src/share/vm/opto/loopTransform.cpp

rev 4329 : [mq]: JDK-8009181

*** 886,895 ****
--- 886,896 ----
  
    // Find common pieces of the loop being guarded with pre & post loops
    CountedLoopNode *main_head = loop->_head->as_CountedLoop();
    assert( main_head->is_normal_loop(), "" );
    CountedLoopEndNode *main_end = main_head->loopexit();
+   guarantee(main_end != NULL, "no loop exit node");
    assert( main_end->outcnt() == 2, "1 true, 1 false path only" );
    uint dd_main_head = dom_depth(main_head);
    uint max = main_head->outcnt();
  
    Node *pre_header= main_head->in(LoopNode::EntryControl);
*** 2552,2568 ****
  
    // store related values are ok
    ok.set(store->_idx);
    ok.set(store->in(MemNode::Memory)->_idx);
  
    // Loop structure is ok
    ok.set(head->_idx);
!   ok.set(head->loopexit()->_idx);
    ok.set(head->phi()->_idx);
    ok.set(head->incr()->_idx);
!   ok.set(head->loopexit()->cmp_node()->_idx);
!   ok.set(head->loopexit()->in(1)->_idx);
  
    // Address elements are ok
    if (con)   ok.set(con->_idx);
    if (shift) ok.set(shift->_idx);
    if (conv)  ok.set(conv->_idx);
--- 2553,2572 ----
  
    // store related values are ok
    ok.set(store->_idx);
    ok.set(store->in(MemNode::Memory)->_idx);
  
+   CountedLoopEndNode* loop_exit = head->loopexit();
+   guarantee(loop_exit != NULL, "no loop exit node");
+ 
    // Loop structure is ok
    ok.set(head->_idx);
!   ok.set(head_exit->_idx);
    ok.set(head->phi()->_idx);
    ok.set(head->incr()->_idx);
!   ok.set(loop_exit->cmp_node()->_idx);
!   ok.set(loop_exit->in(1)->_idx);
  
    // Address elements are ok
    if (con)   ok.set(con->_idx);
    if (shift) ok.set(shift->_idx);
    if (conv)  ok.set(conv->_idx);
*** 2570,2580 ****
    for (uint i = 0; msg == NULL && i < lpt->_body.size(); i++) {
      Node* n = lpt->_body.at(i);
      if (n->outcnt() == 0) continue; // Ignore dead
      if (ok.test(n->_idx)) continue;
      // Backedge projection is ok
!     if (n->is_IfTrue() && n->in(0) == head->loopexit()) continue;
      if (!n->is_AddP()) {
        msg = "unhandled node";
        msg_node = n;
        break;
      }
--- 2574,2584 ----
    for (uint i = 0; msg == NULL && i < lpt->_body.size(); i++) {
      Node* n = lpt->_body.at(i);
      if (n->outcnt() == 0) continue; // Ignore dead
      if (ok.test(n->_idx)) continue;
      // Backedge projection is ok
!     if (n->is_IfTrue() && n->in(0) == loop_exit) continue;
      if (!n->is_AddP()) {
        msg = "unhandled node";
        msg_node = n;
        break;
      }
*** 2583,2593 ****
    // Make sure no unexpected values are used outside the loop
    for (uint i = 0; msg == NULL && i < lpt->_body.size(); i++) {
      Node* n = lpt->_body.at(i);
      // These values can be replaced with other nodes if they are used
      // outside the loop.
!     if (n == store || n == head->loopexit() || n == head->incr() || n == store->in(MemNode::Memory)) continue;
      for (SimpleDUIterator iter(n); iter.has_next(); iter.next()) {
        Node* use = iter.get();
        if (!lpt->_body.contains(use)) {
          msg = "node is used outside loop";
          // lpt->_body.dump();
--- 2587,2597 ----
    // Make sure no unexpected values are used outside the loop
    for (uint i = 0; msg == NULL && i < lpt->_body.size(); i++) {
      Node* n = lpt->_body.at(i);
      // These values can be replaced with other nodes if they are used
      // outside the loop.
!     if (n == store || n == loop_exit || n == head->incr() || n == store->in(MemNode::Memory)) continue;
      for (SimpleDUIterator iter(n); iter.has_next(); iter.next()) {
        Node* use = iter.get();
        if (!lpt->_body.contains(use)) {
          msg = "node is used outside loop";
          // lpt->_body.dump();