169 }
 170 
 171 void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
 172   assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
 173   Node *shift = node->unique_out();
 174   Node *addp = shift->unique_out();
 175   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 176     Node *mem = addp->last_out(j);
 177     if (UseCondCardMark && mem->is_Load()) {
 178       assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 179       // The load is checking if the card has been written so
 180       // replace it with zero to fold the test.
 181       macro->replace_node(mem, macro->intcon(0));
 182       continue;
 183     }
 184     assert(mem->is_Store(), "store required");
 185     macro->replace_node(mem, mem->in(MemNode::Memory));
 186   }
 187 }
 188 
 189 bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(BasicType type) const {
 190   return !use_ReduceInitialCardMarks();

 191 }

 169 }
 170 
 171 void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
 172   assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
 173   Node *shift = node->unique_out();
 174   Node *addp = shift->unique_out();
 175   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 176     Node *mem = addp->last_out(j);
 177     if (UseCondCardMark && mem->is_Load()) {
 178       assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 179       // The load is checking if the card has been written so
 180       // replace it with zero to fold the test.
 181       macro->replace_node(mem, macro->intcon(0));
 182       continue;
 183     }
 184     assert(mem->is_Store(), "store required");
 185     macro->replace_node(mem, mem->in(MemNode::Memory));
 186   }
 187 }
 188 
 189 bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
 190   bool is_oop = type == T_OBJECT || type == T_ARRAY;
 191   return is_oop && (!tightly_coupled_alloc || !use_ReduceInitialCardMarks());
 192 }