RFR: 8327963: C2: fix construction of memory graph around Initialize node to prevent incorrect execution if allocation is removed [v12]

[Roland Westrelin]

On Fri, 19 Sep 2025 13:02:43 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 45 commits:
>> 
>>  - more
>>  - Merge branch 'master' into JDK-8327963
>>  - more
>>  - more
>>  - Merge branch 'master' into JDK-8327963
>>  - more
>>  - more
>>  - lambda return
>>  - lambda clean up
>>  - Merge branch 'master' into JDK-8327963
>>  - ... and 35 more: https://git.openjdk.org/jdk/compare/e16c5100...b701d03e
>
> test/hotspot/jtreg/compiler/escapeAnalysis/TestIterativeEA.java line 53:
> 
>> 51:     analyzer.shouldContain("++++ Eliminated: 26 Allocate");
>> 52:     analyzer.shouldContain("++++ Eliminated: 51 Allocate");
>> 53:     analyzer.shouldContain("++++ Eliminated: 84 Allocate");
> 
> Did you analyze why there are more allocations removed than before in this test case? I did not expect this changeset to have an effect on the number of removed allocations.

There are not more allocations removed. The message is confusing.
"Eliminated: 84 Allocate" logs that node number 84 was eliminated (and not 84 nodes).
This patch changes the number of nodes required at allocations so it also has an impact on node numbering.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24570#discussion_r2368395832