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From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: Re: [PATCH] Added ARM optimised memcpy implementation
Date: Fri, 1 Mar 2013 08:26:17 +0100	[thread overview]
Message-ID: <20130301072617.GP6181@port70.net> (raw)
In-Reply-To: <A879C957-AA17-4737-8268-55B1FB7BB840@gmail.com>

* nwmcsween@gmail.com <nwmcsween@gmail.com> [2013-02-28 19:14:28 -0800]:
> Hmm what does this do that builtins cannot? What I'm asking is why is this more preformant than preload + word-at-a-time.
> 

musl uses naive memcpy if src and dst are not congruent (src%4 != dst%4)

the android asm takes care of that by fetching a 32bytes
from src into registers and dumping it into dst with
apropriate shifts

and in the congruent case 32byte alignment is used (cacheline aligned)


  reply	other threads:[~2013-03-01  7:26 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-01  1:24 Andre Renaud
2013-03-01  1:27 ` Andre Renaud
2013-03-01  3:14   ` nwmcsween
2013-03-01  7:26     ` Szabolcs Nagy [this message]
2013-03-02 20:28       ` Andre Renaud
2013-03-07 21:48 ` Andre Renaud
2013-03-08  8:24   ` Szabolcs Nagy

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