RFR: 8307495: Specialize atomic bitset functions for aix-ppc

[David Briemann]

On Wed, 8 Oct 2025 10:28:15 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> Also refactor so that linux and aix use the same code for ppc.
>
> src/hotspot/os_cpu/aix_ppc/atomicAccess_aix_ppc.hpp line 27:
> 
>> 25: 
>> 26: #ifndef OS_CPU_AIX_PPC_ATOMICACCESS_AIX_PPC_HPP
>> 27: #define OS_CPU_AIX_PPC_ATOMICACCESS_AIX_PPC_HPP
> 
> Maybe remove these guards? The ones in the new file should be sufficient. (The same for the other files.)

As long as no one is adding platform_cpu specific functions removing should be fine.

> src/hotspot/os_cpu/aix_ppc/atomicAccess_aix_ppc.hpp line 30:
> 
>> 28: 
>> 29: // Included in atomicAccess.hpp header file.
>> 30: 
> 
> Maybe add comment like "We use inline assembler which is shared for several PPC64 platforms."

Agree.. good time to update the comment and make it more precise.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27650#discussion_r2413522665
PR Review Comment: https://git.openjdk.org/jdk/pull/27650#discussion_r2413523675