RFR: 8348868: AArch64: Add backend support for SelectFromTwoVector

[Bhavana Kilambi]

On Thu, 20 Feb 2025 05:45:34 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

>> @XiaohongGong , thanks I'll give it a try and get back.
>
> @Bhavana-Kilambi , left shift can not get right indexes here as values `0x2, 0x4` is landed in each B lane. Maybe we can just try with `bsl` for D size types, as it has only two lanes for long/double types with 128-bit vector length.

Hi @XiaohongGong , thanks but bsl instruction only has 8B/16B types. not D type. I'll see how I can do this with bsl.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23570#discussion_r1963101541