RFR: 8317720: RISC-V: Implement Adler32 intrinsic [v7]

[Gui Cao]

On Fri, 17 May 2024 13:44:18 GMT, Gui Cao <gcao at openjdk.org> wrote:

>> ArsenyBochkarev has updated the pull request incrementally with eight additional commits since the last revision:
>> 
>>  - Prettify L_nmax loop
>>  - Add comments in functions
>>  - Add explanation comment for L_nmax_loop
>>  - Fix L_nmax_loop for big lengths
>>  - Fix L_by16 loop step
>>  - Prettify intrinsic
>>  - Use LMUL=4 for most of the calculations
>>  - Use LMUL to load multiple data in one step
>
> I also ran the correctness test on the Banana Pi BPI-F3 board (has RVV1.0):
> 
> Before this patch and disable UseRVV:
> Test `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` is ok
> Before this patch and enable UseRVV:
> Test `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` is ok
> 
> Apply this patch and disable UseRVV:
> Test `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` is ok
> Apply this patch and enable UseRVV:
> Test `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` is Failed
> 
> The TestAdler32.jtr on Failed is as follows: 
> [TestAdler32.jtr.log](https://github.com/openjdk/jdk/files/15350178/TestAdler32.jtr.log)

> Hello @zifeihan! Thanks for your efforts on improving this PR. I don't have access (yet) to Banana Pi board, so I can't debug precisely the case you pointed out. However, I know that vlen for Banana Pi is 256 bit, so I fixed problems for this case and checked functional correctness on QEMU for both 128 and 256 bit, which is OK now. Could you please do a re-run of `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` test?

Sorry for being late, JMH performance test data just finished.
Apply this pr and enable UseRVV:
- [x] Correctness test `test/hotspot/jtreg/compiler/intrinsics/zip/TestAdler32.java` passed normally.
- [x] JMH test `test/micro/org/openjdk/bench/java/util/TestAdler32.java` passed normally. 

Benchmark                      (count)   Mode  Cnt     Score    Error   Units
TestAdler32.testAdler32Update       64  thrpt   25  7865.764 ± 57.876  ops/ms
TestAdler32.testAdler32Update      128  thrpt   25  6361.346 ±  0.178  ops/ms
TestAdler32.testAdler32Update      256  thrpt   25  4595.217 ±  0.166  ops/ms
TestAdler32.testAdler32Update      512  thrpt   25  2941.284 ± 12.318  ops/ms
TestAdler32.testAdler32Update     1024  thrpt   25  1728.568 ±  0.053  ops/ms
TestAdler32.testAdler32Update     2048  thrpt   25   943.173 ±  1.043  ops/ms
TestAdler32.testAdler32Update     5012  thrpt   25   404.343 ±  0.205  ops/ms
TestAdler32.testAdler32Update     8192  thrpt   25   249.495 ±  1.986  ops/ms
TestAdler32.testAdler32Update    16384  thrpt   25   126.168 ±  1.261  ops/ms
TestAdler32.testAdler32Update    32768  thrpt   25    61.925 ±  0.607  ops/ms
TestAdler32.testAdler32Update    65536  thrpt   25    30.866 ±  0.375  ops/ms
Finished running test 'micro:java.util.TestAdler32'

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

PR Comment: https://git.openjdk.org/jdk/pull/18382#issuecomment-2121969207