Examples with Delay gov.sandia.n2a.language.function.Delay used on opensource projects

Example 1 with Delay

use of gov.sandia.n2a.language.function.Delay in project n2a by frothga.

the class JobC method generateDeclarationsLocal.

public void generateDeclarationsLocal(EquationSet s, StringBuilder result) {
    BackendDataC bed = (BackendDataC) s.backendData;
    // Unit class
    result.append("class " + prefix(s) + " : public PartTime<" + T + ">\n");
    result.append("{\n");
    result.append("public:\n");
    // Unit buffers
    if (bed.needLocalDerivative) {
        result.append("  class Derivative\n");
        result.append("  {\n");
        result.append("  public:\n");
        for (Variable v : bed.localDerivative) {
            result.append("    " + type(v) + " " + mangle(v) + ";\n");
        }
        result.append("    Derivative * next;\n");
        result.append("  };\n");
        result.append("\n");
    }
    if (bed.needLocalPreserve) {
        result.append("  class Preserve\n");
        result.append("  {\n");
        result.append("  public:\n");
        for (Variable v : bed.localIntegrated) {
            result.append("    " + type(v) + " " + mangle(v) + ";\n");
        }
        for (Variable v : bed.localDerivativePreserve) {
            result.append("    " + type(v) + " " + mangle(v) + ";\n");
        }
        for (Variable v : bed.localBufferedExternalWriteDerivative) {
            result.append("    " + type(v) + " " + mangle("next_", v) + ";\n");
        }
        result.append("  };\n");
        result.append("\n");
    }
    // Unit variables
    if (bed.needLocalDerivative) {
        result.append("  Derivative * stackDerivative;\n");
    }
    if (bed.needLocalPreserve) {
        result.append("  Preserve * preserve;\n");
    }
    if (bed.pathToContainer == null) {
        result.append("  " + prefix(s.container) + " * container;\n");
    }
    if (s.connectionBindings != null) {
        for (ConnectionBinding c : s.connectionBindings) {
            // we should be able to assume that s.container is non-null; ie: a connection should always operate in some larger container
            result.append("  " + prefix(c.endpoint) + " * " + mangle(c.alias) + ";\n");
        }
    }
    if (s.accountableConnections != null) {
        for (EquationSet.AccountableConnection ac : s.accountableConnections) {
            result.append("  int " + prefix(ac.connection) + "_" + mangle(ac.alias) + "_count;\n");
        }
    }
    if (bed.refcount) {
        result.append("  int refcount;\n");
    }
    if (bed.index != null) {
        result.append("  int __24index;\n");
    }
    if (bed.lastT) {
        // $lastT is for internal use only, so no need for __24 prefix.
        result.append("  " + T + " lastT;\n");
    }
    for (Variable v : bed.localMembers) {
        result.append("  " + type(v) + " " + mangle(v) + ";\n");
    }
    for (Variable v : bed.localBufferedExternal) {
        result.append("  " + type(v) + " " + mangle("next_", v) + ";\n");
    }
    for (EquationSet p : s.parts) {
        result.append("  " + prefix(p) + "_Population " + mangle(p.name) + ";\n");
    }
    for (String columnName : bed.localColumns) {
        result.append("  String " + columnName + ";\n");
    }
    for (EventSource es : bed.eventSources) {
        String eventMonitor = "eventMonitor_" + prefix(es.target.container);
        if (es.monitorIndex > 0)
            eventMonitor += "_" + es.monitorIndex;
        result.append("  std::vector<Part<" + T + "> *> " + eventMonitor + ";\n");
    }
    for (EventTarget et : bed.eventTargets) {
        if (!et.trackOne && et.edge != EventTarget.NONZERO) {
            result.append("  " + T + " " + mangle(et.track.name) + ";\n");
        }
        if (et.timeIndex >= 0) {
            result.append("  " + T + " eventTime" + et.timeIndex + ";\n");
        }
    }
    if (!bed.localFlagType.isEmpty()) {
        result.append("  " + bed.localFlagType + " flags;\n");
    }
