RFR: 8351889: C2 crash: assertion failed: Base pointers must match (addp 344)

[Roland Westrelin]

On Wed, 4 Jun 2025 07:25:54 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> Then what about just the dump of the relevant IR nodes in text form? That is what I meant by `full IR snippets` ;)

Are the omitted inputs to `AddP`s that you'd like to see? Anything else? Do you want to see them added to:

                                /-> CastPP#110
Store#195 -> Phi#360 -> AddP#133 -> AddP#134 -> CastPP#110
                    -> AddP#277 -> AddP#278 -> CastPP#283
                                -> CastPP#283

?

> Is there any (reasonable) way to push the `CastPP` through the `AddP` here? I guess that may mean duplicating some `AddP` in some cases... But it could also give an opportunity for the `CastPP` to common further up that way. What do you think? It is hard for me to see through it without looking at some examples of the IR.

That's not where C2 expects the `CastPP`s to be so I suppose it could be quite disruptive but hard for me to tell how much. Beyond that, wouldn't we need to know if one `CastPP` dominates the other `CastPP` before we can common them and would have the same issue we have here?

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PR Comment: https://git.openjdk.org/jdk/pull/25386#issuecomment-2939858255