tree 6fa59d325ec995871af1c09856cb07a53bc297bb
parent 03d2daf55c97b833d675e9a1e1c0f6c9dfb240b4
author Ko- <k.stoffelen@cs.ru.nl> 1534410117 -0700
committer Ko- <k.stoffelen@cs.ru.nl> 1567424697 +0200

Add optimized bignum multiplication for Aarch64.

x0-x3 are skipped such that function parameters to not have to be moved.
MULADDC_INIT and MULADDC_STOP are mostly empty because it is more
efficient to keep everything in registers (and that should easily be
possible). I considered a MULADDC_HUIT implementation, but could not
think of something that would be more efficient than basically 8
consecutive MULADDC_CORE. You could combine the loads and stores, but
it's probably more efficient to interleave them with arithmetic,
depending on the specific microarchitecture. NEON allows to do a
64x64->128 bit multiplication (and optional accumulation) in one
instruction, but is not great at handling carries.