--- old/src/share/vm/utilities/bitMap.inline.hpp	2017-04-09 17:53:29.291129025 -0400
+++ new/src/share/vm/utilities/bitMap.inline.hpp	2017-04-09 17:53:29.159122292 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -222,13 +222,13 @@
   idx_t res_offset = l_offset;
 
   // check bits including and to the _left_ of offset's position
-  idx_t pos = res_offset & (BitsPerWord - 1);
-  bm_word_t res = (map(index) >> pos) | left_n_bits((int)pos);
+  idx_t pos = bit_in_word(res_offset);
+  bm_word_t res = ~map(index) >> pos; // flip bits and shift for l_offset
 
-  if (res != ~(bm_word_t)0) {
-    // find the position of the 0-bit
-    for (; res & 1; res_offset++) {
-      res = res >> 1;
+  if (res != 0) {
+    // find the position of the 1-bit
+    for (; (res & 1) == 0; ++res_offset) {
+      res >>= 1;
     }
     assert(res_offset >= l_offset, "just checking");
     return MIN2(res_offset, r_offset);