src/hotspot/share/gc/z/zRelocate.cpp

@@ -86,11 +86,11 @@
 uintptr_t ZRelocate::relocate_object_inner(ZForwarding* forwarding, uintptr_t from_index, uintptr_t from_offset) const {
   ZForwardingCursor cursor;
 
   // Lookup forwarding entry
   const ZForwardingEntry entry = forwarding->find(from_index, &cursor);
-  if (entry.from_index() == from_index) {
+  if (entry.populated() && entry.from_index() == from_index) {
     // Already relocated, return new address
     return entry.to_offset();
   }
 
   assert(ZHeap::heap()->is_object_live(ZAddress::good(from_offset)), "Should be live");

@@ -148,11 +148,13 @@
 uintptr_t ZRelocate::forward_object(ZForwarding* forwarding, uintptr_t from_addr) const {
   const uintptr_t from_offset = ZAddress::offset(from_addr);
   const uintptr_t from_index = (from_offset - forwarding->start()) >> forwarding->object_alignment_shift();
   const ZForwardingEntry entry = forwarding->find(from_index);
 
+  assert(entry.populated(), "Should be forwarded");
   assert(entry.from_index() == from_index, "Should be forwarded");
+
   return ZAddress::good(entry.to_offset());
 }
 
 class ZRelocateObjectClosure : public ObjectClosure {
 private: