[serializer] reorder some bytecodes to free up large blocks.

src/snapshot/deserializer.cc

 // Copyright 2016 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/snapshot/deserializer.h"
 
 #include "src/bootstrapper.h"
 #include "src/external-reference-table.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
@@ skipping 751 matching lines @@
         current = reinterpret_cast<Object**>(
             reinterpret_cast<Address>(current) + skip);
         // Fall through.
       }
 
       FOUR_CASES(kHotObject)
       FOUR_CASES(kHotObject + 4) {
         int index = data & kHotObjectMask;
         Object* hot_object = hot_objects_.Get(index);
         UnalignedCopy(current, &hot_object);
-        if (write_barrier_needed) {
+        if (write_barrier_needed && isolate->heap()->InNewSpace(hot_object)) {

[vogelheim, 2016/06/22 09:22:31]

I don't understand this change.

(This looks perfectly sensible, but I just don't get why this is needed and how
it relates to the other parts of this CL.)

[Yang, 2016/06/22 09:43:02]

This is just a drive-by fix to adapt this to what we have in other places.

           Address current_address = reinterpret_cast<Address>(current);
-          SLOW_DCHECK(isolate->heap()->ContainsSlow(current_object_address));
           isolate->heap()->RecordWrite(
               HeapObject::FromAddress(current_object_address),
               static_cast<int>(current_address - current_object_address),
               hot_object);
         }
         current++;
         break;
       }
 
       // Deserialize raw data of fixed length from 1 to 32 words.
@@ skipping 23 matching lines @@
 
       default:
         CHECK(false);
     }
   }
   CHECK_EQ(limit, current);
   return true;
 }
 }  // namespace internal
 }  // namespace v8