RFR: 8355216: Accelerate P-256 arithmetic on aarch64 [v2]

[Andrew Haley]

On Tue, 17 Feb 2026 21:10:44 GMT, Ben Perez <bperez at openjdk.org> wrote:

> I used this format to mirror pmull{2} which has a similar structure.

I take your point. pmull{2} is odd in that the "2" is somewhat redundant in that it is  implied by the types of the operands, so the two versions are identical apart from assertions. All very weird, but that's Arm's doing.

> Open to changing to the INSN format if that's better though

I'm not sure now. You could at least move the first assertion into `_umullv`.

One thing you should do for sure though is move `_umullv` next to its callers.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27946#discussion_r2819466570