RFR: 8316592: RISC-V: implement poly1305 intrinsic [v7]

[ArsenyBochkarev]

On Wed, 8 Nov 2023 18:50:00 GMT, ArsenyBochkarev <duke at openjdk.org> wrote:

>> Yes, what I'm discussing is the case 2.
>> Sorry, I'm still bit concerned.
>> 
>> You said `at the next reduce outside the loop, U_2 would have 0b100 value which would be cleared to safe 0b1 by srli.`, but seems the dest register of srli is tmp1 not U_2, am I right?
>> 
>> If I'm right above, then let's continue the discussion.
>> Let's say at the entry of LINE 4576 `reduce(U_2, U_1, U_0, t1, t2);` (just out of the loop), U_2 == ob11.
>> Then in reduce(), U_2 will be 0b11 at the entry of LINE 4478 `__ add(U_2, U_2, tmp2);`, and tmp2 == 1. Is it possible?
>
> Oh, I see it now. Good catch, thanks! Let's do one final conditional reduce then.

Done.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/16417#discussion_r1387080562