src/hotspot/share/opto/memnode.cpp

*** 3172,3212 ****
    leading->_pair_idx = leading->_idx;
  #endif
  }
  
  MemBarNode* MemBarNode::trailing_membar() const {
    Node* trailing = (Node*)this;
    VectorSet seen(Thread::current()->resource_area());
!   while (!trailing->is_MemBar() || !trailing->as_MemBar()->trailing()) {
!     if (seen.test_set(trailing->_idx)) {
!       // Dying subgraph?
!       return NULL;
      }
-     for (DUIterator_Fast jmax, j = trailing->fast_outs(jmax); j < jmax; j++) {
-       Node* next = trailing->fast_out(j);
-       if (next != trailing && next->is_CFG()) {
          trailing = next;
          break;
        }
      }
    }
    MemBarNode* mb = trailing->as_MemBar();
    assert((mb->_kind == TrailingStore && _kind == LeadingStore) ||
           (mb->_kind == TrailingLoadStore && _kind == LeadingLoadStore), "bad trailing membar");
    assert(mb->_pair_idx == _pair_idx, "bad trailing membar");
    return mb;
  }
  
  MemBarNode* MemBarNode::leading_membar() const {
    VectorSet seen(Thread::current()->resource_area());
    Node* leading = in(0);
    while (leading != NULL && (!leading->is_MemBar() || !leading->as_MemBar()->leading())) {
!     if (seen.test_set(leading->_idx)) {
!       // Dying subgraph?
        return NULL;
      }
      if (leading->is_Region()) {
        leading = leading->in(1);
      } else {
        leading = leading->in(0);
      }
    }
--- 3172,3250 ----
    leading->_pair_idx = leading->_idx;
  #endif
  }
  
  MemBarNode* MemBarNode::trailing_membar() const {
+   ResourceMark rm;
    Node* trailing = (Node*)this;
    VectorSet seen(Thread::current()->resource_area());
!   Node_Stack multis(0);
!   do {
!     Node* c = trailing;
!     uint i = 0;
!     do {
!       trailing = NULL;
!       for (; i < c->outcnt(); i++) {
!         Node* next = c->raw_out(i);
!         if (next != c && next->is_CFG()) {
!           if (c->is_MultiBranch()) {
!             if (multis.node() == c) {
!               multis.set_index(i+1);
!             } else {
!               multis.push(c, i+1);
!             }
            }
            trailing = next;
            break;
          }
        }
+       if (trailing != NULL && !seen.test_set(trailing->_idx)) {
+         break;
+       }
+       while (multis.size() > 0) {
+         c = multis.node();
+         i = multis.index();
+         if (i < c->req()) {
+           break;
+         }
+         multis.pop();
        }
+     } while (multis.size() > 0);
+   } while (!trailing->is_MemBar() || !trailing->as_MemBar()->trailing());
+ 
    MemBarNode* mb = trailing->as_MemBar();
    assert((mb->_kind == TrailingStore && _kind == LeadingStore) ||
           (mb->_kind == TrailingLoadStore && _kind == LeadingLoadStore), "bad trailing membar");
    assert(mb->_pair_idx == _pair_idx, "bad trailing membar");
    return mb;
  }
  
  MemBarNode* MemBarNode::leading_membar() const {
+   ResourceMark rm;
    VectorSet seen(Thread::current()->resource_area());
+   Node_Stack regions(0);
    Node* leading = in(0);
    while (leading != NULL && (!leading->is_MemBar() || !leading->as_MemBar()->leading())) {
!     while (leading == NULL || leading->is_top() || seen.test_set(leading->_idx)) {
!       leading = NULL;
!       while (regions.size() > 0) {
!         Node* r = regions.node();
!         uint i = regions.index();
!         if (i < r->req()) {
!           leading = r->in(i);
!           regions.set_index(i+1);
!         } else {
!           regions.pop();
!         }
!       }
!       if (leading == NULL) {
!         assert(regions.size() == 0, "all paths should have been tried");
          return NULL;
        }
+     }
      if (leading->is_Region()) {
+       regions.push(leading, 2);
        leading = leading->in(1);
      } else {
        leading = leading->in(0);
      }
    }