Re: [lworld] RFR: 8385328: [lworld] C2: assert(phi->_idx >= nodes_size()) failed: only new Phi per instance memory slice still happens after JDK-8374742 [v2]

[Roland Westrelin]

On Wed, 3 Jun 2026 06:26:47 GMT, Dean Long <dl...@openjdk.org> wrote:

>> A `StoreFlat` is not a regular `Store` so it can't be `C2_MISMATCHED`.
>
> If that's the case then we can add assert to check that in the StoreFlatNode 
> ctor, and remove the check for C2_MISMATCHED at the beginning of 
> StoreFlatNode::expand_non_atomic.

Right. I missed that. It seems `C2_MISMATCHED` accesses come from unsafe.
Not sure why `C2_MISMATCHED` would be a problem with `StoreFlat` but for 
`LoadFlat`, I suppose it's safer to not step over a `C2_MISMATCHED` `LoadFlat` 
for the same allocation as `alias_idx` as that one is not going away.

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PR Review Comment: 
https://git.openjdk.org/valhalla/pull/2489#discussion_r3349072544