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

[Dean Long]

On Wed, 17 Dec 2025 14:03:45 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> It seems like "dest" is always an oop here and we don't need to check isa_oopptr().
>
> It is always an heap address. But when used at object creation time, it's not yet an oop. It only becomes one once it is initialized. For those `Store`s to the not yet initialized object, I don't think the base edge is needed (there can't be any safepoint until the object becomes an actual oop) and code elsewhere (`InitializeNode::capture_store()`) doesn't set the base input either.

That makes sense as long as we can guarantee there is no safepoint.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28769#discussion_r2629279971