RFR: 8349908: RISC-V: C2 SelectFromTwoVector [v2]

[Fei Yang]

On Mon, 17 Feb 2025 14:04:55 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review the patch?
>> This optimization is mainly for the vector API.
>> 
>> Thanks
>> 
>> ## Test
>> 
>> ### jtreg
>> test/jdk/jdk/incubator/vector/
>> 
>> ### Performance
>> run on bananapi
>> 
>> master vs patch
>> <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 | Score -master | Error - master | Score - patch | Error - patch | Units | Improvement (master / patch)
>> -- | -- | -- | -- | -- | -- | -- | -- | -- | --
>> SelectFromBenchmark.selectFromByteVector | 1024 | avgt | 10 | 26422.495 | 674.565 | 721.604 | 1.036 | ns/op | 36.616
>> SelectFromBenchmark.selectFromByteVector | 2048 | avgt | 10 | 53964.411 | 1751.618 | 1385.24 | 0.956 | ns/op | 38.957
>> SelectFromBenchmark.selectFromDoubleVector | 1024 | avgt | 10 | 218430.616 | 1369.409 | 7739.774 | 14.408 | ns/op | 28.222
>> SelectFromBenchmark.selectFromDoubleVector | 2048 | avgt | 10 | 387889.456 | 7889.791 | 16197.77 | 66.775 | ns/op | 23.947
>> SelectFromBenchmark.selectFromFloatVector | 1024 | avgt | 10 | 103483.717 | 492.525 | 3580.358 | 29.127 | ns/op | 28.903
>> SelectFromBenchmark.selectFromFloatVector | 2048 | avgt | 10 | 226125.02 | 3118.836 | 7797.025 | 4.346 | ns/op | 29.001
>> SelectFromBenchmark.selectFromIntVector | 1024 | avgt | 10 | 97007.999 | 2607.711 | 2898.38 | 0.833 | ns/op | 33.47
>> SelectFromBenchmark.selectFromIntVector | 2048 | avgt | 10 | 222303.308 | 3096.615 | 6398.214 | 30.345 | ns/op | 34.745
>> SelectFromBenchmark.selectFromLongVector | 1024 | avgt | 10 | 245033.436 | 1652.527 | 6307.773 | 24.597 | ns/op | 38.846
>> SelectFromBenchmark.selectFromLongVector | 2048 | avgt | 10 | 438503.547 | 5972.265 | 17215.996 | 167.442 | ns/op | 25.471
>> SelectFromBenchmark.selectFromShortVector | 1024 | avgt | 10 | 53632.502 | 2159.433 | 1418.215 | 2.953 | ns/op | 37.817
>> SelectFromBenchmark.selectFromShortVector | 2048 | avgt | 10 | 111764.327 | 1220.509 | 3061.386 | 14.716 | ns/op | 36.508
>> 
>> </google-sheets-html-origin>
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   minor

LGTM. Thanks for the update.

src/hotspot/cpu/riscv/riscv_v.ad line 4458:

> 4456:     }
> 4457:     __ vrgather_vv(as_VectorRegister($dst$$reg), as_VectorRegister($src2$$reg),
> 4458:                   as_VectorRegister($tmp$$reg), Assembler::v0_t);

Nit: need one extra space to fix the indentation for this line

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

Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23614#pullrequestreview-2621243021
PR Review Comment: https://git.openjdk.org/jdk/pull/23614#discussion_r1958340720