8265129: Add intrinsic support for JVM.getClassId

Reviewed-by: kvn, mgronlun

src/hotspot/share/c1/c1_Compiler.cpp

@@ -223,11 +223,7 @@ bool Compiler::is_intrinsic_supported(const methodHandle& method) {
 #ifdef JFR_HAVE_INTRINSICS
   case vmIntrinsics::_counterTime:
   case vmIntrinsics::_getEventWriter:
-#if defined(_LP64) || !defined(TRACE_ID_SHIFT)
-  case vmIntrinsics::_getClassId:
 #endif
-#endif
-    break;
   case vmIntrinsics::_getObjectSize:
     break;
   case vmIntrinsics::_blackhole:

src/hotspot/share/c1/c1_LIRGenerator.cpp

@@ -3055,33 +3055,6 @@ void LIRGenerator::do_IfOp(IfOp* x) {
 }
 
 #ifdef JFR_HAVE_INTRINSICS
-void LIRGenerator::do_ClassIDIntrinsic(Intrinsic* x) {
-  CodeEmitInfo* info = state_for(x);
-  CodeEmitInfo* info2 = new CodeEmitInfo(info); // Clone for the second null check
-
-  assert(info != NULL, "must have info");
-  LIRItem arg(x->argument_at(0), this);
-
-  arg.load_item();
-  LIR_Opr klass = new_register(T_METADATA);
-  __ move(new LIR_Address(arg.result(), java_lang_Class::klass_offset(), T_ADDRESS), klass, info);
-  LIR_Opr id = new_register(T_LONG);
-  ByteSize offset = KLASS_TRACE_ID_OFFSET;
-  LIR_Address* trace_id_addr = new LIR_Address(klass, in_bytes(offset), T_LONG);
-
-  __ move(trace_id_addr, id);
-  __ logical_or(id, LIR_OprFact::longConst(0x01l), id);
-  __ store(id, trace_id_addr);
-
-#ifdef TRACE_ID_META_BITS
-  __ logical_and(id, LIR_OprFact::longConst(~TRACE_ID_META_BITS), id);
-#endif
-#ifdef TRACE_ID_SHIFT
-  __ unsigned_shift_right(id, TRACE_ID_SHIFT, id);
-#endif
-
-  __ move(id, rlock_result(x));
-}
 
 void LIRGenerator::do_getEventWriter(Intrinsic* x) {
   LabelObj* L_end = new LabelObj();
@@ -3131,9 +3104,6 @@ void LIRGenerator::do_Intrinsic(Intrinsic* x) {
   }
 
 #ifdef JFR_HAVE_INTRINSICS
-  case vmIntrinsics::_getClassId:
-    do_ClassIDIntrinsic(x);
-    break;
   case vmIntrinsics::_getEventWriter:
     do_getEventWriter(x);
     break;

src/hotspot/share/jfr/jfr.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,12 +25,14 @@
 #include "precompiled.hpp"
 #include "jfr/jfr.hpp"
 #include "jfr/leakprofiler/leakProfiler.hpp"
+#include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdLoadBarrier.inline.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
 #include "jfr/recorder/repository/jfrEmergencyDump.hpp"
 #include "jfr/recorder/service/jfrOptionSet.hpp"
 #include "jfr/recorder/repository/jfrRepository.hpp"
 #include "jfr/support/jfrThreadLocal.hpp"
+#include "runtime/interfaceSupport.inline.hpp"
 #include "runtime/java.hpp"
 #include "runtime/thread.hpp"
 
@@ -109,3 +111,16 @@ bool Jfr::on_flight_recorder_option(const JavaVMOption** option, char* delimiter
 bool Jfr::on_start_flight_recording_option(const JavaVMOption** option, char* delimiter) {
   return JfrOptionSet::parse_start_flight_recording_option(option, delimiter);
 }
+
+JRT_LEAF(void, Jfr::get_class_id_intrinsic(const Klass* klass))
+  assert(klass != NULL, "sanity");
+  JfrTraceIdLoadBarrier::load_barrier(klass);
+JRT_END
+
+address Jfr::epoch_address() {
+  return JfrTraceIdEpoch::epoch_address();
+}
+
+address Jfr::signal_address() {
+  return JfrTraceIdEpoch::signal_address();
+}

src/hotspot/share/jfr/jfr.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,6 +30,7 @@
 
 class JavaThread;
 class Thread;
+class Klass;
 
 extern "C" void JNICALL jfr_register_natives(JNIEnv*, jclass);
 
@@ -54,6 +55,11 @@ class Jfr : AllStatic {
   static void exclude_thread(Thread* thread);
   static bool is_excluded(Thread* thread);
   static void include_thread(Thread* thread);
+
+  // intrinsic support
+  static void get_class_id_intrinsic(const Klass* klass);
+  static address epoch_address();
+  static address signal_address();
 };
 
 #endif // SHARE_JFR_JFR_HPP

src/hotspot/share/jfr/jni/jfrJniMethodRegistration.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,7 +44,7 @@ JfrJniMethodRegistration::JfrJniMethodRegistration(JNIEnv* env) {
       (char*)"destroyJFR", (char*)"()Z", (void*)jfr_destroy_jfr,
       (char*)"emitEvent", (char*)"(JJJ)Z", (void*)jfr_emit_event,
       (char*)"getAllEventClasses", (char*)"()Ljava/util/List;", (void*)jfr_get_all_event_classes,
-      (char*)"getClassIdNonIntrinsic", (char*)"(Ljava/lang/Class;)J", (void*)jfr_class_id,
+      (char*)"getClassId", (char*)"(Ljava/lang/Class;)J", (void*)jfr_class_id,
       (char*)"getPid", (char*)"()Ljava/lang/String;", (void*)jfr_get_pid,
       (char*)"getStackTraceId", (char*)"(I)J", (void*)jfr_stacktrace_id,
       (char*)"getThreadId", (char*)"(Ljava/lang/Thread;)J", (void*)jfr_id_for_thread,

src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -67,8 +67,8 @@ class JfrTraceIdEpoch : AllStatic {
     return _epoch_state;
   }
 
-  static jlong epoch_address() {
+  static address epoch_address() {
-    return (jlong)&_epoch_state;
+    return (address)&_epoch_state;
   }
 
   static u1 current() {
@@ -114,6 +114,10 @@ class JfrTraceIdEpoch : AllStatic {
   static void set_changed_tag_state() {
     _tag_state.signal();
   }
+
+  static address signal_address() {
+    return _tag_state.signaled_address();
+  }
 };
 
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP

src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdLoadBarrier.hpp

@@ -67,12 +67,14 @@ class PackageEntry;
  *
  */
 class JfrTraceIdLoadBarrier : AllStatic {
+  friend class Jfr;
   friend class JfrCheckpointManager;
  private:
   static bool initialize();
   static void clear();
   static void destroy();
   static void enqueue(const Klass* klass);
+  static void load_barrier(const Klass* klass);
  public:
   static traceid load(const ClassLoaderData* cld);
   static traceid load(const Klass* klass);

src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdLoadBarrier.inline.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -65,12 +65,16 @@ inline traceid set_used_and_get(const T* type) {
   return TRACE_ID(type);
 }
 
-inline traceid JfrTraceIdLoadBarrier::load(const Klass* klass) {
+inline void JfrTraceIdLoadBarrier::load_barrier(const Klass* klass) {
-  assert(klass != NULL, "invariant");
-  if (should_tag(klass)) {
     SET_USED_THIS_EPOCH(klass);
     enqueue(klass);
     JfrTraceIdEpoch::set_changed_tag_state();
+}
+
+inline traceid JfrTraceIdLoadBarrier::load(const Klass* klass) {
+  assert(klass != NULL, "invariant");
+  if (should_tag(klass)) {
+    load_barrier(klass);
   }
   assert(USED_THIS_EPOCH(klass), "invariant");
   return TRACE_ID(klass);

src/hotspot/share/jfr/utilities/jfrSignal.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,6 +46,8 @@ class JfrSignal {
     }
     return false;
   }
+
+  address signaled_address() { return (address)&_signaled; }
 };
 
 #endif // SHARE_JFR_UTILITIES_JFRSIGNAL_HPP

src/hotspot/share/opto/escape.cpp

@@ -1106,7 +1106,8 @@ void ConnectionGraph::process_call_arguments(CallNode *call) {
                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
                   strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
                   strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
-                  strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
+                  strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
+                  strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0)
                  ))) {
             call->dump();
             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);

src/hotspot/share/opto/idealKit.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -351,7 +351,8 @@ Node* IdealKit::load(Node* ctl,
                      const Type* t,
                      BasicType bt,
                      int adr_idx,
-                     bool require_atomic_access) {
+                     bool require_atomic_access,
+                     MemNode::MemOrd mo) {
 
   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
   const TypePtr* adr_type = NULL; // debug-mode-only argument
@@ -359,9 +360,9 @@ Node* IdealKit::load(Node* ctl,
   Node* mem = memory(adr_idx);
   Node* ld;
   if (require_atomic_access && bt == T_LONG) {
-    ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, MemNode::unordered);
+    ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo);
   } else {
-    ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, MemNode::unordered);
+    ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo);
   }
   return transform(ld);
 }

src/hotspot/share/opto/idealKit.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -220,7 +220,7 @@ class IdealKit: public StackObj {
              const Type* t,
              BasicType bt,
              int adr_idx,
-             bool require_atomic_access = false);
+             bool require_atomic_access = false, MemNode::MemOrd mo = MemNode::unordered);
 
   // Return the new StoreXNode
   Node* store(Node* ctl,

src/hotspot/share/opto/library_call.cpp

@@ -57,6 +57,10 @@
 #include "utilities/macros.hpp"
 #include "utilities/powerOfTwo.hpp"
 
+#if INCLUDE_JFR
+#include "jfr/jfr.hpp"
+#endif
+
 //---------------------------make_vm_intrinsic----------------------------
 CallGenerator* Compile::make_vm_intrinsic(ciMethod* m, bool is_virtual) {
   vmIntrinsicID id = m->intrinsic_id();
@@ -2802,37 +2806,83 @@ bool LibraryCallKit::inline_native_time_funcs(address funcAddr, const char* func
 
 #ifdef JFR_HAVE_INTRINSICS
 
-/*
+/**
-* oop -> myklass
+ * if oop->klass != null
-* myklass->trace_id |= USED
+ *   // normal class
-* return myklass->trace_id & ~0x3
+ *   epoch = _epoch_state ? 2 : 1
-*/
+ *   if oop->klass->trace_id & ((epoch << META_SHIFT) | epoch)) != epoch {
+ *     ... // enter slow path when the klass is first recorded or the epoch of JFR shifts
+ *   }
+ *   id = oop->klass->trace_id >> TRACE_ID_SHIFT // normal class path
+ * else
+ *   // primitive class
+ *   if oop->array_klass != null
+ *     id = (oop->array_klass->trace_id >> TRACE_ID_SHIFT) + 1 // primitive class path
+ *   else
+ *     id = LAST_TYPE_ID + 1 // void class path
+ *   if (!signaled)
+ *     signaled = true
+ */
 bool LibraryCallKit::inline_native_classID() {
-  Node* cls = null_check(argument(0), T_OBJECT);
+  Node* cls = argument(0);
-  Node* kls = load_klass_from_mirror(cls, false, NULL, 0);
-  kls = null_check(kls, T_OBJECT);
 
-  ByteSize offset = KLASS_TRACE_ID_OFFSET;
+  IdealKit ideal(this);
-  Node* insp = basic_plus_adr(kls, in_bytes(offset));
+#define __ ideal.
-  Node* tvalue = make_load(NULL, insp, TypeLong::LONG, T_LONG, MemNode::unordered);
+  IdealVariable result(ideal); __ declarations_done();
+  Node* kls = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(),
+                                                 basic_plus_adr(cls, java_lang_Class::klass_offset()),
+                                                 TypeRawPtr::BOTTOM, TypeKlassPtr::OBJECT_OR_NULL));
 
-  Node* clsused = longcon(0x01l); // set the class bit
-  Node* orl = _gvn.transform(new OrLNode(tvalue, clsused));
-  const TypePtr *adr_type = _gvn.type(insp)->isa_ptr();
-  store_to_memory(control(), insp, orl, T_LONG, adr_type, MemNode::unordered);
 
-#ifdef TRACE_ID_META_BITS
+  __ if_then(kls, BoolTest::ne, null()); {
-  Node* mbits = longcon(~TRACE_ID_META_BITS);
+    Node* kls_trace_id_addr = basic_plus_adr(kls, in_bytes(KLASS_TRACE_ID_OFFSET));
-  tvalue = _gvn.transform(new AndLNode(tvalue, mbits));
+    Node* kls_trace_id_raw = ideal.load(ideal.ctrl(), kls_trace_id_addr,TypeLong::LONG, T_LONG, Compile::AliasIdxRaw);
-#endif
-#ifdef TRACE_ID_SHIFT
-  Node* cbits = intcon(TRACE_ID_SHIFT);
-  tvalue = _gvn.transform(new URShiftLNode(tvalue, cbits));
-#endif
 
-  set_result(tvalue);
+    Node* epoch_address = makecon(TypeRawPtr::make(Jfr::epoch_address()));
+    Node* epoch = ideal.load(ideal.ctrl(), epoch_address, TypeInt::BOOL, T_BOOLEAN, Compile::AliasIdxRaw);
+    epoch = _gvn.transform(new LShiftLNode(longcon(1), epoch));
+    Node* mask = _gvn.transform(new LShiftLNode(epoch, intcon(META_SHIFT)));
+    mask = _gvn.transform(new OrLNode(mask, epoch));
+    Node* kls_trace_id_raw_and_mask = _gvn.transform(new AndLNode(kls_trace_id_raw, mask));
+
+    float unlikely  = PROB_UNLIKELY(0.999);
+    __ if_then(kls_trace_id_raw_and_mask, BoolTest::ne, epoch, unlikely); {
+      sync_kit(ideal);
+      make_runtime_call(RC_LEAF,
+                        OptoRuntime::get_class_id_intrinsic_Type(),
+                        CAST_FROM_FN_PTR(address, Jfr::get_class_id_intrinsic),
+                        "get_class_id_intrinsic",
+                        TypePtr::BOTTOM,
+                        kls);
+      ideal.sync_kit(this);
+    } __ end_if();
+
+    ideal.set(result,  _gvn.transform(new URShiftLNode(kls_trace_id_raw, ideal.ConI(TRACE_ID_SHIFT))));
+  } __ else_(); {
+    Node* array_kls = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(),
+                                                   basic_plus_adr(cls, java_lang_Class::array_klass_offset()),
+                                                   TypeRawPtr::BOTTOM, TypeKlassPtr::OBJECT_OR_NULL));
+    __ if_then(array_kls, BoolTest::ne, null()); {
+      Node* array_kls_trace_id_addr = basic_plus_adr(array_kls, in_bytes(KLASS_TRACE_ID_OFFSET));
+      Node* array_kls_trace_id_raw = ideal.load(ideal.ctrl(), array_kls_trace_id_addr, TypeLong::LONG, T_LONG, Compile::AliasIdxRaw);
+      Node* array_kls_trace_id = _gvn.transform(new URShiftLNode(array_kls_trace_id_raw, ideal.ConI(TRACE_ID_SHIFT)));
+      ideal.set(result, _gvn.transform(new AddLNode(array_kls_trace_id, longcon(1))));
+    } __ else_(); {
+      // void class case
+      ideal.set(result, _gvn.transform(longcon(LAST_TYPE_ID + 1)));
+    } __ end_if();
+
+    Node* signaled_flag_address = makecon(TypeRawPtr::make(Jfr::signal_address()));
+    Node* signaled = ideal.load(ideal.ctrl(), signaled_flag_address, TypeInt::BOOL, T_BOOLEAN, Compile::AliasIdxRaw, true, MemNode::acquire);
+    __ if_then(signaled, BoolTest::ne, ideal.ConI(1)); {
+      ideal.store(ideal.ctrl(), signaled_flag_address, ideal.ConI(1), T_BOOLEAN, Compile::AliasIdxRaw, MemNode::release, true);
+    } __ end_if();
+  } __ end_if();
+
+  final_sync(ideal);
+  set_result(ideal.value(result));
+#undef __
   return true;
-
 }
 
 bool LibraryCallKit::inline_native_getEventWriter() {

src/hotspot/share/opto/runtime.cpp

@@ -1498,6 +1498,21 @@ const TypeFunc *OptoRuntime::register_finalizer_Type() {
   return TypeFunc::make(domain,range);
 }
 
+#if INCLUDE_JFR
+const TypeFunc *OptoRuntime::get_class_id_intrinsic_Type() {
+  // create input type (domain)
+  const Type **fields = TypeTuple::fields(1);
+  fields[TypeFunc::Parms+0] = TypeInstPtr::KLASS;
+  const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms + 1, fields);
+
+  // create result type (range)
+  fields = TypeTuple::fields(0);
+
+  const TypeTuple *range = TypeTuple::make(TypeFunc::Parms + 0, fields);
+
+  return TypeFunc::make(domain,range);
+}
+#endif
 
 //-----------------------------------------------------------------------------
 // Dtrace support.  entry and exit probes have the same signature

src/hotspot/share/opto/runtime.hpp

@@ -304,6 +304,8 @@ private:
 
   static const TypeFunc* register_finalizer_Type();
 
+  JFR_ONLY(static const TypeFunc* get_class_id_intrinsic_Type();)
+
   // Dtrace support
   static const TypeFunc* dtrace_method_entry_exit_Type();
   static const TypeFunc* dtrace_object_alloc_Type();

src/hotspot/share/runtime/sharedRuntime.cpp

@@ -986,7 +986,6 @@ JRT_ENTRY_NO_ASYNC(void, SharedRuntime::register_finalizer(JavaThread* current,
   InstanceKlass::register_finalizer(instanceOop(obj), CHECK);
 JRT_END
 
-
 jlong SharedRuntime::get_java_tid(Thread* thread) {
   if (thread != NULL) {
     if (thread->is_Java_thread()) {

src/jdk.jfr/share/classes/jdk/jfr/internal/EventWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -166,7 +166,7 @@ public final class EventWriter {
         if (aClass == null) {
             putLong(0L);
         } else {
-            putLong(JVM.getClassIdNonIntrinsic(aClass));
+            putLong(JVM.getClassId(aClass));
         }
     }
 

src/jdk.jfr/share/classes/jdk/jfr/internal/JVM.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -142,9 +142,6 @@ public final class JVM {
     @IntrinsicCandidate
     public static native long getClassId(Class<?> clazz);
 
-    // temporary workaround until we solve intrinsics supporting epoch shift tagging
-    public static native long getClassIdNonIntrinsic(Class<?> clazz);
-
     /**
      * Return process identifier.
      *

test/jdk/jdk/jfr/jvm/TestClearStaleConstants.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -68,7 +68,7 @@ public final class TestClearStaleConstants {
         Class<?> clz = recordClassDefinition(firstClassLoader);
         JVM jvm = JVM.getJVM();
         // we will now tag the defined and loaded clz as being in use (no recordings are running here)
-        jvm.getClassIdNonIntrinsic(clz);
+        jvm.getClassId(clz);
         // null out for unload to occur
         firstClassLoader = null;
         clz = null;

test/jdk/jdk/jfr/jvm/TestJFRIntrinsic.java

@@ -59,24 +59,20 @@ public class TestJFRIntrinsic {
     public Object eventWriter;
 
     public static void main(String... args) throws Exception {
-        /*
+        JVM.getJVM().createNativeJFR();
-        Temporarily excluded until getClassId is reworked to accommodate epoch shift tagging
+        TestJFRIntrinsic ti = new TestJFRIntrinsic();
         Method classid = TestJFRIntrinsic.class.getDeclaredMethod("getClassIdIntrinsic",  Class.class);
         ti.runIntrinsicTest(classid);
-        */
-        TestJFRIntrinsic ti = new TestJFRIntrinsic();
         Method eventWriterMethod = TestJFRIntrinsic.class.getDeclaredMethod("getEventWriterIntrinsic", Class.class);
         ti.runIntrinsicTest(eventWriterMethod);
     }
 
-    /*
     public void getClassIdIntrinsic(Class<?> cls) {
         long exp = JVM.getClassId(cls);
         if (exp == 0) {
             throw new RuntimeException("Class id is zero");
         }
     }
-    */
 
     public void getEventWriterIntrinsic(Class<?> cls) {
         Object o = JVM.getEventWriter();