src/hotspot/share/prims/jvmtiTagMap.cpp

@@ -57,10 +57,13 @@
 #include "runtime/threadSMR.hpp"
 #include "runtime/vframe.hpp"
 #include "runtime/vmThread.hpp"
 #include "runtime/vm_operations.hpp"
 #include "utilities/macros.hpp"
+#if INCLUDE_ZGC
+#include "gc/z/zGlobals.hpp"
+#endif
 
 // JvmtiTagHashmapEntry
 //
 // Each entry encapsulates a reference to the tagged object
 // and the tag value. In addition an entry includes a next pointer which

@@ -176,10 +179,12 @@
     }
   }
 
   // hash a given key (oop) with the specified size
   static unsigned int hash(oop key, int size) {
+    ZGC_ONLY(assert(ZAddressMetadataShift >= sizeof(unsigned int) * BitsPerByte, "cast removes the metadata bits");)
+
     // shift right to get better distribution (as these bits will be zero
     // with aligned addresses)
     unsigned int addr = (unsigned int)(cast_from_oop<intptr_t>(key));
 #ifdef _LP64
     return (addr >> 3) % size;