RFR: 8373343: C2: verify AddP base input only set for heap addresses [v2]

[Dean Long]

On Wed, 17 Dec 2025 14:04:04 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> The base input of `AddP` is expected to only be set for heap accesses
>> but I noticed some inconsistencies so I added an assert in the `AddP`
>> constructor and fixed issues that it caught. AFAFICT, the
>> inconsistencies shouldn't create issues.
>
> Roland Westrelin has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains eight additional commits since the last revision:
> 
>  - review
>  - review
>  - merge
>  - more
>  - more
>  - more
>  - undo
>  - exps

src/hotspot/share/opto/memnode.cpp line 2570:

> 2568:             assert(tkls2->offset() == 0, "not a load of java_mirror");
> 2569: #endif
> 2570:             return adr2->in(AddPNode::Address);

What should the value of adr2->in(AddPNode::Offset) be at this point? 0 or java_mirror_offset()?  Do we need to check it?

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PR Review Comment: https://git.openjdk.org/jdk/pull/28769#discussion_r2629405380