RFR: 8267968: [PPC64] Use prefixed load and addi instructions for better performance in POWER10 [v4]

[Kazunori Ogata]

On Mon, 7 Jun 2021 23:36:23 GMT, Corey Ashford <cashford at openjdk.org> wrote:

>> Kazunori Ogata has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - Rename paddi_or_addi to paddi_or_addi_r0ok because it accepts R0
>>  - Remove unreachable code blocks
>
> I didn't review the details of the commit's functionality, because there are hundreds of details to check there, and to be honest there's a lot I don't understand about working with C2.
> 
> Do you have a set of tests that check different sizes of immediate loads to guarantee you hit every case and emit the correct code?

@CoreyAshford Thank you for your review and heads up.  I double checked if all paths are tested and found there are unreachable blocks.  I removed them.

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

PR: https://git.openjdk.java.net/jdk/pull/4267