717   Node *phi = split_thru_phi( n, n_blk, policy );
 718   if (!phi) return n;
 719 
 720   // Found a Phi to split thru!
 721   // Replace 'n' with the new phi
 722   _igvn.replace_node( n, phi );
 723   // Moved a load around the loop, 'en-registering' something.
 724   if (n_blk->is_Loop() && n->is_Load() &&
 725       !phi->in(LoopNode::LoopBackControl)->is_Load())
 726     C->set_major_progress();
 727 
 728   return phi;
 729 }
 730 
 731 static bool merge_point_too_heavy(Compile* C, Node* region) {
 732   // Bail out if the region and its phis have too many users.
 733   int weight = 0;
 734   for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
 735     weight += region->fast_out(i)->outcnt();
 736   }
 737   int nodes_left = MaxNodeLimit - C->live_nodes();
 738   if (weight * 8 > nodes_left) {
 739 #ifndef PRODUCT
 740     if (PrintOpto)
 741       tty->print_cr("*** Split-if bails out:  %d nodes, region weight %d", C->unique(), weight);
 742 #endif
 743     return true;
 744   } else {
 745     return false;
 746   }
 747 }
 748 
 749 static bool merge_point_safe(Node* region) {
 750   // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode
 751   // having a PhiNode input. This sidesteps the dangerous case where the split
 752   // ConvI2LNode may become TOP if the input Value() does not
 753   // overlap the ConvI2L range, leaving a node which may not dominate its
 754   // uses.
 755   // A better fix for this problem can be found in the BugTraq entry, but
 756   // expediency for Mantis demands this hack.
 757   // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop

 717   Node *phi = split_thru_phi( n, n_blk, policy );
 718   if (!phi) return n;
 719 
 720   // Found a Phi to split thru!
 721   // Replace 'n' with the new phi
 722   _igvn.replace_node( n, phi );
 723   // Moved a load around the loop, 'en-registering' something.
 724   if (n_blk->is_Loop() && n->is_Load() &&
 725       !phi->in(LoopNode::LoopBackControl)->is_Load())
 726     C->set_major_progress();
 727 
 728   return phi;
 729 }
 730 
 731 static bool merge_point_too_heavy(Compile* C, Node* region) {
 732   // Bail out if the region and its phis have too many users.
 733   int weight = 0;
 734   for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
 735     weight += region->fast_out(i)->outcnt();
 736   }
 737   int nodes_left = C->max_node_limit() - C->live_nodes();
 738   if (weight * 8 > nodes_left) {
 739 #ifndef PRODUCT
 740     if (PrintOpto)
 741       tty->print_cr("*** Split-if bails out:  %d nodes, region weight %d", C->unique(), weight);
 742 #endif
 743     return true;
 744   } else {
 745     return false;
 746   }
 747 }
 748 
 749 static bool merge_point_safe(Node* region) {
 750   // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode
 751   // having a PhiNode input. This sidesteps the dangerous case where the split
 752   // ConvI2LNode may become TOP if the input Value() does not
 753   // overlap the ConvI2L range, leaving a node which may not dominate its
 754   // uses.
 755   // A better fix for this problem can be found in the BugTraq entry, but
 756   // expediency for Mantis demands this hack.
 757   // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop