Add a write buffer, aligned so that a single bit tells us whether it has...

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 516 matching lines @@
   // Static variables for RegExp.
   static ExternalReference address_of_static_offsets_vector();
   static ExternalReference address_of_regexp_stack_memory_address();
   static ExternalReference address_of_regexp_stack_memory_size();
 
   // Static variable Heap::NewSpaceStart()
   static ExternalReference new_space_start();
   static ExternalReference new_space_mask();
   static ExternalReference heap_always_allocate_scope_depth();
 
+  // Write barrier.

[Vyacheslav Egorov (Chromium), 2010/12/14 22:40:14]

barrier -> buffer.

[Erik Corry, 2010/12/15 08:00:13]

The write barrier is implemented using a write buffer.  It would be redundant to
have 'write buffer' in the comment would be redundant. 

+  static ExternalReference write_buffer_top();
+
   // Used for fast allocation in generated code.
   static ExternalReference new_space_allocation_top_address();
   static ExternalReference new_space_allocation_limit_address();
 
   static ExternalReference double_fp_operation(Token::Value operation);
   static ExternalReference compare_doubles();
   static ExternalReference power_double_double_function();
   static ExternalReference power_double_int_function();
 
   static ExternalReference handle_scope_next_address();
@@ skipping 167 matching lines @@
   return num_bits_set;
 }
 
 // Computes pow(x, y) with the special cases in the spec for Math.pow.
 double power_double_int(double x, int y);
 double power_double_double(double x, double y);
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_