diff --git a/src/bindings/js.ts b/src/bindings/js.ts
index 59f9685c43..a75272bae2 100644
--- a/src/bindings/js.ts
+++ b/src/bindings/js.ts
@@ -950,13 +950,13 @@ export class JSBuilder extends ExportsWalker {
     if (type.isInternalReference) {
       // Lift reference types
       const clazz = assert(type.getClassOrWrapper(this.program));
-      if (clazz.extends(this.program.arrayBufferInstance.prototype)) {
+      if (clazz.extendsPrototype(this.program.arrayBufferInstance.prototype)) {
         sb.push("__liftBuffer(");
         this.needsLiftBuffer = true;
-      } else if (clazz.extends(this.program.stringInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.stringInstance.prototype)) {
         sb.push("__liftString(");
         this.needsLiftString = true;
-      } else if (clazz.extends(this.program.arrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayPrototype)) {
         let valueType = clazz.getArrayValueType();
         sb.push("__liftArray(");
         this.makeLiftFromMemory(valueType, sb);
@@ -964,7 +964,7 @@ export class JSBuilder extends ExportsWalker {
         sb.push(valueType.alignLog2.toString());
         sb.push(", ");
         this.needsLiftArray = true;
-      } else if (clazz.extends(this.program.staticArrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.staticArrayPrototype)) {
         let valueType = clazz.getArrayValueType();
         sb.push("__liftStaticArray(");
         this.makeLiftFromMemory(valueType, sb);
@@ -972,7 +972,7 @@ export class JSBuilder extends ExportsWalker {
         sb.push(valueType.alignLog2.toString());
         sb.push(", ");
         this.needsLiftStaticArray = true;
-      } else if (clazz.extends(this.program.arrayBufferViewInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayBufferViewInstance.prototype)) {
         sb.push("__liftTypedArray(");
         if (clazz.name == "Uint64Array") {
           sb.push("BigUint64Array");
@@ -1021,13 +1021,13 @@ export class JSBuilder extends ExportsWalker {
     if (type.isInternalReference) {
       // Lower reference types
       const clazz = assert(type.getClassOrWrapper(this.program));
-      if (clazz.extends(this.program.arrayBufferInstance.prototype)) {
+      if (clazz.extendsPrototype(this.program.arrayBufferInstance.prototype)) {
         sb.push("__lowerBuffer(");
         this.needsLowerBuffer = true;
-      } else if (clazz.extends(this.program.stringInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.stringInstance.prototype)) {
         sb.push("__lowerString(");
         this.needsLowerString = true;
-      } else if (clazz.extends(this.program.arrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayPrototype)) {
         let valueType = clazz.getArrayValueType();
         sb.push("__lowerArray(");
         this.makeLowerToMemory(valueType, sb);
@@ -1037,7 +1037,7 @@ export class JSBuilder extends ExportsWalker {
         sb.push(clazz.getArrayValueType().alignLog2.toString());
         sb.push(", ");
         this.needsLowerArray = true;
-      } else if (clazz.extends(this.program.staticArrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.staticArrayPrototype)) {
         let valueType = clazz.getArrayValueType();
         sb.push("__lowerStaticArray(");
         this.makeLowerToMemory(valueType, sb);
@@ -1047,7 +1047,7 @@ export class JSBuilder extends ExportsWalker {
         sb.push(valueType.alignLog2.toString());
         sb.push(", ");
         this.needsLowerStaticArray = true;
-      } else if (clazz.extends(this.program.arrayBufferViewInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayBufferViewInstance.prototype)) {
         let valueType = clazz.getArrayValueType();
         sb.push("__lowerTypedArray(");
         if (valueType == Type.u64) {
@@ -1079,7 +1079,7 @@ export class JSBuilder extends ExportsWalker {
         this.needsLowerInternref = true;
       }
       sb.push(name);
-      if (clazz.extends(this.program.staticArrayPrototype)) {
+      if (clazz.extendsPrototype(this.program.staticArrayPrototype)) {
         // optional last argument for __lowerStaticArray
         let valueType = clazz.getArrayValueType();
         if (valueType.isNumericValue) {
@@ -1397,16 +1397,16 @@ export function liftRequiresExportRuntime(type: Type): bool {
   let program = clazz.program;
   // flat collections lift via memory copy
   if (
-    clazz.extends(program.arrayBufferInstance.prototype) ||
-    clazz.extends(program.stringInstance.prototype) ||
-    clazz.extends(program.arrayBufferViewInstance.prototype)
+    clazz.extendsPrototype(program.arrayBufferInstance.prototype) ||
+    clazz.extendsPrototype(program.stringInstance.prototype) ||
+    clazz.extendsPrototype(program.arrayBufferViewInstance.prototype)
   ) {
     return false;
   }
   // nested collections lift depending on element type
   if (
-    clazz.extends(program.arrayPrototype) ||
-    clazz.extends(program.staticArrayPrototype)
+    clazz.extendsPrototype(program.arrayPrototype) ||
+    clazz.extendsPrototype(program.staticArrayPrototype)
   ) {
     return liftRequiresExportRuntime(clazz.getArrayValueType());
   }
@@ -1428,11 +1428,11 @@ export function lowerRequiresExportRuntime(type: Type): bool {
   // lowers using __new
   let program = clazz.program;
   if (
-    clazz.extends(program.arrayBufferInstance.prototype) ||
-    clazz.extends(program.stringInstance.prototype) ||
-    clazz.extends(program.arrayBufferViewInstance.prototype) ||
-    clazz.extends(program.arrayPrototype) ||
-    clazz.extends(program.staticArrayPrototype)
+    clazz.extendsPrototype(program.arrayBufferInstance.prototype) ||
+    clazz.extendsPrototype(program.stringInstance.prototype) ||
+    clazz.extendsPrototype(program.arrayBufferViewInstance.prototype) ||
+    clazz.extendsPrototype(program.arrayPrototype) ||
+    clazz.extendsPrototype(program.staticArrayPrototype)
   ) {
     return true;
   }
diff --git a/src/bindings/tsd.ts b/src/bindings/tsd.ts
index 75a9af7f91..a7f65bfd9d 100644
--- a/src/bindings/tsd.ts
+++ b/src/bindings/tsd.ts
@@ -249,26 +249,26 @@ export class TSDBuilder extends ExportsWalker {
     if (type.isInternalReference) {
       const sb = new Array<string>();
       const clazz = assert(type.getClassOrWrapper(this.program));
-      if (clazz.extends(this.program.arrayBufferInstance.prototype)) {
+      if (clazz.extendsPrototype(this.program.arrayBufferInstance.prototype)) {
         sb.push("ArrayBuffer");
-      } else if (clazz.extends(this.program.stringInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.stringInstance.prototype)) {
         sb.push("string");
-      } else if (clazz.extends(this.program.arrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayPrototype)) {
         const valueType = clazz.getArrayValueType();
         sb.push("Array<");
         sb.push(this.toTypeScriptType(valueType, mode));
         sb.push(">");
-      } else if (clazz.extends(this.program.staticArrayPrototype)) {
+      } else if (clazz.extendsPrototype(this.program.staticArrayPrototype)) {
         const valueType = clazz.getArrayValueType();
         sb.push("ArrayLike<");
         sb.push(this.toTypeScriptType(valueType, mode));
         sb.push(">");
-      } else if (clazz.extends(this.program.arrayBufferViewInstance.prototype)) {
+      } else if (clazz.extendsPrototype(this.program.arrayBufferViewInstance.prototype)) {
         const valueType = clazz.getArrayValueType();
         if (valueType == Type.i8) {
           sb.push("Int8Array");
         } else if (valueType == Type.u8) {
-          if (clazz.extends(this.program.uint8ClampedArrayPrototype)) {
+          if (clazz.extendsPrototype(this.program.uint8ClampedArrayPrototype)) {
             sb.push("Uint8ClampedArray");
           } else {
             sb.push("Uint8Array");
diff --git a/src/builtins.ts b/src/builtins.ts
index 711f10c152..559dd6d8b4 100644
--- a/src/builtins.ts
+++ b/src/builtins.ts
@@ -861,7 +861,7 @@ function builtin_isArray(ctx: BuiltinContext): ExpressionRef {
   let classReference = type.getClass();
   return reifyConstantType(ctx,
     module.i32(
-      classReference && classReference.extends(compiler.program.arrayPrototype)
+      classReference && classReference.extendsPrototype(compiler.program.arrayPrototype)
         ? 1
         : 0
     )
@@ -10420,26 +10420,26 @@ export function compileRTTI(compiler: Compiler): void {
     assert(instanceId == lastId++);
     let flags: TypeinfoFlags = 0;
     if (instance.isPointerfree) flags |= TypeinfoFlags.POINTERFREE;
-    if (instance != abvInstance && instance.extends(abvPrototype)) {
+    if (instance != abvInstance && instance.extendsPrototype(abvPrototype)) {
       let valueType = instance.getArrayValueType();
       flags |= TypeinfoFlags.ARRAYBUFFERVIEW;
       flags |= TypeinfoFlags.VALUE_ALIGN_0 * typeToRuntimeFlags(valueType);
-    } else if (instance.extends(arrayPrototype)) {
+    } else if (instance.extendsPrototype(arrayPrototype)) {
       let valueType = instance.getArrayValueType();
       flags |= TypeinfoFlags.ARRAY;
       flags |= TypeinfoFlags.VALUE_ALIGN_0 * typeToRuntimeFlags(valueType);
-    } else if (instance.extends(setPrototype)) {
+    } else if (instance.extendsPrototype(setPrototype)) {
       let typeArguments = assert(instance.getTypeArgumentsTo(setPrototype));
       assert(typeArguments.length == 1);
       flags |= TypeinfoFlags.SET;
       flags |= TypeinfoFlags.VALUE_ALIGN_0 * typeToRuntimeFlags(typeArguments[0]);
-    } else if (instance.extends(mapPrototype)) {
+    } else if (instance.extendsPrototype(mapPrototype)) {
       let typeArguments = assert(instance.getTypeArgumentsTo(mapPrototype));
       assert(typeArguments.length == 2);
       flags |= TypeinfoFlags.MAP;
       flags |= TypeinfoFlags.KEY_ALIGN_0   * typeToRuntimeFlags(typeArguments[0]);
       flags |= TypeinfoFlags.VALUE_ALIGN_0 * typeToRuntimeFlags(typeArguments[1]);
-    } else if (instance.extends(staticArrayPrototype)) {
+    } else if (instance.extendsPrototype(staticArrayPrototype)) {
       let valueType = instance.getArrayValueType();
       flags |= TypeinfoFlags.STATICARRAY;
       flags |= TypeinfoFlags.VALUE_ALIGN_0 * typeToRuntimeFlags(valueType);
diff --git a/src/compiler.ts b/src/compiler.ts
index e4d86c7dc2..2d55c91e12 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -556,12 +556,18 @@ export class Compiler extends DiagnosticEmitter {
     for (let _keys = Map_keys(this.pendingInstanceOf), i = 0, k = _keys.length; i < k; ++i) {
       let elem = _keys[i];
       let name = assert(this.pendingInstanceOf.get(elem));
-      if (elem.kind == ElementKind.Class) {
-        this.finalizeInstanceOf(<Class>elem, name);
-      } else if (elem.kind == ElementKind.ClassPrototype) {
-        this.finalizeAnyInstanceOf(<ClassPrototype>elem, name);
-      } else {
-        assert(false);
+      switch (elem.kind) {
+        case ElementKind.Class:
+        case ElementKind.Interface: {
+          this.finalizeInstanceOf(<Class>elem, name);
+          break;
+        }
+        case ElementKind.ClassPrototype:
+        case ElementKind.InterfacePrototype: {
+          this.finalizeAnyInstanceOf(<ClassPrototype>elem, name);
+          break;
+        }
+        default: assert(false);
       }
     }
 
