Use slot instead of value in the write barrier to record write from code.

src/x64/code-stubs-x64.cc

 // Copyright 2012 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 6196 matching lines @@
   Register arg3 = rdx;
   Register arg2 = rsi;
   Register arg1 = rdi;
 #endif
   Register address =
       arg1.is(regs_.address()) ? kScratchRegister : regs_.address();
   ASSERT(!address.is(regs_.object()));
   ASSERT(!address.is(arg1));
   __ Move(address, regs_.address());
   __ Move(arg1, regs_.object());
-  if (mode == INCREMENTAL_COMPACTION) {
-    // TODO(gc) Can we just set address arg2 in the beginning?
-    __ Move(arg2, address);
-  } else {
-    ASSERT(mode == INCREMENTAL);
-    __ movq(arg2, Operand(address, 0));
-  }
+  // TODO(gc) Can we just set address arg2 in the beginning?
+  __ Move(arg2, address);
   __ LoadAddress(arg3, ExternalReference::isolate_address());
   int argument_count = 3;
 
   AllowExternalCallThatCantCauseGC scope(masm);
   __ PrepareCallCFunction(argument_count);
   if (mode == INCREMENTAL_COMPACTION) {
     __ CallCFunction(
         ExternalReference::incremental_evacuation_record_write_function(
             masm->isolate()),
         argument_count);
@@ skipping 240 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64