diff --git a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/BinaryReader.java b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/BinaryReader.java
index 1cb784d353e5..7b8881c43a1d 100644
--- a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/BinaryReader.java
+++ b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/BinaryReader.java
@@ -1047,7 +1047,7 @@ private void parseBlocks() throws IOException {
         }
     }
 
-    private void createEdges(int id, int preds, List<? extends Port> portList, EdgeBuilder factory) throws IOException {
+    private void createEdges(int id, int startNum, List<? extends Port> portList, EdgeBuilder factory) throws IOException {
         int portNum = 0;
         for (Port p : portList) {
             if (p.isList) {
@@ -1055,18 +1055,14 @@ private void createEdges(int id, int preds, List<? extends Port> portList, EdgeB
                 for (int j = 0; j < size; j++) {
                     int in = dataSource.readInt();
                     p.ids.add(in);
-                    if (in >= 0) {
-                        factory.edge(p, in, id, (char) (preds + portNum), j);
-                        portNum++;
-                    }
+                    factory.edge(p, in, id, (char) (startNum + portNum), j);
+                    portNum++;
                 }
             } else {
                 int in = dataSource.readInt();
                 p.ids.add(in);
-                if (in >= 0) {
-                    factory.edge(p, in, id, (char) (preds + portNum), -1);
-                    portNum++;
-                }
+                factory.edge(p, in, id, (char) (startNum + portNum), -1);
+                portNum++;
             }
             p.ids = new ArrayList<>();
         }
diff --git a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/ModelBuilder.java b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
index 16aa960c98a0..c8df87e9c062 100644
--- a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
+++ b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
@@ -87,20 +87,22 @@ public static final class EdgeInfo {
         final int from;
         final int to;
         final char num;
+        final int listIndex;
         final String label;
         final String type;
         final boolean input;
 
         EdgeInfo(int from, int to) {
-            this(from, to, (char) 0, null, null, false);
+            this(from, to, (char) 0, -1, null, null, false);
         }
 
-        EdgeInfo(int from, int to, char num, String label, String type, boolean input) {
+        EdgeInfo(int from, int to, char num, int listIndex, String label, String type, boolean input) {
             this.from = from;
             this.to = to;
             this.label = label;
             this.type = type;
             this.num = num;
+            this.listIndex = listIndex;
             this.input = input;
         }
 
@@ -112,6 +114,10 @@ public int getTo() {
             return to;
         }
 
+        public int getListIndex() {
+            return listIndex;
+        }
+
         @Override
         public boolean equals(Object other) {
             if (other == null) {
@@ -121,12 +127,13 @@ public boolean equals(Object other) {
                 return false;
             }
             EdgeInfo otherEdge = (EdgeInfo) other;
-            return from == otherEdge.from && to == otherEdge.to && num == otherEdge.num && input == otherEdge.input && Objects.equals(label, otherEdge.label) && Objects.equals(type, otherEdge.type);
+            return from == otherEdge.from && to == otherEdge.to && num == otherEdge.num && listIndex == otherEdge.listIndex && input == otherEdge.input && Objects.equals(label, otherEdge.label) &&
+                            Objects.equals(type, otherEdge.type);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(from, to, label);
+            return Objects.hash(from, to, listIndex, label);
         }
     }
 
@@ -335,10 +342,9 @@ protected final InputGraph pushGraph(InputGraph g) {
     }
 
     protected void connectModifiedProperties(FolderElement g) {
-        if (!(g instanceof Properties.MutableOwner)) {
+        if (!(g instanceof Properties.MutableOwner<?> mu)) {
             return;
         }
-        Properties.MutableOwner<?> mu = (Properties.MutableOwner<?>) g;
         GraphDocument doc = g.getOwner();
         if (doc != null) {
             Properties props = doc.getModifiedProperties(g);
@@ -357,8 +363,8 @@ public static String makeGraphName(int dumpId, String format, Object[] args) {
         for (int i = 0; i < args.length; ++i) {
             if (args[i] instanceof BinaryReader.Klass) {
                 String className = args[i].toString();
-                String s = className.substring(className.lastIndexOf(".") + 1); // strip the package
-                                                                                // name
+                // strip the package name
+                String s = className.substring(className.lastIndexOf(".") + 1);
                 int innerClassPos = s.indexOf('$');
                 if (innerClassPos > 0) {
                     /* Remove inner class name. */
@@ -721,8 +727,7 @@ private String createName(NodeClass nodeClass, List<EdgeInfo> edges, String temp
                     String length = m.group(4);
                     if (prop == null) {
                         result = "?";
-                    } else if (length != null && prop instanceof LengthToString) {
-                        LengthToString lengthProp = (LengthToString) prop;
+                    } else if (length != null && prop instanceof LengthToString lengthProp) {
                         switch (length) {
                             case "s":
                                 result = lengthProp.toString(Length.S);
@@ -777,12 +782,19 @@ public void setNodeProperty(String key, Object value) {
         }
     }
 
+    protected static String inputEdgeType(Port p) {
+        EnumValue type = ((TypedPort) p).type;
+        return type == null ? null : type.toString(Length.S);
+    }
+
     @Override
     public void inputEdge(Port p, int from, int to, char num, int index) {
         assert currentNode != null;
-        String label = (p.isList && index >= 0) ? p.name + "[" + index + "]" : p.name;
-        EnumValue type = ((TypedPort) p).type;
-        EdgeInfo ei = new EdgeInfo(from, to, num, label, type == null ? null : type.toString(Length.S), true);
+        // Ignore null edges
+        if (from < 0) {
+            return;
+        }
+        EdgeInfo ei = new EdgeInfo(from, to, num, index, p.name, inputEdgeType(p), true);
         inputEdges.add(ei);
         nodeEdges.add(ei);
     }
@@ -790,14 +802,17 @@ public void inputEdge(Port p, int from, int to, char num, int index) {
     @Override
     public void successorEdge(Port p, int from, int to, char num, int index) {
         assert currentNode != null;
-        String label = (p.isList && index >= 0) ? p.name + "[" + index + "]" : p.name;
-        EdgeInfo ei = new EdgeInfo(to, from, num, label, InputEdge.SUCCESSOR_EDGE_TYPE, false);
+        // Ignore null edges
+        if (from < 0) {
+            return;
+        }
+        EdgeInfo ei = new EdgeInfo(to, from, num, index, p.name, InputEdge.SUCCESSOR_EDGE_TYPE, false);
         successorEdges.add(ei);
         nodeEdges.add(ei);
     }
 
-    protected InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        return InputEdge.createImmutable(fromIndex, toIndex, from, to, label, type);
+    protected InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        return InputEdge.createImmutable(fromIndex, toIndex, from, to, listIndex, label, type);
     }
 
     @Override
@@ -818,13 +833,13 @@ public void makeGraphEdges() {
             if (currentGraph.getNode(e.to) == null) {
                 reportLoadingError(ErrorMessages.edgeEndNodeNotExists(e.label, e.to));
             }
-            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.label, e.type));
+            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.listIndex, e.label, e.type));
         }
         for (EdgeInfo e : inputEdges) {
             assert e.input;
             char fromIndex = (char) (nodesWithSuccessor.contains(graph.getNode(e.from)) ? 1 : 0);
             char toIndex = e.num;
-            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.label, e.type));
+            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.listIndex, e.label, e.type));
         }
     }
 
diff --git a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/model/InputEdge.java b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
index 53a53b05c7cb..13ce12ffd294 100644
--- a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
+++ b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
@@ -26,6 +26,7 @@
 
 import java.lang.ref.WeakReference;
 import java.util.Comparator;
+import java.util.Objects;
 import java.util.WeakHashMap;
 
 public class InputEdge {
@@ -44,10 +45,13 @@ public enum State {
 
     private final char toIndex;
     private final char fromIndex;
+
     private final int from;
     private final int to;
+    private final int listIndex;
     private final String label;
     private final String type;
+
     private State state;
     private int hashCode = -1;
 
