src/share/vm/opto/library_call.cpp

@@ -272,10 +272,11 @@
 
   typedef enum { LS_xadd, LS_xchg, LS_cmpxchg } LoadStoreKind;
   bool inline_unsafe_load_store(BasicType type,  LoadStoreKind kind);
   bool inline_unsafe_ordered_store(BasicType type);
   bool inline_unsafe_fence(vmIntrinsics::ID id);
+  bool inline_onspinwait();
   bool inline_fp_conversions(vmIntrinsics::ID id);
   bool inline_number_methods(vmIntrinsics::ID id);
   bool inline_reference_get();
   bool inline_Class_cast();
   bool inline_aescrypt_Block(vmIntrinsics::ID id);

@@ -627,10 +628,12 @@
 
   case vmIntrinsics::_loadFence:
   case vmIntrinsics::_storeFence:
   case vmIntrinsics::_fullFence:                return inline_unsafe_fence(intrinsic_id());
 
+  case vmIntrinsics::_onSpinWait:             return inline_onspinwait();
+
   case vmIntrinsics::_currentThread:            return inline_native_currentThread();
   case vmIntrinsics::_isInterrupted:            return inline_native_isInterrupted();
 
 #ifdef TRACE_HAVE_INTRINSICS
   case vmIntrinsics::_classID:                  return inline_native_classID();

@@ -2972,10 +2975,15 @@
       fatal_unexpected_iid(id);
       return false;
   }
 }
 
+bool LibraryCallKit::inline_onspinwait() {
+  insert_mem_bar(Op_OnSpinWait);
+  return true;
+}
+
 bool LibraryCallKit::klass_needs_init_guard(Node* kls) {
   if (!kls->is_Con()) {
     return true;
   }
   const TypeKlassPtr* klsptr = kls->bottom_type()->isa_klassptr();

@@ -3355,10 +3363,13 @@
   case vmIntrinsics::_isInstance:
     // nothing is an instance of a primitive type
     query_value = gen_instanceof(obj, kls, safe_for_replace);
     break;
 
+  case vmIntrinsics::_onSpinWait:
+    break;
+
   case vmIntrinsics::_getModifiers:
     p = basic_plus_adr(kls, in_bytes(Klass::modifier_flags_offset()));
     query_value = make_load(NULL, p, TypeInt::INT, T_INT, MemNode::unordered);
     break;