src/hotspot/share/opto/graphKit.cpp

*** 3004,10 ***
--- 3004,83 ---
    }
    speculating = false;
    return false;
  }
  
+ void GraphKit::guard_klass_is_initialized(Node* klass) {
+   assert(ClassInitBarrierMode > 0, "no barriers");
+   int init_state_off = in_bytes(InstanceKlass::init_state_offset());
+   Node* adr = basic_plus_adr(top(), klass, init_state_off);
+   Node* init_state = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
+                                     adr->bottom_type()->is_ptr(), TypeInt::BYTE,
+                                     T_BYTE, MemNode::unordered);
+   init_state = _gvn.transform(init_state);
+ 
+   Node* initialized_state = makecon(TypeInt::make(InstanceKlass::fully_initialized));
+ 
+   Node* chk = _gvn.transform(new CmpINode(initialized_state, init_state));
+   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
+ 
+   switch (ClassInitBarrierMode) {
+     case 1: { // uncommon trap on slow path
+       BuildCutout unless(this, tst, PROB_MAX);
+       // Do not deoptimize this nmethod. Go to Interpreter to initialize class.
+       uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
+       break;
+     }
+     case 2: { // runtime call on slow path
+       if (StressClassInitBarriers) {
+         tst = makecon(TypeInt::ZERO); // always go through slow path
+       }
+       IfNode* iff = create_and_xform_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
+ //    IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
+ 
+       RegionNode* r = new RegionNode(3);
+       r->init_req(1, _gvn.transform(new IfTrueNode(iff)));
+ 
+       set_control(_gvn.transform(new IfFalseNode(iff)));
+ 
+       if (!stopped()) {
+         kill_dead_locals();
+ 
+         Node* call = make_runtime_call(RC_NO_LEAF,
+                                        OptoRuntime::class_init_barrier_Type(),
+                                        OptoRuntime::class_init_barrier_Java(),
+                                        nullptr, TypePtr::BOTTOM,
+                                        klass);
+         // Deoptimization during class init barrier execution should trigger current bytecode reexecution.
+         call->jvms()->set_should_reexecute(true);
+ 
+         // FIXME: deoptimize for now. deoptimize=false doesn't work with late inlining yet.
+         // Parse::create_entry_map() introduces a barrier which uses distinct JVM state (*before* call).
+         // Compilation fails when distinct exception states are combined.
+         make_slow_call_ex(call, env()->Throwable_klass(), /*separate_io_proj=*/true, /*deoptimize=*/true);
+ 
+         Node* fast_io  = call->in(TypeFunc::I_O);
+         Node* fast_mem = call->in(TypeFunc::Memory);
+         // These two phis are pre-filled with copies of of the fast IO and Memory
+         Node* io_phi   = PhiNode::make(r, fast_io,  Type::ABIO);
+         Node* mem_phi  = PhiNode::make(r, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
+ 
+         r->init_req(2, control());
+         io_phi->init_req(2, i_o());
+         mem_phi->init_req(2, reset_memory());
+ 
+         set_all_memory(_gvn.transform(mem_phi));
+         set_i_o(_gvn.transform(io_phi));
+       } else {
+         r->init_req(2, top());
+       }
+       set_control(_gvn.transform(r));
+       break;
+     }
+ 
+     default: fatal("unknown barrier mode: %d", ClassInitBarrierMode);
+   }
+   C->set_has_clinit_barriers(true);
+ }
+ 
  void GraphKit::guard_klass_being_initialized(Node* klass) {
    int init_state_off = in_bytes(InstanceKlass::init_state_offset());
    Node* adr = basic_plus_adr(top(), klass, init_state_off);
    Node* init_state = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
                                      adr->bottom_type()->is_ptr(), TypeInt::BYTE,

*** 3042,13 ***
      uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
    }
  }
  
  void GraphKit::clinit_barrier(ciInstanceKlass* ik, ciMethod* context) {
    if (ik->is_being_initialized()) {
      if (C->needs_clinit_barrier(ik, context)) {
!       Node* klass = makecon(TypeKlassPtr::make(ik));
        guard_klass_being_initialized(klass);
        guard_init_thread(klass);
        insert_mem_bar(Op_MemBarCPUOrder);
      }
    } else if (ik->is_initialized()) {
--- 3115,18 ---
      uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
    }
  }
  
  void GraphKit::clinit_barrier(ciInstanceKlass* ik, ciMethod* context) {
+   if (C->do_clinit_barriers()) {
+     Node* klass = makecon(TypeKlassPtr::make(ik, Type::trust_interfaces));
+     guard_klass_is_initialized(klass);
+     return;
+   }
    if (ik->is_being_initialized()) {
      if (C->needs_clinit_barrier(ik, context)) {
!       Node* klass = makecon(TypeKlassPtr::make(ik, Type::trust_interfaces));
        guard_klass_being_initialized(klass);
        guard_init_thread(klass);
        insert_mem_bar(Op_MemBarCPUOrder);
      }
    } else if (ik->is_initialized()) {