RFR: 8350177: C2 SuperWord: Integer.numberOfLeadingZeros, numberOfTrailingZeros, reverse and bitCount have input types wrongly turncated for byte and short

[Emanuel Peter]

On Mon, 30 Jun 2025 03:52:14 GMT, Jasmine Karthikeyan <jkarthikeyan at openjdk.org> wrote:

>> @jaskarth the tests look better now. I still saw this failure:
>> 
>> `jdk/incubator/vector/Byte64VectorTests.java`
>> 
>> Flags: `-XX:UseAVX=3 -XX:+UnlockDiagnosticVMOptions -XX:+UseKNLSetting` or `-XX:UseAVX=0` or `-XX:UseAVX=2` ... probably no flags are actually required.
>> 
>> `#  assert(false) failed: Unexpected node in SuperWord truncation: ExtractB`
>
> @eme64 Thanks for running it again! I've pushed a fix for the `ExtractB` assert, and a proactive fix marking any nodes with `TypeVect` as their base type as non-truncating.

@jaskarth There is a title mismatch though

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PR Comment: https://git.openjdk.org/jdk/pull/25440#issuecomment-3061682166