--- /dev/null	2017-05-05 06:40:48.273288351 -0700
+++ new/test/hotspot/jtreg/runtime/valhalla/valuetypes/consistency/ConsistencyTest.java	2018-07-18 10:23:20.087871992 -0700
@@ -0,0 +1,290 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @summary Test for value types consistency checks
+ *
+ * @comment CASE [A] ConsistencyTest.java uses Point as a VT, but Mismatched.java uses Point as a POJO Type.
+ * @compile -XDenableValueTypes -XDallowFlattenabilityModifiers  ConsistencyTest.java POJOPoint.java Mismatched.java
+ * @compile -XDenableValueTypes -XDallowFlattenabilityModifiers  ConsistencyTest.java ValuePoint.java
+ * @run main/othervm -Xint  -XX:+EnableValhalla ConsistencyTest
+ * @run main/othervm -Xcomp -XX:+EnableValhalla ConsistencyTest
+ *
+ * @comment CASE [B] ConsistencyTest.java uses Point as a POJO Type, but Mismatched.java uses Point as a VT.
+ * @compile -XDenableValueTypes -XDallowFlattenabilityModifiers  ConsistencyTest.java ValuePoint.java Mismatched.java
+ * @compile -XDenableValueTypes -XDallowFlattenabilityModifiers  ConsistencyTest.java POJOPoint.java
+ * @run main/othervm -Xint  -XX:+EnableValhalla ConsistencyTest
+ * @run main/othervm -Xcomp -XX:+EnableValhalla ConsistencyTest
+ */
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.invoke.*;
+import java.lang.reflect.*;
+import java.util.*;
+
+
+// !!! NOTE !!!
+// ConsistentTest.java and Mismatched.java are compiled separately, such that the classes in the two files
+// will have the exact opposite understanding of whether Point is a VT.
+
+// Each test case for ConsistencyTest is written as a separate class, which must have exactly
+// one of the following 3 annotations: @NegativeTest, @PositiveTest or @LegacyPositiveTest.
+
+// The test case must always fail with an ICCE.
+@Retention(RetentionPolicy.RUNTIME)
+@interface NegativeTest {}
+
+// The test case must always succeed.
+@Retention(RetentionPolicy.RUNTIME)
+@interface PositiveTest {}
+
+// The test case is for a "legacy" class, which doesn't know that Point is a VT. Some
+// operations by such legacy classes are allowed (such as declaring, but not using, a method
+// whose signature includes LPoint;). See LocalMethod in Mismatched.java for an example
+@Retention(RetentionPolicy.RUNTIME)
+@interface LegacyPositiveTest {}
+
+public class ConsistencyTest {
+    public static void main(String[] args) {
+        // Resolve this class now, before some of the test classes try to declare
+        // a field or parameter of this type.
+        Class pointClass = Point.class;
+        boolean isVT = pointClass.isValue();
+        System.out.println("Is class " + pointClass + " a ValueType? " + (isVT ? "YES" : "NO"));
+
+        // Run with "jtreg -DNonVTOnly ConsistencyTest.java", etc, to select a test scenario.
+        if (isVT && (System.getProperty("NonVTOnly") != null)) {
+            System.out.println("-DNonVTOnly is specified. Test skipped");
+            return;
+        }
+        if (!isVT && (System.getProperty("VTOnly") != null)) {
+            System.out.println("-DVTOnly is specified. Test skipped");
+            return;
+        }
+
+        test(
+             "InvokeMethodHandle",
+             "FlattenableField",
+             "NotFlattenableField",
+             "NotFlattenableStaticField",
+             "ValueArrayField",
+             "ResolveClass",
+             "ResolveArray",
+             "ResolveMultiArray",
+             "ResolveMethod",
+             "LocalMethod",
+             "LocalMethodWithArray",
+             "LocalOverridingMethod",
+             "LocalOverridingDefaultMethod",
+             "RemoteMethod",
+             "RemoteMethodNull",
+             "RemoteMethodWithArray",
+             "BothWrongRemoteMethod");
+    }
+    
+    public static void test(String...tests) {
+        List<String> failed = new ArrayList<>();
+        List<Throwable> exceptions = new ArrayList<>();
+        Arrays.sort(tests);
+
+	for (String name : tests) {
+            try {
+                testOne(name);
+            } catch (Throwable t) {
+                failed.add(name);
+                exceptions.add(t);
+            }
+        }
+        if (failed.size() > 0) {
+            System.out.println("-----------------------------------------");
+            for (int i=0; i<failed.size(); i++) {
+                String name = failed.get(i);
+                Throwable t = exceptions.get(i);
+                System.out.println("*** FAILED: " + name);
+                t.printStackTrace(System.out);
+            }
+
+            if (System.getProperty("IgnoreFailures") != null) {
+                System.out.println("-DIgnoreFailures is specified -- I am ignoring the failures so you can test other scenarios");
+            } else {
+                throw new RuntimeException(failed.size() + " test case(s) have failed");
+            }
+        }
+    }
+
+    static void testOne(String name) {
+        System.out.println("Testing " + name);
+        Class c;
+        Method m;
+        try {
+            c = Class.forName(name);
+            m = c.getMethod("run");
+        } catch (IncompatibleClassChangeError  e) {
+            // If you are testing a class that's suppose to throw an ICCE during class
+            // loading, do that in a helper class. See LocalOverridingMethod for an example.
