private void localConnections(int netMap[]) {

    // Exports
    for (int k = 0; k < numExports; k++) {
      ImmutableExport e = exports.get(k);
      int portOffset = portOffsets[k];
      Name expNm = e.name;
      int busWidth = expNm.busWidth();
      int drawn = drawns[k];
      int drawnOffset = drawnOffsets[drawn];
      for (int i = 0; i < busWidth; i++) {
        ImmutableNetLayout.connectMap(
            netMap,
            portOffset + i,
            drawnOffset + (busWidth == drawnWidths[drawn] ? i : i % drawnWidths[drawn]));
        GenMath.MutableInteger nn = netNames.get(expNm.subname(i));
        ImmutableNetLayout.connectMap(netMap, portOffset + i, netNamesOffset + nn.intValue());
      }
    }

    // PortInsts
    for (int k = 0; k < numNodes; k++) {
      ImmutableNodeInst n = nodes.get(k);
      if (isIconOfParent(n)) {
        continue;
      }
      //            NodeProto np = ni.getProto();
      if (n.protoId instanceof PrimitiveNodeId) {
        // Connect global primitives
        Global g = globalInst(n);
        if (g != null) {
          int drawn = drawns[ni_pi[k]];
          ImmutableNetLayout.connectMap(netMap, globals.indexOf(g), drawnOffsets[drawn]);
        }
        if (n.protoId == schem.wireConNode.getId()) {
          connectWireCon(netMap, n);
        }
        continue;
      }
      IconInst iconInst = iconInsts[k];
      if (iconInst == null || iconInst.iconOfParent) {
        continue;
      }

      assert iconInst.nodeInst == n;
      CellId subCellId = (CellId) n.protoId;
      assert subCellId.isIcon() || subCellId.isSchematic();
      EquivalentSchematicExports iconEq = iconInst.eq;
      EquivalentSchematicExports schemEq = iconEq.implementation;
      assert schemEq != null;
      Name nodeName = n.name;
      int arraySize = nodeName.busWidth();
      int numPorts = getNumPorts(n.protoId);
      CellBackup subCell = snapshot.getCell(subCellId);
      for (int m = 0; m < numPorts; m++) {
        ImmutableExport e = subCell.cellRevision.exports.get(m);
        Name busExportName = e.name;
        int busWidth = busExportName.busWidth();
        int drawn = drawns[ni_pi[k] + m];
        if (drawn < 0) {
          continue;
        }
        int width = drawnWidths[drawn];
        if (width != busWidth && width != busWidth * arraySize) {
          continue;
        }
        for (int arrayIndex = 0; arrayIndex < arraySize; arrayIndex++) {
          int nodeOffset = iconInst.netMapOffset + arrayIndex * iconInst.numExtendedExports;
          int busOffset = drawnOffsets[drawn];
          if (width != busWidth) {
            busOffset += busWidth * arrayIndex;
          }
          for (int j = 0; j < busWidth; j++) {
            Name exportName = busExportName.subname(j);
            int portOffset = schemEq.getExportNameMapOffset(exportName);
            if (portOffset < 0) {
              continue;
            }
            ImmutableNetLayout.connectMap(netMap, busOffset + j, nodeOffset + portOffset);
          }
        }
      }
    }

    // Arcs
    for (int arcIndex = 0; arcIndex < numArcs; arcIndex++) {
      ImmutableArcInst a = arcs.get(arcIndex);
      int drawn = drawns[arcsOffset + arcIndex];
      if (drawn < 0) {
        continue;
      }
      if (!a.isUsernamed()) {
        continue;
      }
      int busWidth = drawnWidths[drawn];
      Name arcNm = a.name;
      if (arcNm.busWidth() != busWidth) {
        continue;
      }
      int drawnOffset = drawnOffsets[drawn];
      for (int i = 0; i < busWidth; i++) {
        GenMath.MutableInteger nn = netNames.get(arcNm.subname(i));
        ImmutableNetLayout.connectMap(netMap, drawnOffset + i, netNamesOffset + nn.intValue());
      }
    }

