RFR: 8358032: Use crypto pmull for CRC32/CRC32C intrinsics on Ampere CPU [v4]

[Andrew Haley]

On Thu, 5 Jun 2025 05:16:25 GMT, Liming Liu <lliu at openjdk.org> wrote:

> According to perf, post-increment ops help to reduce the access to TLB on Ampere1 in this case.

Hmm, but it's code in a rather odd style in shared code. And from what I see, the intrinsic is only 22% of the runtime (for 128 bytes) anyway, and you're making the code larger. I certainly don't want to see this sort of thing proliferating in the intrinsics.

In general, it's up to CPU designers to make simple, straightforward code work well.

How important is this?

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PR Review Comment: https://git.openjdk.org/jdk/pull/25609#discussion_r2131885760