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Date: Fri, 10 Feb 2023 01:09:45 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: David Chisnall <theraven@freebsd.org>,
        freebsd-hackers <freebsd-hackers@freebsd.org>
Subject: Re: CFT: snmalloc as libc malloc
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On Thu, Feb 09, 2023 at 09:53:34PM +0100, Mateusz Guzik wrote:
> So, as someone who worked on memcpy previously, I note the variant
> currently implemented in libc is pessimal for sizes > 16 bytes because
> it does not use SIMD. I do have plans to rectify that, but ENOTIME.

Note that you need two kinds of micro-benchmarks for this:
- normal microbenchmark which does the SIMD-enabled memcpy() in a loop
- a microbenchmark which ensures that the SIMD register file ownership
  is re-taken on each iteration (or close to it).

I am sure that the results from #2 would be astonishing and give quite
different prospective on the use of SIMD for basic libc services.