    int i = 0;
    for (Delay d : bed.delays) {
        d.index = i++;
        result.append("  DelayBuffer<" + T + "> delay" + d.index + ";\n");
    }
    result.append("\n");
    // Unit functions
    if (bed.needLocalCtor) {
        result.append("  " + prefix(s) + " ();\n");
    }
    if (bed.needLocalDtor) {
        result.append("  virtual ~" + prefix(s) + " ();\n");
    }
    if (bed.localMembers.size() > 0) {
        result.append("  virtual void clear ();\n");
    }
    if (s.container == null) {
        result.append("  virtual void setPeriod (" + T + " dt);\n");
    }
    if (bed.needLocalDie) {
        result.append("  virtual void die ();\n");
    }
    if (bed.localReference.size() > 0) {
        result.append("  virtual void enterSimulation ();\n");
    }
    result.append("  virtual void leaveSimulation ();\n");
    if (bed.refcount) {
        result.append("  virtual bool isFree ();\n");
    }
    if (bed.needLocalInit) {
        result.append("  virtual void init ();\n");
    }
    if (bed.needLocalIntegrate) {
        result.append("  virtual void integrate ();\n");
    }
    if (bed.needLocalUpdate) {
        result.append("  virtual void update ();\n");
    }
    if (bed.needLocalFinalize) {
        result.append("  virtual bool finalize ();\n");
    }
    if (bed.needLocalUpdateDerivative) {
        result.append("  virtual void updateDerivative ();\n");
    }
    if (bed.needLocalFinalizeDerivative) {
        result.append("  virtual void finalizeDerivative ();\n");
    }
    if (bed.needLocalPreserve) {
        result.append("  virtual void snapshot ();\n");
        result.append("  virtual void restore ();\n");
    }
    if (bed.needLocalDerivative) {
        result.append("  virtual void pushDerivative ();\n");
        result.append("  virtual void multiplyAddToStack (" + T + " scalar);\n");
        result.append("  virtual void multiply (" + T + " scalar);\n");
        result.append("  virtual void addToMembers ();\n");
    }
    if (bed.live != null && !bed.live.hasAttribute("constant")) {
        result.append("  virtual " + T + " getLive ();\n");
    }
    if (bed.xyz != null && s.connected) {
        result.append("  virtual void getXYZ (MatrixFixed<" + T + ",3,1> & xyz);\n");
    }
    if (s.connectionBindings != null) {
        if (bed.p != null) {
            result.append("  virtual " + T + " getP ();\n");
        }
        if (bed.hasProject) {
            result.append("  virtual void getProject (int i, MatrixFixed<" + T + ",3,1> & xyz);\n");
        }
        result.append("  virtual void setPart (int i, Part<" + T + "> * part);\n");
        result.append("  virtual Part<" + T + "> * getPart (int i);\n");
    }
    if (bed.newborn >= 0) {
        result.append("  virtual bool getNewborn ();\n");
    }
    if (s.connectionMatrix != null && s.connectionMatrix.needsMapping) {
        result.append("  virtual int mapIndex (int i, int rc);\n");
    }
    if (bed.eventTargets.size() > 0) {
        result.append("  virtual bool eventTest (int i);\n");
        if (bed.needLocalEventDelay) {
            result.append("  virtual " + T + " eventDelay (int i);\n");
        }
        result.append("  virtual void setLatch (int i);\n");
        if (bed.eventReferences.size() > 0) {
            result.append("  virtual void finalizeEvent ();\n");
        }
    }
    if (bed.accountableEndpoints.size() > 0) {
        result.append("  virtual int getCount (int i);\n");
    }
    if (bed.needLocalPath) {
        result.append("  virtual void path (String & result);\n");
    }
    // Conversions
    Set<Conversion> conversions = s.getConversions();
    for (Conversion pair : conversions) {
        EquationSet source = pair.from;
        EquationSet dest = pair.to;
        result.append("  void " + mangle(source.name) + "_2_" + mangle(dest.name) + " (" + mangle(source.name) + " * from, int " + mangle("$type") + ");\n");
    }
    // Unit class trailer
    result.append("};\n");
    result.append("\n");
}

Example 2 with Delay

use of gov.sandia.n2a.language.function.Delay in project n2a by frothga.

the class InternalBackendData method analyzeEvents.

/**
 *        Find event() calls and collate them (in case the same signature appears several different places
 *        in the equation set).
 *        This must be done before the variables are sorted into sets according to attributes, because we
 *        may need to add the "externalRead" attribute to some of them.
 */
public void analyzeEvents(EquationSet s) {
    analyzeEvents(s, eventTargets, eventReferences, delays);
    // Allocate storage for Event
    int valueIndex = -1;
    int mask = 0;
    int eventIndex = 0;
    for (EventTarget et : eventTargets) {
        if (valueIndex == -1) {
            valueIndex = countLocalFloat++;
            namesLocalFloat.add("eventLatch" + valueIndex);
            eventLatches.add(valueIndex);
            mask = 1;
        }
        et.valueIndex = valueIndex;
        et.mask = mask;
        mask <<= 1;
        // Due to limitations of float-int conversion, only 23 bits are available. Allocate another float.
        if (mask > 0x400000)
            valueIndex = -1;
        if (// We have an auxiliary variable.
        !et.trackOne && et.edge != EventTarget.NONZERO) {
            et.track.readIndex = et.track.writeIndex = allocateLocalFloat(et.track.name);
            // Preemptively add this, because the main analyze() routine won't see it.
            // We put the aux in init so that it can pick up the initial value without a call
            // to EventTarget.test(). Note that dependencies have been set when the aux was
            // created, so it will execute in the correct order with all the other init variables.
            localInit.add(et.track);
        }
        // the same part. Since #2 is already a rare case, we won't worry about trapping this.
        if (et.edge == EventTarget.NONZERO && (et.sources.size() > 1 || et.sources.get(0).container == et.container && (et.delay == 0 || et.delay == -2))) {
            et.timeIndex = allocateLocalFloat("eventTime" + eventIndex);
        }
        // TODO: What if two different event targets in this part reference the same source part? What if the condition is different? The same?
        for (EventSource es : et.sources) {
            EquationSet sourceContainer = es.container;
            InternalBackendData sourceBed = (InternalBackendData) sourceContainer.backendData;
            // TODO: Consolidate monitors that share the same trigger condition.
            es.monitorIndex = sourceBed.allocateLocalObject("eventMonitor_" + s.prefix());
            sourceBed.eventSources.add(es);
        }
        eventIndex++;
    }
    // Allocate storage for Delay
    int i = 0;
    for (Delay d : delays) {
        d.index = allocateLocalObject("delay" + i++);
    }
}

Example 3 with Delay

use of gov.sandia.n2a.language.function.Delay in project n2a by frothga.

the class RendererC method render.

public boolean render(Operator op) {
    for (ProvideOperator po : job.extensions) {
        Boolean result = po.render(this, op);
        if (result != null)
            return result;
    }
    if (op instanceof Add) {
        Add a = (Add) op;
        // Check if this is a string expression
        if (a.name != null) {
            result.append(a.name);
            return true;
        }
        return false;
    }
    if (op instanceof AccessElement) {
        AccessElement ae = (AccessElement) op;
        ae.operands[0].render(this);
        if (ae.operands.length == 2) {
            result.append("[");
            ae.operands[1].render(this);
            result.append("]");
        } else if (ae.operands.length == 3) {
            result.append("(");
            ae.operands[1].render(this);
            result.append(",");
            ae.operands[2].render(this);
            result.append(")");
        }
        return true;
    }
    if (op instanceof AccessVariable) {
        AccessVariable av = (AccessVariable) op;
        result.append(job.resolve(av.reference, this, false));
        return true;
    }
    if (op instanceof Atan) {
        Atan atan = (Atan) op;
        int shift = atan.exponent - atan.exponentNext;
        if (useExponent && shift != 0)
            result.append("(");
        if (atan.operands.length > 1 || useExponent)
            result.append("atan2 (");
        else
            result.append("atan (");
        Operator y = atan.operands[0];
        if (y.getType() instanceof Matrix) {
            y.render(this);
            result.append("[1], ");
            y.render(this);
            result.append("[0]");
        } else {
            y.render(this);
            if (atan.operands.length > 1) {
                result.append(", ");
                // x
                atan.operands[1].render(this);
            } else if (useExponent) {
                int shiftX = Operator.MSB - y.exponent;
                int x = shiftX >= 0 ? 0x1 << shiftX : 0;
                result.append(", " + x);
            }
        }
        result.append(")");
        if (useExponent && shift != 0)
            result.append(printShift(shift) + ")");
        return true;
    }
    if (op instanceof BuildMatrix) {
        BuildMatrix b = (BuildMatrix) op;
        result.append(b.name);
        return true;
    }
    if (op instanceof Columns) {
        Columns c = (Columns) op;
        c.operands[0].render(this);
        result.append(".columns ()");
        return true;
    }
    if (op instanceof Constant) {
        Constant c = (Constant) op;
        Type o = c.value;
        if (o instanceof Scalar) {
            result.append(print(((Scalar) o).value, c.exponentNext));
            return true;
        }
        if (o instanceof Text) {
            result.append("\"" + o.toString() + "\"");
            return true;
        }
        if (o instanceof Matrix) {
            result.append(c.name);
            return true;
        }
        return false;
    }
    if (op instanceof Delay) {
        Delay d = (Delay) op;
        if (d.operands.length == 1) {
            result.append("(");
            d.operands[0].render(this);
            result.append(")");
            return true;
        }
        result.append("delay" + d.index + ".step (Simulator<" + job.T + ">::instance.currentEvent->t, ");
        d.operands[1].render(this);
        result.append(", ");
        d.operands[0].render(this);
        result.append(", ");
        if (d.operands.length > 2)
            d.operands[2].render(this);
        else
            result.append("0");
        result.append(")");
        return true;
    }
    if (op instanceof Event) {
        Event e = (Event) op;
        // The cast to bool gets rid of the specific numeric value from flags.
        // If used in a numeric expression, it should convert to either 1 or 0.
        result.append("((bool) (flags & (" + bed.localFlagType + ") 0x1 << " + e.eventType.valueIndex + "))");
        return true;
    }
    if (op instanceof Exp) {
        Exp e = (Exp) op;
        Operator a = e.operands[0];
        result.append("exp (");
        a.render(this);
        if (useExponent)
            result.append(", " + e.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Gaussian) {
        Gaussian g = (Gaussian) op;
        result.append("gaussian<" + job.T + "> (");
        if (g.operands.length > 0) {
            g.operands[0].render(this);
        }
        result.append(")");
        return true;
    }
    if (op instanceof Grid) {
        Grid g = (Grid) op;
        boolean raw = g.operands.length >= 5 && g.operands[4].getString().contains("raw");
        int shift = g.exponent - g.exponentNext;
        if (useExponent && shift != 0)
            result.append("(");
        result.append("grid");
        if (raw)
            result.append("Raw");
        result.append("<" + job.T + "> (");
        int count = Math.min(4, g.operands.length);
        if (count > 0)
            g.operands[0].render(this);
        for (int i = 1; i < count; i++) {
            result.append(", ");
            g.operands[i].render(this);
        }
        result.append(")");
        if (useExponent && shift != 0)
            result.append(printShift(shift) + ")");
        return true;
    }
    if (op instanceof HyperbolicTangent) {
        HyperbolicTangent t = (HyperbolicTangent) op;
        Operator a = t.operands[0];
        result.append("tanh (");
        a.render(this);
        result.append(")");
        return true;
    }
    if (op instanceof Input) {
        Input i = (Input) op;
        result.append(i.name + "->get (");
        if (// return matrix
        i.operands.length < 3 || i.operands[2].getDouble() < 0) {
            boolean time = i.getMode().contains("time");
            String defaultLine = time ? "-INFINITY" : "0";
            if (i.operands.length > 1) {
                Operator op1 = i.operands[1];
                if (// expression for line
                op1.getType() instanceof Scalar)
                    // expression for line
                    op1.render(this);
                else
                    // op1 is probably the mode flag
                    result.append(defaultLine);
            } else // line is not specified. We're probably just retrieving a dummy matrix to get column count.
            {
