RFR: 8344766: AES/CTR slow at big payloads [v2]

[Jatin Bhateja]

On Wed, 27 Nov 2024 15:09:18 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> This is not just a good idea to trigger OSR and therefore use the intrinsic, it's a good idea because very long data causes an extended time to safepoint. I'd support in all cases limiting the size to about a megabyte, which is what we have here.
>
> Agree with @theRealAph ,  loop induces safe point on back edges which gives opportunity to gc epochs.

> As Andrew points out, giving an intrinsic lots of data, 'backdoors/breaks' a lot of existing algorithms.. from GC not happening because of no safepoint inside the intrinsic, to OSR..
> 
> .. and (what I believe to be issue for performance here) the call count (CompilationThreshold) to get the intrinsic to compile (well, the callee) in the first place. Though as I pointed in the original issue, I am not entirely convinced it was the call count that got the intrinsic back in; experimentally, chunking got the 'outer intrinsic' to compile. (There is an inner intrinsic that works on 16 byte chunks)

Please update the comments in the code accordingly.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22300#discussion_r1860834512