RFR: 8317763: Follow-up to AVX512 intrinsics for Arrays.sort() PR

[Vladimir Kozlov]

On Tue, 10 Oct 2023 18:40:30 GMT, R1chterScale <duke at openjdk.org> wrote:

>> The goal of this PR is to address the follow-up comments to the SIMD accelerated sort PR (#14227) which implemented AVX512 intrinsics for Arrays.sort() methods.
>> The proposed changes are:
>> 
>> 1) Restriction of the AVX512 sort acceleration to only Intel CPUs. A performance regression (due to micro-architectural differences) was reported for AMD Zen4 CPUs in the comments section of PR.
>> 2) Addressing the build failure due to a bug in GCC 12 (which was fixed in version 12.3.1). The details of the bug are at: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105593
>> 3) Minor changes in Javadoc strings
>
> Forgive me, I might be missing something very obvious, but is there any particular reason to entirely disable the SIMD accelerated sort on Zen 4 rather than having an alternate code path for Zen 4 where it has the `compressstoreu` instructions split up into separate `compress` and `storeu` instructions so that Zen 4 platforms can still benefit from a decent degree of performance uplift from AVX512 acceleration of sort?

@R1chterScale or someone can suggest patch for Zen 4 and test it so we can include it into these changes?
Otherwise we will file separate followup RFE as Sandhya suggested?

And yes, I need to run testing before approval but after we decide what to do with Zen 4 in these changes.

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PR Comment: https://git.openjdk.org/jdk/pull/16124#issuecomment-1758306441