@@ -6569,11 +6575,17 @@ export class Compiler extends DiagnosticEmitter {
         }
         let classInstance = assert(overrideInstance.getBoundClassOrInterface());
         builder.addCase(classInstance.id, stmts);
-        // Also alias each extendee inheriting this exact overload
-        let extendees = classInstance.getAllExtendees(instance.declaration.name.text); // without get:/set:
-        for (let _values = Set_values(extendees), a = 0, b = _values.length; a < b; ++a) {
-          let extendee = _values[a];
-          builder.addCase(extendee.id, stmts);
+        // Also alias each extender inheriting this exact overload
+        let extenders = classInstance.extenders;
+        if (extenders) {
+          for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+            let extender = _values[i];
+            let instanceMembers = extender.prototype.instanceMembers;
+            if (instanceMembers && instanceMembers.has(instance.declaration.name.text)) {
+              continue; // skip those not inheriting
+            }
+            builder.addCase(extender.id, stmts);
+          }
         }
       }
     }
@@ -6581,7 +6593,7 @@ export class Compiler extends DiagnosticEmitter {
     // Call the original function if no other id matches and the method is not
     // abstract or part of an interface. Note that doing so will not catch an
     // invalid id, but can reduce code size significantly since we also don't
-    // have to add branches for extendees inheriting the original function.
+    // have to add branches for extenders inheriting the original function.
     let body: ExpressionRef;
     let instanceClass = instance.getBoundClassOrInterface();
     if (!instance.is(CommonFlags.Abstract) && !(instanceClass && instanceClass.kind == ElementKind.Interface)) {
@@ -7432,7 +7444,7 @@ export class Compiler extends DiagnosticEmitter {
     // <nullable> instanceof <nonNullable> - LHS must be != 0
     if (actualType.isNullableReference && !expectedType.isNullableReference) {
 
-      // upcast - check statically
+      // same or upcast - check statically
       if (actualType.nonNullableType.isAssignableTo(expectedType)) {
         return module.binary(
           sizeTypeRef == TypeRef.I64
@@ -7443,8 +7455,8 @@ export class Compiler extends DiagnosticEmitter {
         );
       }
 
-      // downcast - check dynamically
-      if (expectedType.isAssignableTo(actualType)) {
+      // potential downcast - check dynamically
+      if (actualType.nonNullableType.hasSubtypeAssignableTo(expectedType)) {
         if (!(actualType.isUnmanaged || expectedType.isUnmanaged)) {
           if (this.options.pedantic) {
             this.pedantic(
@@ -7477,12 +7489,13 @@ export class Compiler extends DiagnosticEmitter {
     // either none or both nullable
     } else {
 
-      // upcast - check statically
+      // same or upcast - check statically
       if (actualType.isAssignableTo(expectedType)) {
         return module.maybeDropCondition(expr, module.i32(1));
+      }
 
-      // downcast - check dynamically
-      } else if (expectedType.isAssignableTo(actualType)) {
+      // potential downcast - check dynamically
+      if (actualType.hasSubtypeAssignableTo(expectedType)) {
         if (!(actualType.isUnmanaged || expectedType.isUnmanaged)) {
           let temp = flow.getTempLocal(actualType);
           let tempIndex = temp.index;
@@ -7558,19 +7571,32 @@ export class Compiler extends DiagnosticEmitter {
         ), false // managedness is irrelevant here, isn't interrupted
       )
     );
-    let allInstances = new Set<Class>();
-    allInstances.add(instance);
-    instance.getAllExtendeesAndImplementers(allInstances);
-    for (let _values = Set_values(allInstances), i = 0, k = _values.length; i < k; ++i) {
-      let instance = _values[i];
-      stmts.push(
-        module.br("is_instance",
-          module.binary(BinaryOp.EqI32,
-            module.local_get(1, TypeRef.I32),
-            module.i32(instance.id)
+    let allInstances: Set<Class> | null;
+    if (instance.isInterface) {
+      allInstances = instance.implementers;
+    } else {
+      allInstances = new Set();
+      allInstances.add(instance);
+      let extenders = instance.extenders;
+      if (extenders) {
+        for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+          let extender = _values[i];
+          allInstances.add(extender);
+        }
+      }
+    }
+    if (allInstances) {
+      for (let _values = Set_values(allInstances), i = 0, k = _values.length; i < k; ++i) {
+        let instance = _values[i];
+        stmts.push(
+          module.br("is_instance",
+            module.binary(BinaryOp.EqI32,
+              module.local_get(1, TypeRef.I32),
+              module.i32(instance.id)
+            )
           )
-        )
-      );
+        );
+      }
     }
     stmts.push(
       module.return(
@@ -7599,7 +7625,7 @@ export class Compiler extends DiagnosticEmitter {
     if (classReference) {
 
       // static check
-      if (classReference.extends(prototype)) {
+      if (classReference.extendsPrototype(prototype)) {
 
         // <nullable> instanceof <PROTOTYPE> - LHS must be != 0
         if (actualType.isNullableReference) {
@@ -7688,8 +7714,24 @@ export class Compiler extends DiagnosticEmitter {
       let allInstances = new Set<Class>();
       for (let _values = Map_values(instances), i = 0, k = _values.length; i < k; ++i) {
         let instance = _values[i];
-        allInstances.add(instance);
-        instance.getAllExtendeesAndImplementers(allInstances);
+        if (instance.isInterface) {
+          let implementers = instance.implementers;
+          if (implementers) {
+            for (let _values = Set_values(implementers), i = 0, k = _values.length; i < k; ++i) {
+              let implementer = _values[i];
+              allInstances.add(implementer);
+            }
+          }
+        } else {
+          allInstances.add(instance);
+          let extenders = instance.extenders;
+          if (extenders) {
+            for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+              let extender = _values[i];
+              allInstances.add(extender);
+            }
+          }
+        }
       }
       for (let _values = Set_values(allInstances), i = 0, k = _values.length; i < k; ++i) {
         let instance = _values[i];
@@ -7946,7 +7988,7 @@ export class Compiler extends DiagnosticEmitter {
           let parameterTypes = instance.signature.parameterTypes;
           if (parameterTypes.length) {
             let first = parameterTypes[0].getClass();
-            if (first && !first.extends(tsaArrayInstance.prototype)) {
+            if (first && !first.extendsPrototype(tsaArrayInstance.prototype)) {
               arrayInstance = assert(this.resolver.resolveClass(this.program.arrayPrototype, [ stringType ]));
             }
           }
@@ -8014,7 +8056,7 @@ export class Compiler extends DiagnosticEmitter {
 
     // handle static arrays
     let contextualClass = contextualType.getClass();
-    if (contextualClass && contextualClass.extends(program.staticArrayPrototype)) {
+    if (contextualClass && contextualClass.extendsPrototype(program.staticArrayPrototype)) {
       return this.compileStaticArrayLiteral(expression, contextualType, constraints);
     }
 
@@ -8147,7 +8189,7 @@ export class Compiler extends DiagnosticEmitter {
   ): ExpressionRef {
     let program = this.program;
     let module = this.module;
-    assert(!arrayInstance.extends(program.staticArrayPrototype));
+    assert(!arrayInstance.extendsPrototype(program.staticArrayPrototype));
     let elementType = arrayInstance.getArrayValueType(); // asserts
 
     // __newArray(length, alignLog2, classId, staticBuffer)
diff --git a/src/program.ts b/src/program.ts
index 2116651eb8..7ca4cab9f4 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -4182,7 +4182,7 @@ export class ClassPrototype extends DeclaredElement {
   /** Already resolved instances. */
   instances: Map<string,Class> | null = null;
   /** Classes extending this class. */
-  extendees: Set<ClassPrototype> = new Set();
+  extenders: Set<ClassPrototype> = new Set();
   /** Whether this class implicitly extends `Object`. */
   implicitlyExtendsObject: bool = false;
 
@@ -4298,9 +4298,9 @@ export class Class extends TypedElement {
   prototype: ClassPrototype;
   /** Resolved type arguments. */
   typeArguments: Type[] | null;
-  /** Base class, if applicable. */
+  /** Base class, if any. */
   base: Class | null = null;
-  /** Implemented interfaces, if applicable. */
+  /** Directly implemented interfaces, if any. */
   interfaces: Set<Interface> | null = null;
   /** Contextual type arguments for fields and methods. */
   contextualTypeArguments: Map<string,Type> | null = null;
@@ -4318,9 +4318,9 @@ export class Class extends TypedElement {
   rttiFlags: u32 = 0;
   /** Wrapped type, if a wrapper for a basic type. */
   wrappedType: Type | null = null;
-  /** Classes directly extending this class. */
-  extendees: Set<Class> | null = null;
-  /** Classes implementing this interface. */
+  /** Classes directly or indirectly extending this class, if any. */
+  extenders: Set<Class> | null = null;
+  /** Classes directly or indirectly implementing this interface, if any. */
   implementers: Set<Class> | null = null;
   /** Whether the field initialization check has already been performed. */
   didCheckFieldInitialization: bool = false;
@@ -4419,9 +4419,6 @@ export class Class extends TypedElement {
   setBase(base: Class): void {
     assert(!this.base);
     this.base = base;
-    let extendees = base.extendees;
-    if (!extendees) base.extendees = extendees = new Set();
-    extendees.add(this);
 
