pkg log, method (*Logger) Writer() io.Writer
pkg math/bits, func Add(uint, uint, uint) (uint, uint)
pkg math/bits, func Add32(uint32, uint32, uint32) (uint32, uint32)
pkg math/bits, func Add64(uint64, uint64, uint64) (uint64, uint64)
pkg math/bits, func Div(uint, uint, uint) (uint, uint)
pkg math/bits, func Div32(uint32, uint32, uint32) (uint32, uint32)
pkg math/bits, func Div64(uint64, uint64, uint64) (uint64, uint64)

pkg math/bits (windows-amd64), const UintSize = 64
pkg math/bits, const UintSize ideal-int
pkg math/bits, func LeadingZeros(uint) int
pkg math/bits, func LeadingZeros16(uint16) int
pkg math/bits, func LeadingZeros32(uint32) int
pkg math/bits, func LeadingZeros64(uint64) int
pkg math/bits, func LeadingZeros8(uint8) int
pkg math/bits, func Len(uint) int
pkg math/bits, func Len16(uint16) int
pkg math/bits, func Len32(uint32) int

   * Test for avalanche with 2-bit deltas. Most probabilities of output bit(j) differing are well
   * within 50%.
   */
  static void check2BitAvalanche(HashFunction function, int trials, double epsilon) {
    Random rand = new Random(0);
    int keyBits = 32;
    int hashBits = function.bits();
    for (int bit1 = 0; bit1 < keyBits; bit1++) {
      for (int bit2 = 0; bit2 < keyBits; bit2++) {
        if (bit2 <= bit1) continue;

        LockFreeBitArray bits) {
      long bitSize = bits.bitSize();
      long hash64 = Hashing.murmur3_128().hashObject(object, funnel).asLong();
      int hash1 = (int) hash64;
      int hash2 = (int) (hash64 >>> 32);

      boolean bitsChanged = false;
      for (int i = 1; i <= numHashFunctions; i++) {
        int combinedHash = hash1 + (i * hash2);
        // Flip all the bits if it's negative (guaranteed positive number)

  public static HashFunction goodFastHash(int minimumBits) {
    int bits = checkPositiveAndMakeMultipleOf32(minimumBits);

    if (bits == 32) {
      return Murmur3_32HashFunction.GOOD_FAST_HASH_32;
    }
    if (bits <= 128) {
      return Murmur3_128HashFunction.GOOD_FAST_HASH_128;
    }

    // Otherwise, join together some 128-bit murmur3s
    int hashFunctionsNeeded = (bits + 127) / 128;

    assertEquals(
        Hashing.md5().bits() + Hashing.md5().bits(),
        Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits(),
        Hashing.concatenating(asList(Hashing.md5(), Hashing.murmur3_32())).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits() + Hashing.murmur3_128().bits(),

    for (int bits = 10; bits < 63; bits++) {
      for (int i = 0; i < 100; i++) {
        long p = BigInteger.probablePrime(bits, rand).longValue();
        assertTrue(LongMath.isPrime(p));
      }
    }
  }

  @GwtIncompatible // isPrime is GWT-incompatible
  public void testIsPrimeOnRandomComposites() {
    Random rand = new Random(1);
    for (int bits = 5; bits < 32; bits++) {

  public static HashFunction goodFastHash(int minimumBits) {
    int bits = checkPositiveAndMakeMultipleOf32(minimumBits);

    if (bits == 32) {
      return Murmur3_32HashFunction.GOOD_FAST_HASH_32;
    }
    if (bits <= 128) {
      return Murmur3_128HashFunction.GOOD_FAST_HASH_128;
    }

    // Otherwise, join together some 128-bit murmur3s
    int hashFunctionsNeeded = (bits + 127) / 128;

    assertEquals(
        Hashing.md5().bits() + Hashing.md5().bits(),
        Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits(),
        Hashing.concatenating(asList(Hashing.md5(), Hashing.murmur3_32())).bits());
    assertEquals(
        Hashing.md5().bits() + Hashing.murmur3_32().bits() + Hashing.murmur3_128().bits(),

        @ParametricNullness T object,
        Funnel<? super T> funnel,
        int numHashFunctions,
        LockFreeBitArray bits);

    /**
     * Queries {@code numHashFunctions} bits of the given bit array, by hashing a user element;
     * returns {@code true} if and only if all selected bits are set.
     */
    <T extends @Nullable Object> boolean mightContain(
        @ParametricNullness T object,