--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/test/hotspot/gtest/gc/z/test_zForwardingTable.cpp	2018-06-08 19:47:00.922487616 +0200
@@ -0,0 +1,167 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * ORACLE PROPRIETARY/CONFIDENTIAL.  Use is subject to license terms.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zForwardingTable.inline.hpp"
+#include "unittest.hpp"
+
+using namespace testing;
+
+#define CAPTURE_DELIM "\n"
+#define CAPTURE1(expression) #expression << " evaluates to " << expression
+#define CAPTURE2(e0, e1)                 CAPTURE1(e0) << CAPTURE_DELIM << CAPTURE1(e1)
+
+#define CAPTURE(expression) CAPTURE1(expression)
+
+class ZForwardingTableTest : public Test {
+public:
+  // Helper functions
+
+  static bool is_power_of_2(size_t value) {
+    return ::is_power_of_2((intptr_t)value);
+  }
+
+  class SequenceToFromIndex : AllStatic {
+  public:
+    static uintptr_t even(uint32_t sequence_number) {
+      return sequence_number * 2;
+    }
+    static uintptr_t odd(uint32_t sequence_number) {
+      return even(sequence_number) + 1;
+    }
+    static uintptr_t one_to_one(uint32_t sequence_number) {
+      return sequence_number;
+    }
+  };
+
+  // Test functions
+
+  static void setup(ZForwardingTable& table) {
+    EXPECT_PRED1(is_power_of_2, table._size) << CAPTURE(table._size);
+  }
+
+  static void find_empty(ZForwardingTable& table) {
+    size_t size = table._size;
+    size_t entries_to_check = size * 2;
+
+    for (uint32_t i = 0; i < entries_to_check; i++) {
+      uintptr_t from_index = SequenceToFromIndex::one_to_one(i);
+
+      EXPECT_TRUE(table.find(from_index).is_empty()) << CAPTURE2(from_index, size);
+    }
+
+    EXPECT_TRUE(table.find(uintptr_t(-1)).is_empty()) << CAPTURE(size);
+  }
+
+  static void find_full(ZForwardingTable& table) {
+    size_t size = table._size;
+    size_t entries_to_populate = size;
+
+    // Populate
+    for (uint32_t i = 0; i < entries_to_populate; i++) {
+      uintptr_t from_index = SequenceToFromIndex::one_to_one(i);
+
+      ZForwardingTableCursor cursor;
+      ZForwardingTableEntry entry = table.find(from_index, &cursor);
+      ASSERT_TRUE(entry.is_empty()) << CAPTURE2(from_index, size);
+
+      table.insert(from_index, from_index, &cursor);
+    }
+
+    // Verify
+    for (uint32_t i = 0; i < entries_to_populate; i++) {
+      uintptr_t from_index = SequenceToFromIndex::one_to_one(i);
+
+      ZForwardingTableEntry entry = table.find(from_index);
+      ASSERT_FALSE(entry.is_empty()) << CAPTURE2(from_index, size);
+
+      ASSERT_EQ(entry.from_index(), from_index) << CAPTURE(size);
+      ASSERT_EQ(entry.to_offset(), from_index) << CAPTURE(size);
+    }
+  }
+
+  static void find_every_other(ZForwardingTable& table) {
+    size_t size = table._size;
+    size_t entries_to_populate = size / 2;
+
+    // Populate even from indices
+    for (uint32_t i = 0; i < entries_to_populate; i++) {
+      uintptr_t from_index = SequenceToFromIndex::even(i);
+
+      ZForwardingTableCursor cursor;
+      ZForwardingTableEntry entry = table.find(from_index, &cursor);
+      ASSERT_TRUE(entry.is_empty()) << CAPTURE2(from_index, size);
+
+      table.insert(from_index, from_index, &cursor);
+    }
+
+    // Verify populated even indices
+    for (uint32_t i = 0; i < entries_to_populate; i++) {
+      uintptr_t from_index = SequenceToFromIndex::even(i);
+
+      ZForwardingTableCursor cursor;
+      ZForwardingTableEntry entry = table.find(from_index, &cursor);
+      ASSERT_FALSE(entry.is_empty()) << CAPTURE2(from_index, size);
+
+      ASSERT_EQ(entry.from_index(), from_index) << CAPTURE(size);
+      ASSERT_EQ(entry.to_offset(), from_index) << CAPTURE(size);
+    }
+
+    // Verify empty odd indices
+    //
+    // This check could be done on a larger range of sequence numbers,
+    // but currently entries_to_populate is used.
+    for (uint32_t i = 0; i < entries_to_populate; i++) {
+      uintptr_t from_index = SequenceToFromIndex::odd(i);
+
+      ZForwardingTableEntry entry = table.find(from_index);
+
+      ASSERT_TRUE(entry.is_empty()) << CAPTURE2(from_index, size);
+    }
+  }
+
+  static void test(void (*function)(ZForwardingTable&), uint32_t size) {
+    // Setup
+    ZForwardingTable table;
+    table.setup(size);
+    ASSERT_FALSE(table.is_null());
+
+    // Actual test function
+    (*function)(table);
+
+    // Teardown
+    table.reset();
+    ASSERT_TRUE(table.is_null());
+  }
+
+  // Run the given function with a few different input values.
+  static void test(void (*function)(ZForwardingTable&)) {
+    test(function, 1);
+    test(function, 2);
+    test(function, 3);
+    test(function, 4);
+    test(function, 7);
+    test(function, 8);
+    test(function, 1023);
+    test(function, 1024);
+    test(function, 1025);
+  }
+};
+
+TEST_F(ZForwardingTableTest, setup) {
+  test(&ZForwardingTableTest::setup);
+}
+
+TEST_F(ZForwardingTableTest, find_empty) {
+  test(&ZForwardingTableTest::find_empty);
+}
+
+TEST_F(ZForwardingTableTest, find_full) {
+  test(&ZForwardingTableTest::find_full);
+}
+
+TEST_F(ZForwardingTableTest, find_every_other) {
+  test(&ZForwardingTableTest::find_every_other);
+}