func (d *poolDequeue) unpack(ptrs uint64) (head, tail uint32) {
	const mask = 1<<dequeueBits - 1
	head = uint32((ptrs >> dequeueBits) & mask)
	tail = uint32(ptrs & mask)
	return
}

func (d *poolDequeue) pack(head, tail uint32) uint64 {
	const mask = 1<<dequeueBits - 1
	return (uint64(head) << dequeueBits) |
		uint64(tail&mask)
}

// pushHead adds val at the head of the queue. It returns false if the

// the signal handler is currently set to the Go signal handler or not.
// This is uint32 rather than bool so that we can use atomic instructions.
var handlingSig [_NSIG]uint32

// channels for synchronizing signal mask updates with the signal mask
// thread
var (
	disableSigChan  chan uint32
	enableSigChan   chan uint32
	maskUpdatedChan chan struct{}
)

func init() {
	// _NSIG is the number of signals on this operating system.

  void insertEntry(int entryIndex, @ParametricNullness E object, int hash, int mask) {
    super.insertEntry(entryIndex, object, hash, mask);
    setSucceeds(lastEntry, entryIndex);
    setSucceeds(entryIndex, ENDPOINT);
  }

  @Override
  void moveLastEntry(int dstIndex, int mask) {
    int srcIndex = size() - 1;
    super.moveLastEntry(dstIndex, mask);

    setSucceeds(getPredecessor(dstIndex), getSuccessor(dstIndex));

  void insertEntry(int entryIndex, @ParametricNullness E object, int hash, int mask) {
    super.insertEntry(entryIndex, object, hash, mask);
    setSucceeds(lastEntry, entryIndex);
    setSucceeds(entryIndex, ENDPOINT);
  }

  @Override
  void moveLastEntry(int dstIndex, int mask) {
    int srcIndex = size() - 1;
    super.moveLastEntry(dstIndex, mask);

    setSucceeds(getPredecessor(dstIndex), getSuccessor(dstIndex));

	}

	// Bits 0:51 (bytes 0:8, bits 0:64, shift 0, mask 51).
	v.l0 = byteorder.LeUint64(x[0:8])
	v.l0 &= maskLow51Bits
	// Bits 51:102 (bytes 6:14, bits 48:112, shift 3, mask 51).
	v.l1 = byteorder.LeUint64(x[6:14]) >> 3
	v.l1 &= maskLow51Bits
	// Bits 102:153 (bytes 12:20, bits 96:160, shift 6, mask 51).
	v.l2 = byteorder.LeUint64(x[12:20]) >> 6
	v.l2 &= maskLow51Bits

      setPredecessor(succ, pred);
    }
  }

  @Override
  void insertEntry(
      int entryIndex, @ParametricNullness K key, @ParametricNullness V value, int hash, int mask) {
    super.insertEntry(entryIndex, key, value, hash, mask);
    setSucceeds(lastEntry, entryIndex);
    setSucceeds(entryIndex, ENDPOINT);
  }

  @Override
  void accessEntry(int index) {
    if (accessOrder) {

	gpRegMask      regMask        // general purpose integer register mask
	fpRegMask      regMask        // floating point register mask
	fp32RegMask    regMask        // floating point register mask
	fp64RegMask    regMask        // floating point register mask
	specialRegMask regMask        // special register mask
	intParamRegs   []int8         // register numbers of integer param (in/out) registers

			case ipTag:
				l := len(value)
				var ip, mask []byte

				switch l {
				case 8:
					ip = value[:4]
					mask = value[4:]

				case 32:
					ip = value[:16]
					mask = value[16:]

				default:
					return nil, nil, nil, nil, fmt.Errorf("x509: IP constraint contained value of length %d", l)
				}

				if !isValidIPMask(mask) {

				}
				switch sa := sa.(type) {
				case *syscall.SockaddrInet4:
					ifat = append(ifat, &IPNet{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3]), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv4len)})
				case *syscall.SockaddrInet6:
					ifa := &IPNet{IP: make(IP, IPv6len), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv6len)}
					copy(ifa.IP, sa.Addr[:])
					ifat = append(ifat, ifa)
				}
			}

		m := bucketMask(h.B)
		b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.BucketSize)))
		if c := h.oldbuckets; c != nil {
			if !h.sameSizeGrow() {
				// There used to be half as many buckets; mask down one more power of two.
				m >>= 1
			}
			oldb := (*bmap)(add(c, (hash&m)*uintptr(t.BucketSize)))
			if !evacuated(oldb) {
				b = oldb
			}
		}
	}
	for ; b != nil; b = b.overflow(t) {