     // Inherit contextual type arguments from base class
     let inheritedTypeArguments = base.contextualTypeArguments;
@@ -4439,6 +4436,63 @@ export class Class extends TypedElement {
         }
       }
     }
+
+    // This class and its extenders now extend each direct or indirect base class
+    base.propagateExtenderUp(this);
+    let extenders = this.extenders;
+    if (extenders) {
+      for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+        let extender = _values[i];
+        base.propagateExtenderUp(extender);
+      }
+    }
+
+    // Direct or indirect base interfaces are now implemented by this class and its extenders
+    let nextBase: Class | null = base;
+    do {
+      let baseInterfaces = nextBase.interfaces;
+      if (baseInterfaces) {
+        for (let _values = Set_values(baseInterfaces), i = 0, k = _values.length; i < k; ++i) {
+          let baseInterface = _values[i];
+          this.propagateInterfaceDown(baseInterface);
+        }
+      }
+      nextBase = nextBase.base;
+    } while (nextBase);
+  }
+
+  /** Propagates an extender to this class and its base classes. */
+  private propagateExtenderUp(extender: Class): void {
+    // Start with this class, adding the extender to it. Repeat for the class's
+    // bases that are indirectly extended by the extender.
+    let nextBase: Class | null = this;
+    do {
+      let extenders = nextBase.extenders;
+      if (!extenders) nextBase.extenders = extenders = new Set();
+      extenders.add(extender);
+      nextBase = nextBase.base;
+    } while (nextBase);
+  }
+
+  /** Propagates an interface and its base interfaces to this class and its extenders. */
+  private propagateInterfaceDown(iface: Interface): void {
+    // Start with the interface itself, adding this class and its extenders to
+    // its implementers. Repeat for the interface's bases that are indirectly
+    // implemented by means of being extended by the interface.
+    let nextIface: Interface | null = iface;
+    let extenders = this.extenders;
+    do {
+      let implementers = nextIface.implementers;
+      if (!implementers) nextIface.implementers = implementers = new Set();
+      implementers.add(this);
+      if (extenders) {
+        for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+          let extender = _values[i];
+          implementers.add(extender);
+        }
+      }
+      nextIface = <Interface | null>nextIface.base;
+    } while (nextIface);
   }
 
   /** Adds an interface. */
@@ -4446,28 +4500,53 @@ export class Class extends TypedElement {
     let interfaces = this.interfaces;
     if (!interfaces) this.interfaces = interfaces = new Set();
     interfaces.add(iface);
-    let implementers = iface.implementers;
-    if (!implementers) iface.implementers = implementers = new Set();
-    implementers.add(this);
+
+    // This class and its extenders now implement the interface and its bases
+    this.propagateInterfaceDown(iface);
   }
 
   /** Tests if a value of this class type is assignable to a target of the specified class type. */
   isAssignableTo(target: Class): bool {
-    let current: Class | null = this;
-    do {
-      if (current == target) return true;
-      if (target.kind == ElementKind.Interface) {
-        let interfaces = current.interfaces;
-        if (interfaces) {
-          for (let _values = Set_values(interfaces), i = 0, k = _values.length; i < k; ++i) {
-            let iface = _values[i];
-            if (iface.isAssignableTo(target)) return true;
-          }
-        }
+    // Q: When does the assignment in the comment below succeed?
+    if (target.isInterface) {
+      if (this.isInterface) {
+        // targetInterface = thisInterface
+        return this == target || this.extends(target);
+      } else {
+        // targetInterface = thisClass
+        return this.implements(<Interface>target);
       }
-      current = current.base;
-    } while (current);
-    return false;
+    } else {
+      if (this.isInterface) {
+        // targetClass = thisInterface
+        return target == this.program.objectInstance;
+      } else {
+        // targetClass = thisClass
+        return this == target || this.extends(target);
+      }
+    }
+  }
+
+  /** Tests if any subclass of this class is assignable to a target of the specified class type. */
+  hasSubclassAssignableTo(target: Class): bool {
+    // Q: When can the cast in the comment below succeed? (while an assignment would not)
+    if (target.isInterface) {
+      if (this.isInterface) {
+        // <TargetInterface>thisInterface
+        return this.hasImplementerImplementing(<Interface>target);
+      } else {
+        // <TargetInterface>thisClass
+        return this.hasExtenderImplementing(<Interface>target);
+      }
+    } else {
+      if (this.isInterface) {
+        // <TargetClass>thisInterface
+        return this.hasImplementer(target);
+      } else {
+        // <TargetClass>thisClass
+        return this.hasExtender(target);
+      }
+    }
   }
 
   /** Looks up the operator overload of the specified kind. */
@@ -4608,7 +4687,7 @@ export class Class extends TypedElement {
   }
 
   /** Tests if this class extends the specified prototype. */
-  extends(prototype: ClassPrototype): bool {
+  extendsPrototype(prototype: ClassPrototype): bool {
     return this.prototype.extends(prototype);
   }
 
@@ -4627,11 +4706,11 @@ export class Class extends TypedElement {
     let current: Class = this;
     let program = this.program;
     let arrayPrototype = program.arrayPrototype;
-    if (this.extends(arrayPrototype)) {
+    if (this.extendsPrototype(arrayPrototype)) {
       return this.getTypeArgumentsTo(arrayPrototype)![0];
     }
     let staticArrayPrototype = program.staticArrayPrototype;
-    if (this.extends(staticArrayPrototype)) {
+    if (this.extendsPrototype(staticArrayPrototype)) {
       return this.getTypeArgumentsTo(staticArrayPrototype)![0];
     }
     let abvInstance = program.arrayBufferViewInstance;
@@ -4706,42 +4785,50 @@ export class Class extends TypedElement {
     return true;
   }
 
-  /** Gets all extendees of this class (that do not have the specified instance member). */
-  getAllExtendees(exceptIfMember: string | null = null, out: Set<Class> = new Set()): Set<Class> {
-    let extendees = this.extendees;
-    if (extendees) {
-      for (let _values = Set_values(extendees), i = 0, k = _values.length; i < k; ++i) {
-        let extendee = _values[i];
-        if (exceptIfMember) {
-          let instanceMembers = extendee.prototype.instanceMembers;
-          if (instanceMembers && instanceMembers.has(exceptIfMember)) continue;
-        }
-        out.add(extendee);
-        extendee.getAllExtendees(exceptIfMember, out);
-      }
-    }
-    return out;
+  /** Tests if this class or interface extends the given class or interface. */
+  extends(other: Class): bool {
+    return other.hasExtender(this);
+  }
+
+  /** Tests if this class has a direct or indirect extender matching the given class. */
+  hasExtender(other: Class): bool {
+    let extenders = this.extenders;
+    return extenders != null && extenders.has(other);
   }
 
-  /** Gets all extendees and implementers of this class. */
-  getAllExtendeesAndImplementers(out: Set<Class> = new Set()): Set<Class> {
-    let extendees = this.extendees;
-    if (extendees) {
-      for (let _values = Set_values(extendees), i = 0, k = _values.length; i < k; ++i) {
-        let extendee = _values[i];
-        out.add(extendee);
-        extendee.getAllExtendeesAndImplementers(out);
+  /** Tests if this class has a direct or indirect extender that implements the given interface. */
+  hasExtenderImplementing(other: Interface): bool {
+    let extenders = this.extenders;
+    if (extenders) {
+      for (let _values = Set_values(extenders), i = 0, k = _values.length; i < k; ++i) {
+        let extender = _values[i];
+        if (extender.implements(other)) return true;
       }
     }
+    return false;
+  }
+
+  /** Tests if this class directly or indirectly implements the given interface. */
+  implements(other: Interface): bool {
+    return other.hasImplementer(this);
+  }
+
+  /** Tests if this interface has a direct or indirect implementer matching the given class. */
+  hasImplementer(other: Class): bool {
+    let implementers = this.implementers;
+    return implementers != null && implementers.has(other);
+  }
+
+  /** Tests if this interface has an implementer implementing the given interface. */
+  hasImplementerImplementing(other: Interface): bool {
     let implementers = this.implementers;
     if (implementers) {
       for (let _values = Set_values(implementers), i = 0, k = _values.length; i < k; ++i) {
         let implementer = _values[i];
-        out.add(implementer);
-        implementer.getAllExtendeesAndImplementers(out);
+        if (implementer.implements(other)) return true;
       }
     }
-    return out;
+    return false;
   }
 }
 
diff --git a/src/types.ts b/src/types.ts
index baad2a89f5..5e22db7ce3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -506,6 +506,14 @@ export class Type {
     return this.kind == target.kind;
   }
 
