*** old/src/share/vm/opto/block.cpp	Mon Sep 14 15:54:43 2015
--- new/src/share/vm/opto/block.cpp	Mon Sep 14 15:54:42 2015

*** 391,401 ****
--- 391,401 ----
  uint PhaseCFG::build_cfg() {
    Arena *a = Thread::current()->resource_area();
    VectorSet visited(a);
  
    // Allocate stack with enough space to avoid frequent realloc
!   Node_Stack nstack(a, C->unique() >> 1);
!   Node_Stack nstack(a, C->live_nodes() >> 1);
    nstack.push(_root, 0);
    uint sum = 0;                 // Counter for blocks
  
    while (nstack.is_nonempty()) {
      // node and in's index from stack's top