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From: Matteo Croce <mcroce@linux.microsoft.com>
To: Guo Ren <guoren@kernel.org>
Cc: linux-riscv <linux-riscv@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Atish Patra <atish.patra@wdc.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Akira Tsukamoto <akira.tsukamoto@gmail.com>,
	Drew Fustini <drew@beagleboard.org>,
	Bin Meng <bmeng.cn@gmail.com>
Subject: Re: [PATCH 1/3] riscv: optimized memcpy
Date: Wed, 16 Jun 2021 20:52:13 +0200	[thread overview]
Message-ID: <CAFnufp1OHdRd-tbB+Hi0UnXARtxGPdkK6MJktnaNCNt65d3Oew@mail.gmail.com> (raw)
In-Reply-To: <CAJF2gTTreOvQYYXHBYxznB9+vMaASKg8vwA5mkqVo1T6=eVhzw@mail.gmail.com>

On Wed, Jun 16, 2021 at 1:46 PM Guo Ren <guoren@kernel.org> wrote:
>
> Hi Matteo,
>
> Have you tried Glibc generic implementation code?
> ref: https://lore.kernel.org/linux-arch/20190629053641.3iBfk9-I_D29cDp9yJnIdIg7oMtHNZlDmhLQPTumhEc@z/#t
>
> If Glibc codes have the same performance in your hardware, then you
> could give a generic implementation first.
>

Hi,

I had a look, it seems that it's a C unrolled version with the
'register' keyword.
The same one was already merged in nios2:
https://elixir.bootlin.com/linux/latest/source/arch/nios2/lib/memcpy.c#L68

I copied _wordcopy_fwd_aligned() from Glibc, and I have a very similar
result of the other versions:

[  563.359126] Strings selftest: memcpy(src+7, dst+7): 257 Mb/s

Regards,
-- 
per aspera ad upstream

  reply	other threads:[~2021-06-16 18:52 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15  2:38 [PATCH 0/3] riscv: optimized mem* functions Matteo Croce
2021-06-15  2:38 ` [PATCH 1/3] riscv: optimized memcpy Matteo Croce
2021-06-15  8:57   ` David Laight
2021-06-15 13:08     ` Bin Meng
2021-06-15 13:18       ` David Laight
2021-06-15 13:28         ` Bin Meng
2021-06-15 16:12           ` Emil Renner Berthing
2021-06-16  0:33             ` Bin Meng
2021-06-16  2:01               ` Matteo Croce
2021-06-16  8:24                 ` David Laight
2021-06-16 10:48                   ` Akira Tsukamoto
2021-06-16 19:06                   ` Matteo Croce
2021-06-15 13:44         ` Matteo Croce
2021-06-16 11:46   ` Guo Ren
2021-06-16 18:52     ` Matteo Croce [this message]
2021-06-17 21:30       ` David Laight
2021-06-17 21:48         ` Matteo Croce
2021-06-18  0:32           ` Matteo Croce
2021-06-18  1:05             ` Matteo Croce
2021-06-18  8:32               ` David Laight
2021-06-15  2:38 ` [PATCH 2/3] riscv: optimized memmove Matteo Croce
2021-06-15  2:38 ` [PATCH 3/3] riscv: optimized memset Matteo Croce
2021-06-15  2:43 ` [PATCH 0/3] riscv: optimized mem* functions Bin Meng
2024-01-28 11:10 [PATCH 0/3] riscv: optimize memcpy/memmove/memset Jisheng Zhang
2024-01-28 11:10 ` [PATCH 1/3] riscv: optimized memcpy Jisheng Zhang
2024-01-28 12:35   ` David Laight
2024-01-30 12:11   ` Nick Kossifidis

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