[jdk17u-dev] RFR: 8309254: Implement fast-path for ASCII-compatible CharsetEncoders on RISC-V

[Fei Yang]

On Tue, 11 Jul 2023 09:06:38 GMT, Dingli Zhang <dzhang at openjdk.org> wrote:

> I would like to backport [JDK-8309254](https://bugs.openjdk.org/browse/JDK-8309254). 
> The backport is not clean because 17u has no  [JDK-8302908](https://bugs.openjdk.org/browse/JDK-8302908), which use v0 as mask register.
> The test `test/hotspot/jtreg/compiler/intrinsics/string/TestEncodeIntrinsics.java` passed and command log with "-XX:+PrintOptoAssembly" output is similar to the mainline:
> 
> ...
> 240     Encode ISO array R12, R11, R13 -> R10 # KILL R12, R11, R13, R28, V1-V3
> ...
> 0118    Encode ASCII array R12, R11, R13 -> R10 # KILL R12, R11, R13, R25, V1-V3
> ...

Looks good. (Not a JDK Updates Reviewer)
I think this is on par with https://bugs.openjdk.org/browse/JDK-8274243 which has been backported to jdk17u.

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Marked as reviewed by fyang (Committer).

PR Review: https://git.openjdk.org/jdk17u-dev/pull/1567#pullrequestreview-1524181399