RFR: 8295948: Support for Zicbop/prefetch instructions on RISC-V [v4]

[Fei Yang]

On Thu, 3 Nov 2022 16:36:49 GMT, Ludovic Henry <luhenry at openjdk.org> wrote:

>> The OpenJDK supports generating prefetch instructions on most platforms. RISC-V supports through the Zicbop extension the use of prefetch instructions. We want to make sure we use these instructions whenever they are available.
>> 
>> It passes `hotspot:tier1` test suite
>
> Ludovic Henry has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - fixup! remove dead code
>  - remove dead code

Updated changes looks good except for the indentation issue.

src/hotspot/os_cpu/linux_riscv/prefetch_linux_riscv.inline.hpp line 32:

> 30: 
> 31: inline void Prefetch::read(const void *loc, intx interval) {
> 32:     if (interval >= 0 && UseZicbop) {

You might want to fix indentation for Prefetch::read/write here.

-------------

Marked as reviewed by fyang (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10884