RFR: 8282024: add EscapeAnalysis statistics under PrintOptoStatistics [v7]

[aamarsh]

On Tue, 3 May 2022 16:46:20 GMT, Xin Liu <xliu at openjdk.org> wrote:

>> aamarsh has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:
>> 
>>   adding escape analysis and scalar replacement statistics
>
> src/hotspot/share/opto/macro.cpp line 2608:
> 
>> 2606: }
>> 2607: 
>> 2608: int PhaseMacroExpand::count_MemBar() {
> 
> I am not sure about this procedural. Even though you use Unique_Node_List, is it still possible to count the same membar multiple times?  or maybe a backedge cause an infinitely loop? 
> 
> I think you can use Compile::identify_useful_nodes to collect all useful nodes and then count MemBar nodes.

@navyxliu Since no nodes are ever removed from the list, I think this issue is avoided. If we find a loop back to a node we have already searched and attempt to push this node at line 2620, it will not be added to the list because it already exists.

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PR: https://git.openjdk.java.net/jdk/pull/8019