RFR: 8369902: C2 SuperWord: wrong result because filterin NaN instead of zero in MemPointerParser::canonicalize_raw_summands [v3]

[Emanuel Peter]

On Fri, 17 Oct 2025 13:16:28 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 incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains nine additional commits since the last revision:
>> 
>>  - Merge branch 'master' into JDK-8369902-SW-VPointer-NaN-zero
>>  - Update test/hotspot/jtreg/compiler/loopopts/superword/TestMemorySegmentFilterSummands.java
>>    
>>    Co-authored-by: Manuel Hässig <manuel at haessig.org>
>>  - add comments to TestAliasingFuzzer.java
>>  - typo
>>  - add fuzzer test
>>  - test improvements and fix
>>  - second test
>>  - rename test
>>  - JDK-8369902
>
> Thank you for fixing my bug as well and doing the work to find a 64-bit reproducer, @eme64! Also, thanks for providing an explanation for the NaNs in the MemPointer parsing.
> 
> The change looks good to me. I only have a suggestion to simplify your scenarios.

@mhaessig Thanks for reviewing and the suggestion :)
I addressed both your comments.

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PR Comment: https://git.openjdk.org/jdk/pull/27848#issuecomment-3420672630