[jdk17u-dev] Withdrawn: 8268276: Base64 Decoding optimization for x86 using AVX-512

[Scott Gibbons]

On Tue, 25 Oct 2022 22:24:51 GMT, Scott Gibbons <duke at openjdk.org> wrote:

> This is a backport of JDK-8268276: Base64 Decoding optimization for x86 using AVX-512.
> 
> We have had numerous customer requests for this functionality to be backported due to the ~19x performance improvement.
>  
> Original patch does not apply cleanly to 17u, because of a bug that was identified in the original commit, but not fixed until the later Base64 Encode acceleration enhancement was complete.  The fix is on line 6039 of src/hotspot/cpu/x86/stubGenerator_x86_64.cpp and has been included in this PR.  All four "translatedX" registers needed to be checked for illegal characters in the input stream.
> 
> Risk: I view the risk of this backport to be minimal.  This code has been in use for many months with no bugs reported.
>  
> Testing: x86_64 build, affected tests, tier1, tier2
>  
> Thanks,
> --Scott

This pull request has been closed without being integrated.

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PR: https://git.openjdk.org/jdk17u-dev/pull/840