@@ -60,13 +64,17 @@ public InputEdge(char fromIndex, char toIndex, int from, int to) {
     }
 
     public InputEdge(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        this(fromIndex, toIndex, from, to, label, type, State.SAME);
+        this(fromIndex, toIndex, from, to, -1, label, type, State.SAME);
+    }
+
+    public InputEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        this(fromIndex, toIndex, from, to, listIndex, label, type, State.SAME);
     }
 
     static WeakHashMap<InputEdge, WeakReference<InputEdge>> immutableCache = new WeakHashMap<>();
 
-    public static synchronized InputEdge createImmutable(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        InputEdge edge = new InputEdge(fromIndex, toIndex, from, to, label, type, State.IMMUTABLE);
+    public static synchronized InputEdge createImmutable(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        InputEdge edge = new InputEdge(fromIndex, toIndex, from, to, listIndex, label, type, State.IMMUTABLE);
         WeakReference<InputEdge> result = immutableCache.get(edge);
         if (result != null) {
             InputEdge edge2 = result.get();
@@ -78,18 +86,19 @@ public static synchronized InputEdge createImmutable(char fromIndex, char toInde
         return edge;
     }
 
-    public InputEdge(char fromIndex, char toIndex, int from, int to, String label, String type, State state) {
+    public InputEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type, State state) {
         this.toIndex = toIndex;
         this.fromIndex = fromIndex;
         this.from = from;
         this.to = to;
+        this.listIndex = listIndex;
         this.state = state;
         this.label = label;
         this.type = type;
 
-        int hash = (from << 20 | to << 8 | toIndex << 4 | fromIndex);
+        int hash = Objects.hash(from, to, fromIndex, toIndex, listIndex);
         if (state == State.IMMUTABLE) {
-            hash = hash << 5 ^ label.hashCode();
+            hash = Objects.hash(hash, label);
         }
         this.hashCode = hash;
     }
@@ -108,7 +117,7 @@ public void setState(State x) {
         this.state = x;
         // terminal state
         if (state == State.IMMUTABLE) {
-            hashCode = hashCode << 5 ^ label.hashCode();
+            hashCode = Objects.hash(hashCode, label);
         }
     }
 
@@ -120,10 +129,6 @@ public char getFromIndex() {
         return fromIndex;
     }
 
-    public String getName() {
-        return "in" + toIndex;
-    }
-
     public int getFrom() {
         return from;
     }
@@ -132,21 +137,32 @@ public int getTo() {
         return to;
     }
 
+    public int getListIndex() {
+        return listIndex;
+    }
+
     public String getLabel() {
         return label;
     }
 
+    public String getDisplayLabel() {
+        String ret = getLabel();
+        if (listIndex >= 0) {
+            ret = ret + "[" + listIndex + "]";
+        }
+        return ret;
+    }
+
     public String getType() {
         return type;
     }
 
     @Override
     public boolean equals(Object o) {
-        if (!(o instanceof InputEdge)) {
+        if (!(o instanceof InputEdge conn2)) {
             return false;
         }
-        InputEdge conn2 = (InputEdge) o;
-        boolean result = conn2.fromIndex == fromIndex && conn2.toIndex == toIndex && conn2.from == from && conn2.to == to;
+        boolean result = conn2.fromIndex == fromIndex && conn2.toIndex == toIndex && conn2.from == from && conn2.to == to && conn2.listIndex == listIndex;
         if (result && (state == State.IMMUTABLE || conn2.state == State.IMMUTABLE)) {
             // Immutable instances must be exactly the same
             return conn2.state == state && conn2.label.equals(label);
diff --git a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/BinaryReader.java b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/BinaryReader.java
index 1cb784d353e5..7b8881c43a1d 100644
--- a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/BinaryReader.java
+++ b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/BinaryReader.java
@@ -1047,7 +1047,7 @@ private void parseBlocks() throws IOException {
         }
     }
 
-    private void createEdges(int id, int preds, List<? extends Port> portList, EdgeBuilder factory) throws IOException {
+    private void createEdges(int id, int startNum, List<? extends Port> portList, EdgeBuilder factory) throws IOException {
         int portNum = 0;
         for (Port p : portList) {
             if (p.isList) {
@@ -1055,18 +1055,14 @@ private void createEdges(int id, int preds, List<? extends Port> portList, EdgeB
                 for (int j = 0; j < size; j++) {
                     int in = dataSource.readInt();
                     p.ids.add(in);
-                    if (in >= 0) {
-                        factory.edge(p, in, id, (char) (preds + portNum), j);
-                        portNum++;
-                    }
+                    factory.edge(p, in, id, (char) (startNum + portNum), j);
+                    portNum++;
                 }
             } else {
                 int in = dataSource.readInt();
                 p.ids.add(in);
-                if (in >= 0) {
-                    factory.edge(p, in, id, (char) (preds + portNum), -1);
-                    portNum++;
-                }
+                factory.edge(p, in, id, (char) (startNum + portNum), -1);
+                portNum++;
             }
             p.ids = new ArrayList<>();
         }
diff --git a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/ModelBuilder.java b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
index 16aa960c98a0..c8df87e9c062 100644
--- a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
+++ b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/ModelBuilder.java
@@ -87,20 +87,22 @@ public static final class EdgeInfo {
         final int from;
         final int to;
         final char num;
+        final int listIndex;
         final String label;
         final String type;
         final boolean input;
 
         EdgeInfo(int from, int to) {
-            this(from, to, (char) 0, null, null, false);
+            this(from, to, (char) 0, -1, null, null, false);
         }
 
-        EdgeInfo(int from, int to, char num, String label, String type, boolean input) {
+        EdgeInfo(int from, int to, char num, int listIndex, String label, String type, boolean input) {
             this.from = from;
             this.to = to;
             this.label = label;
             this.type = type;
             this.num = num;
+            this.listIndex = listIndex;
             this.input = input;
         }
 
@@ -112,6 +114,10 @@ public int getTo() {
             return to;
         }
 
+        public int getListIndex() {
+            return listIndex;
+        }
+
         @Override
         public boolean equals(Object other) {
             if (other == null) {
@@ -121,12 +127,13 @@ public boolean equals(Object other) {
                 return false;
             }
             EdgeInfo otherEdge = (EdgeInfo) other;
-            return from == otherEdge.from && to == otherEdge.to && num == otherEdge.num && input == otherEdge.input && Objects.equals(label, otherEdge.label) && Objects.equals(type, otherEdge.type);
+            return from == otherEdge.from && to == otherEdge.to && num == otherEdge.num && listIndex == otherEdge.listIndex && input == otherEdge.input && Objects.equals(label, otherEdge.label) &&
+                            Objects.equals(type, otherEdge.type);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(from, to, label);
+            return Objects.hash(from, to, listIndex, label);
         }
     }
 
