Incremental mode now works for x64. The only difference

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
===================================================================
--- src/arm/macro-assembler-arm.h	(revision 8221)
+++ src/arm/macro-assembler-arm.h	(working copy)
@@ -191,18 +191,23 @@
                      Condition cc,
                      Label* condition_met);
 
-  // Check if object is in new space.
-  // scratch can be object itself, but it will be clobbered.
-  void InNewSpace(Register object,
-                  Register scratch,
-                  Condition cond,  // eq for new space, ne otherwise.
-                  Label* branch);
+  // Check if object is in new space.  Jumps if the object is not in new space.
+  // The register scratch can be object itself, but it will be clobbered.
+  void JumpIfNotInNewSpace(Register object,
+                           Register scratch,
+                           Label* branch) {
+    InNewSpace(object, scratch, ne, branch);
+  }
 
-  // Check if an object has a given incremental marking color.  The color bits
-  // are found by splitting the address at the bit offset indicated by the
-  // mask: bits that are zero in the mask are used for the address of the
-  // bitmap, and bits that are one in the mask are used for the index of the
-  // bit.
+  // 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,
@@ -230,8 +235,7 @@
   // garbage collector.
   void IsDataObject(Register value,
                     Register scratch,
-                    Label* not_data_object,
-                    Label::Distance not_data_object_distance);
+                    Label* not_data_object);
 
   // Notify the garbage collector that we wrote a pointer into an object.
   // |object| is the object being stored into, |value| is the object being
@@ -1138,6 +1142,12 @@
                            Register scratch1,
                            Register scratch2);
 
+  // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
+  void InNewSpace(Register object,
+                  Register scratch,
+                  Condition cond,  // eq for new space, ne otherwise.
+                  Label* branch);
+
   // Helper for finding the mark bits for an address.  Afterwards, the
   // bitmap register points at the word with the mark bits and the mask
   // the position of the first bit.  Leaves addr_reg unchanged.