The way reloc entries are visited by the ObjectVisitor is architecture...

src/serialize.cc

 // Copyright 2006-2008 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 1281 matching lines @@
   CHECK(target == NULL ? encoding == 0 : encoding != 0);
   int representation;
   // Can't use a ternary operator because of gcc.
   if (rinfo->IsCodedSpecially()) {
     representation = kStartOfObject + kFromCode;
   } else {
     representation = kStartOfObject + kPlain;
   }
   sink_->Put(kExternalReference + representation, "ExternalReference");
   sink_->PutInt(encoding, "reference id");
-  bytes_processed_so_far_ += Assembler::kExternalTargetSize;
+  bytes_processed_so_far_ += rinfo->target_address_size();
 }
 
 
 void Serializer::ObjectSerializer::VisitCodeTarget(RelocInfo* rinfo) {
   CHECK(RelocInfo::IsCodeTarget(rinfo->rmode()));
   Address target_start = rinfo->target_address_address();
   OutputRawData(target_start);
   Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
   serializer_->SerializeObject(target, kFromCode, kFirstInstruction);
-  bytes_processed_so_far_ += Assembler::kCallTargetSize;
+  bytes_processed_so_far_ += rinfo->target_address_size();
 }
 
 
 void Serializer::ObjectSerializer::VisitExternalAsciiString(
     v8::String::ExternalAsciiStringResource** resource_pointer) {
   Address references_start = reinterpret_cast<Address>(resource_pointer);
   OutputRawData(references_start);
   for (int i = 0; i < Natives::GetBuiltinsCount(); i++) {
     Object* source = Heap::natives_source_cache()->get(i);
     if (!source->IsUndefined()) {
@@ skipping 103 matching lines @@
       fullness_[space] = RoundUp(fullness_[space], Page::kPageSize);
     }
   }
   int allocation_address = fullness_[space];
   fullness_[space] = allocation_address + size;
   return allocation_address;
 }
 
 
 } }  // namespace v8::internal