@@ -335,10 +342,9 @@ protected final InputGraph pushGraph(InputGraph g) {
     }
 
     protected void connectModifiedProperties(FolderElement g) {
-        if (!(g instanceof Properties.MutableOwner)) {
+        if (!(g instanceof Properties.MutableOwner<?> mu)) {
             return;
         }
-        Properties.MutableOwner<?> mu = (Properties.MutableOwner<?>) g;
         GraphDocument doc = g.getOwner();
         if (doc != null) {
             Properties props = doc.getModifiedProperties(g);
@@ -357,8 +363,8 @@ public static String makeGraphName(int dumpId, String format, Object[] args) {
         for (int i = 0; i < args.length; ++i) {
             if (args[i] instanceof BinaryReader.Klass) {
                 String className = args[i].toString();
-                String s = className.substring(className.lastIndexOf(".") + 1); // strip the package
-                                                                                // name
+                // strip the package name
+                String s = className.substring(className.lastIndexOf(".") + 1);
                 int innerClassPos = s.indexOf('$');
                 if (innerClassPos > 0) {
                     /* Remove inner class name. */
@@ -721,8 +727,7 @@ private String createName(NodeClass nodeClass, List<EdgeInfo> edges, String temp
                     String length = m.group(4);
                     if (prop == null) {
                         result = "?";
-                    } else if (length != null && prop instanceof LengthToString) {
-                        LengthToString lengthProp = (LengthToString) prop;
+                    } else if (length != null && prop instanceof LengthToString lengthProp) {
                         switch (length) {
                             case "s":
                                 result = lengthProp.toString(Length.S);
@@ -777,12 +782,19 @@ public void setNodeProperty(String key, Object value) {
         }
     }
 
+    protected static String inputEdgeType(Port p) {
+        EnumValue type = ((TypedPort) p).type;
+        return type == null ? null : type.toString(Length.S);
+    }
+
     @Override
     public void inputEdge(Port p, int from, int to, char num, int index) {
         assert currentNode != null;
-        String label = (p.isList && index >= 0) ? p.name + "[" + index + "]" : p.name;
-        EnumValue type = ((TypedPort) p).type;
-        EdgeInfo ei = new EdgeInfo(from, to, num, label, type == null ? null : type.toString(Length.S), true);
+        // Ignore null edges
+        if (from < 0) {
+            return;
+        }
+        EdgeInfo ei = new EdgeInfo(from, to, num, index, p.name, inputEdgeType(p), true);
         inputEdges.add(ei);
         nodeEdges.add(ei);
     }
@@ -790,14 +802,17 @@ public void inputEdge(Port p, int from, int to, char num, int index) {
     @Override
     public void successorEdge(Port p, int from, int to, char num, int index) {
         assert currentNode != null;
-        String label = (p.isList && index >= 0) ? p.name + "[" + index + "]" : p.name;
-        EdgeInfo ei = new EdgeInfo(to, from, num, label, InputEdge.SUCCESSOR_EDGE_TYPE, false);
+        // Ignore null edges
+        if (from < 0) {
+            return;
+        }
+        EdgeInfo ei = new EdgeInfo(to, from, num, index, p.name, InputEdge.SUCCESSOR_EDGE_TYPE, false);
         successorEdges.add(ei);
         nodeEdges.add(ei);
     }
 
-    protected InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        return InputEdge.createImmutable(fromIndex, toIndex, from, to, label, type);
+    protected InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        return InputEdge.createImmutable(fromIndex, toIndex, from, to, listIndex, label, type);
     }
 
     @Override
@@ -818,13 +833,13 @@ public void makeGraphEdges() {
             if (currentGraph.getNode(e.to) == null) {
                 reportLoadingError(ErrorMessages.edgeEndNodeNotExists(e.label, e.to));
             }
-            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.label, e.type));
+            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.listIndex, e.label, e.type));
         }
         for (EdgeInfo e : inputEdges) {
             assert e.input;
             char fromIndex = (char) (nodesWithSuccessor.contains(graph.getNode(e.from)) ? 1 : 0);
             char toIndex = e.num;
-            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.label, e.type));
+            graph.addEdge(immutableEdge(fromIndex, toIndex, e.from, e.to, e.listIndex, e.label, e.type));
         }
     }
 
diff --git a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/model/InputEdge.java b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
index 53a53b05c7cb..13ce12ffd294 100644
--- a/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
+++ b/visualizer/IdealGraphVisualizer/Data/src/main/java/jdk/graal/compiler/graphio/parsing/model/InputEdge.java
@@ -26,6 +26,7 @@
 
 import java.lang.ref.WeakReference;
 import java.util.Comparator;
+import java.util.Objects;
 import java.util.WeakHashMap;
 
 public class InputEdge {
@@ -44,10 +45,13 @@ public enum State {
 
     private final char toIndex;
     private final char fromIndex;
+
     private final int from;
     private final int to;
+    private final int listIndex;
     private final String label;
     private final String type;
+
     private State state;
     private int hashCode = -1;
 
