[jdk21u-dev] RFR: 8325277: [21u] Backout test change of JDK-8291809

[SendaoYan]

On Mon, 27 Oct 2025 20:55:54 GMT, Paul Hohensee <phh at openjdk.org> wrote:

>> Hi all,
>> 
>> As discuss in [JDK-8325277](https://bugs.openjdk.org/browse/JDK-8325277), we want to backout the "backport JDK-8291809 to jdk21u-dev".
>> 
>> The test_divc and test_divc_n cannot be vectorized on 128-bit vector platforms with JDK 21u due to algorithmic constraints in superword.cpp, which led to the reported failure in [JDK-8325277](https://bugs.openjdk.org/browse/JDK-8325277).
>> Starting from JDK 23, the algorithm has been significantly improved, and both cases can now be vectorized on 128-bit platforms, allowing the test to pass.
>> 
>> Test-fix only, risk is low.
>> 
>> Testing:
>> 
>> - [x] Run tests compiler/c2/cr7200264/TestSSE2IntVect.java compiler/c2/cr7200264/TestSSE4IntVect.java on linux-x64
>> - [x] Run tests compiler/c2/cr7200264/TestSSE2IntVect.java compiler/c2/cr7200264/TestSSE4IntVect.java on linux-aarch64 without SVE2, jtreg shows no test.
>> - [x] Run tests compiler/c2/cr7200264/TestSSE2IntVect.java compiler/c2/cr7200264/TestSSE4IntVect.java on linux-aarch64 with SVE2, jtreg shows no test.
>
> Marked as reviewed by phh (Reviewer).

Thanks for the reviews @phohensee

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PR Comment: https://git.openjdk.org/jdk21u-dev/pull/2381#issuecomment-3454308943