+  /** Tests if this type has a subtype assignable to the target type. */
+  hasSubtypeAssignableTo(target: Type): bool {
+    let thisClass = this.getClass();
+    let targetClass = target.getClass();
+    if (!thisClass || !targetClass) return false; // TODO: what about basic types?
+    return thisClass.hasSubclassAssignableTo(targetClass);
+  }
+
   /** Tests if a value of this type can be changed to the target type using `changetype`. */
   isChangeableTo(target: Type): bool {
     // special in that it allows integer references as well
diff --git a/tests/compiler/instanceof.debug.wat b/tests/compiler/instanceof.debug.wat
index 10167dda24..fc52a65e08 100644
--- a/tests/compiler/instanceof.debug.wat
+++ b/tests/compiler/instanceof.debug.wat
@@ -1,7 +1,7 @@
 (module
+ (type $i32_=>_none (func_subtype (param i32) func))
  (type $i32_=>_i32 (func_subtype (param i32) (result i32) func))
  (type $i32_i32_=>_none (func_subtype (param i32 i32) func))
- (type $i32_=>_none (func_subtype (param i32) func))
  (type $none_=>_none (func_subtype func))
  (type $i32_i32_=>_i32 (func_subtype (param i32 i32) (result i32) func))
  (type $i32_i32_i32_=>_none (func_subtype (param i32 i32 i32) func))
@@ -42,10 +42,14 @@
  (global $instanceof/nullAnimal (mut i32) (i32.const 0))
  (global $instanceof/nullCat (mut i32) (i32.const 0))
  (global $instanceof/nullBlackcat (mut i32) (i32.const 0))
+ (global $instanceof/w (mut i32) (i32.const 0))
+ (global $instanceof/x (mut i32) (i32.const 0))
+ (global $instanceof/y (mut i32) (i32.const 0))
+ (global $instanceof/z (mut i32) (i32.const 0))
  (global $~lib/rt/__rtti_base i32 (i32.const 464))
- (global $~lib/memory/__data_end i32 (i32.const 524))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33292))
- (global $~lib/memory/__heap_base i32 (i32.const 33292))
+ (global $~lib/memory/__data_end i32 (i32.const 560))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33328))
+ (global $~lib/memory/__heap_base i32 (i32.const 33328))
  (memory $0 1)
  (data (i32.const 12) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e\00\00\00\00\00")
  (data (i32.const 76) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
@@ -56,7 +60,7 @@
  (data (i32.const 320) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 348) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 412) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1a\00\00\00i\00n\00s\00t\00a\00n\00c\00e\00o\00f\00.\00t\00s\00\00\00")
- (data (i32.const 464) "\0e\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00")
+ (data (i32.const 464) "\17\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00")
  (table $0 1 1 funcref)
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
@@ -2278,835 +2282,1291 @@
   i32.const 0
   return
  )
- (func $start:instanceof (type $none_=>_none)
-  (local $0 i32)
-  (local $1 i32)
-  (local $2 i32)
-  (local $3 i32)
-  (local $4 i32)
-  (local $5 i32)
-  (local $6 i32)
-  (local $7 i32)
-  (local $8 i32)
-  (local $9 i32)
-  (local $10 i32)
-  (local $11 i32)
-  (local $12 i32)
-  (local $13 i32)
-  (local $14 i32)
-  (local $15 i32)
-  (local $16 i32)
-  (local $17 i32)
-  (local $18 i32)
-  (local $19 i32)
-  (local $20 i32)
-  global.get $~lib/memory/__stack_pointer
-  i32.const 84
-  i32.sub
-  global.set $~lib/memory/__stack_pointer
-  call $~stack_check
-  global.get $~lib/memory/__stack_pointer
-  i32.const 0
-  i32.const 84
-  memory.fill $0
-  memory.size $0
-  i32.const 16
-  i32.shl
-  global.get $~lib/memory/__heap_base
-  i32.sub
+ (func $instanceof/assertStaticTrue<instanceof/W,~lib/object/Object> (type $i32_=>_none) (param $value i32)
   i32.const 1
-  i32.shr_u
-  global.set $~lib/rt/itcms/threshold
-  i32.const 144
-  call $~lib/rt/itcms/initLazy
-  global.set $~lib/rt/itcms/pinSpace
-  i32.const 176
-  call $~lib/rt/itcms/initLazy
-  global.set $~lib/rt/itcms/toSpace
-  i32.const 320
-  call $~lib/rt/itcms/initLazy
-  global.set $~lib/rt/itcms/fromSpace
-  i32.const 0
-  call $instanceof/A#constructor
-  global.set $instanceof/a
-  i32.const 0
-  call $instanceof/B#constructor
-  global.set $instanceof/b
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/X,~lib/object/Object> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,~lib/object/Object> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
-  i32.const 0
-  i32.eqz
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,~lib/object/Object> (type $i32_=>_none) (param $value i32)
+  i32.const 1
   drop
-  i32.const 0
-  i32.eqz
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/IA,~lib/object/Object> (type $i32_=>_none) (param $value i32)
+  i32.const 1
   drop
-  i32.const 0
-  i32.eqz
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/IB,~lib/object/Object> (type $i32_=>_none) (param $value i32)
+  i32.const 1
   drop
-  i32.const 0
-  i32.eqz
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/IC,~lib/object/Object> (type $i32_=>_none) (param $value i32)
+  i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/a
-  local.tee $0
-  i32.store $0
-  local.get $0
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/ID,~lib/object/Object> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/W> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $0
-   call $~instanceof|instanceof/B
+   local.get $1
+   call $~instanceof|instanceof/W
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 18
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
   i32.const 1
   drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/X
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Y
+  end
   i32.eqz
-  drop
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
   i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IA> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/IA
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IB> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/IB
+  end
   i32.eqz
-  drop
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
   i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/IC
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/ID
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
+ )
+ (func $instanceof/assertStaticTrue<instanceof/W,instanceof/W> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/W,instanceof/X> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/W,instanceof/Y> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/W,instanceof/Z> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/X,instanceof/W> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/Y,instanceof/W> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/Z,instanceof/W> (type $i32_=>_none) (param $value i32)
   i32.const 0
   i32.eqz
   drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/X,instanceof/X> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
-  i32.const 0
-  call $instanceof/isI32<i32>
+  return
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  if
+  if (result i32)
    i32.const 0
-   i32.const 432
-   i32.const 62
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+  else
+   local.get $1
+   call $~instanceof|instanceof/Y
   end
-  f64.const 0
-  call $instanceof/isI32<f64>
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 63
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  i32.const 0
-  call $instanceof/isI32<u32>
-  i32.eqz
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  if
+  if (result i32)
    i32.const 0
-   i32.const 432
-   i32.const 64
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
   end
-  i32.const 0
-  call $instanceof/isI32<u16>
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 65
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $instanceof/an
-  i32.const 0
-  i32.ne
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/X,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Y
+  end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 68
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
   i32.const 1
   drop
-  i32.const 1
-  global.set $instanceof/an
-  global.get $instanceof/an
-  i32.const 0
-  i32.ne
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/X,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
+  end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 71
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
   i32.const 1
   drop
-  i32.const 0
-  call $instanceof/Child<i32>#constructor
-  global.set $instanceof/child
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/X> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/Y> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
-  i32.const 0
+  return
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/Y,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 1
-  drop
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
+  end
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
   i32.const 1
   drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/Y,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
-  drop
-  i32.const 0
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
+  end
   i32.eqz
+  if
+   i32.const 0
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
   drop
-  i32.const 0
-  call $instanceof/Child<f32>#constructor
-  global.set $instanceof/childAsParent
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/X> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/Y> (type $i32_=>_none) (param $value i32)
   i32.const 1
   drop
-  i32.const 0
-  i32.eqz
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/childAsParent
+  return
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/IA,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
   local.tee $1
-  i32.store $0 offset=4
-  local.get $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
    local.get $1
-   call $~instanceof|instanceof/Child<f32>
+   call $~instanceof|instanceof/IC
   end
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 94
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  i32.const 0
-  i32.eqz
+  i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/childAsParent
-  local.tee $2
-  i32.store $0 offset=8
-  local.get $2
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/IB,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $2
-   call $~anyinstanceof|instanceof/Child
+   local.get $1
+   call $~instanceof|instanceof/IC
   end
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 96
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
-  i32.eqz
-  drop
-  i32.const 0
-  call $instanceof/Animal#constructor
-  global.set $instanceof/animal
-  i32.const 0
-  call $instanceof/Cat#constructor
-  global.set $instanceof/cat
-  i32.const 0
-  call $instanceof/BlackCat#constructor
-  global.set $instanceof/blackcat
   i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/animal
-  local.tee $3
-  i32.store $0 offset=12
-  local.get $3
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/IA,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $3
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 111
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/animal
-  local.tee $4
-  i32.store $0 offset=16
-  local.get $4
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/IB,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $4
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 112
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
   i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/cat
-  local.tee $5
-  i32.store $0 offset=20
-  local.get $5
+ )
+ (func $instanceof/assertStaticFalse<instanceof/IA,instanceof/IE> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/IB,instanceof/IE> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IA,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $5
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/IC
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 115
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/cat
-  local.tee $6
-  i32.store $0 offset=24
-  local.get $6
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IB,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $6
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/IC
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 116
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
   i32.const 1
   drop
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/blackcat
-  local.tee $7
-  i32.store $0 offset=28
-  local.get $7
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IA,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $7
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 119
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/blackcat
-  local.tee $8
-  i32.store $0 offset=32
-  local.get $8
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IB,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $8
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 120
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.const 0
-  call $instanceof/Animal#constructor
-  global.set $instanceof/nullableAnimal
-  i32.const 0
-  call $instanceof/Cat#constructor
-  global.set $instanceof/nullableCat
-  i32.const 0
-  call $instanceof/BlackCat#constructor
-  global.set $instanceof/nullableBlackcat
-  global.get $instanceof/nullableAnimal
-  i32.const 0
-  i32.ne
-  i32.eqz
-  if
+   local.set $check
    i32.const 0
-   i32.const 432
-   i32.const 126
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableAnimal
-  local.tee $9
-  i32.store $0 offset=36
-  local.get $9
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertStaticTrue<instanceof/X,instanceof/IA> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/X,instanceof/IB> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $9
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 127
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableAnimal
-  local.tee $10
-  i32.store $0 offset=40
-  local.get $10
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $10
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/IC
   end
-  i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 128
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 19
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $instanceof/nullableCat
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertStaticFalse<instanceof/X,instanceof/IE> (type $i32_=>_none) (param $value i32)
   i32.const 0
-  i32.ne
   i32.eqz
-  if
-   i32.const 0
-   i32.const 432
-   i32.const 130
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableCat
-  local.tee $11
-  i32.store $0 offset=44
-  local.get $11
+  drop
+  return
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/X,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $11
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/ID
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 131
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableCat
-  local.tee $12
-  i32.store $0 offset=48
-  local.get $12
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/X,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $12
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/IC
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 132
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $instanceof/nullableBlackcat
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/IA> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/IB> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Y,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/Y,instanceof/IE> (type $i32_=>_none) (param $value i32)
   i32.const 0
-  i32.ne
   i32.eqz
-  if
-   i32.const 0
-   i32.const 432
-   i32.const 134
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableBlackcat
-  local.tee $13
-  i32.store $0 offset=52
-  local.get $13
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/IA> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/IB> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/ID> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticTrue<instanceof/Z,instanceof/IC> (type $i32_=>_none) (param $value i32)
+  i32.const 1
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/Z,instanceof/IE> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/IA,instanceof/W> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/IB,instanceof/W> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/IC,instanceof/W> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertStaticFalse<instanceof/ID,instanceof/W> (type $i32_=>_none) (param $value i32)
+  i32.const 0
+  i32.eqz
+  drop
+  return
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IA,instanceof/X> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $13
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/X
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 135
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullableBlackcat
-  local.tee $14
-  i32.store $0 offset=56
-  local.get $14
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IB,instanceof/X> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $14
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/X
   end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 136
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  global.get $instanceof/nullAnimal
-  i32.const 0
-  i32.ne
-  i32.eqz
-  i32.eqz
-  if
+   local.set $check
    i32.const 0
-   i32.const 432
-   i32.const 142
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullAnimal
-  local.tee $15
-  i32.store $0 offset=60
-  local.get $15
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IA,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $15
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/Y
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 143
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullAnimal
-  local.tee $16
-  i32.store $0 offset=64
-  local.get $16
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IB,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $16
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/Y
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 144
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  global.get $instanceof/nullCat
-  i32.const 0
-  i32.ne
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IC,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Y
+  end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 146
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullCat
-  local.tee $17
-  i32.store $0 offset=68
-  local.get $17
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/ID,instanceof/Y> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $17
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/Y
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 147
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullCat
-  local.tee $18
-  i32.store $0 offset=72
-  local.get $18
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IA,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $18
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/Z
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 148
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $instanceof/nullBlackcat
-  i32.const 0
-  i32.ne
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IB,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Z
+  end
   i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 150
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullBlackcat
-  local.tee $19
-  i32.store $0 offset=76
-  local.get $19
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/IC,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $19
-   call $~instanceof|instanceof/Cat
+   local.get $1
+   call $~instanceof|instanceof/Z
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 151
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  global.get $instanceof/nullBlackcat
-  local.tee $20
-  i32.store $0 offset=80
-  local.get $20
+  i32.const 1
+  drop
+ )
+ (func $instanceof/assertDynamicTrue<instanceof/ID,instanceof/Z> (type $i32_=>_none) (param $value i32)
+  (local $1 i32)
+  (local $check i32)
+  local.get $value
+  local.tee $1
   i32.eqz
   if (result i32)
    i32.const 0
   else
-   local.get $20
-   call $~instanceof|instanceof/BlackCat
+   local.get $1
+   call $~instanceof|instanceof/Z
   end
   i32.eqz
-  i32.eqz
   if
    i32.const 0
-   i32.const 432
-   i32.const 152
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
+   local.set $check
+   i32.const 0
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 432
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
   end
-  global.get $~lib/memory/__stack_pointer
-  i32.const 84
-  i32.add
-  global.set $~lib/memory/__stack_pointer
+  i32.const 1
+  drop
  )
  (func $~instanceof|instanceof/B (type $i32_=>_i32) (param $0 i32) (result i32)
   (local $1 i32)
@@ -3201,67 +3661,239 @@
   end
   i32.const 1
  )
- (func $~lib/rt/__visit_globals (type $i32_=>_none) (param $0 i32)
+ (func $~instanceof|instanceof/W (type $i32_=>_i32) (param $0 i32) (result i32)
   (local $1 i32)
-  global.get $instanceof/a
-  local.tee $1
-  if
-   local.get $1
+  block $is_instance
    local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/b
-  local.tee $1
-  if
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
    local.get $1
-   local.get $0
-   call $~lib/rt/itcms/__visit
+   i32.const 14
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
   end
-  global.get $instanceof/an
-  local.tee $1
-  if
-   local.get $1
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/X (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
    local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/child
-  local.tee $1
-  if
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
    local.get $1
-   local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/childAsParent
-  local.tee $1
-  if
+   i32.const 15
+   i32.eq
+   br_if $is_instance
    local.get $1
-   local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/animal
-  local.tee $1
-  if
+   i32.const 18
+   i32.eq
+   br_if $is_instance
    local.get $1
-   local.get $0
-   call $~lib/rt/itcms/__visit
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
   end
-  global.get $instanceof/cat
-  local.tee $1
-  if
-   local.get $1
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/Y (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
    local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/blackcat
-  local.tee $1
-  if
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
    local.get $1
-   local.get $0
-   call $~lib/rt/itcms/__visit
-  end
-  global.get $instanceof/nullableAnimal
-  local.tee $1
-  if
+   i32.const 18
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/Z (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/IA (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
+   local.get $1
+   i32.const 15
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 18
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/IB (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
+   local.get $1
+   i32.const 15
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 18
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/IC (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
+   local.get $1
+   i32.const 18
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~instanceof|instanceof/ID (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  block $is_instance
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   local.set $1
+   local.get $1
+   i32.const 18
+   i32.eq
+   br_if $is_instance
+   local.get $1
+   i32.const 21
+   i32.eq
+   br_if $is_instance
+   i32.const 0
+   return
+  end
+  i32.const 1
+ )
+ (func $~lib/rt/__visit_globals (type $i32_=>_none) (param $0 i32)
+  (local $1 i32)
+  global.get $instanceof/a
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/b
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/an
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/child
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/childAsParent
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/animal
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/cat
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/blackcat
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/nullableAnimal
+  local.tee $1
+  if
    local.get $1
    local.get $0
    call $~lib/rt/itcms/__visit
@@ -3301,6 +3933,34 @@
    local.get $0
    call $~lib/rt/itcms/__visit
   end
+  global.get $instanceof/w
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/x
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/y
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/z
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 224
   local.get $0
   call $~lib/rt/itcms/__visit
@@ -3327,25 +3987,55 @@
  )
  (func $~lib/rt/__visit_members (type $i32_i32_=>_none) (param $0 i32) (param $1 i32)
   block $invalid
-   block $instanceof/BlackCat
-    block $instanceof/Cat
-     block $instanceof/Animal
-      block $instanceof/SomethingElse<i32>
-       block $instanceof/Parent<f32>
-        block $instanceof/Child<f32>
-         block $instanceof/Parent<i32>
-          block $instanceof/Child<i32>
-           block $instanceof/B
-            block $instanceof/A
-             block $~lib/arraybuffer/ArrayBufferView
-              block $~lib/string/String
-               block $~lib/arraybuffer/ArrayBuffer
-                block $~lib/object/Object
-                 local.get $0
-                 i32.const 8
-                 i32.sub
-                 i32.load $0
-                 br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $instanceof/A $instanceof/B $instanceof/Child<i32> $instanceof/Parent<i32> $instanceof/Child<f32> $instanceof/Parent<f32> $instanceof/SomethingElse<i32> $instanceof/Animal $instanceof/Cat $instanceof/BlackCat $invalid
+   block $instanceof/IE
+    block $instanceof/Z
+     block $instanceof/IC
+      block $instanceof/ID
+       block $instanceof/Y
+        block $instanceof/IA
+         block $instanceof/IB
+          block $instanceof/X
+           block $instanceof/W
+            block $instanceof/BlackCat
+             block $instanceof/Cat
+              block $instanceof/Animal
+               block $instanceof/SomethingElse<i32>
+                block $instanceof/Parent<f32>
+                 block $instanceof/Child<f32>
+                  block $instanceof/Parent<i32>
+                   block $instanceof/Child<i32>
+                    block $instanceof/B
+                     block $instanceof/A
+                      block $~lib/arraybuffer/ArrayBufferView
+                       block $~lib/string/String
+                        block $~lib/arraybuffer/ArrayBuffer
+                         block $~lib/object/Object
+                          local.get $0
+                          i32.const 8
+                          i32.sub
+                          i32.load $0
+                          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $instanceof/A $instanceof/B $instanceof/Child<i32> $instanceof/Parent<i32> $instanceof/Child<f32> $instanceof/Parent<f32> $instanceof/SomethingElse<i32> $instanceof/Animal $instanceof/Cat $instanceof/BlackCat $instanceof/W $instanceof/X $instanceof/IB $instanceof/IA $instanceof/Y $instanceof/ID $instanceof/IC $instanceof/Z $instanceof/IE $invalid
+                         end
+                         return
+                        end
+                        return
+                       end
+                       return
+                      end
+                      local.get $0
+                      local.get $1
+                      call $~lib/arraybuffer/ArrayBufferView~visit
+                      return
+                     end
+                     return
+                    end
+                    return
+                   end
+                   return
+                  end
+                  return
+                 end
+                 return
                 end
                 return
                end
@@ -3353,9 +4043,6 @@
               end
               return
              end
-             local.get $0
-             local.get $1
-             call $~lib/arraybuffer/ArrayBufferView~visit
              return
             end
             return
@@ -3385,16 +4072,1783 @@
  )
  (func $~stack_check (type $none_=>_none)
   global.get $~lib/memory/__stack_pointer
-  global.get $~lib/memory/__data_end
-  i32.lt_s
-  if
-   i32.const 33312
-   i32.const 33360
-   i32.const 1
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
+  global.get $~lib/memory/__data_end
+  i32.lt_s
+  if
+   i32.const 33360
+   i32.const 33408
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $start:instanceof (type $none_=>_none)
+  (local $0 i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  (local $6 i32)
+  (local $7 i32)
+  (local $8 i32)
+  (local $9 i32)
+  (local $10 i32)
+  (local $11 i32)
+  (local $12 i32)
+  (local $13 i32)
+  (local $14 i32)
+  (local $15 i32)
+  (local $16 i32)
+  (local $17 i32)
+  (local $18 i32)
+  (local $19 i32)
+  (local $20 i32)
+  (local $21 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 88
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.const 88
+  memory.fill $0
+  memory.size $0
+  i32.const 16
+  i32.shl
+  global.get $~lib/memory/__heap_base
+  i32.sub
+  i32.const 1
+  i32.shr_u
+  global.set $~lib/rt/itcms/threshold
+  i32.const 144
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/pinSpace
+  i32.const 176
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/toSpace
+  i32.const 320
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/fromSpace
+  i32.const 0
+  call $instanceof/A#constructor
+  global.set $instanceof/a
+  i32.const 0
+  call $instanceof/B#constructor
+  global.set $instanceof/b
+  i32.const 1
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/a
+  local.tee $0
+  i32.store $0
+  local.get $0
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $0
+   call $~instanceof|instanceof/B
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 41
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  call $instanceof/isI32<i32>
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 85
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  f64.const 0
+  call $instanceof/isI32<f64>
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 86
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $instanceof/isI32<u32>
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 87
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $instanceof/isI32<u16>
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 88
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/an
+  i32.const 0
+  i32.ne
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 91
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  i32.const 1
+  global.set $instanceof/an
+  global.get $instanceof/an
+  i32.const 0
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 94
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  i32.const 0
+  call $instanceof/Child<i32>#constructor
+  global.set $instanceof/child
+  i32.const 1
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 1
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  call $instanceof/Child<f32>#constructor
+  global.set $instanceof/childAsParent
+  i32.const 1
+  drop
+  i32.const 1
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/childAsParent
+  local.tee $1
+  i32.store $0 offset=4
+  local.get $1
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $1
+   call $~instanceof|instanceof/Child<f32>
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 117
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  i32.eqz
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/childAsParent
+  local.tee $2
+  i32.store $0 offset=8
+  local.get $2
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $2
+   call $~anyinstanceof|instanceof/Child
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 119
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  i32.eqz
+  drop
+  i32.const 0
+  call $instanceof/Animal#constructor
+  global.set $instanceof/animal
+  i32.const 0
+  call $instanceof/Cat#constructor
+  global.set $instanceof/cat
+  i32.const 0
+  call $instanceof/BlackCat#constructor
+  global.set $instanceof/blackcat
+  i32.const 1
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/animal
+  local.tee $3
+  i32.store $0 offset=12
+  local.get $3
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $3
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 134
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/animal
+  local.tee $4
+  i32.store $0 offset=16
+  local.get $4
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $4
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 135
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/cat
+  local.tee $5
+  i32.store $0 offset=20
+  local.get $5
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $5
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 138
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/cat
+  local.tee $6
+  i32.store $0 offset=24
+  local.get $6
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $6
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 139
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/blackcat
+  local.tee $7
+  i32.store $0 offset=28
+  local.get $7
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $7
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 142
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/blackcat
+  local.tee $8
+  i32.store $0 offset=32
+  local.get $8
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $8
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 143
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $instanceof/Animal#constructor
+  global.set $instanceof/nullableAnimal
+  i32.const 0
+  call $instanceof/Cat#constructor
+  global.set $instanceof/nullableCat
+  i32.const 0
+  call $instanceof/BlackCat#constructor
+  global.set $instanceof/nullableBlackcat
+  global.get $instanceof/nullableAnimal
