112     // no_ctrl, but that doesn't buy much latitude.
113     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, T_BYTE, adr_type);
114     __ if_then(card_val, BoolTest::ne, dirty);
115   }
116 
117   // Smash dirty value into card
118   __ store(__ ctrl(), card_adr, dirty, T_BYTE, adr_type, MemNode::unordered);
119 
120   if (UseCondCardMark) {
121     __ end_if();
122   }
123 
124   // Final sync IdealKit and GraphKit.
125   kit->final_sync(ideal);
126 }
127 
128 bool CardTableBarrierSetC2::use_ReduceInitialCardMarks() const {
129   return ReduceInitialCardMarks;
130 }
131 
132 void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
133   assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
134   Node *shift = node->unique_out();
135   Node *addp = shift->unique_out();
136   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
137     Node *mem = addp->last_out(j);
138     if (UseCondCardMark && mem->is_Load()) {
139       assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
140       // The load is checking if the card has been written so
141       // replace it with zero to fold the test.
142       macro->replace_node(mem, macro->intcon(0));
143       continue;






144     }
145     assert(mem->is_Store(), "store required");
146     macro->replace_node(mem, mem->in(MemNode::Memory));
147   }
148 }
149 
150 bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const {
151   bool is_oop = is_reference_type(type);
152   return is_oop && (!tightly_coupled_alloc || !use_ReduceInitialCardMarks());
153 }

112     // no_ctrl, but that doesn't buy much latitude.
113     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, T_BYTE, adr_type);
114     __ if_then(card_val, BoolTest::ne, dirty);
115   }
116 
117   // Smash dirty value into card
118   __ store(__ ctrl(), card_adr, dirty, T_BYTE, adr_type, MemNode::unordered);
119 
120   if (UseCondCardMark) {
121     __ end_if();
122   }
123 
124   // Final sync IdealKit and GraphKit.
125   kit->final_sync(ideal);
126 }
127 
128 bool CardTableBarrierSetC2::use_ReduceInitialCardMarks() const {
129   return ReduceInitialCardMarks;
130 }
131 
132 void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
133   assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
134   for (DUIterator_Last imin, i = node->last_outs(imin); i >= imin; --i) {
135     Node* shift = node->last_out(i);
136     for (DUIterator_Last jmin, j = shift->last_outs(jmin); j >= jmin; --j) {
137       Node* addp = shift->last_out(j);
138       for (DUIterator_Last kmin, k = addp->last_outs(kmin); k >= kmin; --k) {
139         Node* mem = addp->last_out(k);
140         if (UseCondCardMark && mem->is_Load()) {
141           assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
142           // The load is checking if the card has been written so
143           // replace it with zero to fold the test.
144           igvn->replace_node(mem, igvn->intcon(0));
145           continue;
146         }
147         assert(mem->is_Store(), "store required");
148         igvn->replace_node(mem, mem->in(MemNode::Memory));
149       }
150     }


151   }
152 }
153 
154 bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const {
155   bool is_oop = type == T_OBJECT || type == T_ARRAY;
156   return is_oop && (!tightly_coupled_alloc || !use_ReduceInitialCardMarks());
157 }