Generalize HeapObject alignment requirements.

src/heap/mark-compact.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 1923 matching lines @@
 
       offset += 2;
       current_cell >>= 2;
 
       // TODO(hpayer): Refactor EvacuateObject and call this function instead.
       if (heap()->ShouldBePromoted(object->address(), size) &&
           TryPromoteObject(object, size)) {
         continue;
       }
 
-      AllocationAlignment alignment = object->NeedsToEnsureDoubleAlignment()
-                                          ? kDoubleAligned
-                                          : kWordAligned;
+      AllocationAlignment alignment = object->RequiredAlignment();
       AllocationResult allocation = new_space->AllocateRaw(size, alignment);
       if (allocation.IsRetry()) {
         if (!new_space->AddFreshPage()) {
           // Shouldn't happen. We are sweeping linearly, and to-space
           // has the same number of pages as from-space, so there is
           // always room.
           UNREACHABLE();
         }
         allocation = new_space->AllocateRaw(size, alignment);
         DCHECK(!allocation.IsRetry());
@@ skipping 1141 matching lines @@
 }
 
 
 bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
                                             int object_size) {
   DCHECK(object_size <= Page::kMaxRegularHeapObjectSize);
 
   OldSpace* old_space = heap()->old_space();
 
   HeapObject* target;
-  AllocationAlignment alignment =
-      object->NeedsToEnsureDoubleAlignment() ? kDoubleAligned : kWordAligned;
+  AllocationAlignment alignment = object->RequiredAlignment();
   AllocationResult allocation = old_space->AllocateRaw(object_size, alignment);
   if (allocation.To(&target)) {
     MigrateObject(target, object, object_size, old_space->identity());
     heap()->IncrementPromotedObjectsSize(object_size);
     return true;
   }
 
   return false;
 }
 
@@ skipping 203 matching lines @@
 
     if (*cell == 0) continue;
 
     int live_objects = MarkWordToObjectStarts(*cell, offsets);
     for (int i = 0; i < live_objects; i++) {
       Address object_addr = cell_base + offsets[i] * kPointerSize;
       HeapObject* object = HeapObject::FromAddress(object_addr);
       DCHECK(Marking::IsBlack(Marking::MarkBitFrom(object)));
 
       int size = object->Size();
-
-      AllocationAlignment alignment = object->NeedsToEnsureDoubleAlignment()
-                                          ? kDoubleAligned
-                                          : kWordAligned;
+      AllocationAlignment alignment = object->RequiredAlignment();
       HeapObject* target_object;
       AllocationResult allocation = space->AllocateRaw(size, alignment);
       if (!allocation.To(&target_object)) {
         // If allocation failed, use emergency memory and re-try allocation.
         CHECK(space->HasEmergencyMemory());
         space->UseEmergencyMemory();
         allocation = space->AllocateRaw(size, alignment);
       }
       if (!allocation.To(&target_object)) {
         // OS refused to give us memory.
@@ skipping 1417 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }
 }  // namespace v8::internal