+  i32.const 0
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 149
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableAnimal
+  local.tee $9
+  i32.store $0 offset=36
+  local.get $9
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $9
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 150
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableAnimal
+  local.tee $10
+  i32.store $0 offset=40
+  local.get $10
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $10
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 151
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/nullableCat
+  i32.const 0
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 153
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableCat
+  local.tee $11
+  i32.store $0 offset=44
+  local.get $11
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $11
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 154
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableCat
+  local.tee $12
+  i32.store $0 offset=48
+  local.get $12
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $12
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 155
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/nullableBlackcat
+  i32.const 0
+  i32.ne
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 157
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableBlackcat
+  local.tee $13
+  i32.store $0 offset=52
+  local.get $13
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $13
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 158
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullableBlackcat
+  local.tee $14
+  i32.store $0 offset=56
+  local.get $14
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $14
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 159
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/nullAnimal
+  i32.const 0
+  i32.ne
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 165
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullAnimal
+  local.tee $15
+  i32.store $0 offset=60
+  local.get $15
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $15
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 166
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullAnimal
+  local.tee $16
+  i32.store $0 offset=64
+  local.get $16
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $16
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 167
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/nullCat
+  i32.const 0
+  i32.ne
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 169
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullCat
+  local.tee $17
+  i32.store $0 offset=68
+  local.get $17
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $17
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 170
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullCat
+  local.tee $18
+  i32.store $0 offset=72
+  local.get $18
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $18
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 171
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $instanceof/nullBlackcat
+  i32.const 0
+  i32.ne
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 173
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullBlackcat
+  local.tee $19
+  i32.store $0 offset=76
+  local.get $19
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $19
+   call $~instanceof|instanceof/Cat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 174
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  global.get $instanceof/nullBlackcat
+  local.tee $20
+  i32.store $0 offset=80
+  local.get $20
+  i32.eqz
+  if (result i32)
+   i32.const 0
+  else
+   local.get $20
+   call $~instanceof|instanceof/BlackCat
+  end
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 432
+   i32.const 175
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $instanceof/W#constructor
+  global.set $instanceof/w
+  i32.const 0
+  call $instanceof/X#constructor
+  global.set $instanceof/x
+  i32.const 0
+  call $instanceof/Y#constructor
+  global.set $instanceof/y
+  i32.const 0
+  call $instanceof/Z#constructor
+  global.set $instanceof/z
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/W,~lib/object/Object>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,~lib/object/Object>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,~lib/object/Object>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,~lib/object/Object>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IA,~lib/object/Object>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IB,~lib/object/Object>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IA,~lib/object/Object>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IB,~lib/object/Object>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IC,~lib/object/Object>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/ID,~lib/object/Object>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IA,~lib/object/Object>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IB,~lib/object/Object>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/IC,~lib/object/Object>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/ID,~lib/object/Object>
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/W>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IA>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IB>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IA>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IB>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IC>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IA>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IB>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/ID>
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/W,instanceof/W>
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/W,instanceof/X>
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/W,instanceof/Y>
+  global.get $instanceof/w
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/W,instanceof/Z>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/X,instanceof/W>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/Y,instanceof/W>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/Z,instanceof/W>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/X>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/Y>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/Z>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/Y>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/Y,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/Y,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/Z>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/IA,instanceof/IC>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/IB,instanceof/IC>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/IA,instanceof/ID>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/IB,instanceof/ID>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/IE>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/IE>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/IC>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/IC>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/ID>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/ID>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/IE>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/IE>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/IE>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/IE>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IA>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IB>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/X,instanceof/ID>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicFalse<instanceof/X,instanceof/IC>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/X,instanceof/IE>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IA>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IB>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/ID>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/IC>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/X,instanceof/IE>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IA>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/X,instanceof/IB>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/X,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/X,instanceof/IE>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IA>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IB>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/ID>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IC>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/Y,instanceof/IE>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IA>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IB>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Y,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/Y,instanceof/IE>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/IA>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/IB>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/ID>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticTrue<instanceof/Z,instanceof/IC>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/Z,instanceof/IE>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/W>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/W>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/W>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/W>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IC,instanceof/W>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/ID,instanceof/W>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IA,instanceof/W>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IB,instanceof/W>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/IC,instanceof/W>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertStaticFalse<instanceof/ID,instanceof/W>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/X>
+  global.get $instanceof/x
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/X>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/X>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/Y>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/Y>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IC,instanceof/Y>
+  global.get $instanceof/y
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/ID,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IC,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/ID,instanceof/Y>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IA,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IB,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/IC,instanceof/Z>
+  global.get $instanceof/z
+  local.set $21
+  global.get $~lib/memory/__stack_pointer
+  local.get $21
+  i32.store $0 offset=84
+  local.get $21
+  call $instanceof/assertDynamicTrue<instanceof/ID,instanceof/Z>
+  global.get $~lib/memory/__stack_pointer
+  i32.const 88
+  i32.add
+  global.set $~lib/memory/__stack_pointer
  )
  (func $~lib/object/Object#constructor (type $i32_=>_i32) (param $this i32) (result i32)
   (local $1 i32)
@@ -3721,4 +6175,136 @@
   global.set $~lib/memory/__stack_pointer
   local.get $1
  )
+ (func $instanceof/W#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 14
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  call $~lib/object/Object#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $instanceof/X#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 15
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  call $~lib/object/Object#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $instanceof/Y#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 18
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  call $instanceof/X#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $instanceof/Z#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 21
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  call $instanceof/Y#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
 )
diff --git a/tests/compiler/instanceof.release.wat b/tests/compiler/instanceof.release.wat
index 285a61dcad..25eebb2edc 100644
--- a/tests/compiler/instanceof.release.wat
+++ b/tests/compiler/instanceof.release.wat
@@ -1,7 +1,7 @@
 (module
+ (type $i32_=>_none (func_subtype (param i32) func))
  (type $i32_=>_i32 (func_subtype (param i32) (result i32) func))
  (type $none_=>_none (func_subtype func))
- (type $i32_=>_none (func_subtype (param i32) func))
  (type $i32_i32_=>_none (func_subtype (param i32 i32) func))
  (type $none_=>_i32 (func_subtype (result i32) func))
  (type $i32_i32_i32_i32_=>_none (func_subtype (param i32 i32 i32 i32) func))
@@ -28,7 +28,11 @@
  (global $instanceof/nullableAnimal (mut i32) (i32.const 0))
  (global $instanceof/nullableCat (mut i32) (i32.const 0))
  (global $instanceof/nullableBlackcat (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34316))
+ (global $instanceof/w (mut i32) (i32.const 0))
+ (global $instanceof/x (mut i32) (i32.const 0))
+ (global $instanceof/y (mut i32) (i32.const 0))
+ (global $instanceof/z (mut i32) (i32.const 0))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34352))
  (memory $0 1)
  (data (i32.const 1036) "<")
  (data (i32.const 1048) "\02\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e")
@@ -42,7 +46,7 @@
  (data (i32.const 1384) "\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
  (data (i32.const 1436) ",")
  (data (i32.const 1448) "\02\00\00\00\1a\00\00\00i\00n\00s\00t\00a\00n\00c\00e\00o\00f\00.\00t\00s")
- (data (i32.const 1488) "\0e\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 ")
+ (data (i32.const 1488) "\17\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00 ")
  (export "memory" (memory $0))
  (start $~start)
  (func $~lib/rt/itcms/visitRoots (type $none_=>_none)
@@ -114,6 +118,30 @@
    local.get $0
    call $byn-split-outlined-A$~lib/rt/itcms/__visit
   end
+  global.get $instanceof/w
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/x
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/y
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
+  global.get $instanceof/z
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
   i32.const 1248
   call $byn-split-outlined-A$~lib/rt/itcms/__visit
   i32.const 1056
@@ -191,7 +219,7 @@
     i32.load $0 offset=8
     i32.eqz
     local.get $0
-    i32.const 34316
+    i32.const 34352
     i32.lt_u
     i32.and
     i32.eqz
@@ -819,10 +847,10 @@
   if
    unreachable
   end
-  i32.const 34320
+  i32.const 34352
   i32.const 0
   i32.store $0
-  i32.const 35888
+  i32.const 35920
   i32.const 0
   i32.store $0
   loop $for-loop|0
@@ -833,7 +861,7 @@
     local.get $0
     i32.const 2
     i32.shl
-    i32.const 34320
+    i32.const 34352
     i32.add
     i32.const 0
     i32.store $0 offset=4
@@ -851,7 +879,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 34320
+      i32.const 34352
       i32.add
       i32.const 0
       i32.store $0 offset=96
@@ -869,13 +897,13 @@
     br $for-loop|0
    end
   end
-  i32.const 34320
-  i32.const 35892
+  i32.const 34352
+  i32.const 35924
   memory.size $0
   i32.const 16
   i32.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 34320
+  i32.const 34352
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (type $none_=>_i32) (result i32)
@@ -960,7 +988,7 @@
      local.set $0
      loop $while-continue|0
       local.get $0
-      i32.const 34316
+      i32.const 34352
       i32.lt_u
       if
        local.get $0
@@ -1060,7 +1088,7 @@
      unreachable
     end
     local.get $0
-    i32.const 34316
+    i32.const 34352
     i32.lt_u
     if
      local.get $0
@@ -1083,7 +1111,7 @@
      i32.const 4
      i32.add
      local.tee $0
-     i32.const 34316
+     i32.const 34352
      i32.ge_u
      if
       global.get $~lib/rt/tlsf/ROOT
@@ -1435,26 +1463,261 @@
   memory.fill $0
   local.get $0
  )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X> (type $i32_=>_none) (param $0 i32)
+  local.get $0
+  if (result i32)
+   block $__inlined_func$~instanceof|instanceof/X (result i32)
+    block $is_instance
+     block $tablify|0
+      local.get $0
+      i32.const 8
+      i32.sub
+      i32.load $0
+      i32.const 15
+      i32.sub
+      br_table $is_instance $tablify|0 $tablify|0 $is_instance $tablify|0 $tablify|0 $is_instance $tablify|0
+     end
+     i32.const 0
+     br $__inlined_func$~instanceof|instanceof/X
+    end
+    i32.const 1
+   end
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1456
+   i32.const 12
+   i32.const 5
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y> (type $i32_=>_none) (param $0 i32)
+  local.get $0
+  if (result i32)
+   block $__inlined_func$~instanceof|instanceof/Y (result i32)
+    block $is_instance
+     local.get $0
+     i32.const 8
+     i32.sub
+     i32.load $0
+     local.tee $0
+     i32.const 18
+     i32.eq
+     br_if $is_instance
+     local.get $0
+     i32.const 21
+     i32.eq
+     br_if $is_instance
+     i32.const 0
