
   * @throws ArithmeticException of the next-higher power of two is not representable as an {@code

 *
 * @author Louis Wasserman
 * @since 11.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class BigIntegerMath {
  /**
   * Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
   * {@code BigInteger.valueOf(2).pow(log2(x, CEILING))}.
   *
   * @throws IllegalArgumentException if {@code x <= 0}
   * @since 20.0
   */

  @VisibleForTesting static final long MAX_SIGNED_POWER_OF_TWO = 1L << (Long.SIZE - 2);

  /**
   * Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
   * {@code checkedPow(2, log2(x, CEILING))}.
   *
   * @throws IllegalArgumentException if {@code x <= 0}
   * @throws ArithmeticException of the next-higher power of two is not representable as a {@code

@ElementTypesAreNonnullByDefault
abstract class Striped64 extends Number {
  /*
   * This class maintains a lazily-initialized table of atomically
   * updated variables, plus an extra "base" field. The table size
   * is a power of two. Indexing uses masked per-thread hash codes.
   * Nearly all declarations in this class are package-private,
   * accessed directly by subclasses.
   *
   * Table entries are of class Cell; a variant of AtomicLong padded

   * can hold setSize elements with the desired load factor.
   */
  @VisibleForTesting
  static int chooseTableSize(int setSize) {
    if (setSize == 1) {
      return 2;
    }
    // Correct the size for open addressing to match desired load factor.
    // Round up to the next highest power of 2.
    int tableSize = Integer.highestOneBit(setSize - 1) << 1;

   * can hold setSize elements with the desired load factor.
   */
  @VisibleForTesting
  static int chooseTableSize(int setSize) {
    if (setSize == 1) {
      return 2;
    }
    // Correct the size for open addressing to match desired load factor.
    // Round up to the next highest power of 2.
    int tableSize = Integer.highestOneBit(setSize - 1) << 1;

public class LongMathTest extends TestCase {
  @SuppressWarnings("ConstantOverflow")
  public void testMaxSignedPowerOfTwo() {
    assertTrue(LongMath.isPowerOfTwo(LongMath.MAX_SIGNED_POWER_OF_TWO));
    assertFalse(LongMath.isPowerOfTwo(LongMath.MAX_SIGNED_POWER_OF_TWO * 2));
  }

  public void testCeilingPowerOfTwo() {
    for (long x : POSITIVE_LONG_CANDIDATES) {

public class LongMathTest extends TestCase {
  @SuppressWarnings("ConstantOverflow")
  public void testMaxSignedPowerOfTwo() {
    assertTrue(LongMath.isPowerOfTwo(LongMath.MAX_SIGNED_POWER_OF_TWO));
    assertFalse(LongMath.isPowerOfTwo(LongMath.MAX_SIGNED_POWER_OF_TWO * 2));
  }

  public void testCeilingPowerOfTwo() {
    for (long x : POSITIVE_LONG_CANDIDATES) {

   * is merely copied. Only as the power set is iterated are the individual subsets created, and
   * these subsets themselves occupy only a small constant amount of memory.
   *
   * @param set the set of elements to construct a power set from
   * @return the power set, as an immutable set of immutable sets

@ElementTypesAreNonnullByDefault
abstract class Striped64 extends Number {
  /*
   * This class maintains a lazily-initialized table of atomically
   * updated variables, plus an extra "base" field. The table size
   * is a power of two. Indexing uses masked per-thread hash codes.
   * Nearly all declarations in this class are package-private,
   * accessed directly by subclasses.
   *
   * Table entries are of class Cell; a variant of AtomicLong padded