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From: Ralf Baechle <ralf@linux-mips.org>
To: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>,
	u1@terran.org, linux-mips@linux-mips.org
Subject: Re: MIPS checksum bug
Date: Fri, 19 Sep 2008 00:07:35 +0200	[thread overview]
Message-ID: <20080918220734.GA19222@linux-mips.org> (raw)
In-Reply-To: <Pine.LNX.4.55.0809171917580.17103@cliff.in.clinika.pl>

On Wed, Sep 17, 2008 at 07:21:23PM +0100, Maciej W. Rozycki wrote:

> > >  Hmm, what's the purpose of doing the fold in csum_partial() then?
> > 
> > Well, maybe odd-byte handling requires 16-bit holded values?
> 
>  It should be enough to swap odd and even bytes in the word in the
> unaligned path.  Though perhaps extra code to do masking would make it no
> shorter/faster than what we have now; however the aligned path would
> benefit.  Hmm...

Which is a truely weird operation - but MIPS R2 happens to have a wonderful
instruction for this operation, WSBH / DSBH.

  Ralf

  reply	other threads:[~2008-09-18 22:07 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <072748C6-07A9-4167-A8A5-80D0F7D9C784@darkforest.org>
2008-09-17  5:15 ` MIPS checksum bug Bryan Phillippe
2008-09-17 10:40   ` Maciej W. Rozycki
2008-09-17 13:23     ` Atsushi Nemoto
2008-09-17 14:46       ` Maciej W. Rozycki
2008-09-17 15:27         ` Atsushi Nemoto
2008-09-17 18:21           ` Maciej W. Rozycki
2008-09-18 22:07             ` Ralf Baechle [this message]
2008-09-19 10:12               ` Maciej W. Rozycki
2008-09-19 11:23                 ` Ralf Baechle
2008-09-19 11:47                   ` [PATCH] MIPS checksum fix Ralf Baechle
2008-09-19 12:07                     ` Ralf Baechle
2008-09-19 12:15                       ` Maciej W. Rozycki
2008-09-19 14:09                       ` Atsushi Nemoto
2008-09-19 15:02                         ` Maciej W. Rozycki
2008-09-20 15:09                         ` Ralf Baechle
2008-09-23 21:52                       ` Bryan Phillippe
2008-09-23 22:06                         ` Ralf Baechle
2008-09-29 15:28                         ` Atsushi Nemoto
2008-09-19 12:26                   ` MIPS checksum bug Maciej W. Rozycki
2008-09-19 16:04                     ` Bryan Phillippe
2008-09-17 22:52       ` Bryan Phillippe
2008-09-18 16:17         ` Atsushi Nemoto
2008-09-19  1:14           ` Ralf Baechle
2008-09-19 15:43           ` Atsushi Nemoto
2008-09-19 16:09             ` Maciej W. Rozycki
2008-09-19 16:35               ` Thiemo Seufer
2008-09-19 23:18                 ` Maciej W. Rozycki
2008-09-20  0:13               ` Ralf Baechle
2008-09-20 13:45                 ` Atsushi Nemoto
2008-09-18  4:43     ` Bryan Phillippe
2008-09-18 10:06       ` Maciej W. Rozycki

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