@@ -60,13 +64,17 @@ public InputEdge(char fromIndex, char toIndex, int from, int to) {
     }
 
     public InputEdge(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        this(fromIndex, toIndex, from, to, label, type, State.SAME);
+        this(fromIndex, toIndex, from, to, -1, label, type, State.SAME);
+    }
+
+    public InputEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        this(fromIndex, toIndex, from, to, listIndex, label, type, State.SAME);
     }
 
     static WeakHashMap<InputEdge, WeakReference<InputEdge>> immutableCache = new WeakHashMap<>();
 
-    public static synchronized InputEdge createImmutable(char fromIndex, char toIndex, int from, int to, String label, String type) {
-        InputEdge edge = new InputEdge(fromIndex, toIndex, from, to, label, type, State.IMMUTABLE);
+    public static synchronized InputEdge createImmutable(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
+        InputEdge edge = new InputEdge(fromIndex, toIndex, from, to, listIndex, label, type, State.IMMUTABLE);
         WeakReference<InputEdge> result = immutableCache.get(edge);
         if (result != null) {
             InputEdge edge2 = result.get();
@@ -78,18 +86,19 @@ public static synchronized InputEdge createImmutable(char fromIndex, char toInde
         return edge;
     }
 
-    public InputEdge(char fromIndex, char toIndex, int from, int to, String label, String type, State state) {
+    public InputEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type, State state) {
         this.toIndex = toIndex;
         this.fromIndex = fromIndex;
         this.from = from;
         this.to = to;
+        this.listIndex = listIndex;
         this.state = state;
         this.label = label;
         this.type = type;
 
-        int hash = (from << 20 | to << 8 | toIndex << 4 | fromIndex);
+        int hash = Objects.hash(from, to, fromIndex, toIndex, listIndex);
         if (state == State.IMMUTABLE) {
-            hash = hash << 5 ^ label.hashCode();
+            hash = Objects.hash(hash, label);
         }
         this.hashCode = hash;
     }
@@ -108,7 +117,7 @@ public void setState(State x) {
         this.state = x;
         // terminal state
         if (state == State.IMMUTABLE) {
-            hashCode = hashCode << 5 ^ label.hashCode();
+            hashCode = Objects.hash(hashCode, label);
         }
     }
 
@@ -120,10 +129,6 @@ public char getFromIndex() {
         return fromIndex;
     }
 
-    public String getName() {
-        return "in" + toIndex;
-    }
-
     public int getFrom() {
         return from;
     }
@@ -132,21 +137,32 @@ public int getTo() {
         return to;
     }
 
+    public int getListIndex() {
+        return listIndex;
+    }
+
     public String getLabel() {
         return label;
     }
 
+    public String getDisplayLabel() {
+        String ret = getLabel();
+        if (listIndex >= 0) {
+            ret = ret + "[" + listIndex + "]";
+        }
+        return ret;
+    }
+
     public String getType() {
         return type;
     }
 
     @Override
     public boolean equals(Object o) {
-        if (!(o instanceof InputEdge)) {
+        if (!(o instanceof InputEdge conn2)) {
             return false;
         }
-        InputEdge conn2 = (InputEdge) o;
-        boolean result = conn2.fromIndex == fromIndex && conn2.toIndex == toIndex && conn2.from == from && conn2.to == to;
+        boolean result = conn2.fromIndex == fromIndex && conn2.toIndex == toIndex && conn2.from == from && conn2.to == to && conn2.listIndex == listIndex;
         if (result && (state == State.IMMUTABLE || conn2.state == State.IMMUTABLE)) {
             // Immutable instances must be exactly the same
             return conn2.state == state && conn2.label.equals(label);
diff --git a/visualizer/IdealGraphVisualizer/Data/src/main/java/org/graalvm/visualizer/data/serialization/lazy/ScanningModelBuilder.java b/visualizer/IdealGraphVisualizer/Data/src/main/java/org/graalvm/visualizer/data/serialization/lazy/ScanningModelBuilder.java
index 3a002b189500..91554e7f0716 100644
--- a/visualizer/IdealGraphVisualizer/Data/src/main/java/org/graalvm/visualizer/data/serialization/lazy/ScanningModelBuilder.java
+++ b/visualizer/IdealGraphVisualizer/Data/src/main/java/org/graalvm/visualizer/data/serialization/lazy/ScanningModelBuilder.java
@@ -280,20 +280,20 @@ public void makeGraphEdges() {
     }
 
     @Override
-    public InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, String label, String type) {
+    public InputEdge immutableEdge(char fromIndex, char toIndex, int from, int to, int listIndex, String label, String type) {
         return null;
     }
 
     @Override
     public void successorEdge(Port p, int from, int to, char num, int index) {
-        if (scanGraph) {
+        if (scanGraph && from >= 0) {
             entry.getGraphMeta().addEdge(from, to);
         }
     }
 
     @Override
     public void inputEdge(Port p, int from, int to, char num, int index) {
-        if (scanGraph) {
+        if (scanGraph && from >= 0) {
             entry.getGraphMeta().addEdge(from, to);
         }
     }
diff --git a/visualizer/IdealGraphVisualizer/Difference/src/main/java/org/graalvm/visualizer/difference/Difference.java b/visualizer/IdealGraphVisualizer/Difference/src/main/java/org/graalvm/visualizer/difference/Difference.java
index 118e1ddccf3f..b1698a98f47d 100644
--- a/visualizer/IdealGraphVisualizer/Difference/src/main/java/org/graalvm/visualizer/difference/Difference.java
+++ b/visualizer/IdealGraphVisualizer/Difference/src/main/java/org/graalvm/visualizer/difference/Difference.java
@@ -236,7 +236,7 @@ private static DiffGraph createDiff(InputGraph a, InputGraph b, DiffGraph graph,
             if (nodeFrom == null || nodeTo == null) {
                 System.out.println("Unexpected edge : " + from + " -> " + to);
             } else {
-                InputEdge newEdge = new InputEdge(fromIndex, toIndex, nodeFrom.getId(), nodeTo.getId(), e.getLabel(), e.getType());
+                InputEdge newEdge = new InputEdge(fromIndex, toIndex, nodeFrom.getId(), nodeTo.getId(), e.getListIndex(), e.getLabel(), e.getType());
                 if (!newEdges.contains(newEdge)) {
                     markAsDeleted(newEdge);
                     newEdges.add(newEdge);
@@ -256,7 +256,7 @@ private static DiffGraph createDiff(InputGraph a, InputGraph b, DiffGraph graph,
             if (nodeFrom == null || nodeTo == null) {
                 System.out.println("Unexpected edge : " + from + " -> " + to);
             } else {
-                InputEdge newEdge = new InputEdge(fromIndex, toIndex, nodeFrom.getId(), nodeTo.getId(), e.getLabel(), e.getType());
+                InputEdge newEdge = new InputEdge(fromIndex, toIndex, nodeFrom.getId(), nodeTo.getId(), e.getListIndex(), e.getLabel(), e.getType());
                 if (!newEdges.contains(newEdge)) {
                     markAsNew(newEdge);
                     newEdges.add(newEdge);
diff --git a/visualizer/IdealGraphVisualizer/Graph/src/main/java/org/graalvm/visualizer/graph/Diagram.java b/visualizer/IdealGraphVisualizer/Graph/src/main/java/org/graalvm/visualizer/graph/Diagram.java
index 761bdcca05ba..238f619c268a 100644
--- a/visualizer/IdealGraphVisualizer/Graph/src/main/java/org/graalvm/visualizer/graph/Diagram.java
+++ b/visualizer/IdealGraphVisualizer/Graph/src/main/java/org/graalvm/visualizer/graph/Diagram.java
@@ -308,7 +308,7 @@ public static Diagram createDiagram(InputGraph graph, String nodeText) {
             assert toFigure.getInputSlots().size() >= toIndex + 1;
             InputSlot inputSlot = toFigure.getInputSlots().get(toIndex);
 
