Revert of Embedded constant pools.

test/cctest/test-constantpool.cc

-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Test embedded constant pool builder code.
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test constant pool array code.
 
 #include "src/v8.h"
 
-#include "src/assembler.h"
+#include "src/factory.h"
+#include "src/objects.h"
 #include "test/cctest/cctest.h"
 
 using namespace v8::internal;
 
-const ConstantPoolEntry::Type kPtrType = ConstantPoolEntry::INTPTR;
-const ConstantPoolEntry::Type kDblType = ConstantPoolEntry::DOUBLE;
-const ConstantPoolEntry::Access kRegAccess = ConstantPoolEntry::REGULAR;
-const ConstantPoolEntry::Access kOvflAccess = ConstantPoolEntry::OVERFLOWED;
-
-const int kReachBits = 6;  // Use reach of 64-bytes to test overflow.
-const int kReach = 1 << kReachBits;
-
-
-TEST(ConstantPoolPointers) {
-  ConstantPoolBuilder builder(kReachBits, kReachBits);
-  const int kRegularCount = kReach / kPointerSize;
-  ConstantPoolEntry::Access access;
-  int pos = 0;
-  intptr_t value = 0;
-  bool sharing_ok = true;
-
-  CHECK(builder.IsEmpty());
-  while (builder.NextAccess(kPtrType) == kRegAccess) {
-    access = builder.AddEntry(pos++, value++, sharing_ok);
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(pos, kRegularCount);
-
-  access = builder.AddEntry(pos, value, sharing_ok);
-  CHECK_EQ(access, kOvflAccess);
-}
-
-
-TEST(ConstantPoolDoubles) {
-  ConstantPoolBuilder builder(kReachBits, kReachBits);
-  const int kRegularCount = kReach / kDoubleSize;
-  ConstantPoolEntry::Access access;
-  int pos = 0;
-  double value = 0.0;
-
-  CHECK(builder.IsEmpty());
-  while (builder.NextAccess(kDblType) == kRegAccess) {
-    access = builder.AddEntry(pos++, value);
-    value += 0.5;
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(pos, kRegularCount);
-
-  access = builder.AddEntry(pos, value);
-  CHECK_EQ(access, kOvflAccess);
-}
-
-
-TEST(ConstantPoolMixedTypes) {
-  ConstantPoolBuilder builder(kReachBits, kReachBits);
-  const int kRegularCount = (((kReach / (kDoubleSize + kPointerSize)) * 2) +
-                             ((kPointerSize < kDoubleSize) ? 1 : 0));
-  ConstantPoolEntry::Type type = kPtrType;
-  ConstantPoolEntry::Access access;
-  int pos = 0;
-  intptr_t ptrValue = 0;
-  double dblValue = 0.0;
-  bool sharing_ok = true;
-
-  CHECK(builder.IsEmpty());
-  while (builder.NextAccess(type) == kRegAccess) {
-    if (type == kPtrType) {
-      access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-      type = kDblType;
+static ConstantPoolArray::Type kTypes[] = { ConstantPoolArray::INT64,
+                                            ConstantPoolArray::CODE_PTR,
+                                            ConstantPoolArray::HEAP_PTR,
+                                            ConstantPoolArray::INT32 };
+static ConstantPoolArray::LayoutSection kSmall =
+    ConstantPoolArray::SMALL_SECTION;
+static ConstantPoolArray::LayoutSection kExtended =
+    ConstantPoolArray::EXTENDED_SECTION;
+
+Code* DummyCode(LocalContext* context) {
+  CompileRun("function foo() {};");
+  i::Handle<i::JSFunction> fun = v8::Utils::OpenHandle(
+      *v8::Local<v8::Function>::Cast(
+          (*context)->Global()->Get(v8_str("foo"))));
+  return fun->code();
+}
+
+
+TEST(ConstantPoolSmall) {
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  // Check construction.
