On Tue, 29 Sep 2026 23:16:56 GMT, Mohamed Issa <[email protected]> wrote:

>> It turns out the 2-step FP16 to integral conversion process is usually more 
>> beneficial on platforms that support AVX10.2 instructions. This is mainly 
>> due to the reduced instruction count and automatic special case handling 
>> (e.g., NaN). With that in mind, the changes in this PR go back to the 
>> original approach when the AVX10.2 vectorized path is detected in the C2 
>> compiler. There are also some updates to the JTREG tests and JMH benchmarks.
>> 
>> The JTREG test listed below was used to verify correctness with 
>> `-XX:-UseSuperWord` and `-XX:+UseSuperWord` JVM options applied. All 
>> modifications and tests used [OpenJDK 
>> v28-b15](https://github.com/openjdk/jdk/releases/tag/jdk-28%2B15) as the 
>> baseline build.
>> 
>> 1. 
>> `jtreg:test/hotspot/jtreg/compiler/vectorapi/TestFloat16ToIntegralConv.java`
>> 
>> ---------
>> - [x] I confirm that I make this contribution in accordance with the 
>> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
>
> Mohamed Issa 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 five additional 
> commits since the last revision:
> 
>  - Merge branch 'master' into user/missa-prime/avx10_2
>  - Use AVX512 direct conversion for scalar half-precision path and add new 
> classes to JMH source.
>  - Remove AVX10.2 fp16 to byte direct conversion vector instruction as it 
> causes correctness issues.
>  - Use AVX10.2 fp16 to byte direct conversion vector instruction whenever 
> possible.
>  - Disable AVX512 FP16 direct conversion on targets that support AVX10.2

@missa-prime 
Your change (at version 8bd8b7f9f5e8c9187138514910dacb6a25aec5c3) is now ready 
to be sponsored by a Committer.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/32957#issuecomment-5903502871

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