--- old/src/hotspot/share/utilities/bitMap.cpp 2017-10-10 17:37:31.741450751 -0400 +++ new/src/hotspot/share/utilities/bitMap.cpp 2017-10-10 17:37:31.170209936 -0400 @@ -626,7 +626,7 @@ table[i] = num_set_bits(i); } - if (!Atomic::replace_if_null(table, &_pop_count_table)) { + if (!Atomic::cmpxchg_if_null(table, &_pop_count_table)) { guarantee(_pop_count_table != NULL, "invariant"); FREE_C_HEAP_ARRAY(idx_t, table); }