[heap] Use struct Entry to fill inlined promotion queue entries.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 389af1bec1108e5040d27d90666fe48275976140..9734d5544b117b13bb054cc05cd645a0278fd62e 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1581,13 +1581,12 @@ void PromotionQueue::RelocateQueueHead() {
   emergency_stack_ = new List<Entry>(2 * entries_count);
 
   while (head_start != head_end) {
-    int size = static_cast<int>(*(head_start++));
-    HeapObject* obj = reinterpret_cast<HeapObject*>(*(head_start++));
+    struct Entry* entry = reinterpret_cast<struct Entry*>(head_start);

[ulan, 2016/03/11 12:16:55]

I think we need to increment head_start here.

[Hannes Payer (out of office), 2016/03/11 12:23:19]

Done.

     // New space allocation in SemiSpaceCopyObject marked the region
     // overlapping with promotion queue as uninitialized.
-    MSAN_MEMORY_IS_INITIALIZED(&size, sizeof(size));
-    MSAN_MEMORY_IS_INITIALIZED(&obj, sizeof(obj));
-    emergency_stack_->Add(Entry(obj, size));
+    MSAN_MEMORY_IS_INITIALIZED(&entry->size_, sizeof(size));
+    MSAN_MEMORY_IS_INITIALIZED(&entry->obj_, sizeof(obj));
+    emergency_stack_->Add(*entry);
   }
   rear_ = head_end;
 }
@@ -1945,7 +1944,7 @@ Address Heap::DoScavenge(ObjectVisitor* scavenge_visitor,
     {
       while (!promotion_queue()->is_empty()) {
         HeapObject* target;
-        int size;
+        intptr_t size;
         promotion_queue()->remove(&target, &size);
 
         // Promoted object might be already partially visited
@@ -1954,7 +1953,8 @@ Address Heap::DoScavenge(ObjectVisitor* scavenge_visitor,
         // to new space.
         DCHECK(!target->IsMap());
 
-        IteratePointersToFromSpace(target, size, &Scavenger::ScavengeObject);
+        IteratePointersToFromSpace(target, static_cast<int>(size),
+                                   &Scavenger::ScavengeObject);
       }
     }