+  ConstantPoolArray::NumberOfEntries small(3, 1, 2, 1);
+  Handle<ConstantPoolArray> array = factory->NewConstantPoolArray(small);
+
+  int expected_counts[] = { 3, 1, 2, 1 };
+  int expected_first_idx[] = { 0, 3, 4, 6 };
+  int expected_last_idx[] = { 2, 3, 5, 6 };
+  for (int i = 0; i < 4; i++) {
+    CHECK_EQ(expected_counts[i], array->number_of_entries(kTypes[i], kSmall));
+    CHECK_EQ(expected_first_idx[i], array->first_index(kTypes[i], kSmall));
+    CHECK_EQ(expected_last_idx[i], array->last_index(kTypes[i], kSmall));
+  }
+  CHECK(!array->is_extended_layout());
+
+  // Check getters and setters.
+  int64_t big_number = V8_2PART_UINT64_C(0x12345678, 9ABCDEF0);
+  Handle<Object> object = factory->NewHeapNumber(4.0, IMMUTABLE, TENURED);
+  Code* code = DummyCode(&context);
+  array->set(0, big_number);
+  array->set(1, 0.5);
+  array->set(2, 3e-24);
+  array->set(3, code->entry());
+  array->set(4, code);
+  array->set(5, *object);
+  array->set(6, 50);
+  CHECK_EQ(big_number, array->get_int64_entry(0));
+  CHECK_EQ(0.5, array->get_int64_entry_as_double(1));
+  CHECK_EQ(3e-24, array->get_int64_entry_as_double(2));
+  CHECK_EQ(code->entry(), array->get_code_ptr_entry(3));
+  CHECK_EQ(code, array->get_heap_ptr_entry(4));
+  CHECK_EQ(*object, array->get_heap_ptr_entry(5));
+  CHECK_EQ(50, array->get_int32_entry(6));
+}
+
+
+TEST(ConstantPoolExtended) {
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  // Check construction.
+  ConstantPoolArray::NumberOfEntries small(1, 2, 3, 4);
+  ConstantPoolArray::NumberOfEntries extended(5, 6, 7, 8);
+  Handle<ConstantPoolArray> array =
+      factory->NewExtendedConstantPoolArray(small, extended);
+
+  // Check small section.
+  int small_counts[] = { 1, 2, 3, 4 };
+  int small_first_idx[] = { 0, 1, 3, 6 };
+  int small_last_idx[] = { 0, 2, 5, 9 };
+  for (int i = 0; i < 4; i++) {
+    CHECK_EQ(small_counts[i], array->number_of_entries(kTypes[i], kSmall));
+    CHECK_EQ(small_first_idx[i], array->first_index(kTypes[i], kSmall));
+    CHECK_EQ(small_last_idx[i], array->last_index(kTypes[i], kSmall));
+  }
+
+  // Check extended layout.
+  CHECK(array->is_extended_layout());
+  int extended_counts[] = { 5, 6, 7, 8 };
+  int extended_first_idx[] = { 10, 15, 21, 28 };
+  int extended_last_idx[] = { 14, 20, 27, 35 };
+  for (int i = 0; i < 4; i++) {
+    CHECK_EQ(extended_counts[i],
+             array->number_of_entries(kTypes[i], kExtended));
+    CHECK_EQ(extended_first_idx[i], array->first_index(kTypes[i], kExtended));
+    CHECK_EQ(extended_last_idx[i], array->last_index(kTypes[i], kExtended));
+  }
+
+  // Check small and large section's don't overlap.
+  int64_t small_section_int64 = V8_2PART_UINT64_C(0x56781234, DEF09ABC);
+  Code* small_section_code_ptr = DummyCode(&context);
+  Handle<Object> small_section_heap_ptr =
+      factory->NewHeapNumber(4.0, IMMUTABLE, TENURED);
+  int32_t small_section_int32 = 0xab12cd45;
+
+  int64_t extended_section_int64 = V8_2PART_UINT64_C(0x12345678, 9ABCDEF0);
+  Code* extended_section_code_ptr = DummyCode(&context);
+  Handle<Object> extended_section_heap_ptr =
+      factory->NewHeapNumber(5.0, IMMUTABLE, TENURED);
+  int32_t extended_section_int32 = 0xef67ab89;
+
+  for (int i = array->first_index(ConstantPoolArray::INT64, kSmall);
+       i <= array->last_index(ConstantPoolArray::INT32, kSmall); i++) {
+    if (i <= array->last_index(ConstantPoolArray::INT64, kSmall)) {
+      array->set(i, small_section_int64);
+    } else if (i <= array->last_index(ConstantPoolArray::CODE_PTR, kSmall)) {
+      array->set(i, small_section_code_ptr->entry());
+    } else if (i <= array->last_index(ConstantPoolArray::HEAP_PTR, kSmall)) {
+      array->set(i, *small_section_heap_ptr);
     } else {
-      access = builder.AddEntry(pos++, dblValue);
-      dblValue += 0.5;
-      type = kPtrType;
+      CHECK(i <= array->last_index(ConstantPoolArray::INT32, kSmall));
+      array->set(i, small_section_int32);
     }
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(pos, kRegularCount);
-
-  access = builder.AddEntry(pos++, ptrValue, sharing_ok);
-  CHECK_EQ(access, kOvflAccess);
-  access = builder.AddEntry(pos, dblValue);
-  CHECK_EQ(access, kOvflAccess);
-}
-
-
-TEST(ConstantPoolMixedReach) {
-  const int ptrReachBits = kReachBits + 2;
-  const int ptrReach = 1 << ptrReachBits;
-  const int dblReachBits = kReachBits;
-  const int dblReach = kReach;
-  const int dblRegularCount =
-      Min(dblReach / kDoubleSize, ptrReach / (kDoubleSize + kPointerSize));
-  const int ptrRegularCount =
-      ((ptrReach - (dblRegularCount * (kDoubleSize + kPointerSize))) /
-       kPointerSize) +
-      dblRegularCount;
-  ConstantPoolBuilder builder(ptrReachBits, dblReachBits);
-  ConstantPoolEntry::Access access;
-  int pos = 0;
-  intptr_t ptrValue = 0;
-  double dblValue = 0.0;
-  bool sharing_ok = true;
-  int ptrCount = 0;
-  int dblCount = 0;
-
-  CHECK(builder.IsEmpty());
-  while (builder.NextAccess(kDblType) == kRegAccess) {
-    access = builder.AddEntry(pos++, dblValue);
-    dblValue += 0.5;
-    dblCount++;
-    CHECK_EQ(access, kRegAccess);
-
-    access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-    ptrCount++;
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(dblCount, dblRegularCount);
-
-  while (ptrCount < ptrRegularCount) {
-    access = builder.AddEntry(pos++, dblValue);
-    dblValue += 0.5;
-    CHECK_EQ(access, kOvflAccess);
-
-    access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-    ptrCount++;
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK_EQ(builder.NextAccess(kPtrType), kOvflAccess);
-
-  access = builder.AddEntry(pos++, ptrValue, sharing_ok);
-  CHECK_EQ(access, kOvflAccess);
-  access = builder.AddEntry(pos, dblValue);
-  CHECK_EQ(access, kOvflAccess);
-}
-
-
-TEST(ConstantPoolSharing) {
-  ConstantPoolBuilder builder(kReachBits, kReachBits);
-  const int kRegularCount = (((kReach / (kDoubleSize + kPointerSize)) * 2) +
-                             ((kPointerSize < kDoubleSize) ? 1 : 0));
-  ConstantPoolEntry::Access access;
-
-  CHECK(builder.IsEmpty());
-
-  ConstantPoolEntry::Type type = kPtrType;
-  int pos = 0;
-  intptr_t ptrValue = 0;
-  double dblValue = 0.0;
-  bool sharing_ok = true;
-  while (builder.NextAccess(type) == kRegAccess) {
-    if (type == kPtrType) {
-      access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-      type = kDblType;
+  }
+  for (int i = array->first_index(ConstantPoolArray::INT64, kExtended);
+       i <= array->last_index(ConstantPoolArray::INT32, kExtended); i++) {
+    if (i <= array->last_index(ConstantPoolArray::INT64, kExtended)) {
+      array->set(i, extended_section_int64);
+    } else if (i <= array->last_index(ConstantPoolArray::CODE_PTR, kExtended)) {
+      array->set(i, extended_section_code_ptr->entry());
+    } else if (i <= array->last_index(ConstantPoolArray::HEAP_PTR, kExtended)) {
+      array->set(i, *extended_section_heap_ptr);
     } else {
-      access = builder.AddEntry(pos++, dblValue);
-      dblValue += 0.5;
-      type = kPtrType;
+      CHECK(i <= array->last_index(ConstantPoolArray::INT32, kExtended));
+      array->set(i, extended_section_int32);
     }
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(pos, kRegularCount);
-
-  type = kPtrType;
-  ptrValue = 0;
-  dblValue = 0.0;
-  while (pos < kRegularCount * 2) {
-    if (type == kPtrType) {
-      access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-      type = kDblType;
+  }
+
+  for (int i = array->first_index(ConstantPoolArray::INT64, kSmall);
+       i <= array->last_index(ConstantPoolArray::INT32, kSmall); i++) {
+    if (i <= array->last_index(ConstantPoolArray::INT64, kSmall)) {
+      CHECK_EQ(small_section_int64, array->get_int64_entry(i));
+    } else if (i <= array->last_index(ConstantPoolArray::CODE_PTR, kSmall)) {
+      CHECK_EQ(small_section_code_ptr->entry(), array->get_code_ptr_entry(i));
+    } else if (i <= array->last_index(ConstantPoolArray::HEAP_PTR, kSmall)) {
+      CHECK_EQ(*small_section_heap_ptr, array->get_heap_ptr_entry(i));
     } else {
-      access = builder.AddEntry(pos++, dblValue);
-      dblValue += 0.5;
-      type = kPtrType;
+      CHECK(i <= array->last_index(ConstantPoolArray::INT32, kSmall));
+      CHECK_EQ(small_section_int32, array->get_int32_entry(i));
     }
-    CHECK_EQ(access, kRegAccess);
-  }
-
-  access = builder.AddEntry(pos++, ptrValue, sharing_ok);
-  CHECK_EQ(access, kOvflAccess);
-  access = builder.AddEntry(pos, dblValue);
-  CHECK_EQ(access, kOvflAccess);
-}
-
-
-TEST(ConstantPoolNoSharing) {
-  ConstantPoolBuilder builder(kReachBits, kReachBits);
-  const int kRegularCount = (((kReach / (kDoubleSize + kPointerSize)) * 2) +
-                             ((kPointerSize < kDoubleSize) ? 1 : 0));
-  ConstantPoolEntry::Access access;
-
-  CHECK(builder.IsEmpty());
-
-  ConstantPoolEntry::Type type = kPtrType;
-  int pos = 0;
-  intptr_t ptrValue = 0;
-  double dblValue = 0.0;
-  bool sharing_ok = false;
-  while (builder.NextAccess(type) == kRegAccess) {
-    if (type == kPtrType) {
-      access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-      type = kDblType;
+  }
+  for (int i = array->first_index(ConstantPoolArray::INT64, kExtended);
+       i <= array->last_index(ConstantPoolArray::INT32, kExtended); i++) {
+    if (i <= array->last_index(ConstantPoolArray::INT64, kExtended)) {
+      CHECK_EQ(extended_section_int64, array->get_int64_entry(i));
+    } else if (i <= array->last_index(ConstantPoolArray::CODE_PTR, kExtended)) {
+      CHECK_EQ(extended_section_code_ptr->entry(),
+               array->get_code_ptr_entry(i));
+    } else if (i <= array->last_index(ConstantPoolArray::HEAP_PTR, kExtended)) {
+      CHECK_EQ(*extended_section_heap_ptr, array->get_heap_ptr_entry(i));
     } else {
-      access = builder.AddEntry(pos++, dblValue);
-      dblValue += 0.5;
-      type = kPtrType;
+      CHECK(i <= array->last_index(ConstantPoolArray::INT32, kExtended));
+      CHECK_EQ(extended_section_int32, array->get_int32_entry(i));
     }
-    CHECK_EQ(access, kRegAccess);
-  }
-  CHECK(!builder.IsEmpty());
-  CHECK_EQ(pos, kRegularCount);
-
-  type = kPtrType;
-  ptrValue = 0;
-  dblValue = 0.0;
-  sharing_ok = true;
-  while (pos < kRegularCount * 2) {
-    if (type == kPtrType) {
-      access = builder.AddEntry(pos++, ptrValue++, sharing_ok);
-      type = kDblType;
-      CHECK_EQ(access, kOvflAccess);
-    } else {
-      access = builder.AddEntry(pos++, dblValue);
-      dblValue += 0.5;
-      type = kPtrType;
-      CHECK_EQ(access, kRegAccess);
-    }
-  }
-
-  access = builder.AddEntry(pos++, ptrValue, sharing_ok);
-  CHECK_EQ(access, kOvflAccess);
-  access = builder.AddEntry(pos, dblValue);
-  CHECK_EQ(access, kOvflAccess);
-}
+  }
+}
+
+
+static void CheckIterator(Handle<ConstantPoolArray> array,
+                          ConstantPoolArray::Type type,
+                          int expected_indexes[],
+                          int count) {
+  int i = 0;
+  ConstantPoolArray::Iterator iter(*array, type);
+  while (!iter.is_finished()) {
+    CHECK_EQ(expected_indexes[i++], iter.next_index());
+  }
+  CHECK_EQ(count, i);
+}
+
+
+TEST(ConstantPoolIteratorSmall) {
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  ConstantPoolArray::NumberOfEntries small(1, 5, 2, 0);
+  Handle<ConstantPoolArray> array = factory->NewConstantPoolArray(small);
+
+  int expected_int64_indexs[] = { 0 };
+  CheckIterator(array, ConstantPoolArray::INT64, expected_int64_indexs, 1);
+  int expected_code_indexs[] = { 1, 2, 3, 4, 5 };
+  CheckIterator(array, ConstantPoolArray::CODE_PTR, expected_code_indexs, 5);
+  int expected_heap_indexs[] = { 6, 7 };
+  CheckIterator(array, ConstantPoolArray::HEAP_PTR, expected_heap_indexs, 2);
+  int expected_int32_indexs[1];
+  CheckIterator(array, ConstantPoolArray::INT32, expected_int32_indexs, 0);
+}
+
+
+TEST(ConstantPoolIteratorExtended) {
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  ConstantPoolArray::NumberOfEntries small(1, 0, 0, 4);
+  ConstantPoolArray::NumberOfEntries extended(5, 0, 3, 0);
+  Handle<ConstantPoolArray> array =
+      factory->NewExtendedConstantPoolArray(small, extended);
+
+  int expected_int64_indexs[] = { 0, 5, 6, 7, 8, 9 };
+  CheckIterator(array, ConstantPoolArray::INT64, expected_int64_indexs, 6);
+  int expected_code_indexs[1];
+  CheckIterator(array, ConstantPoolArray::CODE_PTR, expected_code_indexs, 0);
+  int expected_heap_indexs[] = { 10, 11, 12 };
+  CheckIterator(array, ConstantPoolArray::HEAP_PTR, expected_heap_indexs, 3);
+  int expected_int32_indexs[] = { 1, 2, 3, 4 };
+  CheckIterator(array, ConstantPoolArray::INT32, expected_int32_indexs, 4);
+}
+
+
+TEST(ConstantPoolPreciseGC) {
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  ConstantPoolArray::NumberOfEntries small(1, 0, 0, 1);
+  Handle<ConstantPoolArray> array = factory->NewConstantPoolArray(small);
+
+  // Check that the store buffer knows which entries are pointers and which are
+  // not.  To do this, make non-pointer entries which look like new space
+  // pointers but are actually invalid and ensure the GC doesn't try to move
+  // them.
