Base64 encoding algorithm enhancements for ppc64 ?

[Gustavo Romero]

Hi Matthias,

On 07/19/2018 01:05 PM, Baesken, Matthias wrote:
> Hello, when looking into  some jtreg  test issues I came across  that  for x86_64  some enhancements
> 
> to Base64 encoding   were contributed  recently .
> 
> Please see :
> 
> JDK-8205528 <https://bugs.openjdk.java.net/browse/JDK-8205528> :  Base64 encoding algorithm using AVX512 instructions
> 
> https://bugs.openjdk.java.net/browse/JDK-8205528
> 
> http://hg.openjdk.java.net/jdk/jdk/rev/480a96a43b62
> 
> Do we have something similar  for  ppc64  ?

No, not currently in the PPC64 / JVM.
Your idea would be to use the VSX for Base64 encoding using SIMD instructions, right?
You probably already have references on hand, but just in case there are a few
refs (on Intel - I don't know any on Power so far) on this page:
http://0x80.pl/notesen/2016-01-12-sse-base64-encoding.html  


> If not do you think it’s worth  doing it for  this architecture as well ?

I'm not sure. On our side I'm not aware of any workload relying heavily on
that so I did not see any comments on it being worth to be implemented for PPC64.
On Intel it looks like that it's possible to get at least a 2x improvement, so
maybe an initial quick test could be done outside the JVM to get a feeling about
it on PPC64? I can help to run/test it on POWER9. If it proves reasonable, I
think it's a matter of available manpower to do that :)

BTW, I discuss from time to time with Martin, Volker, and Goetz features pending
and possibly interesting to be implemented on PPC64 (like GHASH - which is in
my TODO list). What do you think about creating a Wiki section, like in [1], to
track these things?


Best regards,
Gustavo

[1] https://wiki.openjdk.java.net/pages/viewpage.action?pageId=13041681