RFR: 8303553: AArch64: Add BCAX backend rule

[changpeng1997]

On Thu, 30 Mar 2023 03:19:17 GMT, changpeng1997 <duke at openjdk.org> wrote:

>> We have `MacroLogicVNode` in the middle-end, can it be used to leverage the ternary logical instructions of SVE2 by selectively creating the node if the truth table is supported? Thanks a lot.
>
>> We have `MacroLogicVNode` in the middle-end, can it be used to leverage the ternary logical instructions of SVE2 by selectively creating the node if the truth table is supported? Thanks a lot.
> 
> Hi. I found that there were only two ternary logical instructions in SVE2 (BCAX, EOR3).
> Maybe we need not to leverage them in the middle-end by using `MacroLogicVNode`.

> @changpeng1997 There are also the bit-select instructions (`BSL`, `BSL1N`, `BSL2N`, `NBSL`).

Yes, but they are not logic-operation instructions.

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PR Comment: https://git.openjdk.org/jdk/pull/13222#issuecomment-1489905666