--- a/hotspot/src/share/vm/gc/g1/g1BiasedArray.hpp	Fri Jun 12 17:29:14 2015 -0400
+++ b/hotspot/src/share/vm/gc/g1/g1BiasedArray.hpp	Fri Jun 12 19:49:54 2015 -0400
@@ -128,6 +128,14 @@
     return biased_base()[biased_index];
   }
 
+  // Return the index of the element of the given array that covers the given
+  // word in the heap.
+  idx_t get_index_by_address(HeapWord* value) const {
+    idx_t biased_index = ((uintptr_t)value) >> this->shift_by();
+    this->verify_biased_index(biased_index);
+    return biased_index - _bias;
+  }
+
   // Set the value of the array entry that corresponds to the given array.
   void set_by_address(HeapWord * address, T value) {
     idx_t biased_index = ((uintptr_t)address) >> this->shift_by();
@@ -135,6 +143,18 @@
     biased_base()[biased_index] = value;
   }
 
+  // Set the value of all array entries that correspond to addresses
+  // in the specified MemRegion.
+  void set_by_address(MemRegion range, T value) {
+    idx_t biased_start = ((uintptr_t)range.start()) >> this->shift_by();
+    idx_t biased_last = ((uintptr_t)range.last()) >> this->shift_by();
+    this->verify_biased_index(biased_start);
+    this->verify_biased_index(biased_last);
+    for (idx_t i = biased_start; i <= biased_last; i++) {
+      biased_base()[i] = value;
+    }
+  }
+
 protected:
   // Returns the address of the element the given address maps to
   T* address_mapped_to(HeapWord* address) {