Special case the recording of constant pool entries in the slot buffer.

src/mark-compact.cc

 // Copyright 2012 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 4352 matching lines @@
   } else if (RelocInfo::IsJSReturn(rmode)) {
     return SlotsBuffer::JS_RETURN_SLOT;
   }
   UNREACHABLE();
   return SlotsBuffer::NUMBER_OF_SLOT_TYPES;
 }
 
 
 void MarkCompactCollector::RecordRelocSlot(RelocInfo* rinfo, Object* target) {
   Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
+  RelocInfo::Mode rmode = rinfo->rmode();
   if (target_page->IsEvacuationCandidate() &&
       (rinfo->host() == NULL ||
        !ShouldSkipEvacuationSlotRecording(rinfo->host()))) {
-    if (!SlotsBuffer::AddTo(&slots_buffer_allocator_,
-                            target_page->slots_buffer_address(),
-                            SlotTypeForRMode(rinfo->rmode()),
-                            rinfo->pc(),
-                            SlotsBuffer::FAIL_ON_OVERFLOW)) {
+    bool success;
+    if (RelocInfo::IsEmbeddedObject(rmode) && rinfo->IsInConstantPool()) {
+      // This doesn't need to be typed since it is just a normal heap pointer.
+      Object** target_pointer =
+          reinterpret_cast<Object**>(rinfo->constant_pool_entry_address());
+      success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
+                                   target_page->slots_buffer_address(),
+                                   target_pointer,
+                                   SlotsBuffer::FAIL_ON_OVERFLOW);
+    } else if (RelocInfo::IsCodeTarget(rmode) && rinfo->IsInConstantPool()) {
+      success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
+                                   target_page->slots_buffer_address(),
+                                   SlotsBuffer::CODE_ENTRY_SLOT,
+                                   rinfo->constant_pool_entry_address(),
+                                   SlotsBuffer::FAIL_ON_OVERFLOW);
+    } else {
+      success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
+                                  target_page->slots_buffer_address(),
+                                  SlotTypeForRMode(rmode),
+                                  rinfo->pc(),
+                                  SlotsBuffer::FAIL_ON_OVERFLOW);
+    }
+    if (!success) {
       EvictEvacuationCandidate(target_page);
     }
   }
 }
 
 
 void MarkCompactCollector::RecordCodeEntrySlot(Address slot, Code* target) {
   Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
   if (target_page->IsEvacuationCandidate() &&
       !ShouldSkipEvacuationSlotRecording(reinterpret_cast<Object**>(slot))) {
@@ skipping 86 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal