RFR: 8312332: C2: Refactor SWPointer out from SuperWord [v3]

[Emanuel Peter]

On Mon, 11 Sep 2023 07:02:35 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> src/hotspot/share/opto/loopnode.hpp line 236:
>> 
>>> 234: 
>>> 235:   // Cached CountedLoopEndNode of pre loop for main loops
>>> 236:   CountedLoopEndNode* _pre_loop_end;
>> 
>> Is it safe to cached this node? What happens if the node were ever to be replaced?
>
> Ah, we need to access it via `pre_loop_end()` which has asserts that check the consistency. Ok.

We just have to make sure that this field is never accessed directly. What happens if people start using it elsewhere?

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PR Review Comment: https://git.openjdk.org/jdk/pull/15013#discussion_r1321097993