Revert r4715.

src/ia32/macro-assembler-ia32.h

 // Copyright 2006-2009 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 41 matching lines @@
 class JumpTarget;
 
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler: public Assembler {
  public:
   MacroAssembler(void* buffer, int size);
 
   // ---------------------------------------------------------------------------
   // GC Support
 
-  // For page containing |object| mark region covering |addr| dirty.
-  // RecordWriteHelper only works if the object is not in new
+  // Set the remebered set bit for an address which points into an
+  // object. RecordWriteHelper only works if the object is not in new
   // space.
   void RecordWriteHelper(Register object,
                          Register addr,
                          Register scratch);
 
   // Check if object is in new space.
   // scratch can be object itself, but it will be clobbered.
   void InNewSpace(Register object,
                   Register scratch,
                   Condition cc,  // equal for new space, not_equal otherwise.
                   Label* branch);
 
-  // For page containing |object| mark region covering [object+offset] dirty.
+  // Set the remembered set bit for [object+offset].
   // object is the object being stored into, value is the object being stored.
   // If offset is zero, then the scratch register contains the array index into
   // the elements array represented as a Smi.
   // All registers are clobbered by the operation.
   void RecordWrite(Register object,
                    int offset,
                    Register value,
                    Register scratch);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
@@ skipping 509 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_