[heap] Black is encoded with 11, grey with 10.

src/x64/macro-assembler-x64.h

 // Copyright 2012 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_X64_MACRO_ASSEMBLER_X64_H_
 #define V8_X64_MACRO_ASSEMBLER_X64_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/base/flags.h"
@@ skipping 212 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,
                         Label::Distance distance = Label::kFar) {
     InNewSpace(object, scratch, equal, branch, distance);
   }
 
   // Check if an object has the black incremental marking color.  Also uses rcx!
-  void JumpIfBlack(Register object,
-                   Register scratch0,
-                   Register scratch1,
-                   Label* on_black,
-                   Label::Distance on_black_distance = Label::kFar);
+  void JumpIfBlack(Register object, Register bitmap_scratch,
+                   Register mask_scratch, Label* on_black,
+                   Label::Distance on_black_distance);
 
   // 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,
                    Label* value_is_white, Label::Distance distance);
 
   // 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
@@ skipping 1488 matching lines @@
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_