RFR: 8327109: Refactor data graph cloning used in create_new_if_for_predicate() into separate class [v3]

[Christian Hagedorn]

On Mon, 4 Mar 2024 09:31:28 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Christian Hagedorn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove dead declaration
>
> src/hotspot/share/opto/replacednodes.cpp line 211:
> 
>> 209:     }
>> 210:     // Map from current node to cloned/replaced node
>> 211:     OrigToNewHashtable clones(hash_table_size, hash_table_size);
> 
> Nice.
> Not your problem here. But should there not be a ResouceMark before this hashtable? There is one at the beginning of the function, but we create many of these hashtables in a loop, without any ResourceMarks in between reclaiming the memory...
> A but then the hashmaps and stack/to_fix etc would allocate from the ResourceArea, but start at different ResourceMarks... bad idea. Hmm.

As discussed offline, we should probably go over all uses of resource allocated things like `Node_Lists`, `Node_Stack` etc. at some point and check if there are missing resource marks.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/18080#discussion_r1511109952