Avoid write-barriers when initializing newly created Code object.

src/objects.cc

 // Copyright 2011 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 7637 matching lines @@
 
 void Code::Relocate(intptr_t delta) {
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);
   }
   CPU::FlushICache(instruction_start(), instruction_size());
 }
 
 
 void Code::CopyFrom(const CodeDesc& desc) {
+  ASSERT(Marking::Color(this) == Marking::WHITE_OBJECT);
+
   // copy code
   memmove(instruction_start(), desc.buffer, desc.instr_size);
 
   // copy reloc info
   memmove(relocation_start(),
           desc.buffer + desc.buffer_size - desc.reloc_size,
           desc.reloc_size);
 
   // unbox handles and relocate
   intptr_t delta = instruction_start() - desc.buffer;
   int mode_mask = RelocInfo::kCodeTargetMask |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
                   RelocInfo::ModeMask(RelocInfo::GLOBAL_PROPERTY_CELL) |
                   RelocInfo::kApplyMask;
   Assembler* origin = desc.origin;  // Needed to find target_object on X64.
   for (RelocIterator it(this, mode_mask); !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (mode == RelocInfo::EMBEDDED_OBJECT) {
       Handle<Object> p = it.rinfo()->target_object_handle(origin);
-      it.rinfo()->set_target_object(*p);
+      it.rinfo()->set_target_object(*p, SKIP_WRITE_BARRIER);
     } else if (mode == RelocInfo::GLOBAL_PROPERTY_CELL) {
       Handle<JSGlobalPropertyCell> cell  = it.rinfo()->target_cell_handle();
-      it.rinfo()->set_target_cell(*cell);
+      it.rinfo()->set_target_cell(*cell, SKIP_WRITE_BARRIER);
     } else if (RelocInfo::IsCodeTarget(mode)) {
       // rewrite code handles in inline cache targets to direct
       // pointers to the first instruction in the code object
       Handle<Object> p = it.rinfo()->target_object_handle(origin);
       Code* code = Code::cast(*p);
-      it.rinfo()->set_target_address(code->instruction_start());
+      it.rinfo()->set_target_address(code->instruction_start(),
+                                     SKIP_WRITE_BARRIER);
     } else {
       it.rinfo()->apply(delta);
     }
   }
   CPU::FlushICache(instruction_start(), instruction_size());
 }
 
 
 // Locate the source position which is closest to the address in the code. This
 // is using the source position information embedded in the relocation info.
@@ skipping 4885 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single break point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal