diff --git a/test/cctest/heap/utils-inl.h b/test/cctest/heap/utils-inl.h
new file mode 100644
index 0000000..f255bb6
--- /dev/null
+++ b/test/cctest/heap/utils-inl.h
@@ -0,0 +1,137 @@
+// 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.
+
+#ifndef HEAP_UTILS_H_
+#define HEAP_UTILS_H_
+
+#include "src/factory.h"
+#include "src/heap/heap-inl.h"
+#include "src/heap/incremental-marking.h"
+#include "src/heap/mark-compact.h"
+#include "src/isolate.h"
+
+
+namespace v8 {
+namespace internal {
+
+static int LenFromSize(int size) {
+  return (size - FixedArray::kHeaderSize) / kPointerSize;
+}
+
+
+static inline std::vector<Handle<FixedArray>> CreatePadding(
+    Heap* heap, int padding_size, PretenureFlag tenure,
+    int object_size = Page::kMaxRegularHeapObjectSize) {
+  std::vector<Handle<FixedArray>> handles;
+  Isolate* isolate = heap->isolate();
+  int allocate_memory;
+  int length;
+  int free_memory = padding_size;
+  if (tenure == i::TENURED) {
+    heap->old_space()->EmptyAllocationInfo();
+    int overall_free_memory = static_cast<int>(heap->old_space()->Available());
+    CHECK(padding_size <= overall_free_memory || overall_free_memory == 0);
+  } else {
+    heap->new_space()->DisableInlineAllocationSteps();
+    int overall_free_memory =
+        static_cast<int>(*heap->new_space()->allocation_limit_address() -
+                         *heap->new_space()->allocation_top_address());
+    CHECK(padding_size <= overall_free_memory || overall_free_memory == 0);
+  }
+  while (free_memory > 0) {
+    if (free_memory > object_size) {
+      allocate_memory = object_size;
+      length = LenFromSize(allocate_memory);
+    } else {
+      allocate_memory = free_memory;
+      length = LenFromSize(allocate_memory);
+      if (length <= 0) {
+        // Not enough room to create another fixed array. Let's create a filler.
+        heap->CreateFillerObjectAt(*heap->old_space()->allocation_top_address(),
+                                   free_memory);
+        break;
+      }
+    }
+    handles.push_back(isolate->factory()->NewFixedArray(length, tenure));
+    CHECK((tenure == NOT_TENURED && heap->InNewSpace(*handles.back())) ||
+          (tenure == TENURED && heap->InOldSpace(*handles.back())));
+    free_memory -= allocate_memory;
+  }
+  return handles;
+}
+
+
+// Helper function that simulates a full new-space in the heap.
+static inline bool FillUpOnePage(v8::internal::NewSpace* space) {
+  space->DisableInlineAllocationSteps();
+  int space_remaining = static_cast<int>(*space->allocation_limit_address() -
+                                         *space->allocation_top_address());
+  if (space_remaining == 0) return false;
+  CreatePadding(space->heap(), space_remaining, i::NOT_TENURED);
+  return true;
+}
+
+
+// Helper function that simulates a fill new-space in the heap.
+static inline void AllocateAllButNBytes(v8::internal::NewSpace* space,
+                                        int extra_bytes) {
+  space->DisableInlineAllocationSteps();
+  int space_remaining = static_cast<int>(*space->allocation_limit_address() -
+                                         *space->allocation_top_address());
+  CHECK(space_remaining >= extra_bytes);
+  int new_linear_size = space_remaining - extra_bytes;
+  if (new_linear_size == 0) return;
+  CreatePadding(space->heap(), new_linear_size, i::NOT_TENURED);
+}
+
+
+static inline void FillCurrentPage(v8::internal::NewSpace* space) {
+  AllocateAllButNBytes(space, 0);
+}
+
+
+static inline void SimulateFullSpace(v8::internal::NewSpace* space) {
+  FillCurrentPage(space);
+  while (FillUpOnePage(space)) {
+  }
+}
+
+
+// Helper function that simulates a full old-space in the heap.
+static inline void SimulateFullSpace(v8::internal::PagedSpace* space) {
+  space->EmptyAllocationInfo();
+  space->ResetFreeList();
+  space->ClearStats();
+}
+
+
+// Helper function that simulates many incremental marking steps until
+// marking is completed.
+static inline void SimulateIncrementalMarking(i::Heap* heap,
+                                              bool force_completion = true) {
+  i::MarkCompactCollector* collector = heap->mark_compact_collector();
+  i::IncrementalMarking* marking = heap->incremental_marking();
+  if (collector->sweeping_in_progress()) {
+    collector->EnsureSweepingCompleted();
+  }
+  CHECK(marking->IsMarking() || marking->IsStopped());
+  if (marking->IsStopped()) {
+    heap->StartIncrementalMarking();
+  }
+  CHECK(marking->IsMarking());
+  if (!force_completion) return;
+
+  while (!marking->IsComplete()) {
+    marking->Step(i::MB, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD);
+    if (marking->IsReadyToOverApproximateWeakClosure()) {
+      marking->FinalizeIncrementally();
+    }
+  }
+  CHECK(marking->IsComplete());
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // HEAP_UTILS_H_