+     br $__inlined_func$~instanceof|instanceof/Y
+    end
+    i32.const 1
+   end
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1456
+   i32.const 12
+   i32.const 5
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z> (type $i32_=>_none) (param $0 i32)
+  local.get $0
+  if (result i32)
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   i32.const 21
+   i32.eq
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1456
+   i32.const 12
+   i32.const 5
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y> (type $i32_=>_none) (param $0 i32)
+  local.get $0
+  if (result i32)
+   block $__inlined_func$~instanceof|instanceof/Y (result i32)
+    block $is_instance
+     local.get $0
+     i32.const 8
+     i32.sub
+     i32.load $0
+     local.tee $0
+     i32.const 18
+     i32.eq
+     br_if $is_instance
+     local.get $0
+     i32.const 21
+     i32.eq
+     br_if $is_instance
+     i32.const 0
+     br $__inlined_func$~instanceof|instanceof/Y
+    end
+    i32.const 1
+   end
+  else
+   i32.const 0
+  end
+  if
+   i32.const 0
+   i32.const 1456
+   i32.const 19
+   i32.const 5
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z> (type $i32_=>_none) (param $0 i32)
+  local.get $0
+  if (result i32)
+   local.get $0
+   i32.const 8
+   i32.sub
+   i32.load $0
+   i32.const 21
+   i32.eq
+  else
+   i32.const 0
+  end
+  if
+   i32.const 0
+   i32.const 1456
+   i32.const 19
+   i32.const 5
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $~lib/rt/__visit_members (type $i32_=>_none) (param $0 i32)
+  block $invalid
+   block $instanceof/IE
+    block $instanceof/Z
+     block $instanceof/IC
+      block $instanceof/ID
+       block $instanceof/Y
+        block $instanceof/IA
+         block $instanceof/IB
+          block $instanceof/X
+           block $instanceof/W
+            block $instanceof/BlackCat
+             block $instanceof/Cat
+              block $instanceof/Animal
+               block $instanceof/SomethingElse<i32>
+                block $instanceof/Parent<f32>
+                 block $instanceof/Child<f32>
+                  block $instanceof/Parent<i32>
+                   block $instanceof/Child<i32>
+                    block $instanceof/B
+                     block $instanceof/A
+                      block $~lib/arraybuffer/ArrayBufferView
+                       block $~lib/string/String
+                        block $~lib/arraybuffer/ArrayBuffer
+                         block $~lib/object/Object
+                          local.get $0
+                          i32.const 8
+                          i32.sub
+                          i32.load $0
+                          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $instanceof/A $instanceof/B $instanceof/Child<i32> $instanceof/Parent<i32> $instanceof/Child<f32> $instanceof/Parent<f32> $instanceof/SomethingElse<i32> $instanceof/Animal $instanceof/Cat $instanceof/BlackCat $instanceof/W $instanceof/X $instanceof/IB $instanceof/IA $instanceof/Y $instanceof/ID $instanceof/IC $instanceof/Z $instanceof/IE $invalid
+                         end
+                         return
+                        end
+                        return
+                       end
+                       return
+                      end
+                      local.get $0
+                      i32.load $0
+                      local.tee $0
+                      if
+                       local.get $0
+                       call $byn-split-outlined-A$~lib/rt/itcms/__visit
+                      end
+                      return
+                     end
+                     return
+                    end
+                    return
+                   end
+                   return
+                  end
+                  return
+                 end
+                 return
+                end
+                return
+               end
+               return
+              end
+              return
+             end
+             return
+            end
+            return
+           end
+           return
+          end
+          return
+         end
+         return
+        end
+        return
+       end
+       return
+      end
+      return
+     end
+     return
+    end
+    return
+   end
+   return
+  end
+  unreachable
+ )
+ (func $~start (type $none_=>_none)
+  call $start:instanceof
+ )
  (func $start:instanceof (type $none_=>_none)
   (local $0 i32)
   (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 84
+  i32.const 88
   i32.sub
   global.set $~lib/memory/__stack_pointer
   block $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
    i32.const 0
-   i32.const 84
+   i32.const 88
    memory.fill $0
    memory.size $0
    i32.const 16
    i32.shl
-   i32.const 34316
+   i32.const 34352
    i32.sub
    i32.const 1
    i32.shr_u
@@ -1491,7 +1754,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1532,7 +1795,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 18
+    i32.const 41
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1541,7 +1804,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 68
+    i32.const 91
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1553,7 +1816,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1571,7 +1834,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1609,7 +1872,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1627,7 +1890,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1548
+   i32.const 1584
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1679,7 +1942,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 94
+    i32.const 117
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1716,7 +1979,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 96
+    i32.const 119
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1760,7 +2023,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 111
+    i32.const 134
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1783,7 +2046,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 112
+    i32.const 135
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1820,7 +2083,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 115
+    i32.const 138
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1843,7 +2106,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 116
+    i32.const 139
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1880,7 +2143,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 119
+    i32.const 142
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1904,7 +2167,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 120
+    i32.const 143
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1922,7 +2185,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 126
+    i32.const 149
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1958,7 +2221,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 127
+    i32.const 150
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1981,7 +2244,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 128
+    i32.const 151
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -1991,7 +2254,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 130
+    i32.const 153
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2028,7 +2291,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 131
+    i32.const 154
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2051,7 +2314,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 132
+    i32.const 155
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2061,7 +2324,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 134
+    i32.const 157
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2098,7 +2361,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 135
+    i32.const 158
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2122,7 +2385,7 @@
    if
     i32.const 0
     i32.const 1456
-    i32.const 136
+    i32.const 159
     i32.const 1
     call $~lib/builtins/abort
     unreachable
@@ -2147,125 +2410,726 @@
    i32.const 0
    i32.store $0 offset=80
    local.get $0
-   i32.const 84
-   i32.add
+   i32.const 4
+   i32.sub
    global.set $~lib/memory/__stack_pointer
-   return
-  end
-  i32.const 34336
-  i32.const 34384
-  i32.const 1
-  i32.const 1
-  call $~lib/builtins/abort
-  unreachable
- )
- (func $~lib/rt/__visit_members (type $i32_=>_none) (param $0 i32)
-  block $invalid
-   block $instanceof/BlackCat
-    block $instanceof/Cat
-     block $instanceof/Animal
-      block $instanceof/SomethingElse<i32>
-       block $instanceof/Parent<f32>
-        block $instanceof/Child<f32>
-         block $instanceof/Parent<i32>
-          block $instanceof/Child<i32>
-           block $instanceof/B
-            block $instanceof/A
-             block $~lib/arraybuffer/ArrayBufferView
-              block $~lib/string/String
-               block $~lib/arraybuffer/ArrayBuffer
-                block $~lib/object/Object
-                 local.get $0
-                 i32.const 8
-                 i32.sub
-                 i32.load $0
-                 br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $instanceof/A $instanceof/B $instanceof/Child<i32> $instanceof/Parent<i32> $instanceof/Child<f32> $instanceof/Parent<f32> $instanceof/SomethingElse<i32> $instanceof/Animal $instanceof/Cat $instanceof/BlackCat $invalid
-                end
-                return
-               end
-               return
-              end
-              return
-             end
-             local.get $0
-             i32.load $0
-             local.tee $0
-             if
-              local.get $0
-              call $byn-split-outlined-A$~lib/rt/itcms/__visit
-             end
-             return
-            end
-            return
-           end
-           return
-          end
-          return
-         end
-         return
-        end
-        return
-       end
-       return
-      end
-      return
-     end
-     return
-    end
-    return
-   end
-   return
-  end
-  unreachable
- )
- (func $~start (type $none_=>_none)
-  call $start:instanceof
- )
- (func $~lib/object/Object#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
-  global.get $~lib/memory/__stack_pointer
-  i32.const 4
-  i32.sub
-  global.set $~lib/memory/__stack_pointer
-  global.get $~lib/memory/__stack_pointer
-  i32.const 1548
-  i32.lt_s
-  if
-   i32.const 34336
-   i32.const 34384
-   i32.const 1
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  global.get $~lib/memory/__stack_pointer
-  i32.const 0
-  i32.store $0
-  local.get $0
-  i32.eqz
-  if
    global.get $~lib/memory/__stack_pointer
+   i32.const 1584
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
    i32.const 0
+   i32.store $0
+   local.get $0
+   i32.const 14
    call $~lib/rt/itcms/__new
    local.tee $0
    i32.store $0
-  end
-  global.get $~lib/memory/__stack_pointer
-  i32.const 4
-  i32.add
-  global.set $~lib/memory/__stack_pointer
-  local.get $0
- )
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   call $~lib/object/Object#constructor
+   local.tee $0
+   i32.store $0
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $0
+   global.set $instanceof/w
+   i32.const 0
+   call $instanceof/X#constructor
+   global.set $instanceof/x
+   i32.const 0
+   call $instanceof/Y#constructor
+   global.set $instanceof/y
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.sub
+   global.set $~lib/memory/__stack_pointer
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1584
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   i32.const 0
+   i32.store $0
+   local.get $0
+   i32.const 21
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store $0
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   call $instanceof/Y#constructor
+   local.tee $0
+   i32.store $0
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $0
+   global.set $instanceof/z
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/w
+   local.tee $2
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $3
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $1
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $3
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $3
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $1
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $1
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $1
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $1
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $2
+   i32.store $0 offset=84
+   local.get $2
+   if (result i32)
+    local.get $2
+    i32.const 8
+    i32.sub
+    i32.load $0
+    i32.const 14
+    i32.eq
+   else
+    i32.const 0
+   end
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1456
+    i32.const 12
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/w
+   local.tee $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicFalse<instanceof/X,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   i32.store $0 offset=84
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/x
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/X>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/y
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Y>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   global.get $instanceof/z
+   local.tee $0
+   i32.store $0 offset=84
+   local.get $0
+   call $instanceof/assertDynamicTrue<~lib/object/Object,instanceof/Z>
+   global.get $~lib/memory/__stack_pointer
+   i32.const 88
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   return
+  end
+  i32.const 34384
+  i32.const 34432
+  i32.const 1
+  i32.const 1
+  call $~lib/builtins/abort
+  unreachable
+ )
+ (func $~lib/object/Object#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1584
+  i32.lt_s
+  if
+   i32.const 34384
+   i32.const 34432
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $0
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $0
+ )
  (func $instanceof/A#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.sub
   global.set $~lib/memory/__stack_pointer
   global.get $~lib/memory/__stack_pointer
-  i32.const 1548
+  i32.const 1584
   i32.lt_s
   if
-   i32.const 34336
    i32.const 34384
+   i32.const 34432
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2300,11 +3164,11 @@
   i32.sub
   global.set $~lib/memory/__stack_pointer
   global.get $~lib/memory/__stack_pointer
-  i32.const 1548
+  i32.const 1584
   i32.lt_s
   if
-   i32.const 34336
    i32.const 34384
+   i32.const 34432
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2339,11 +3203,11 @@
   i32.sub
   global.set $~lib/memory/__stack_pointer
   global.get $~lib/memory/__stack_pointer
-  i32.const 1548
+  i32.const 1584
   i32.lt_s
   if
-   i32.const 34336
    i32.const 34384
+   i32.const 34432
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2379,11 +3243,11 @@
   i32.sub
   global.set $~lib/memory/__stack_pointer
   global.get $~lib/memory/__stack_pointer
-  i32.const 1548
+  i32.const 1584
   i32.lt_s
   if
-   i32.const 34336
    i32.const 34384
+   i32.const 34432
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2409,6 +3273,84 @@
   global.set $~lib/memory/__stack_pointer
   local.get $0
  )
+ (func $instanceof/X#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1584
+  i32.lt_s
+  if
+   i32.const 34384
+   i32.const 34432
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $0
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 15
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  call $~lib/object/Object#constructor
+  local.tee $0
+  i32.store $0
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $0
+ )
+ (func $instanceof/Y#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1584
+  i32.lt_s
+  if
+   i32.const 34384
+   i32.const 34432
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $0
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 18
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  call $instanceof/X#constructor
+  local.tee $0
+  i32.store $0
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $0
+ )
  (func $byn-split-outlined-A$~lib/rt/itcms/__visit (type $i32_=>_none) (param $0 i32)
   global.get $~lib/rt/itcms/white
   local.get $0
diff --git a/tests/compiler/instanceof.ts b/tests/compiler/instanceof.ts
index c394d51808..6c1c8db6aa 100644
--- a/tests/compiler/instanceof.ts
+++ b/tests/compiler/instanceof.ts
@@ -1,3 +1,26 @@
+function assertStaticTrue<T,U>(value: T): void {
+  if (value instanceof U) return;
+  ERROR("should be statically true");
+}
+function assertStaticFalse<T,U>(value: T): void {
+  if (!(value instanceof U)) return;
+  ERROR("should be statically false");
+}
+function assertDynamicTrue<T,U>(value: T): void {
+  if (!(value instanceof U)) {
+    var check: i32 = 0;
+    assert(false);
+  }
+  assert(isDefined(check));
+}
+function assertDynamicFalse<T,U>(value: T): void {
+  if (value instanceof U) {
+    var check: i32 = 0;
+    assert(false);
+  }
+  assert(isDefined(check));
+}
+
 class A {}
 class B extends A {}
 
