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

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