Make InToSpace/InFromSpace use the page header.

src/spaces.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 373 matching lines @@
 }
 
 
 void Page::InitializeAsAnchor(PagedSpace* owner) {
   set_owner(owner);
   set_prev_page(this);
   set_next_page(this);
 }
 
 
-NewSpacePage* NewSpacePage::Initialize(Heap* heap, Address start) {
+NewSpacePage* NewSpacePage::Initialize(Heap* heap,
+                                       Address start,
+                                       SemiSpaceId id) {
   MemoryChunk* chunk = MemoryChunk::Initialize(heap,
                                                start,
                                                Page::kPageSize,
                                                NOT_EXECUTABLE,
                                                heap->new_space());
   chunk->initialize_scan_on_scavenge(true);
   chunk->SetFlag(MemoryChunk::IN_NEW_SPACE);
+  if (id == kSecondSemiSpace) {
+    chunk->SetFlag(MemoryChunk::SEMI_SPACE_TAG);
+  } else {
+    ASSERT(!chunk->IsFlagSet(MemoryChunk::SEMI_SPACE_TAG));
+  }
   heap->incremental_marking()->SetNewSpacePageFlags(chunk);
   return static_cast<NewSpacePage*>(chunk);
 }
 
 
 MemoryChunk* MemoryChunk::Initialize(Heap* heap,
                                      Address base,
                                      size_t size,
                                      Executability executable,
                                      Space* owner) {
@@ skipping 616 matching lines @@
 
 bool SemiSpace::Commit() {
   ASSERT(!is_committed());
   if (!heap()->isolate()->memory_allocator()->CommitBlock(
       start_, capacity_, executable())) {
     return false;
   }
   committed_ = true;
   // TODO(gc): When more than one page is present, initialize and
   // chain them all.
-  current_page_ = NewSpacePage::Initialize(heap(), start_);
+  current_page_ = NewSpacePage::Initialize(heap(), start_, id_);
   return true;
 }
 
 
 bool SemiSpace::Uncommit() {
   ASSERT(is_committed());
   if (!heap()->isolate()->memory_allocator()->UncommitBlock(
       start_, capacity_)) {
     return false;
   }
@@ skipping 1216 matching lines @@
   for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
     if (obj->IsCode()) {
       Code* code = Code::cast(obj);
       isolate->code_kind_statistics()[code->kind()] += code->Size();
     }
   }
 }
 #endif  // DEBUG
 
 } }  // namespace v8::internal