RFR: 8312425: [vectorapi] AArch64: Optimize vector math operations with SLEEF [v11]

[Andrew Haley]

On Tue, 9 Jul 2024 12:08:50 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review the patch?
>> This pr is based on previous work and discussion in [pr 16234](https://github.com/openjdk/jdk/pull/16234), [pr 18294](https://github.com/openjdk/jdk/pull/18294).
>> * NOTE: This pr depends on https://github.com/openjdk/jdk/pull/19185, which includes a README, a script to generate sleef inline headers and generated sleef inline headers.
>> 
>> Compared with previous prs, the major change in this pr is to integrate the source of sleef (for the steps, please check `src/jdk.incubator.vector/linux/native/libvectormath/README`), rather than depends on external sleef things (header or lib) at build or run time.
>> Besides of this change, also modify the previous changes accordingly, e.g. remove some uncessary files or changes especially in make dir of jdk.
>> 
>> Besides of the code changes, one important task is to handle the legal process.
>> 
>> Thanks!
>> 
>> ## Test
>> tests:
>> * test/jdk/jdk/incubator/vector/
>> * test/hotspot/jtreg/compiler/vectorapi/
>> 
>> options:
>> * -XX:UseSVE=1 -XX:+EnableVectorSupport -XX:+UseVectorStubs
>> * -XX:UseSVE=0 -XX:+EnableVectorSupport -XX:+UseVectorStubs
>> * -XX:+EnableVectorSupport -XX:-UseVectorStubs
>> 
>> ## Performance
>> 
>> ### Options
>> * +intrinsic: 'FORK=1;ITER=10;WARMUP_ITER=10;JAVA_OPTIONS=-XX:+UnlockExperimentalVMOptions -XX:+EnableVectorSupport -XX:+UseVectorStubs'
>> * -intrinsic: 'FORK=1;ITER=10;WARMUP_ITER=10;JAVA_OPTIONS=-XX:+UnlockExperimentalVMOptions -XX:+EnableVectorSupport -XX:-UseVectorStubs'
>> 
>> ### Float
>> data
>> <google-sheets-html-origin style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">
>> Benchmark | (size) | Mode | Cnt | Error | Units | Score +intrinsic (UseSVE=1) | Score -intrinsic | Improvement(UseSVE=1) | Score +intrinsic (UseSVE=0) | Score -intrinsic | Improvement (UseSVE=0)
>> -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --
>> Float128Vector.ACOS | 1024 | thrpt | 10 | 0.015 | ops/ms | 245.439 | 101.483 | 2.419 | 245.733 | 102.033 | 2.408
>> Float128Vector.ASIN | 1024 | thrpt | 10 | 0.013 | ops/ms | 296.702 | 103.559 | 2.865 | 296.741 | 103.18 | 2.876
>> Float128Vector.ATAN | 1024 | thrpt | 10 | 0.004 | ops/ms | 196.862 | 49.627 | 3.967 | 195.891 | 49.771 | 3.936
>> Float128Vector.ATAN...
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   skip TANH

> Compared to current implementation in #19185, my bit concern about [This branch](https://github.com/fitzsim/jdk/commits/regenerate-sleef-headers-1/) is the future maintainence effort when we need to update the sleef source along with the cmake changes, also when new platforms support of sleef are added in jdk.

That's a fair point.  However, it's probably less work than any adequate alternative proposed thus far.

> In another hand, I'm not sure if [This branch](https://github.com/fitzsim/jdk/commits/regenerate-sleef-headers-1/) qualify the traceability requirement discussed above.

I'm sure it's fine: we have readable source code in the preferred form, along with a script that generates it from the corresponding SLEEF release.

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PR Comment: https://git.openjdk.org/jdk/pull/18605#issuecomment-2238734507