RFR: 8365581: Optimize Java implementation of P256 arithmetic [v4]

[Jamil Nimeh]

On Tue, 9 Sep 2025 16:46:10 GMT, Ben Perez <bperez at openjdk.org> wrote:

>> There are several places where MontgomeryIntegerPolynomialP256.mult() can be optimized. In particular, since modulus[2] = 0 several multiplications can be removed. Other multiplications can be replaced by shifts, which also saves time. Preliminary tests indicate an improvement between 5-10%.
>
> Ben Perez has updated the pull request incrementally with one additional commit since the last revision:
> 
>   removed unnecessary subtraction

Marked as reviewed by jnimeh (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/26792#pullrequestreview-3235163498