Respect double alignment in Mark-compact collector.

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 1922 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;
       }
 
-      AllocationResult allocation = new_space->AllocateRaw(size);
+      AllocationResult allocation;
+#ifndef V8_HOST_ARCH_64_BIT
+      if (object->NeedsToEnsureDoubleAlignment()) {
+        allocation = new_space->AllocateRawDoubleAligned(size);
+      } else {
+        allocation = new_space->AllocateRaw(size);
+      }
+#else
+      allocation = new_space->AllocateRaw(size);
+#endif
       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();
         }
+#ifndef V8_HOST_ARCH_64_BIT
+        if (object->NeedsToEnsureDoubleAlignment()) {
+          allocation = new_space->AllocateRawDoubleAligned(size);
+        } else {
+          allocation = new_space->AllocateRaw(size);
+        }
+#else
         allocation = new_space->AllocateRaw(size);
+#endif
         DCHECK(!allocation.IsRetry());
       }
       Object* target = allocation.ToObjectChecked();
 
       MigrateObject(HeapObject::cast(target), object, size, NEW_SPACE);
       heap()->IncrementSemiSpaceCopiedObjectSize(size);
     }
     *cells = 0;
   }
   return survivors_size;
@@ skipping 1108 matching lines @@
 }
 
 
 bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
                                             int object_size) {
   DCHECK(object_size <= Page::kMaxRegularHeapObjectSize);
 
   OldSpace* old_space = heap()->old_space();
 
   HeapObject* target;
-  AllocationResult allocation = old_space->AllocateRaw(object_size);
+  AllocationResult allocation;
+#ifndef V8_HOST_ARCH_64_BIT
+  if (object->NeedsToEnsureDoubleAlignment()) {
+    allocation = old_space->AllocateRawDoubleAligned(object_size);
+  } else {
+    allocation = old_space->AllocateRaw(object_size);
+  }
+#else
+  allocation = old_space->AllocateRaw(object_size);
+#endif
   if (allocation.To(&target)) {
     MigrateObject(target, object, object_size, old_space->identity());
     heap()->IncrementPromotedObjectsSize(object_size);
     return true;
   }
 
   return false;
 }
 
 
@@ skipping 1640 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