PING^3: RFD: C2 bug: 8157306 random infrequent null pointer exceptions in javac

[Andrew Haley]

On 04/08/16 04:35, Vladimir Kozlov wrote:

> I can't reproduce the problem any more with latest hs-comp
> sources. Andrew, can you verify this fix?

Yes, you're right.

Wouldn't it make sense to surround that code with
! needs_anti_dependence_check() ?

Like so:

  latency_from_uses(nul_chk);
  latency_from_uses(best);

  // insert anti-dependences to defs in this block
  if (! best->needs_anti_dependence_check()) {
    for (uint k = 1; k < block->number_of_nodes(); k++) {
      Node *n = block->get_node(k);
      if (n->needs_anti_dependence_check() &&
          n->in(LoadNode::Memory) == best->in(StoreNode::Memory)) {
        // Found anti-dependent load
        insert_anti_dependences(block, n);
      }
    }
  }

Andrew.