                result.append(defaultLine);
            }
        } else // return scalar
        {
            i.operands[1].render(this);
            result.append(", ");
            i.operands[2].render(this);
        }
        result.append(")");
        return true;
    }
    if (op instanceof Log) {
        Log l = (Log) op;
        Operator a = l.operands[0];
        result.append("log (");
        a.render(this);
        if (useExponent)
            result.append(", " + a.exponentNext + ", " + l.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Max) {
        Max m = (Max) op;
        for (int i = 0; i < m.operands.length - 1; i++) {
            Operator a = m.operands[i];
            result.append("max (");
            renderType(a);
            result.append(", ");
        }
        Operator b = m.operands[m.operands.length - 1];
        renderType(b);
        for (int i = 0; i < m.operands.length - 1; i++) result.append(")");
        return true;
    }
    if (op instanceof Min) {
        Min m = (Min) op;
        for (int i = 0; i < m.operands.length - 1; i++) {
            Operator a = m.operands[i];
            result.append("min (");
            renderType(a);
            result.append(", ");
        }
        Operator b = m.operands[m.operands.length - 1];
        renderType(b);
        for (int i = 0; i < m.operands.length - 1; i++) result.append(")");
        return true;
    }
    if (op instanceof Modulo) {
        Modulo m = (Modulo) op;
        Operator a = m.operand0;
        Operator b = m.operand1;
        result.append("modFloor (");
        moduloParam(a);
        result.append(", ");
        moduloParam(b);
        result.append(")");
        return true;
    }
    if (op instanceof Norm) {
        Norm n = (Norm) op;
        Operator A = n.operands[0];
        result.append("norm (");
        A.render(this);
        result.append(", ");
        n.operands[1].render(this);
        if (useExponent)
            result.append(", " + A.exponentNext + ", " + n.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Output) {
        Output o = (Output) op;
        result.append(o.name + "->trace (Simulator<" + job.T + ">::instance.currentEvent->t, ");
        if (// column name is explicit
        o.hasColumnName) {
            o.operands[2].render(this);
        } else // column name is generated, so use prepared string value
        {
            result.append(o.columnName);
        }
        result.append(", ");
        o.operands[1].render(this);
        if (useExponent)
            result.append(", " + o.operands[1].exponentNext);
        result.append(", ");
        if (// No mode string
        o.operands.length < 4) {
            // null
            result.append("0");
        } else if (// Mode string is constant
        o.operands[3] instanceof Constant) {
            result.append("\"" + o.operands[3] + "\"");
        } else if (// Mode string is calculated
        o.operands[3] instanceof Add) {
            Add a = (Add) o.operands[3];
            // No need for cast or call c_str()
            result.append(a.name);
        }
        // else badness
        result.append(")");
        return true;
    }
    if (op instanceof Power) {
        Power p = (Power) op;
        Operator a = p.operand0;
        Operator b = p.operand1;
        result.append("pow (");
        a.render(this);
        result.append(", ");
        b.render(this);
        if (useExponent)
            result.append(", " + a.exponentNext + ", " + p.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Pulse) {
        Pulse p = (Pulse) op;
        Operator t = p.operands[0];
        result.append("pulse (");
        renderType(t);
        for (int i = 1; i < p.operands.length; i++) {
            result.append(", ");
            renderType(p.operands[i]);
        }
        result.append(")");
        return true;
    }
    if (op instanceof ReadMatrix) {
        ReadMatrix r = (ReadMatrix) op;
        // Currently, ReadMatrix sets its exponent = exponentNext, so we will never do a shift here.
        // Any shifting should be handled by matrixHelper while loading and converting the matrix to integer.
        // matrices are held in pointers, so need to dereference
        result.append("*" + r.name + "->A");
        return true;
    }
    if (op instanceof Rows) {
        Rows r = (Rows) op;
        r.operands[0].render(this);
        result.append(".rows ()");
        return true;
    }
    if (op instanceof Sat) {
        Sat s = (Sat) op;
        Operator a = s.operands[0];
        Operator lower = s.operands[1];
        Operator upper;
        if (s.operands.length >= 3)
            upper = s.operands[2];
        else
            upper = lower;
        result.append("max (");
        if (s.operands.length == 2)
            result.append("-1 * (");
        renderType(lower);
        if (s.operands.length == 2)
            result.append(")");
        result.append(", min (");
        renderType(upper);
        result.append(", ");
        renderType(a);
        result.append("))");
        return true;
    }
    if (op instanceof SquareRoot) {
        SquareRoot s = (SquareRoot) op;
        Operator a = s.operands[0];
        result.append("sqrt (");
        a.render(this);
        if (useExponent)
            result.append(", " + a.exponentNext + ", " + s.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof SumSquares) {
        SumSquares ss = (SumSquares) op;
        Operator A = ss.operands[0];
        result.append("sumSquares (");
        A.render(this);
        if (useExponent)
            result.append(", " + A.exponentNext + ", " + ss.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Tangent) {
        Tangent t = (Tangent) op;
        Operator a = t.operands[0];
        result.append("tan (");
        a.render(this);
        if (useExponent)
            result.append(", " + a.exponentNext + ", " + t.exponentNext);
        result.append(")");
        return true;
    }
    if (op instanceof Uniform) {
        Uniform u = (Uniform) op;
        result.append("uniform<" + job.T + "> (");
        for (int i = 0; i < u.operands.length; i++) {
            if (i > 0)
                result.append(", ");
            u.operands[i].render(this);
        }
        result.append(")");
        return true;
    }
    return super.render(op);
}

Example 4 with Delay

use of gov.sandia.n2a.language.function.Delay in project n2a by frothga.

the class InternalBackendData method analyzeEvents.

public static void analyzeEvents(EquationSet s, List<EventTarget> eventTargets, List<Variable> eventReferences, List<Delay> delays) {
    class EventVisitor implements Visitor {

        public boolean found;

        public boolean visit(Operator op) {
            if (op instanceof Delay) {
                delays.add((Delay) op);
            } else if (op instanceof Event) {
                found = true;
                Event de = (Event) op;
                if (// this event has not yet been analyzed
                de.eventType == null) {
                    final EventTarget et = new EventTarget(de);
                    int targetIndex = eventTargets.indexOf(et);
                    if (// event target already exists
                    targetIndex >= 0) {
                        de.eventType = eventTargets.get(targetIndex);
                    } else // we must create a new event target, or more properly, fill in the event target we just used as a query object
                    {
                        // Create an entry and save the index
                        targetIndex = eventTargets.size();
                        eventTargets.add(et);
                        de.eventType = et;
                        et.container = s;
                        // Determine edge type
                        if (de.operands.length < 3) {
                            et.edge = EventTarget.RISE;
                        } else if (de.operands[2] instanceof Constant) {
                            Constant c = (Constant) de.operands[2];
                            if (c.value instanceof Text) {
                                Text t = (Text) c.value;
                                if (t.value.equalsIgnoreCase("nonzero"))
                                    et.edge = EventTarget.NONZERO;
                                else if (t.value.equalsIgnoreCase("change"))
                                    et.edge = EventTarget.CHANGE;
                                else if (t.value.equalsIgnoreCase("fall"))
                                    et.edge = EventTarget.FALL;
                                else
                                    et.edge = EventTarget.RISE;
                            } else {
                                Backend.err.get().println("ERROR: event() edge type must be a string.");
                                throw new Backend.AbortRun();
                            }
                        } else {
                            Backend.err.get().println("ERROR: event() edge type must be constant.");
                            throw new Backend.AbortRun();
                        }
                        // Allocate auxiliary variable
                        if (de.operands[0] instanceof AccessVariable) {
                            AccessVariable av = (AccessVariable) de.operands[0];
                            VariableReference reference = av.reference;
                            Variable v = reference.variable;
                            // then the user has broken the rule that we can't see temporaries in other parts.
                            if (v.hasAttribute("temporary") && v.container != s) {
                                Backend.err.get().println("WARNING: Cannot be temporary due to event monitor: " + v.fullName() + " from " + s.name);
                                v.removeAttribute("temporary");
                            }
                            // so fall through to the !trackOne case below.
                            if (!v.hasAttribute("temporary")) {
                                // ensure it's buffered, so we can detect change
                                v.addAttribute("externalRead");
                                et.trackOne = true;
                                // just a holder for the reference
                                et.track = new Variable("");
                                et.track.reference = reference;
                            }
                        }
                        if (// Expression, so create auxiliary variable. Aux not needed for NONZERO, because no change detection.
                        !et.trackOne && et.edge != EventTarget.NONZERO) {
                            et.track = new Variable("$eventAux" + targetIndex);
                            et.track.container = s;
                            et.track.type = new Scalar(0);
                            et.track.reference = new VariableReference();
                            et.track.reference.variable = et.track;
                            // Make executable so it can be directly evaluated during the init cycle.
                            et.track.equations = new TreeSet<EquationEntry>();
                            EquationEntry ee = new EquationEntry(et.track, "");
                            et.track.equations.add(ee);
                            ee.expression = et.event.operands[0].deepCopy();
                            ee.expression.addDependencies(et.track);
                        }
                        // Locate any temporaries for evaluation.
                        // Tie into the dependency graph using a phantom variable (which can go away afterward without damaging the graph).
                        // TODO: for more efficiency, we could have separate lists of temporaries for the condition and delay operands
                        // TODO: for more efficiency, cut off search for temporaries along a given branch of the tree at the first non-temporary.
                        final Variable phantom = new Variable("event");
                        phantom.uses = new IdentityHashMap<Variable, Integer>();
                        phantom.container = s;
                        et.event.visit(new Visitor() {

                            public boolean visit(Operator op) {
                                if (op instanceof AccessVariable) {
                                    AccessVariable av = (AccessVariable) op;
                                    Variable v = av.reference.variable;
                                    if (v.hasAttribute("temporary") && !phantom.uses.containsKey(v))
                                        phantom.uses.put(v, 1);
                                    return false;
                                }
                                return true;
                            }
                        });
                        // Scan all variables in equation set to see if we need them
                        for (Variable t : s.ordered) {
                            if (t.hasAttribute("temporary") && phantom.dependsOn(t) != null)
                                et.dependencies.add(t);
                        }
                        // Note the default is already set to -1 (no care)
                        class DelayVisitor implements Visitor {

                            TreeSet<EquationSet> containers = new TreeSet<EquationSet>();

                            public boolean visit(Operator op) {
                                if (op instanceof AccessVariable) {
                                    AccessVariable av = (AccessVariable) op;
                                    // could include the target part itself, if in fact we use local variables
                                    containers.add(av.reference.variable.container);
                                    return false;
                                }
                                return true;
                            }
                        }
                        DelayVisitor dv = new DelayVisitor();
                        if (de.operands.length >= 2) {
                            if (de.operands[1] instanceof Constant) {
                                Constant c = (Constant) de.operands[1];
                                et.delay = (float) ((Scalar) c.value).value;
                                if (et.delay < 0)
                                    et.delay = -1;
                            } else {
                                // indicates that we need to evaluate delay at run time
                                et.delay = -2;
                                de.operands[1].visit(dv);
                            }
                        }
                        // Set up monitors in source parts
                        class ConditionVisitor implements Visitor {

                            TreeSet<EquationSet> containers = new TreeSet<EquationSet>();

                            public boolean visit(Operator op) {
                                if (op instanceof AccessVariable) {
                                    AccessVariable av = (AccessVariable) op;
                                    Variable v = av.reference.variable;
                                    EquationSet sourceContainer = v.container;
                                    containers.add(sourceContainer);
                                    // Set up monitors for values that can vary during update.
                                    if (!v.hasAttribute("constant") && !v.hasAttribute("initOnly") && !et.monitors(sourceContainer)) {
                                        EventSource es = new EventSource(sourceContainer, et);
                                        // null means self-reference, a special case handled in Part
                                        if (sourceContainer != s)
                                            es.reference = av.reference;
                                        et.sources.add(es);
                                    }
                                    return false;
                                }
                                return true;
                            }
                        }
                        ConditionVisitor cv = new ConditionVisitor();
                        de.operands[0].visit(cv);
                        // Special case for event with no references that vary
                        if (et.sources.isEmpty()) {
                            // We can avoid creating a self monitor if we know for certain that the event will never fire
                            boolean neverFires = false;
                            if (de.operands[0] instanceof Constant) {
                                if (et.edge == EventTarget.NONZERO) {
                                    Type op0 = ((Constant) de.operands[0]).value;
                                    if (op0 instanceof Scalar) {
                                        neverFires = ((Scalar) op0).value == 0;
                                    } else {
                                        Backend.err.get().println("ERROR: Condition for event() must resolve to a number.");
                                        throw new Backend.AbortRun();
                                    }
                                } else {
                                    neverFires = true;
                                }
                            }
                            if (!neverFires) {
                                EventSource es = new EventSource(s, et);
                                // This is a self-reference, so es.reference should be null.
                                et.sources.add(es);
                            }
                        }
                        // Determine if monitor needs to test every target, or if one representative target is sufficient
                        for (EventSource source : et.sources) {
                            // associated with any given source instance, so every target must be evaluated separately.
                            if (cv.containers.size() > 1)
                                source.testEach = true;
                            if (dv.containers.size() > 1 || (dv.containers.size() == 1 && dv.containers.first() != source.container))
                                source.delayEach = true;
                        }
                    }
                }
            }
            return true;
        }
    }
    EventVisitor eventVisitor = new EventVisitor();
    for (Variable v : s.variables) {
        eventVisitor.found = false;
        v.visit(eventVisitor);
        if ((eventVisitor.found || v.dependsOnEvent()) && v.reference.variable != v)
            eventReferences.add(v);
    }
}