    // Globals of proxies
    for (IconInst iconInst : iconInsts) {
      if (iconInst == null || iconInst.iconOfParent) {
        continue;
      }
      Set<Global> excludeGlobals = null;
      if (iconInstExcludeGlobals != null) {
        excludeGlobals = iconInstExcludeGlobals.get(iconInst);
      }
      for (int k = 0; k < iconInst.nodeInst.name.busWidth(); k++) {
        EquivalentSchematicExports eq = iconInst.eq.implementation;
        assert eq.implementation == eq;
        int numGlobals = eq.portOffsets[0];
        if (numGlobals == 0) {
          continue;
        }
        int nodableOffset = iconInst.netMapOffset + k * iconInst.numExtendedExports;
        for (int i = 0; i < numGlobals; i++) {
          Global g = eq.globals.get(i);
          if (excludeGlobals != null && excludeGlobals.contains(g)) {
            continue;
          }
          ImmutableNetLayout.connectMap(netMap, this.globals.indexOf(g), nodableOffset + i);
        }
      }
    }

    ImmutableNetLayout.closureMap(netMap);
  }
  ImmutableNetSchem(Snapshot snapshot, CellId cellId) {
    assert cellId.isIcon() || cellId.isSchematic();
    this.snapshot = snapshot;
    this.cellId = cellId;
    //        System.out.println("begin ImmutableNetSchem " + cellId);
    techPool = snapshot.techPool;
    schem = techPool.getSchematics();
    busPinPortId = schem != null ? schem.busPinNode.getPort(0).getId() : null;
    busArc = schem != null ? schem.bus_arc : null;
    cellTree = snapshot.getCellTree(cellId);
    cellBackup = cellTree.top;
    m = cellBackup.getMemoization();
    cellRevision = cellBackup.cellRevision;
    exports = cellRevision.exports;
    nodes = cellRevision.nodes;
    arcs = cellRevision.arcs;
    numExports = cellRevision.exports.size();
    numNodes = cellRevision.nodes.size();
    numArcs = cellRevision.arcs.size();

    CellId implementationCellId = cellId;
    if (cellId.isIcon()) {
      CellId mainSchemId = snapshot.getMainSchematics(cellId);
      if (mainSchemId != null) {
        getEquivExports(mainSchemId);
        implementationCellId = mainSchemId;
      }
    }
    this.implementationCellId = implementationCellId;

    // init connections
    ni_pi = new int[numNodes];
    int offset = numExports;
    for (int i = 0; i < numNodes; i++) {
      ImmutableNodeInst n = nodes.get(i);
      ni_pi[i] = offset;
      offset += getNumPorts(n.protoId);
    }
    arcsOffset = offset;
    offset += numArcs;

    headConn = new int[offset];
    tailConn = new int[offset];
    drawns = new int[offset];
    for (int i = numExports; i < arcsOffset; i++) {
      headConn[i] = i;
      tailConn[i] = i;
    }
    for (int i = 0; i < numExports; i++) {
      int portOffset = i;
      ImmutableExport export = exports.get(i);
      int orig = getPortInstOffset(export.originalNodeId, export.originalPortId);
      headConn[portOffset] = headConn[orig];
      headConn[orig] = portOffset;
      tailConn[portOffset] = -1;
    }
    for (int arcIndex = 0; arcIndex < numArcs; arcIndex++) {
      ImmutableArcInst a = arcs.get(arcIndex);
      int arcOffset = arcsOffset + arcIndex;
      int head = getPortInstOffset(a.headNodeId, a.headPortId);
      headConn[arcOffset] = headConn[head];
      headConn[head] = arcOffset;
      int tail = getPortInstOffset(a.tailNodeId, a.tailPortId);
      tailConn[arcOffset] = tailConn[tail];
      tailConn[tail] = arcOffset;
    }

    makeDrawns();

    initNetnames();

    portOffsets = new int[numExports + 1];
    drawnNames = new Name[numDrawns];
    drawnWidths = new int[numDrawns];
    drawnOffsets = new int[numDrawns];

    calcDrawnWidths();

    initNodables();

    int mapSize = netNamesOffset + netNames.size();
    int[] netMapN = ImmutableNetLayout.initMap(mapSize);
    localConnections(netMapN);

    int[] netMapP = netMapN.clone();
    int[] netMapA = netMapN.clone();
    internalConnections(netMapN, netMapP, netMapA);

    ImmutableNetLayout.closureMap(netMapN);
    ImmutableNetLayout.closureMap(netMapP);
    ImmutableNetLayout.closureMap(netMapA);

    //        updatePortImplementation();

    updateInterface(netMapN, netMapP, netMapA);
    //        System.out.println("end ImmutableNetSchem " + cellId);
  }