--- /dev/null	2019-12-04 18:44:18.020007537 +0000
+++ new/test/jdk/java/foreign/TestMemoryAlignment.java	2019-12-09 18:15:53.236423905 +0000
@@ -0,0 +1,136 @@
+/*
+ *  Copyright (c) 2019, 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
+ * @run testng TestMemoryAlignment
+ */
+
+import jdk.incubator.foreign.MemoryLayouts;
+import jdk.incubator.foreign.MemoryLayout;
+
+import jdk.incubator.foreign.GroupLayout;
+import jdk.incubator.foreign.MemoryLayout.PathElement;
+import jdk.incubator.foreign.MemoryAddress;
+import jdk.incubator.foreign.MemorySegment;
+import jdk.incubator.foreign.SequenceLayout;
+import jdk.incubator.foreign.ValueLayout;
+import java.lang.invoke.VarHandle;
+import java.util.stream.LongStream;
+
+import org.testng.annotations.*;
+import static org.testng.Assert.*;
+
+public class TestMemoryAlignment {
+
+    @Test(dataProvider = "alignments")
+    public void testAlignedAccess(long align) {
+        ValueLayout layout = MemoryLayouts.BITS_32_BE;
+        assertEquals(layout.bitAlignment(), 32);
+        ValueLayout aligned = layout.withBitAlignment(align);
+        assertEquals(aligned.bitAlignment(), align); //unreasonable alignment here, to make sure access throws
+        VarHandle vh = aligned.varHandle(int.class);
+        try (MemorySegment segment = MemorySegment.allocateNative(aligned)) {
+            MemoryAddress addr = segment.baseAddress();
+            vh.set(addr, -42);
+            int val = (int)vh.get(addr);
+            assertEquals(val, -42);
+        }
+    }
+
+    @Test(dataProvider = "alignments")
+    public void testUnalignedAccess(long align) {
+        ValueLayout layout = MemoryLayouts.BITS_32_BE;
+        assertEquals(layout.bitAlignment(), 32);
+        ValueLayout aligned = layout.withBitAlignment(align);
+        MemoryLayout alignedGroup = MemoryLayout.ofStruct(MemoryLayouts.PAD_8, aligned);
+        assertEquals(alignedGroup.bitAlignment(), align);
+        VarHandle vh = aligned.varHandle(int.class);
+        try (MemorySegment segment = MemorySegment.allocateNative(alignedGroup)) {
+            MemoryAddress addr = segment.baseAddress();
+            vh.set(addr.offset(1L), -42);
+            assertEquals(align, 8); //this is the only case where access is aligned
+        } catch (IllegalStateException ex) {
+            assertNotEquals(align, 8); //if align != 8, access is always unaligned
+        }
+    }
+
+    @Test(dataProvider = "alignments")
+    public void testUnalignedPath(long align) {
+        MemoryLayout layout = MemoryLayouts.BITS_32_BE;
+        MemoryLayout aligned = layout.withBitAlignment(align).withName("value");
+        GroupLayout alignedGroup = MemoryLayout.ofStruct(MemoryLayouts.PAD_8, aligned);
+        try {
+            alignedGroup.varHandle(int.class, PathElement.groupElement("value"));
+            assertEquals(align, 8); //this is the only case where path is aligned
+        } catch (UnsupportedOperationException ex) {
+            assertNotEquals(align, 8); //if align != 8, path is always unaligned
+        }
+    }
+
+    @Test(dataProvider = "alignments")
+    public void testUnalignedSequence(long align) {
+        SequenceLayout layout = MemoryLayout.ofSequence(5, MemoryLayouts.BITS_32_BE.withBitAlignment(align));
+        VarHandle vh = layout.varHandle(int.class, PathElement.sequenceElement());
+        try (MemorySegment segment = MemorySegment.allocateNative(layout)) {
+            MemoryAddress addr = segment.baseAddress();
+            for (long i = 0 ; i < 5 ; i++) {
+                vh.set(addr, i, -42);
+            }
+            assertTrue(align <= 32); //if align <= 32, access is always aligned
+        } catch (IllegalStateException ex) {
+            assertTrue(align > 32); //if align > 32, access is always unaligned (for some elements)
+        }
+    }
+
+    @Test
+    public void testPackedAccess() {
+        ValueLayout vChar = MemoryLayouts.BITS_8_BE;
+        ValueLayout vShort = MemoryLayouts.BITS_16_BE;
+        ValueLayout vInt = MemoryLayouts.BITS_32_BE;
+        //mimic pragma pack(1)
+        GroupLayout g = MemoryLayout.ofStruct(vChar.withBitAlignment(8).withName("a"),
+                               vShort.withBitAlignment(8).withName("b"),
+                               vInt.withBitAlignment(8).withName("c"));
+        assertEquals(g.bitAlignment(), 8);
+        VarHandle vh_c = g.varHandle(byte.class, PathElement.groupElement("a"));
+        VarHandle vh_s = g.varHandle(short.class, PathElement.groupElement("b"));
+        VarHandle vh_i = g.varHandle(int.class, PathElement.groupElement("c"));
+        try (MemorySegment segment = MemorySegment.allocateNative(g)) {
+            MemoryAddress addr = segment.baseAddress();
+            vh_c.set(addr, Byte.MIN_VALUE);
+            assertEquals(vh_c.get(addr), Byte.MIN_VALUE);
+            vh_s.set(addr, Short.MIN_VALUE);
+            assertEquals(vh_s.get(addr), Short.MIN_VALUE);
+            vh_i.set(addr, Integer.MIN_VALUE);
+            assertEquals(vh_i.get(addr), Integer.MIN_VALUE);
+        }
+    }
+
+    @DataProvider(name = "alignments")
+    public Object[][] createAlignments() {
+        return LongStream.range(3, 32)
+                .mapToObj(v -> new Object[] { 1L << v })
+                .toArray(Object[][]::new);
+    }
+}