src/share/vm/opto/compile.cpp

rev 9414 : 8217230: assert(t == t_no_spec) failure in NodeHash::check_no_speculative_types()
Summary: Remove dead node from C2 IR.
Reviewed-by: roland, neliasso

*** 2082,2098 ****
  
  // Remove edges from "root" to each SafePoint at a backward branch.
  // They were inserted during parsing (see add_safepoint()) to make
  // infinite loops without calls or exceptions visible to root, i.e.,
  // useful.
! void Compile::remove_root_to_sfpts_edges() {
    Node *r = root();
    if (r != NULL) {
      for (uint i = r->req(); i < r->len(); ++i) {
        Node *n = r->in(i);
        if (n != NULL && n->is_SafePoint()) {
          r->rm_prec(i);
          --i;
        }
      }
    }
  }
--- 2082,2101 ----
  
  // Remove edges from "root" to each SafePoint at a backward branch.
  // They were inserted during parsing (see add_safepoint()) to make
  // infinite loops without calls or exceptions visible to root, i.e.,
  // useful.
! void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
    Node *r = root();
    if (r != NULL) {
      for (uint i = r->req(); i < r->len(); ++i) {
        Node *n = r->in(i);
        if (n != NULL && n->is_SafePoint()) {
          r->rm_prec(i);
+         if (n->outcnt() == 0) {
+           igvn.remove_dead_node(n);
+         }
          --i;
        }
      }
    }
  }
*** 2152,2162 ****
      if (failing())  return;
    }
  
    // Now that all inlining is over, cut edge from root to loop
    // safepoints
!   remove_root_to_sfpts_edges();
  
    // Remove the speculative part of types and clean up the graph from
    // the extra CastPP nodes whose only purpose is to carry them. Do
    // that early so that optimizations are not disrupted by the extra
    // CastPP nodes.
--- 2155,2165 ----
      if (failing())  return;
    }
  
    // Now that all inlining is over, cut edge from root to loop
    // safepoints
!   remove_root_to_sfpts_edges(igvn);
  
    // Remove the speculative part of types and clean up the graph from
    // the extra CastPP nodes whose only purpose is to carry them. Do
    // that early so that optimizations are not disrupted by the extra
    // CastPP nodes.