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

[Vladimir Kozlov]

On 8/4/16 4:30 PM, Andrew Haley wrote:
> 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() ?

Yes, we should do it.

Thanks,
Vladimir

>
> 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.
>