-            Connection c = d.createConnection(inputSlot, outputSlot, e.getLabel(), e.getType());
+            Connection c = d.createConnection(inputSlot, outputSlot, e.getDisplayLabel(), e.getType());
 
             if (e.getState() == InputEdge.State.NEW) {
                 c.setStyle(Connection.ConnectionStyle.BOLD);
diff --git a/visualizer/mx.visualizer/mx_visualizer.py b/visualizer/mx.visualizer/mx_visualizer.py
index 969e95b896d1..28d87114e638 100644
--- a/visualizer/mx.visualizer/mx_visualizer.py
+++ b/visualizer/mx.visualizer/mx_visualizer.py
@@ -59,7 +59,7 @@ def source_dirs(self):
     def classpath_repr(self, resolve=True):
         src = os.path.join(self.dir, 'IdealGraphVisualizer', self.name, 'src')
         if not os.path.exists(src):
-            mx.abort("Cannot find {0}".format(src))
+            mx.abort(f"Cannot find {src}")
         return src
 
     def output_dir(self, relative=False):
@@ -107,7 +107,7 @@ def __init__(self, subject, args, vmbuild, vm):
         self.vmbuild = vmbuild
 
     def __str__(self):
-        return 'Building NetBeans for {}'.format(self.subject)
+        return f'Building NetBeans for {self.subject}'
 
     def needsBuild(self, newestInput):
         return (True, 'Let us re-build everytime')
@@ -123,24 +123,22 @@ def build(self):
                 lib_path = lib.classpath_repr(resolve=False)
                 link_name = os.path.join(libs_dir, os.path.basename(lib_path))
                 from_path = os.path.relpath(lib_path, os.path.dirname(link_name))
-                mx.log("Symlink {0}, {1}".format(from_path, link_name))
+                mx.log(f"Symlink {from_path}, {link_name}")
                 os.symlink(from_path, link_name)
         mx.log('Symlinks must be copied!')
 
         env = os.environ.copy()
         env["MAVEN_OPTS"] = "-Djava.awt.headless=true -Dpolyglot.engine.WarnInterpreterOnly=false"
 
-        mx.logv('Setting PATH to {}'.format(os.environ["PATH"]))
-        mx.logv('Calling java -version')
-        mx.run(['java', '-version'])
+        mx.logv(f"Setting PATH to {os.environ['PATH']}")
 
-        mx.log('Invoking maven for {} for {} in {}'.format(' '.join(self.subject.build_commands), self.subject.name, self.subject.baseDir))
+        mx.log(f"Invoking maven for {' '.join(self.subject.build_commands)} for {self.subject.name} in {self.subject.baseDir}")
         run_maven(self.subject.build_commands, nonZeroIsFatal=True, cwd=self.subject.baseDir, env=env)
 
         for output_dir in self.subject.output_dirs:
             os.chmod(os.path.join(self.subject.output_dir(), output_dir, 'bin', 'idealgraphvisualizer'), 0o755)
 
-        mx.log('...finished build of {}'.format(self.subject))
+        mx.log(f'...finished build of {self.subject}')
 
     def clean(self, forBuild=False):
         if self.subject.mxLibs: