--- old/src/hotspot/share/utilities/bitMap.cpp 2018-01-04 02:53:35.009884873 -0500 +++ new/src/hotspot/share/utilities/bitMap.cpp 2018-01-04 02:53:34.621864991 -0500 @@ -628,7 +628,7 @@ table[i] = num_set_bits(i); } - if (Atomic::cmpxchg(table, &_pop_count_table, (BitMap::idx_t*)NULL) != NULL) { + if (!Atomic::replace_if_null(table, &_pop_count_table)) { guarantee(_pop_count_table != NULL, "invariant"); FREE_C_HEAP_ARRAY(idx_t, table); }