RFR: 8320206: Some intrinsics/stubs missing vzeroupper on x86_64

Fri Nov 17 16:00:30 UTC 2023

On Wed, 15 Nov 2023 21:28:46 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

> The following intrinsics/stubs are missing vzeroupper:
> adler32 (since JDK17)
> count_positives (since JDK 9)
> chacha20 (since JDK 20)
> string indexOfChar (since JDK 9)
> 
> Adding the missing vzeroupper to avoid AVX-SSE transition penalties.

My testing tier1-4,xcomp,stress for version v00 passed.

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Marked as reviewed by kvn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16678#pullrequestreview-1737342726