--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp	Wed Apr 11 16:18:45 2012 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp	Wed Apr 18 07:21:15 2012 -0400
@@ -52,12 +52,15 @@
 class HeapRegion;
 class HeapRegionSetBase;
 
-#define HR_FORMAT SIZE_FORMAT":(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]"
+#define HR_FORMAT "%u:(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]"
 #define HR_FORMAT_PARAMS(_hr_) \
                 (_hr_)->hrs_index(), \
                 (_hr_)->is_survivor() ? "S" : (_hr_)->is_young() ? "E" : "-", \
                 (_hr_)->bottom(), (_hr_)->top(), (_hr_)->end()
 
+// sentinel value for hrs_index
+#define G1_NULL_HRS_INDEX ((uint) -1)
+
 // A dirty card to oop closure for heap regions. It
 // knows how to get the G1 heap and how to use the bitmap
 // in the concurrent marker used by G1 to filter remembered
@@ -235,7 +238,7 @@
 
  protected:
   // The index of this region in the heap region sequence.
-  size_t  _hrs_index;
+  uint  _hrs_index;
 
   HumongousType _humongous_type;
   // For a humongous region, region in which it starts.
@@ -342,7 +345,7 @@
 
  public:
   // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
-  HeapRegion(size_t hrs_index,
+  HeapRegion(uint hrs_index,
              G1BlockOffsetSharedArray* sharedOffsetArray,
              MemRegion mr, bool is_zeroed);
 
@@ -389,7 +392,7 @@
 
   // If this region is a member of a HeapRegionSeq, the index in that
   // sequence, otherwise -1.
-  size_t hrs_index() const { return _hrs_index; }
+  uint hrs_index() const { return _hrs_index; }
 
   // The number of bytes marked live in the region in the last marking phase.
   size_t marked_bytes()    { return _prev_marked_bytes; }