Record code slots that may point to evacuation candidate objects after deoptimizing them.

src/heap/mark-compact.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/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 3218 matching lines @@
   // The target object has to be black.
   CHECK(Marking::IsBlack(Marking::MarkBitFrom(object)));
 
   // The target object is black but we don't know if the source slot is black.
   // The source object could have died and the slot could be part of a free
   // space. Use the mark bit iterator to find out about liveness of the slot.
   CHECK(IsSlotInBlackObjectSlow(Page::FromAddress(slot), slot));
 }
 
 
-void MarkCompactCollector::RemoveObjectSlots(HeapObject* invalid_object) {
+void MarkCompactCollector::RemoveObjectSlots(Address start_slot,
+                                             Address end_slot) {
   // Remove entries by replacing them with an old-space slot containing a smi
   // that is located in an unmovable page.
   int npages = evacuation_candidates_.length();
   for (int i = 0; i < npages; i++) {
     Page* p = evacuation_candidates_[i];
     DCHECK(p->IsEvacuationCandidate() ||
            p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
     if (p->IsEvacuationCandidate()) {
-      SlotsBuffer::RemoveObjectSlots(heap_, p->slots_buffer(), invalid_object);
+      SlotsBuffer::RemoveObjectSlots(heap_, p->slots_buffer(), start_slot,
+                                     end_slot);
     }
   }
 }
 
 
 void MarkCompactCollector::EvacuateNewSpace() {
   // There are soft limits in the allocation code, designed trigger a mark
   // sweep collection by failing allocations.  But since we are already in
   // a mark-sweep allocation, there is no sense in trying to trigger one.
   AlwaysAllocateScope scope(isolate());
@@ skipping 1236 matching lines @@
         ++slot_idx;
         DCHECK(slot_idx < slots_count);
       }
     }
     buffer = buffer->next();
   }
 }
 
 
 void SlotsBuffer::RemoveObjectSlots(Heap* heap, SlotsBuffer* buffer,
-                                    HeapObject* invalid_object) {
+                                    Address start_slot, Address end_slot) {
   // Remove entries by replacing them with an old-space slot containing a smi
   // that is located in an unmovable page.
   const ObjectSlot kRemovedEntry = HeapObject::RawField(
       heap->empty_fixed_array(), FixedArrayBase::kLengthOffset);
   DCHECK(Page::FromAddress(reinterpret_cast<Address>(kRemovedEntry))
              ->NeverEvacuate());
 
   while (buffer != NULL) {
     SlotsBuffer::ObjectSlot* slots = buffer->slots_;
     intptr_t slots_count = buffer->idx_;
     bool is_typed_slot = false;
 
     for (int slot_idx = 0; slot_idx < slots_count; ++slot_idx) {
       ObjectSlot slot = slots[slot_idx];
       if (!IsTypedSlot(slot)) {
         Address slot_address = reinterpret_cast<Address>(slot);
-        if (slot_address >= invalid_object->address() &&
-            slot_address <
-                (invalid_object->address() + invalid_object->Size())) {
+        if (slot_address >= start_slot && slot_address < end_slot) {
           slots[slot_idx] = kRemovedEntry;
           if (is_typed_slot) {
             slots[slot_idx - 1] = kRemovedEntry;
           }
         }
         is_typed_slot = false;
       } else {
         is_typed_slot = true;
         DCHECK(slot_idx < slots_count);
       }
@@ skipping 160 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8