RFR: 8318650: Optimized subword gather for x86 targets. [v3]

[Sandhya Viswanathan]

On Fri, 3 Nov 2023 22:44:39 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Restricting masked sub-word gather to AVX512 target to align with integral gather support.
>
> src/hotspot/cpu/x86/x86.ad line 4152:
> 
>> 4150: 
>> 4151: instruct vgather_subwordLE8B_off(vec dst, memory mem, rRegP idx, rRegI offset, rRegP tmp, rRegI rtmp) %{
>> 4152:   predicate(is_subword_type(Matcher::vector_element_basic_type(n)) && Matcher::vector_length_in_bytes(n) <= 8);
> 
> !VM_Version::supports_avx512bw() is missing for non avx3 cases.

This comment is still pending?

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PR Review Comment: https://git.openjdk.org/jdk/pull/16354#discussion_r1383806980