[heap] Move to page lookups for SemiSpace, NewSpace, and Heap containment methods

src/heap/slots-buffer.cc

 // Copyright 2015 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/slots-buffer.h"
 
 #include "src/assembler.h"
 #include "src/heap/heap.h"
 #include "src/objects-inl.h"
 
@@ skipping 38 matching lines @@
 
     for (int slot_idx = 0; slot_idx < slots_count; ++slot_idx) {
       ObjectSlot slot = slots[slot_idx];
       if (!IsTypedSlot(slot)) {
         Object* object = *slot;
         // Slots are invalid when they currently:
         // - do not point to a heap object (SMI)
         // - point to a heap object in new space
         // - are not within a live heap object on a valid pointer slot
         // - point to a heap object not on an evacuation candidate
-        if (!object->IsHeapObject() || heap->InNewSpace(object) ||
+        if (!object->IsHeapObject() ||
             !heap->mark_compact_collector()->IsSlotInLiveObject(
                 reinterpret_cast<Address>(slot)) ||
+            heap->InNewSpace(object) ||

[Hannes Payer (out of office), 2016/02/09 14:40:22]

Can you leave a todo(mlippautz) here, which says that you are going to move the
new space check back where it was before when double unboxed slots are filtered
using the new method?

[Michael Lippautz, 2016/02/09 14:50:28]

Done.

             !Page::FromAddress(reinterpret_cast<Address>(object))
                  ->IsEvacuationCandidate()) {
           // TODO(hpayer): Instead of replacing slots with kRemovedEntry we
           // could shrink the slots buffer in-place.
           slots[slot_idx] = kRemovedEntry;
         }
       } else {
         ++slot_idx;
         DCHECK(slot_idx < slots_count);
       }
@@ skipping 80 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 }  // namespace internal
 }  // namespace v8