+  Handle<HeapObject> object = factory->NewHeapNumber(4.0);
+  Object* raw_ptr = *object;
+  // If interpreted as a pointer, this should be right inside the heap number
+  // which will cause a crash when trying to lookup the 'map' pointer.
+  intptr_t invalid_ptr = reinterpret_cast<intptr_t>(raw_ptr) + kInt32Size;
+  int32_t invalid_ptr_int32 = static_cast<int32_t>(invalid_ptr);
+  int64_t invalid_ptr_int64 = static_cast<int64_t>(invalid_ptr);
+  array->set(0, invalid_ptr_int64);
+  array->set(1, invalid_ptr_int32);
+
+  // Ensure we perform a scan on scavenge for the constant pool's page.
+  MemoryChunk::FromAddress(array->address())->set_scan_on_scavenge(true);
+  heap->CollectGarbage(NEW_SPACE);
+
+  // Check the object was moved by GC.
+  CHECK_NE(*object, raw_ptr);
+
+  // Check the non-pointer entries weren't changed.
+  CHECK_EQ(invalid_ptr_int64, array->get_int64_entry(0));
+  CHECK_EQ(invalid_ptr_int32, array->get_int32_entry(1));
+}
+
+
+TEST(ConstantPoolCompacting) {
+  if (i::FLAG_never_compact) return;
+  i::FLAG_always_compact = true;
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(context->GetIsolate());
+
+  ConstantPoolArray::NumberOfEntries small(0, 0, 1, 0);
+  ConstantPoolArray::NumberOfEntries extended(0, 0, 1, 0);
+  Handle<ConstantPoolArray> array =
+      factory->NewExtendedConstantPoolArray(small, extended);
+
+  // Start a second old-space page so that the heap pointer added to the
+  // constant pool array ends up on the an evacuation candidate page.
+  Page* first_page = heap->old_space()->anchor()->next_page();
+  {
+    HandleScope scope(isolate);
+    int dummy_array_size = Page::kMaxRegularHeapObjectSize - 92 * KB;
+    Handle<HeapObject> temp =
+        factory->NewFixedDoubleArray(dummy_array_size / kDoubleSize, TENURED);
+    CHECK(heap->InOldSpace(temp->address()));
+    Handle<HeapObject> heap_ptr =
+        factory->NewHeapNumber(5.0, IMMUTABLE, TENURED);
+    CHECK(heap->InOldSpace(heap_ptr->address()));
+    CHECK(!first_page->Contains(heap_ptr->address()));
+    array->set(0, *heap_ptr);
+    array->set(1, *heap_ptr);
+  }
+
+  // Check heap pointers are correctly updated on GC.
+  Object* old_ptr = array->get_heap_ptr_entry(0);
+  Handle<Object> object(old_ptr, isolate);
+  CHECK_EQ(old_ptr, *object);
+  CHECK_EQ(old_ptr, array->get_heap_ptr_entry(1));
+
+  // Force compacting garbage collection.
+  CHECK(FLAG_always_compact);
+  heap->CollectAllGarbage();
+
+  CHECK_NE(old_ptr, *object);
+  CHECK_EQ(*object, array->get_heap_ptr_entry(0));
+  CHECK_EQ(*object, array->get_heap_ptr_entry(1));
+}