Re: [PATCH crypto-next v2 1/3] crypto: poly1305 - add new 32 and 64-bit generic versions

Martin Willi
2019-12-12T12:09:11Z

Hi Jason,

> These two C implementations from Zinc -- a 32x32 one and a 64x64 one,
> depending on the platform -- come from Andrew Moon's public domain
> poly1305-donna portable code, modified for usage in the kernel. The
> precomputation in the 32-bit version and the use of 64x64 multiplies
> in the 64-bit version make these perform better than the code it
> replaces.

Can you provide some numbers to testify that? In my tests, the 32-bit
version gives me exact the same results.

The 64-bit version is roughly 10% faster. However, what are the
platforms where the 64-bit version matters? Won't any SIMD version
outperform the 64-bit version anyway?

Martin