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Message-ID: <d55e0390c7187b09f820e123b05df1e5e680df0b.camel@strongswan.org>
Subject: Re: [PATCH crypto-next v2 1/3] crypto: poly1305 - add new 32 and
 64-bit generic versions
From:   Martin Willi <martin@strongswan.org>
To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     linux-crypto@vger.kernel.org
Date:   Thu, 12 Dec 2019 13:03:27 +0100
In-Reply-To: <20191212093008.217086-1-Jason@zx2c4.com>
References: <20191211170936.385572-1-Jason@zx2c4.com>
         <20191212093008.217086-1-Jason@zx2c4.com>
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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