+            throw new RuntimeException("Unexpected IncompatibleClassChangeError. Please use a helper class.", e);
+        } catch (ClassNotFoundException | NoSuchMethodException e) {
+            throw new RuntimeException("Unexpected Exception", e);
+        }
+        
+        int count = 0;
+        Throwable ICCE = null;
+        boolean expectICCE = false;
+        if (c.getAnnotation(NegativeTest.class) != null) {
+            count ++;
+            expectICCE = true;
+        }
+        if (c.getAnnotation(PositiveTest.class) != null) {
+            count ++;
+            expectICCE = false;
+        }
+        if (c.getAnnotation(LegacyPositiveTest.class) != null) {
+            count ++;
+            if (!Point.class.isValue()) {
+                // The classes in this file think that Point is NOT a VT.
+                // We have loaded a Point class that is NOT a VT.
+                // - however -
+                // In this test case, are calling a class X (defined in Mismatched.java)
+                // that uses Point as a VT. The operation in X must fail with an ICCE.
+                expectICCE = true;
+            } else {
+                expectICCE = false;
+            }
+        }
+        if (count != 1) {
+            throw new RuntimeException("Class " + name + " must have exactly one annotation of" +
+                                       " @NegativeTest, @PositiveTest, or @LegacyPositiveTest");
+        }
+
+        try {
+            m.invoke(null);
+        } catch (IllegalAccessException | IllegalArgumentException e) {
+            throw new RuntimeException("Unexpected Exception", e);
+        } catch (InvocationTargetException e) {
+            Throwable t = e.getCause();
+            while (t != null) {
+                if (t instanceof IncompatibleClassChangeError) {
+                    ICCE = t;
+                }
+                t = t.getCause();
+            }
+        }
+
+        if (ICCE != null) {
+            if (!expectICCE) {
+                ICCE.printStackTrace();
+                throw new RuntimeException("FAILED: " + name + " received ICCE unexpectedly", ICCE);
+            }
+            System.out.println("    ICCE = " + ICCE);
+        }
+        if  (ICCE == null) {
+            if (expectICCE) {
+                throw new RuntimeException("FAILED: " + name + " did not receive ICCE as expected");
+            }
+            System.out.println("    ICCE = <none>");
+        }
+    }
+}
+
+// This class has a *correct* notion of whether Point is a VT
+class CorrectProvider {
+    static __NotFlattened Point p; // to get a null value
+
+    static Point getPoint() {
+        return Point.createPoint();
+    }
+    static Point getNullPoint() {
+        return p;
+    }
+    static Point[] getPointArray() {
+        return new Point[10];
+    }
+}
+
+//----------------------------------------------------------------------
+// Here are the test cases. More test cases are in Mismatched.java
+//----------------------------------------------------------------------
+
+// It must not be possible to override a method with a mismatched type
+@NegativeTest
+class LocalOverridingMethod {
+    static class Helper extends Parent {
+        Point foo() {
+            return Point.createPoint();
+        }
+    }
+    public static void run() {
+        new Helper();
+    }
+}
+
+// It must not be possible to override a default method with a mismatched type
+@NegativeTest
+class LocalOverridingDefaultMethod {
+    static class Helper implements InterfaceWithDefault {
+        public Point foo() {
+            return Point.createPoint();
+        }
+    }
+    public static void run() {
+        new Helper();
+    }
+}
+
+// Cannot call a method whose signature contains a mismatched VT.
+@NegativeTest
+class RemoteMethod {
+    public static void run() {
+	Point p = Provider.getPoint();
+    }
+}
+
+// Cannot call a method whose parameter is a mismatched VT, even if you are passing null.
+@NegativeTest
+class RemoteMethodNull {
+    static __NotFlattened Point p; // to get a null value
+    public static void run() {
+	Provider.processPoint(p);
+    }
+}
+
+// Cannot call a method whose signature contains an array of a mismatched VT, even if you are passing null.
+@NegativeTest
+class RemoteMethodWithArray {
+    public static void run() {
+	Provider.foo(null);
+    }
+}
+
+// You shouldn't be able to invoke a method defined by a class who has a different idea of whether Point is VT.
+@NegativeTest
+class InvokeMethodHandle {
+    public static void run() throws Throwable {
+        MethodHandles.Lookup lookup = MethodHandles.lookup();
+        MethodType mt = MethodType.methodType(Point.class);
+        MethodHandle mh = lookup.findStatic(CorrectProvider.class, "getNullPoint", mt);
+        InvokeMethodHandle_mismatched.test(mh);
+    }
+}
--- /dev/null	2017-05-05 06:40:48.273288351 -0700
+++ new/test/hotspot/jtreg/runtime/valhalla/valuetypes/consistency/Mismatched.java	2018-07-18 10:23:21.255916746 -0700
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.lang.invoke.*;
+
+class Parent {
+    Point foo() {
+	return Point.createPoint();
+    }
+}
+
+interface InterfaceWithDefault {
+    default Point foo() {
+        return Point.createPoint();
+    }
+}
+
+class Provider {
+    static Point getPoint() {
+	return Point.createPoint();
+    }
+    static void foo(Point[] array) { }
+
+    static void processPoint(Point p) { }
+}
+
+// It's OK to declare a Flattenable field of a mismatched type, but only from a legacy class that doesn't know Point is a VT.
+@LegacyPositiveTest
+class FlattenableField {
+    static class Helper {
+        // test assumes __Flattenable is the default for non static fields
+        Point p;
+    }
+    public static void run() {
+        // Helper will fail to load if it's not a legacy class (i.e., it declares that Point is a VT, but
+        // point ends up not being a VT.
+        new Helper();
+    }
+}
+
+// It's OK to declare a NonFlattenable field of a mismatched type
+@PositiveTest
+class NotFlattenableField {
+    __NotFlattened Point p;
+    public static void run() {};
+}
+
+// It's OK to declare a NonFlattenable static field of a mismatched type
+@PositiveTest
+class NotFlattenableStaticField {
+    __NotFlattened static Point p;
+    public static void run() {}
+}
+
+// It's OK to declare a NonFlattenable static field of a mismatched type
+@PositiveTest
+class ValueArrayField {
+    Point[]  p;
+    public static void run() {};
+}
+
+// Cannot resolve the Point class if your idea of whether it's a ValueType is wrong.
+@NegativeTest
+class ResolveClass {
+    public static void run() {
+        Class c = Point.class;
+	//TODO Point p = Point.createPoint();
+    }
+}
+
+// It's NOT OK to resolve the array class of Point even if your idea of whether it's a ValueType is wrong.
+@NegativeTest
+class ResolveArray {
+    public static void run() {
+	Point[] array = new Point[5];
+    }
+}
+
+// Yet it's OK to resolve a higher-dimensional array class of Point even if your idea of whether it's a ValueType is wrong. (BUG??)
+@PositiveTest
+class ResolveMultiArray {
+    public static void run() {
+	Point[][] array = new Point[5][4];
+    }
+}
+
+// Cannot resolve a method in the Point class if your idea of whether it's a ValueType is wrong.
+@NegativeTest
+class ResolveMethod {
+    public static void run() {
+	Point.createPoint();
+    }
+}
+
+// It's OK for a legacy class to declare (but not use) a method whose signature contains a mismatched VT.
+@LegacyPositiveTest
+class LocalMethod {
+    static class Helper {
+        Point foo() {
+            return Point.createPoint();
+        }
+    }
+    public static void run() {
+        new Helper();
+    }
+}
+
+// It's OK for a legacy class to declare (but not use) a method whose signature contains a array of a mismatched VT.
+@LegacyPositiveTest
+class LocalMethodWithArray {
+    static class Helper {
+        void foo(Point[] array) { }
+    }
+    public static void run() {
+        new Helper();
+    }
+}
+
+
+// Two legacy classes can call each other's methods, as long as both of them
+// have the wrong understanding of whether Point is a VT.
+@LegacyPositiveTest
+class BothWrongRemoteMethod {
+    static __NotFlattened Point p; // to get a null value
+    public static void run() {
+	Provider.processPoint(p);
+    }
+}
+
+// helper class used by InvokeMethodHandle (defined in ConsistencyTest.java).
+class InvokeMethodHandle_mismatched {
+    static void test(MethodHandle mh) throws Throwable {
+        Point p = (Point)mh.invoke();
+        System.out.println("(should not get here) Point = " + p);
+    }
+}
--- /dev/null	2017-05-05 06:40:48.273288351 -0700
+++ new/test/hotspot/jtreg/runtime/valhalla/valuetypes/consistency/POJOPoint.java	2018-07-18 10:23:22.431961806 -0700
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// Point is a plain-old-java-object Type.
+class Point {
+    final int x;
+    final int y;
+
+    public int getX() { return x; }
+    public int getY() { return y; }
+
+    public static Point createPoint() {
+	return new Point();
+    }
+    
+    public Point() {
+	x = 0;
+	y = 0;
+    }
+}
--- /dev/null	2017-05-05 06:40:48.273288351 -0700
+++ new/test/hotspot/jtreg/runtime/valhalla/valuetypes/consistency/ValuePoint.java	2018-07-18 10:23:23.736011771 -0700
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// Point is a Value Type.
+__ByValue final class Point {
+    final int x;
+    final int y;
+
+    private Point() {
+        x = 0;
+        y = 0;
+    }
+
+    public int getX() { return x; }
+    public int getY() { return y; }
+
+    public static Point createPoint() {
+        Point p = __MakeDefault Point();
+        return p;
+    }
+}