--- old/src/hotspot/share/gc/z/zCollectedHeap.cpp	2019-09-17 15:01:30.573081583 +0200
+++ new/src/hotspot/share/gc/z/zCollectedHeap.cpp	2019-09-17 15:01:30.317073204 +0200
@@ -365,14 +365,12 @@
   _heap.verify();
 }
 
-bool ZCollectedHeap::is_oop(oop object) const {
-  return CollectedHeap::is_oop(object) && _heap.is_oop(object);
+bool ZCollectedHeap::is_oop_location(void* addr) const {
+  return is_object_aligned(addr) &&
+         (uintptr_t)addr >= ZAddressSpaceStart &&
+         (uintptr_t)addr < ZAddressSpaceEnd;
 }
 
-void ZCollectedHeap::check_oop_location(void* addr) const {
-  assert(is_object_aligned(addr), "address is not aligned");
-
-  const uintptr_t addr_int = reinterpret_cast<uintptr_t>(addr);
-  assert(addr_int >= ZAddressSpaceStart, "address is outside of the heap");
-  assert(addr_int < ZAddressSpaceEnd,    "address is outside of the heap");
+bool ZCollectedHeap::is_oop(oop object) const {
+  return CollectedHeap::is_oop(object) && _heap.is_oop(object);
 }