src/share/vm/opto/loopTransform.cpp

*** 677,686 ****
--- 677,690 ----
    clone_loop( loop, old_new, dd_main_exit );
    assert( old_new[main_end ->_idx]->Opcode() == Op_CountedLoopEnd, "" );
    CountedLoopNode *post_head = old_new[main_head->_idx]->as_CountedLoop();
    post_head->set_post_loop(main_head);
  
+   // Reduce the post-loop trip count.
+   CountedLoopEndNode* post_end = old_new[main_end ->_idx]->as_CountedLoopEnd();
+   post_end->_prob = PROB_FAIR;
+ 
    // Build the main-loop normal exit.
    IfFalseNode *new_main_exit = new (C, 1) IfFalseNode(main_end);
    _igvn.register_new_node_with_optimizer( new_main_exit );
    set_idom(new_main_exit, main_end, dd_main_exit );
    set_loop(new_main_exit, loop->_parent);
*** 746,755 ****
--- 750,762 ----
    CountedLoopNode*    pre_head = old_new[main_head->_idx]->as_CountedLoop();
    CountedLoopEndNode* pre_end  = old_new[main_end ->_idx]->as_CountedLoopEnd();
    pre_head->set_pre_loop(main_head);
    Node *pre_incr = old_new[incr->_idx];
  
+   // Reduce the pre-loop trip count.
+   pre_end->_prob = PROB_FAIR;
+ 
    // Find the pre-loop normal exit.
    Node* pre_exit = pre_end->proj_out(false);
    assert( pre_exit->Opcode() == Op_IfFalse, "" );
    IfFalseNode *new_pre_exit = new (C, 1) IfFalseNode(pre_end);
    _igvn.register_new_node_with_optimizer( new_pre_exit );
*** 765,776 ****
    Node *min_bol  = new (C, 2) BoolNode( min_cmp, b_test );
    register_new_node( min_opaq, new_pre_exit );
    register_new_node( min_cmp , new_pre_exit );
    register_new_node( min_bol , new_pre_exit );
  
!   // Build the IfNode
!   IfNode *min_iff = new (C, 2) IfNode( new_pre_exit, min_bol, PROB_FAIR, COUNT_UNKNOWN );
    _igvn.register_new_node_with_optimizer( min_iff );
    set_idom(min_iff, new_pre_exit, dd_main_head);
    set_loop(min_iff, loop->_parent);
  
    // Plug in the false-path, taken if we need to skip main-loop
--- 772,783 ----
    Node *min_bol  = new (C, 2) BoolNode( min_cmp, b_test );
    register_new_node( min_opaq, new_pre_exit );
    register_new_node( min_cmp , new_pre_exit );
    register_new_node( min_bol , new_pre_exit );
  
!   // Build the IfNode (assume the main-loop is executed always).
!   IfNode *min_iff = new (C, 2) IfNode( new_pre_exit, min_bol, PROB_ALWAYS, COUNT_UNKNOWN );
    _igvn.register_new_node_with_optimizer( min_iff );
    set_idom(min_iff, new_pre_exit, dd_main_head);
    set_loop(min_iff, loop->_parent);
  
    // Plug in the false-path, taken if we need to skip main-loop