--- a/src/hotspot/share/gc/g1/heapRegion.cpp	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/hotspot/share/gc/g1/heapRegion.cpp	Thu Oct 17 20:53:35 2019 +0100
@@ -49,6 +49,7 @@
 
 int    HeapRegion::LogOfHRGrainBytes = 0;
 int    HeapRegion::LogOfHRGrainWords = 0;
+int    HeapRegion::LogCardsPerRegion = 0;
 size_t HeapRegion::GrainBytes        = 0;
 size_t HeapRegion::GrainWords        = 0;
 size_t HeapRegion::CardsPerRegion    = 0;
@@ -105,6 +106,8 @@
   guarantee(CardsPerRegion == 0, "we should only set it once");
   CardsPerRegion = GrainBytes >> G1CardTable::card_shift;
 
+  LogCardsPerRegion = log2_long((jlong) CardsPerRegion);
+
   if (G1HeapRegionSize != GrainBytes) {
     FLAG_SET_ERGO(G1HeapRegionSize, GrainBytes);
   }
@@ -116,7 +119,7 @@
   assert(!in_collection_set(),
          "Should not clear heap region %u in the collection set", hrm_index());
 
-  set_young_index_in_cset(-1);
+  clear_young_index_in_cset();
   clear_index_in_opt_cset();
   uninstall_surv_rate_group();
   set_free();