RFR: 8312425: [vectorapi] AArch64: Optimize vector math operations with SLEEF [v4]

[Magnus Ihse Bursie]

On Fri, 15 Mar 2024 13:58:05 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review this patch?
>> Thanks
>> 
>> This is a continuation of work based on [1] by @XiaohongGong, most work was done in that pr. In this new pr, just rebased the code in [1], then added some minor changes (renaming of calling method, add libsleef as extra lib in CI cross-build on aarch64 in github workflow); I aslo tested the combination of following scenarios:
>> * at build time
>>   * with/without sleef
>>   * with/without sve support 
>> * at runtime
>>   * with/without sleef
>>   * with/without sve support 
>> 
>> [1] https://github.com/openjdk/jdk/pull/16234
>> 
>> ## Regression Test
>> * test/jdk/jdk/incubator/vector/
>> * test/hotspot/jtreg/compiler/vectorapi/
>> 
>> ## Performance Test
>> Previously, @XiaohongGong has shared the data: https://github.com/openjdk/jdk/pull/16234#issuecomment-1767727028
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix jni includes

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 8545:

> 8543:     char ebuf[1024];
> 8544:     char dll_name[JVM_MAXPATHLEN];
> 8545:     if (os::dll_locate_lib(dll_name, sizeof(dll_name), Arguments::get_dll_dir(), "vectormath")) {

1. You load the library here.

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 8569:

> 8567: 
> 8568:       // Math vector stubs implemented with SVE for scalable vector size.
> 8569:       if (UseSVE > 0) {

2. You check UseSVE here.

If the library could not be loaded, you would not even reach here.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18294#discussion_r1537259422
PR Review Comment: https://git.openjdk.org/jdk/pull/18294#discussion_r1537260140