Type Switch scalability issue

pom.xml

@@ -54,8 +54,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>19</source>
-                    <target>19</target>
+                    <source>21</source>
+                    <target>21</target>
                 </configuration>
             </plugin>
         </plugins>

src/main/java/red/hat/puzzles/polymorphism/TypeSwitchScalabilityBenchmark.java

@@ -0,0 +1,98 @@
+package red.hat.puzzles.polymorphism;
+
+import org.openjdk.jmh.annotations.*;
+
+import java.io.Serializable;
+import java.util.concurrent.TimeUnit;
+import java.util.function.IntSupplier;
+
+@State(Scope.Benchmark)
+@Measurement(iterations = 5, time = 200, timeUnit = TimeUnit.MILLISECONDS)
+@Warmup(iterations = 15, time = 200, timeUnit = TimeUnit.MILLISECONDS)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Fork(2)
+public class TypeSwitchScalabilityBenchmark {
+
+    private static final class SerializableIntGarbage implements IntSupplier, Serializable {
+        private final int value;
+
+        public SerializableIntGarbage(int value) {
+            this.value = value;
+        }
+
+        @Override
+        public int getAsInt() {
+            return value;
+        }
+    }
+
+    private static final class SerializableInt implements IntSupplier, Serializable {
+        private final int value;
+
+        public SerializableInt(int value) {
+            this.value = value;
+        }
+
+        @Override
+        public int getAsInt() {
+            return value;
+        }
+    }
+
+    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
+    private static boolean serialize(Serializable o) {
+        // NO-OP, we live dangerously here :P
+        return true;
+    }
+
+    static boolean serialize(Object o) {
+        return switch (o) {
+            case Serializable value -> serialize(value);
+            default -> false;
+        };
+    }
+
+    static int getAsInt(Object o) {
+        return switch (o) {
+            case IntSupplier value -> value.getAsInt();
+            default -> -1;
+        };
+    }
+
+    private Object o;
+    @Param({"false", "true"})
+    private boolean typePollution;
+
+    @Setup
+    public void init() {
+        if (typePollution) {
+            o = new SerializableIntGarbage(0);
+            for (int i = 0; i < 11000; i++) {
+                doSerialize();
+                doGetAsInt();
+            }
+            o = new SerializableInt(0);
+            for (int i = 0; i < 11000; i++) {
+                doSerialize();
+                doGetAsInt();
+            }
+        }
+        o = new SerializableInt(0);
+
+    }
+
+    @Benchmark
+    @Group
+    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
+    public boolean doSerialize() {
+        return serialize(o);
+    }
+
+    @Benchmark
+    @Group
+    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
+    public int doGetAsInt() {
+        return getAsInt(o);
+    }
+
+}