RFR: 8348868: AArch64: Add backend support for SelectFromTwoVector [v15]

[erifan]

On Thu, 24 Jul 2025 07:37:46 GMT, Bhavana Kilambi <bkilambi at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/aarch64.ad line 923:
>> 
>>> 921:     V24, V24_H, V24_J, V24_K
>>> 922: );
>>> 923: 
>> 
>> Not a big matter, but it looks better to me if you can move this change `after line 810` of this file.
>
> Thanks but I feel having all the vector classes (like for vecA, vecX etc) together would be better and keeping the reg_class definitions with other reg_class feels better to me. Hope that's ok?

ACK

>> src/hotspot/cpu/aarch64/aarch64.ad line 5091:
>> 
>>> 5089:   format %{ %}
>>> 5090:   interface(REG_INTER);
>>> 5091: %}
>> 
>> Ditto, I tend to moving this change `after line 5101` of this file.
>
> Same explanation here. the registers are matching `vReg` which can be either `vecA`, `vecD` or `vecX` and thus I placed the operand definitions right after the `vReg` definition.

ACK

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23570#discussion_r2227776401
PR Review Comment: https://git.openjdk.org/jdk/pull/23570#discussion_r2227777777