Estimate a (close) upper bound on the size of black-marked objects on each page.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index bc7903f515a2abacc8589c534786aed4dcb8b6e3..9ca98c29b4a31b7181d9a3af2aae4eb937523c07 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -137,13 +137,6 @@ class MacroAssembler: public Assembler {
                       Label* object_is_white_and_not_data,
                       Label::Distance distance);
 
-  // Detects conservatively whether an object is data-only, ie it does need to
-  // be scanned by the garbage collector.
-  void JumpIfDataObject(Register value,
-                        Register scratch,
-                        Label* not_data_object,
-                        Label::Distance not_data_object_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.
@@ -803,7 +796,7 @@ class MacroAssembler: public Assembler {
   // 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.  Uses ecx as scratch and leaves addr_reg
-  // unchanged.
+  // unchanged, unless it's also mask_reg.

[Erik Corry, 2011/06/24 09:46:17]

The implementation asserts that none of the registers are aliased so it seems
inconsistent for this comment to describe what happens if they are.

[Lasse Reichstein, 2011/06/24 11:09:08]

Ack, forgot to change comment back when I reverted my change to the function.

   inline void GetMarkBits(Register addr_reg,
                           Register bitmap_reg,
                           Register mask_reg);