netdev - Re: [PATCH] net: Remove branch in csum

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Message-ID: <Yh4TfnHuTmCqWZDb@shell.armlinux.org.uk>
Date:   Tue, 1 Mar 2022 12:37:18 +0000
From:   "Russell King (Oracle)" <linux@...linux.org.uk>
To:     David Laight <David.Laight@...lab.com>
Cc:     'Christophe Leroy' <christophe.leroy@...roup.eu>,
        'Segher Boessenkool' <segher@...nel.crashing.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] net: Remove branch in csum_shift()

On Tue, Mar 01, 2022 at 11:41:06AM +0000, David Laight wrote:
> From: Christophe Leroy
> > Sent: 01 March 2022 11:15
> ...
> > Looks like ARM also does better code with the generic implementation as
> > it seems to have some looking like conditional instructions 'rorne' and
> > 'strne'.
> 
> In arm32 (and I think arm64) every instruction is conditional.

Almost every instruction in arm32. There are a number of unconditional
instructions that were introduced.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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