linux-kernel - Re: Fast memcpy patch

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Date:	Wed, 23 Nov 2011 20:07:39 +0800
From:	Cong Wang <xiyou.wangcong@...il.com>
To:	"N. Coesel" <nico@...dev.nl>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Fast memcpy patch

On Wed, Nov 23, 2011 at 7:25 PM, N. Coesel <nico@...dev.nl> wrote:
> Dear readers,
> I noticed the Linux kernel still uses a byte-by-byte copy method for memcpy.
> Since most memory allocations are aligned to the integer size of a cpu it is
> often faster to copy by using the CPU's native word size. The patch below
> does that. The code is already at work in many 16 and 32 bit embedded
> products. It should also work for 64 bit platforms. So far I only tested 16
> and 32 bit platforms.

Which arch are you referring?

At least on x86, it has optimized memcpy(), see arch/x86/lib/memcpy_32.c
and arch/x86/include/asm/string_64.h.
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