On Tue, 8 Oct 2024 19:25:24 GMT, Jatin Bhateja <jbhat...@openjdk.org> wrote:

>> Hi All,
>> 
>> As per the discussion on panama-dev mailing list[1], patch adds the support 
>> for following new vector operators.
>> 
>> 
>>      . SUADD   : Saturating unsigned addition.
>>      . SADD    : Saturating signed addition. 
>>      . SUSUB   : Saturating unsigned subtraction.
>>      . SSUB    : Saturating signed subtraction.
>>      . UMAX    : Unsigned max
>>      . UMIN    : Unsigned min.
>>      
>> 
>> New vector operators are applicable to only integral types since their 
>> values wraparound in over/underflowing scenarios after setting appropriate 
>> status flags. For floating point types, as per IEEE 754 specs there are 
>> multiple schemes to handler underflow, one of them is gradual underflow 
>> which transitions the value to subnormal range. Similarly, overflow 
>> implicitly saturates the floating-point value to an Infinite value.
>> 
>> As the name suggests, these are saturating operations, i.e. the result of 
>> the computation is strictly capped by lower and upper bounds of the result 
>> type and is not wrapped around in underflowing or overflowing scenarios.
>> 
>> Summary of changes:
>> - Java side implementation of new vector operators.
>> - Add new scalar saturating APIs for each of the above saturating vector 
>> operator in corresponding primitive box classes, fallback implementation of 
>> vector operators is based over it.
>> - C2 compiler IR and inline expander changes.
>> - Optimized x86 backend implementation for new vector operators and their 
>> predicated counterparts.
>> - Extends existing VectorAPI Jtreg test suite to cover new operations.
>> 
>> Kindly review and share your feedback.
>> 
>> Best Regards,
>> PS: Intrinsification and auto-vectorization of new core-lib API will be 
>> addressed separately in a follow-up patch.
>> 
>> [1] https://mail.openjdk.org/pipermail/panama-dev/2024-May/020408.html
>
> Jatin Bhateja has updated the pull request with a new target base due to a 
> merge or a rebase. The pull request now contains 26 commits:
> 
>  - Merge branch 'JDK-8338201' of http://github.com/jatin-bhateja/jdk into 
> JDK-8338201
>  - Update VectorMath.java
>  - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8338201
>  - Typographical error fixups
>  - Doc fixups
>  - Typographic error
>  - Merge stashing and re-commit
>  - Tuning extra spaces.
>  - Tests for newly added VectorMath.* operations
>  - Test cleanups.
>  - ... and 16 more: https://git.openjdk.org/jdk/compare/7312eea3...ce76c3e5

Hi @vnkozlov , Can you kindly run this through your test infrastructure. We 
have two review approvals for Java and x86 backend code.

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

PR Comment: https://git.openjdk.org/jdk/pull/20507#issuecomment-2405554905

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