On Fri, 15 May 2026 09:52:20 GMT, Ferenc Rakoczi <[email protected]> wrote:
>> An aarch64 implementation of the MontgomeryIntegerPolynomial256.mult() >> method and IntegerPolynomial.conditionalAssign(). Since 64-bit >> multiplication is not supported on Neon and manually performing this >> operation with 32-bit limbs is slower than with GPRs, a hybrid neon/gpr >> approach is used. Neon instructions are used to compute intermediate values >> used in the last two iterations of the main "loop", while the GPRs compute >> the first few iterations. At the method level this improves performance by >> ~9% and at the API level roughly 5%. >> >> >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Ferenc Rakoczi has updated the pull request incrementally with one additional > commit since the last revision: > > Accepting more suggestions from Andrew Dinn. src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 8377: > 8375: VSeq<4> b_vec(20); > 8376: > 8377: __ ldr(a9, Address(aLimbs, 64)); It makes things more obvious to a maintainer and avoids mistakes should anything need patching if you use 8 * BytesPerLong here instead of 64 and likewise for all the other hard-wired Address offsets used throughout this method. That way the offsets directly relate to the vector and GPR counts mentioned in the comments. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/30941#discussion_r3279780174
