On Thu, 11 Jun 2026 10:02:12 GMT, Roland Westrelin <[email protected]> wrote:

>> The bug is caused by a mismatch in the way `LoadFlat` and `StoreFlat`
>> are handled in `ConnectionGraph::find_inst_mem()` and
>> `MemNode::optimize_simple_memory_chain()`. Once EA has run a first
>> time, found some value array allocations as non escaping, and removed
>> their `LoadFlat`/`StoreFlat`, igvn runs and is able to further
>> transform the memory subgraph which introduces inconsistencies that
>> are then caught the next time EA runs.
>> 
>> The fix tries to make sure `ConnectionGraph::find_inst_mem()` and
>> `MemNode::optimize_simple_memory_chain()` handle `LoadFlat` and
>> `StoreFlat` similarly.
>> 
>> ---------
>> - [x] I confirm that I make this contribution in accordance with the 
>> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
>
> Roland Westrelin has updated the pull request with a new target base due to a 
> merge or a rebase. The pull request now contains 11 commits:
> 
>  - review
>  - Merge branch 'lworld' into JDK-8385328
>  - more
>  - review
>  - review
>  - Merge branch 'lworld' into JDK-8385328
>  - more
>  - review
>  - whitespaces
>  - more
>  - ... and 1 more: 
> https://git.openjdk.org/valhalla/compare/abebcaa0...fa48b671

src/hotspot/share/opto/escape.cpp line 4549:

> 4547: //
> 4548: #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
> 4549: 

I suggest a helper function that adds asserts, something like:
Suggestion:

static bool same_instance_as(const TypeOopPtr* t1, const TypeOopPtr* t2) {
  assert(t1->is_known_instance(), "known instance expected during EA phase");
  assert(t2->is_known_instance(), "known instance expected during EA phase");
  return t1->instance_id() == t2->instance_id();
}

and using it below.

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

PR Review Comment: 
https://git.openjdk.org/valhalla/pull/2489#discussion_r3432027892

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