RFR: 8324751: C2 SuperWord: Aliasing Analysis runtime check [v2]

[Emanuel Peter]

On Mon, 28 Jul 2025 11:02:20 GMT, Manuel Hässig <mhaessig at openjdk.org> wrote:

>> Emanuel Peter has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 190 commits:
>> 
>>  - manual merge with master
>>  - fix include order
>>  - manual merge with master
>>  - rm multiversioning testing
>>  - more comments cleanu
>>  - comment cleanup
>>  - more descriptions / proof
>>  - improve comments
>>  - fix test and code
>>  - small comment addition
>>  - ... and 180 more: https://git.openjdk.org/jdk/compare/f40381e4...d7e856d8
>
> src/hotspot/share/opto/mempointer.hpp line 731:
> 
>> 729:   }
>> 730: 
>> 731:   bool is_valid() const { return _int_group >= 0; }
> 
> Why is _int_group not a `uint` if it is always positive or 0?

I don't think it matters too much here. But I do use this as the `is_valid` flag, and I do create invalid summands with the default constructor like this:
`MemPointerRawSummand(nullptr, NoOverflowInt::make_NaN(), NoOverflowInt::make_NaN(), -1) {}`

Do you see an issue with this, or a significant inefficiency?

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PR Review Comment: https://git.openjdk.org/jdk/pull/24278#discussion_r2249628473