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

src/heap/heap.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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 1563 matching lines @@
   Page* p = Page::FromAllocationTop(reinterpret_cast<Address>(rear_));
   intptr_t* head_start = rear_;
   intptr_t* head_end = Min(front_, reinterpret_cast<intptr_t*>(p->area_end()));
 
   int entries_count =
       static_cast<int>(head_end - head_start) / kEntrySizeInWords;
 
   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;
 }
 
 
 class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
  public:
   explicit ScavengeWeakObjectRetainer(Heap* heap) : heap_(heap) {}
 
   virtual Object* RetainAs(Object* object) {
@@ skipping 337 matching lines @@
       } else {
         new_space_front =
             NewSpacePage::FromLimit(new_space_front)->next_page()->area_start();
       }
     }
 
     // Promote and process all the to-be-promoted objects.
     {
       while (!promotion_queue()->is_empty()) {
         HeapObject* target;
-        int size;
+        intptr_t size;
         promotion_queue()->remove(&target, &size);
 
         // Promoted object might be already partially visited
         // during old space pointer iteration. Thus we search specifically
         // for pointers to from semispace instead of looking for pointers
         // to new space.
         DCHECK(!target->IsMap());
 
-        IteratePointersToFromSpace(target, size, &Scavenger::ScavengeObject);
+        IteratePointersToFromSpace(target, static_cast<int>(size),
+                                   &Scavenger::ScavengeObject);
       }
     }
 
     // Take another spin if there are now unswept objects in new space
     // (there are currently no more unswept promoted objects).
   } while (new_space_front != new_space_.top());
 
   return new_space_front;
 }
 
@@ skipping 4381 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8