src/hotspot/share/opto/loopopts.cpp

*** 1092,1113 ****
  //------------------------------place_near_use---------------------------------
  // Place some computation next to use but not inside inner loops.
  // For inner loop uses move it to the preheader area.
  Node *PhaseIdealLoop::place_near_use( Node *useblock ) const {
    IdealLoopTree *u_loop = get_loop( useblock );
!   return (u_loop->_irreducible || u_loop->_child)
!     ? useblock
!     : u_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
  }
  
  
  bool PhaseIdealLoop::identical_backtoback_ifs(Node *n) {
    if (!n->is_If()) {
      return false;
    }
    Node* region = NULL;
    bool shenandoah_evac = ShenandoahWriteBarrierNode::is_evacuation_in_progress_test(n);
    if (shenandoah_evac) {
      assert(UseShenandoahGC, "for shenandoah only");
      region = ShenandoahWriteBarrierNode::evacuation_in_progress_test_ctrl(n);
    } else {
      region = n->in(0);
--- 1092,1121 ----
  //------------------------------place_near_use---------------------------------
  // Place some computation next to use but not inside inner loops.
  // For inner loop uses move it to the preheader area.
  Node *PhaseIdealLoop::place_near_use( Node *useblock ) const {
    IdealLoopTree *u_loop = get_loop( useblock );
!   if (u_loop->_irreducible) {
!     return useblock;
!   }
!   if (u_loop->_child) {
!     if (useblock == u_loop->_head && u_loop->_head->is_OuterStripMinedLoop()) {
!       return u_loop->_head->in(LoopNode::EntryControl);
!     }
!     return useblock;
!   }
!   return u_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
  }
  
  
  bool PhaseIdealLoop::identical_backtoback_ifs(Node *n) {
    if (!n->is_If()) {
      return false;
    }
    Node* region = NULL;
    bool shenandoah_evac = ShenandoahWriteBarrierNode::is_evacuation_in_progress_test(n);
+   bool shenandoah_heap_stable = ShenandoahWriteBarrierNode::is_heap_stable_test(n);
    if (shenandoah_evac) {
      assert(UseShenandoahGC, "for shenandoah only");
      region = ShenandoahWriteBarrierNode::evacuation_in_progress_test_ctrl(n);
    } else {
      region = n->in(0);
*** 1122,1131 ****
--- 1130,1143 ----
    }
    if (shenandoah_evac) {
      if (!ShenandoahWriteBarrierNode::is_evacuation_in_progress_test(dom)) {
        return false;
      }
+   } else if (shenandoah_heap_stable) {
+     if (!ShenandoahWriteBarrierNode::is_heap_stable_test(dom)) {
+       return false;
+     }
    } else {
      if (dom->in(1) != n->in(1)) {
        return false;
      }
    }