src/cpu/ppc/vm/c1_Runtime1_ppc.cpp

*** 725,749 ****
        }
        break;
  
  #if INCLUDE_ALL_GCS
      case g1_pre_barrier_slow_id:
        {
          BarrierSet* bs = Universe::heap()->barrier_set();
          if (bs->kind() != BarrierSet::G1SATBCTLogging) {
            goto unimplemented_entry;
          }
  
          __ set_info("g1_pre_barrier_slow_id", dont_gc_arguments);
  
          // Using stack slots: pre_val (pre-pushed), spill tmp, spill tmp2.
          const int stack_slots = 3;
          Register pre_val = R0; // previous value of memory
          Register tmp  = R14;
          Register tmp2 = R15;
  
!         Label refill, restart;
          int satb_q_index_byte_offset =
            in_bytes(JavaThread::satb_mark_queue_offset() +
                     SATBMarkQueue::byte_offset_of_index());
          int satb_q_buf_byte_offset =
            in_bytes(JavaThread::satb_mark_queue_offset() +
--- 725,758 ----
        }
        break;
  
  #if INCLUDE_ALL_GCS
      case g1_pre_barrier_slow_id:
+     case g1_pre_barrier_slow_with_recheck_id:
        {
          BarrierSet* bs = Universe::heap()->barrier_set();
          if (bs->kind() != BarrierSet::G1SATBCTLogging) {
            goto unimplemented_entry;
          }
  
+         if (id == g1_pre_barrier_slow_id) {
            __ set_info("g1_pre_barrier_slow_id", dont_gc_arguments);
+         } else {
+           __ set_info("g1_pre_barrier_slow_with_recheck_id", dont_gc_arguments);
+         }
  
          // Using stack slots: pre_val (pre-pushed), spill tmp, spill tmp2.
          const int stack_slots = 3;
          Register pre_val = R0; // previous value of memory
          Register tmp  = R14;
          Register tmp2 = R15;
  
!         Label refill, restart, marking_not_active;;
!    
!         int satb_q_active_byte_offset =
!           in_bytes(JavaThread::satb_mark_queue_offset() +
!                    SATBMarkQueue::byte_offset_of_active());
          int satb_q_index_byte_offset =
            in_bytes(JavaThread::satb_mark_queue_offset() +
                     SATBMarkQueue::byte_offset_of_index());
          int satb_q_buf_byte_offset =
            in_bytes(JavaThread::satb_mark_queue_offset() +
*** 751,760 ****
--- 760,781 ----
  
          // Spill
          __ std(tmp, -16, R1_SP);
          __ std(tmp2, -24, R1_SP);
  
+         if (id == g1_pre_barrier_slow_with_recheck_id) {
+           // Is marking still active?
+           if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
+             __ lwz(tmp, satb_q_active_byte_offset, R16_thread);
+           } else {
+             guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+             __ lbz(tmp, satb_q_active_byte_offset, R16_thread);
+           }
+           __ cmpdi(CCR0, tmp, 0);
+           __ beq(CCR0, marking_not_active);
+         }
+ 
          __ bind(restart);
          // Load the index into the SATB buffer. SATBMarkQueue::_index is a
          // size_t so ld_ptr is appropriate.
          __ ld(tmp, satb_q_index_byte_offset, R16_thread);
  
*** 767,776 ****
--- 788,798 ----
          __ addi(tmp, tmp, -oopSize);
  
          __ std(tmp, satb_q_index_byte_offset, R16_thread);
          __ stdx(pre_val, tmp2, tmp); // [_buf + index] := <address_of_card>
  
+         __ bind(marking_not_active);
          // Restore temp registers and return-from-leaf.
          __ ld(tmp2, -24, R1_SP);
          __ ld(tmp, -16, R1_SP);
          __ blr();