@@ -150,3 +173,191 @@ assert(!(nullCat instanceof BlackCat)); // dynamic false
 assert(!(nullBlackcat instanceof Animal));   // static false
 assert(!(nullBlackcat instanceof Cat));      // dynamic false
 assert(!(nullBlackcat instanceof BlackCat)); // dynamic false
+
+// Interfaces
+
+//  IA    W
+//   |
+//  IB    IC   IE
+//   |   /
+//   X  ID
+//   | /
+//   Y
+//   |
+//   Z
+class W {}
+interface IA {}
+interface IB extends IA {}
+class X implements IB {}
+interface IC {}
+interface ID extends IC {}
+class Y extends X implements ID {}
+class Z extends Y {}
+interface IE {}
+
+let w = new W();
+let x = new X();
+let y = new Y();
+let z = new Z();
+
+// <x> instanceof Object
+
+assertStaticTrue<W,Object>(w);
+assertStaticTrue<X,Object>(x);
+assertStaticTrue<Y,Object>(y);
+assertStaticTrue<Z,Object>(z);
+
+assertStaticTrue<IA,Object>(x);
+assertStaticTrue<IB,Object>(x);
+assertStaticTrue<IA,Object>(y);
+assertStaticTrue<IB,Object>(y);
+assertStaticTrue<IC,Object>(y);
+assertStaticTrue<ID,Object>(y);
+assertStaticTrue<IA,Object>(z);
+assertStaticTrue<IB,Object>(z);
+assertStaticTrue<IC,Object>(z);
+assertStaticTrue<ID,Object>(z);
+
+// Object instanceof <x>
+
+assertDynamicTrue<Object,W>(w);
+assertDynamicTrue<Object,X>(x);
+assertDynamicTrue<Object,X>(y);
+assertDynamicTrue<Object,X>(z);
+assertDynamicTrue<Object,Y>(y);
+assertDynamicTrue<Object,Y>(z);
+assertDynamicTrue<Object,Z>(z);
+
+assertDynamicTrue<Object,IA>(x);
+assertDynamicTrue<Object,IB>(x);
+assertDynamicTrue<Object,IA>(y);
+assertDynamicTrue<Object,IB>(y);
+assertDynamicTrue<Object,IC>(y);
+assertDynamicTrue<Object,ID>(y);
+assertDynamicTrue<Object,IA>(z);
+assertDynamicTrue<Object,IB>(z);
+assertDynamicTrue<Object,IC>(z);
+assertDynamicTrue<Object,ID>(z);
+
+// <class> instanceof <class>
+
+assertStaticTrue<W,W>(w);
+assertStaticFalse<W,X>(w);
+assertStaticFalse<W,Y>(w);
+assertStaticFalse<W,Z>(w);
+assertStaticFalse<X,W>(x);
+assertStaticFalse<Y,W>(y);
+assertStaticFalse<Z,W>(z);
+
+assertStaticTrue<X,X>(x);
+assertDynamicFalse<X,Y>(x);
+assertDynamicFalse<X,Z>(x);
+assertStaticTrue<X,X>(y);
+assertDynamicTrue<X,Y>(y);
+assertDynamicFalse<X,Z>(y);
+assertStaticTrue<X,X>(z);
+assertDynamicTrue<X,Y>(z);
+assertDynamicTrue<X,Z>(z);
+
+assertStaticTrue<Y,X>(y);
+assertStaticTrue<Y,Y>(y);
+assertDynamicFalse<Y,Z>(y);
+assertStaticTrue<Y,X>(z);
+assertStaticTrue<Y,Y>(z);
+assertDynamicTrue<Y,Z>(z);
+
+assertStaticTrue<Z,X>(z);
+assertStaticTrue<Z,Y>(z);
+assertStaticTrue<Z,Z>(z);
+
+// <interface> instanceof <interface>
+
+assertDynamicFalse<IA,IC>(x);
+assertDynamicFalse<IB,IC>(x);
+assertDynamicFalse<IA,ID>(x);
+assertDynamicFalse<IB,ID>(x);
+assertStaticFalse<IA,IE>(x);
+assertStaticFalse<IB,IE>(x);
+
+assertDynamicTrue<IA,IC>(y);
+assertDynamicTrue<IB,IC>(y);
+assertDynamicTrue<IA,ID>(y);
+assertDynamicTrue<IB,ID>(y);
+assertStaticFalse<IA,IE>(y);
+assertStaticFalse<IB,IE>(y);
+
+assertDynamicTrue<IA,IC>(z);
+assertDynamicTrue<IB,IC>(z);
+assertDynamicTrue<IA,ID>(z);
+assertDynamicTrue<IB,ID>(z);
+assertStaticFalse<IA,IE>(z);
+assertStaticFalse<IB,IE>(z);
+
+// <class> instanceof <interface>
+
+assertStaticTrue<X,IA>(x);
+assertStaticTrue<X,IB>(x);
+assertDynamicFalse<X,ID>(x);
+assertDynamicFalse<X,IC>(x);
+assertStaticFalse<X,IE>(x);
+assertStaticTrue<X,IA>(y);
+assertStaticTrue<X,IB>(y);
+assertDynamicTrue<X,ID>(y);
+assertDynamicTrue<X,IC>(y);
+assertStaticFalse<X,IE>(y);
+assertStaticTrue<X,IA>(z);
+assertStaticTrue<X,IB>(z);
+assertDynamicTrue<X,ID>(z);
+assertDynamicTrue<X,IC>(z);
+assertStaticFalse<X,IE>(z);
+
+assertStaticTrue<Y,IA>(y);
+assertStaticTrue<Y,IB>(y);
+assertStaticTrue<Y,ID>(y);
+assertStaticTrue<Y,IC>(y);
+assertStaticFalse<Y,IE>(y);
+assertStaticTrue<Y,IA>(z);
+assertStaticTrue<Y,IB>(z);
+assertStaticTrue<Y,ID>(z);
+assertStaticTrue<Y,IC>(z);
+assertStaticFalse<Y,IE>(z);
+
+assertStaticTrue<Z,IA>(z);
+assertStaticTrue<Z,IB>(z);
+assertStaticTrue<Z,ID>(z);
+assertStaticTrue<Z,IC>(z);
+assertStaticFalse<Z,IE>(z);
+
+// <interface> instanceof <class>
+
+assertStaticFalse<IA,W>(x);
+assertStaticFalse<IB,W>(x);
+assertStaticFalse<IA,W>(y);
+assertStaticFalse<IB,W>(y);
+assertStaticFalse<IC,W>(y);
+assertStaticFalse<ID,W>(y);
+assertStaticFalse<IA,W>(z);
+assertStaticFalse<IB,W>(z);
+assertStaticFalse<IC,W>(z);
+assertStaticFalse<ID,W>(z);
+
+assertDynamicTrue<IA,X>(x);
+assertDynamicTrue<IB,X>(x);
+assertDynamicTrue<IA,X>(y);
+assertDynamicTrue<IB,X>(y);
+assertDynamicTrue<IA,X>(z);
+assertDynamicTrue<IB,X>(z);
+
+assertDynamicTrue<IA,Y>(y);
+assertDynamicTrue<IB,Y>(y);
+assertDynamicTrue<IC,Y>(y);
+assertDynamicTrue<ID,Y>(y);
+assertDynamicTrue<IA,Y>(z);
+assertDynamicTrue<IB,Y>(z);
+assertDynamicTrue<IC,Y>(z);
+assertDynamicTrue<ID,Y>(z);
+
+assertDynamicTrue<IA,Z>(z);
+assertDynamicTrue<IB,Z>(z);
+assertDynamicTrue<IC,Z>(z);
+assertDynamicTrue<ID,Z>(z);