Request for Reviews(M): 7092905: C2: Keep track of the number of dead nodes

[Vladimir Kozlov]

Bharadwaj,

These changes look much better. Sorry, I suggested to add verify_live_node_count() method before but your current code don't need it, just use count_live_nodes_by_graph_walk(). An other note: without LogCompilation verification code should produce some info on tty.

Thanks,
Vladimir

On Oct 28, 2012, at 8:12 PM, Bharadwaj Yadavalli wrote:

> I'd like to get a code review of the changes at http://cr.openjdk.java.net/~bharadwaj/7092905/webrev_01/
> 
> These changes are made to keep an (almost) accurate running count of the reachable (live) flow graph nodes. This will result in a more realistic node count for various phases of C2 to decide on whether to proceed with optimizations or not. Prior to these changes, C2 bails out of compilation based on the number of nodes created which typically larger than the number of reachable (live) nodes.
> 
> I observed no significant degradation in C2 compilation time of all classes in rt.jar time due to these changes.
> 
> Thanks,
> 
> Bharadwaj
>