src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp

*** 127,27 ***
  
  bool CardTableBarrierSetC2::use_ReduceInitialCardMarks() const {
    return ReduceInitialCardMarks;
  }
  
! void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
    assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
!   Node *shift = node->unique_out();
!   Node *addp = shift->unique_out();
!   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
!     Node *mem = addp->last_out(j);
!     if (UseCondCardMark && mem->is_Load()) {
!       assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
!       // The load is checking if the card has been written so
!       // replace it with zero to fold the test.
!       macro->replace_node(mem, macro->intcon(0));
!       continue;
      }
-     assert(mem->is_Store(), "store required");
-     macro->replace_node(mem, mem->in(MemNode::Memory));
    }
  }
  
  bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const {
!   bool is_oop = is_reference_type(type);
    return is_oop && (!tightly_coupled_alloc || !use_ReduceInitialCardMarks());
  }
--- 127,31 ---
  
  bool CardTableBarrierSetC2::use_ReduceInitialCardMarks() const {
    return ReduceInitialCardMarks;
  }
  
! void CardTableBarrierSetC2::eliminate_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
    assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required");
!   for (DUIterator_Last imin, i = node->last_outs(imin); i >= imin; --i) {
!     Node* shift = node->last_out(i);
!     for (DUIterator_Last jmin, j = shift->last_outs(jmin); j >= jmin; --j) {
!       Node* addp = shift->last_out(j);
!       for (DUIterator_Last kmin, k = addp->last_outs(kmin); k >= kmin; --k) {
!         Node* mem = addp->last_out(k);
!         if (UseCondCardMark && mem->is_Load()) {
!           assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
!           // The load is checking if the card has been written so
!           // replace it with zero to fold the test.
+           igvn->replace_node(mem, igvn->intcon(0));
+           continue;
+         }
+         assert(mem->is_Store(), "store required");
+         igvn->replace_node(mem, mem->in(MemNode::Memory));
+       }
      }
    }
  }
  
  bool CardTableBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const {
!   bool is_oop = type == T_OBJECT || type == T_ARRAY;
    return is_oop && (!tightly_coupled_alloc || !use_ReduceInitialCardMarks());
  }