Do not mark from native code. Check color and call incremental marker instead.

src/ppc/macro-assembler-ppc.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PPC_MACRO_ASSEMBLER_PPC_H_
 #define V8_PPC_MACRO_ASSEMBLER_PPC_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/frames.h"
@@ skipping 194 matching lines @@
   // Check if object is in new space.  Jumps if the object is in new space.
   // The register scratch can be object itself, but it will be clobbered.
   void JumpIfInNewSpace(Register object, Register scratch, Label* branch) {
     InNewSpace(object, scratch, eq, branch);
   }
 
   // Check if an object has a given incremental marking color.
   void HasColor(Register object, Register scratch0, Register scratch1,
                 Label* has_color, int first_bit, int second_bit);
 
-  void JumpIfBlack(Register object, Register scratch0, Register scratch1,
-                   Label* on_black);
-
-  // Checks the color of an object.  If the object is already grey or black
-  // then we just fall through, since it is already live.  If it is white and
-  // we can determine that it doesn't need to be scanned, then we just mark it
-  // black and fall through.  For the rest we jump to the label so the
-  // incremental marker can fix its assumptions.
-  void EnsureNotWhite(Register object, Register scratch1, Register scratch2,
-                      Register scratch3, Label* object_is_white_and_not_data);
-
-  // Detects conservatively whether an object is data-only, i.e. it does need to
-  // be scanned by the garbage collector.
-  void JumpIfDataObject(Register value, Register scratch,
-                        Label* not_data_object);
+  // Checks the color of an object.  If the object is white we jump to the
+  // incremental marker.
+  void JumpIfWhite(Register value, Register scratch1, Register scratch2,
+                   Register scratch3, Label* value_is_white);
 
   // Notify the garbage collector that we wrote a pointer into an object.
   // |object| is the object being stored into, |value| is the object being
   // stored.  value and scratch registers are clobbered by the operation.
   // The offset is the offset from the start of the object, not the offset from
   // the tagged HeapObject pointer.  For use with FieldMemOperand(reg, off).
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
@@ skipping 1344 matching lines @@
 #define ACCESS_MASM(masm)    \
   masm->stop(__FILE_LINE__); \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PPC_MACRO_ASSEMBLER_PPC_H_