src/share/vm/opto/loopopts.cpp

rev 4533 : 8014811: loopTransform.cpp assert(cmp_end->in(2) == limit) failed
Summary: Stop current iteration of loop opts if partial_peel() failed and it created node clones outside processed loop.
Reviewed-by: roland

*** 1924,1935 ****
  }
  
  
  //------------------------------ clone_for_use_outside_loop -------------------------------------
  // clone "n" for uses that are outside of loop
! void PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) {
! 
    assert(worklist.size() == 0, "should be empty");
    for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
      Node* use = n->fast_out(j);
      if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) {
        worklist.push(use);
--- 1924,1935 ----
  }
  
  
  //------------------------------ clone_for_use_outside_loop -------------------------------------
  // clone "n" for uses that are outside of loop
! int PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) {
!   int cloned = 0;
    assert(worklist.size() == 0, "should be empty");
    for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
      Node* use = n->fast_out(j);
      if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) {
        worklist.push(use);
*** 1945,1954 ****
--- 1945,1955 ----
      assert(j < use->req(), "must be there");
  
      // clone "n" and insert it between the inputs of "n" and the use outside the loop
      Node* n_clone = n->clone();
      _igvn.replace_input_of(use, j, n_clone);
+     cloned++;
      Node* use_c;
      if (!use->is_Phi()) {
        use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0);
      } else {
        // Use in a phi is considered a use in the associated predecessor block
*** 1962,1971 ****
--- 1963,1973 ----
      if (TracePartialPeeling) {
        tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx);
      }
  #endif
    }
+   return cloned;
  }
  
  
  //------------------------------ clone_for_special_use_inside_loop -------------------------------------
  // clone "n" for special uses that are in the not_peeled region.
*** 2480,2489 ****
--- 2482,2492 ----
    }
  #endif
  
    // Evacuate nodes in peel region into the not_peeled region if possible
    uint new_phi_cnt = 0;
+   uint cloned_for_outside_use = 0;
    for (i = 0; i < peel_list.size();) {
      Node* n = peel_list.at(i);
  #if !defined(PRODUCT)
    if (TracePartialPeeling) n->dump();
  #endif
*** 2498,2509 ****
          if ( !has_use_internal_to_set(n, peel, loop) ) {
  
            // if not pinned and not a load (which maybe anti-dependent on a store)
            // and not a CMove (Matcher expects only bool->cmove).
            if ( n->in(0) == NULL && !n->is_Load() && !n->is_CMove() ) {
!             clone_for_use_outside_loop( loop, n, worklist );
! 
              sink_list.push(n);
              peel     >>= n->_idx; // delete n from peel set.
              not_peel <<= n->_idx; // add n to not_peel set.
              peel_list.remove(i);
              incr = false;
--- 2501,2511 ----
          if ( !has_use_internal_to_set(n, peel, loop) ) {
  
            // if not pinned and not a load (which maybe anti-dependent on a store)
            // and not a CMove (Matcher expects only bool->cmove).
            if ( n->in(0) == NULL && !n->is_Load() && !n->is_CMove() ) {
!             cloned_for_outside_use += clone_for_use_outside_loop( loop, n, worklist );
              sink_list.push(n);
              peel     >>= n->_idx; // delete n from peel set.
              not_peel <<= n->_idx; // add n to not_peel set.
              peel_list.remove(i);
              incr = false;
*** 2536,2545 ****
--- 2538,2553 ----
        remove_cmpi_loop_exit(new_peel_if, loop);
      }
      // Inhibit more partial peeling on this loop
      assert(!head->is_partial_peel_loop(), "not partial peeled");
      head->mark_partial_peel_failed();
+     if (cloned_for_outside_use > 0) {
+       // Terminate this round of loop opts because
+       // the graph outside this loop was changed.
+       C->set_major_progress();
+       return true;
+     }
      return false;
    }
  
    // Step 3: clone loop, retarget control, and insert new phis