RFR: 8355216: Accelerate P-256 arithmetic on aarch64

[Andrew Haley]

On Fri, 24 Oct 2025 13:57:30 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> An aarch64 implementation of the `MontgomeryIntegerPolynomial256.mult()` method
>
> src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 7403:
> 
>> 7401:     // c3 &= LIMB_MASK;
>> 7402: 
>> 7403:     __ ldr(mod_j, __ post(mod_ptr, 8));
> 
> Best not to use post-increment if you can avoid it.

It adds a dependency chain between each use.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27946#discussion_r2460624122