RFR: 8344122: IGV: Extend c2 IdealGraphPrinter to send subgraphs to IGV [v5]

[Christian Hagedorn]

On Fri, 15 Nov 2024 09:22:05 GMT, Tobias Holenstein <tholenstein at openjdk.org> wrote:

>> IGV XML already support to define which graphs are visible when opened. Extend the IdealGraphPrinter::print... in C2 to define which nodes should be visible in IGV when sent over the network
>> 
>> ### Add a new option "!" to dump_bfs
>> The option ! send the printed nodes of dump_bfs to IGV and shows them 
>> 
>> p find_node(0)->dump_bfs(1,0,"dcmxo+!")
>> 
>> dist dump
>> ---------------------------------------------
>>    1  51  Return  === 46 6 47 8 9 returns 39  [[ 0 ]] 
>>    0   0  Root  === 0 51  [[ 0 1 3 26 ]] 
>> Method printed over network stream to IGV
>> 
>> 
>> <img width="668" alt="dump" src="https://github.com/user-attachments/assets/d476e8b0-c444-4cd3-b40d-4a8f35caba83">
>
> Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/hotspot/share/opto/compile.cpp
>   
>   Co-authored-by: Roberto Castañeda Lozano <robcasloz at users.noreply.github.com>

That's very handy and useful! Looks good to me, too.

src/hotspot/share/opto/compile.cpp line 5306:

> 5304:   }
> 5305:   tty->print_cr("Method printed over network stream to IGV");
> 5306:   _debug_network_printer->print(name, (Node*)C->root(), visible_nodes);

Cast is not required I think:
Suggestion:

  _debug_network_printer->print(name, C->root(), visible_nodes);

-------------

Marked as reviewed by chagedorn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22076#pullrequestreview-2439119135
PR Review Comment: https://git.openjdk.org/jdk/pull/22076#discussion_r1844147417