Revert r4715.

src/arm/macro-assembler-arm.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 96 matching lines @@
 
 
   // 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,  // eq for new space, ne otherwise
                   Label* branch);
 
 
-  // For the page containing |object| mark the region covering [object+offset]
-  // dirty. The object address must be in the first 8K of an allocated page.
+  // Set the remebered set bit for an offset into an
+  // object. RecordWriteHelper only works if the object is not in new
+  // space.
   void RecordWriteHelper(Register object, Register offset, Register scracth);
 
-  // For the page containing |object| mark the region covering [object+offset]
-  // dirty. The object address must be in the first 8K of an allocated page.
-  // The 'scratch' register is used in the implementation and all 3 registers
-  // are clobbered by the operation, as well as the ip register.
+  // Sets the remembered set bit for [address+offset], where address is the
+  // address of the heap object 'object'.  The address must be in the first 8K
+  // of an allocated page. The 'scratch' register is used in the
+  // implementation and all 3 registers are clobbered by the operation, as
+  // well as the ip register.
   void RecordWrite(Register object, Register offset, Register scratch);
 
   // Push two registers.  Pushes leftmost register first (to highest address).
   void Push(Register src1, Register src2, Condition cond = al) {
     ASSERT(!src1.is(src2));
     if (src1.code() > src2.code()) {
       stm(db_w, sp, src1.bit() | src2.bit(), cond);
     } else {
       str(src1, MemOperand(sp, 4, NegPreIndex), cond);
       str(src2, MemOperand(sp, 4, NegPreIndex), cond);
@@ skipping 508 matching lines @@
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_