376   Node *x = new (C) GotoNode(NULL);
 377   x->init_req(0, x);
 378   _goto = matcher.match_tree(x);
 379   assert(_goto != NULL, "");
 380   _goto->set_req(0,_goto);
 381 
 382   // Build the CFG in Reverse Post Order
 383   _number_of_blocks = build_cfg();
 384   _root_block = get_block_for_node(_root);
 385 }
 386 
 387 // Build a proper looking CFG.  Make every block begin with either a StartNode
 388 // or a RegionNode.  Make every block end with either a Goto, If or Return.
 389 // The RootNode both starts and ends it's own block.  Do this with a recursive
 390 // backwards walk over the control edges.
 391 uint PhaseCFG::build_cfg() {
 392   Arena *a = Thread::current()->resource_area();
 393   VectorSet visited(a);
 394 
 395   // Allocate stack with enough space to avoid frequent realloc
 396   Node_Stack nstack(a, C->unique() >> 1);
 397   nstack.push(_root, 0);
 398   uint sum = 0;                 // Counter for blocks
 399 
 400   while (nstack.is_nonempty()) {
 401     // node and in's index from stack's top
 402     // 'np' is _root (see above) or RegionNode, StartNode: we push on stack
 403     // only nodes which point to the start of basic block (see below).
 404     Node *np = nstack.node();
 405     // idx > 0, except for the first node (_root) pushed on stack
 406     // at the beginning when idx == 0.
 407     // We will use the condition (idx == 0) later to end the build.
 408     uint idx = nstack.index();
 409     Node *proj = np->in(idx);
 410     const Node *x = proj->is_block_proj();
 411     // Does the block end with a proper block-ending Node?  One of Return,
 412     // If or Goto? (This check should be done for visited nodes also).
 413     if (x == NULL) {                    // Does not end right...
 414       Node *g = _goto->clone(); // Force it to end in a Goto
 415       g->set_req(0, proj);
 416       np->set_req(idx, g);

 376   Node *x = new (C) GotoNode(NULL);
 377   x->init_req(0, x);
 378   _goto = matcher.match_tree(x);
 379   assert(_goto != NULL, "");
 380   _goto->set_req(0,_goto);
 381 
 382   // Build the CFG in Reverse Post Order
 383   _number_of_blocks = build_cfg();
 384   _root_block = get_block_for_node(_root);
 385 }
 386 
 387 // Build a proper looking CFG.  Make every block begin with either a StartNode
 388 // or a RegionNode.  Make every block end with either a Goto, If or Return.
 389 // The RootNode both starts and ends it's own block.  Do this with a recursive
 390 // backwards walk over the control edges.
 391 uint PhaseCFG::build_cfg() {
 392   Arena *a = Thread::current()->resource_area();
 393   VectorSet visited(a);
 394 
 395   // Allocate stack with enough space to avoid frequent realloc
 396   Node_Stack nstack(a, C->live_nodes() >> 1);
 397   nstack.push(_root, 0);
 398   uint sum = 0;                 // Counter for blocks
 399 
 400   while (nstack.is_nonempty()) {
 401     // node and in's index from stack's top
 402     // 'np' is _root (see above) or RegionNode, StartNode: we push on stack
 403     // only nodes which point to the start of basic block (see below).
 404     Node *np = nstack.node();
 405     // idx > 0, except for the first node (_root) pushed on stack
 406     // at the beginning when idx == 0.
 407     // We will use the condition (idx == 0) later to end the build.
 408     uint idx = nstack.index();
 409     Node *proj = np->in(idx);
 410     const Node *x = proj->is_block_proj();
 411     // Does the block end with a proper block-ending Node?  One of Return,
 412     // If or Goto? (This check should be done for visited nodes also).
 413     if (x == NULL) {                    // Does not end right...
 414       Node *g = _goto->clone(); // Force it to end in a Goto
 415       g->set_req(0, proj);
 416       np->set_req(idx, g);