[PATCH] SSE2/SSSE3 optimized version of get_checksum1() for x86-64
Sebastian Andrzej Siewior
rsync at ml.breakpoint.cc
Mon May 18 19:44:18 UTC 2020
On 2020-05-18 17:55:58 [+0200], Jorrit Jongma via rsync wrote:
> I don't disagree that MD5 could (or even should) be replaced so it is
> no longer the bottleneck in several real-world cases (including mine).
> However this patch is not for MD5 performance, rather for the rolling
> checksum rsync uses to match blocks on existing files on both ends to
> reduce transfer size.
Still. You claim in your patch that
| Benchmarks C SSE2 SSSE3
| - Intel i7-7700hq 1850 MB/s 2550 MB/s 4050 MB/s
while xxhash  claims on a Core i5-3340M @2.7GHz that:
|Version Speed on 64-bit Speed on 32-bit
|XXH64 13.8 GB/s 1.9 GB/s
so using xxhash64 for that work would also boost !x86 platforms.
However your patch has the benefit that no changes are required on the
remote side. I like that.
More information about the rsync