195 
196   return false;
197 }
198 
199 Node* G1BarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
200   DecoratorSet decorators = access.decorators();
201   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
202   bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
203   bool no_keepalive = (decorators & AS_NO_KEEPALIVE) != 0;
204   // If we are reading the value of the referent field of a Reference object, we
205   // need to record the referent in an SATB log buffer using the pre-barrier
206   // mechanism. Also we need to add a memory barrier to prevent commoning reads
207   // from this field across safepoints, since GC can change its value.
208   bool need_read_barrier = ((on_weak || on_phantom) && !no_keepalive);
209   if (access.is_oop() && need_read_barrier) {
210     access.set_barrier_data(G1C2BarrierPre);
211   }
212   return CardTableBarrierSetC2::load_at_resolved(access, val_type);
213 }
214 
215 void G1BarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
216   eliminate_gc_barrier_data(node);
217 }
218 
219 void G1BarrierSetC2::eliminate_gc_barrier_data(Node* node) const {
220   if (node->is_LoadStore()) {
221     LoadStoreNode* loadstore = node->as_LoadStore();
222     loadstore->set_barrier_data(0);
223   } else if (node->is_Mem()) {
224     MemNode* mem = node->as_Mem();
225     mem->set_barrier_data(0);
226   }
227 }
228 
229 static void refine_barrier_by_new_val_type(const Node* n) {
230   if (n->Opcode() != Op_StoreP &&
231       n->Opcode() != Op_StoreN) {
232     return;
233   }
234   MemNode* store = n->as_Mem();
235   const Node* newval = n->in(MemNode::ValueIn);
236   assert(newval != nullptr, "");
237   const Type* newval_bottom = newval->bottom_type();
238   TypePtr::PTR newval_type = newval_bottom->make_ptr()->ptr();

195 
196   return false;
197 }
198 
199 Node* G1BarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
200   DecoratorSet decorators = access.decorators();
201   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
202   bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
203   bool no_keepalive = (decorators & AS_NO_KEEPALIVE) != 0;
204   // If we are reading the value of the referent field of a Reference object, we
205   // need to record the referent in an SATB log buffer using the pre-barrier
206   // mechanism. Also we need to add a memory barrier to prevent commoning reads
207   // from this field across safepoints, since GC can change its value.
208   bool need_read_barrier = ((on_weak || on_phantom) && !no_keepalive);
209   if (access.is_oop() && need_read_barrier) {
210     access.set_barrier_data(G1C2BarrierPre);
211   }
212   return CardTableBarrierSetC2::load_at_resolved(access, val_type);
213 }
214 
215 void G1BarrierSetC2::eliminate_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
216   eliminate_gc_barrier_data(node);
217 }

218 void G1BarrierSetC2::eliminate_gc_barrier_data(Node* node) const {
219   if (node->is_LoadStore()) {
220     LoadStoreNode* loadstore = node->as_LoadStore();
221     loadstore->set_barrier_data(0);
222   } else if (node->is_Mem()) {
223     MemNode* mem = node->as_Mem();
224     mem->set_barrier_data(0);
225   }
226 }
227 
228 static void refine_barrier_by_new_val_type(const Node* n) {
229   if (n->Opcode() != Op_StoreP &&
230       n->Opcode() != Op_StoreN) {
231     return;
232   }
233   MemNode* store = n->as_Mem();
234   const Node* newval = n->in(MemNode::ValueIn);
235   assert(newval != nullptr, "");
236   const Type* newval_bottom = newval->bottom_type();
237   TypePtr::PTR newval_type = newval_bottom->make_ptr()->ptr();