netdev - Re: [PATCH 2/2] enic: Silence Sparse Warning: "dubious: x

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20120224.175006.1161090053765926485.davem@davemloft.net>
Date:	Fri, 24 Feb 2012 17:50:06 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	santoshprasadnayak@...il.com
Cc:	benve@...co.com, roprabhu@...co.com, neepatel@...co.com,
	nistrive@...co.com, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [PATCH 2/2] enic: Silence Sparse Warning: "dubious: x | !y"

From: santosh nayak <santoshprasadnayak@...il.com>
Date: Fri, 24 Feb 2012 22:27:34 +0530

> From: Santosh Nayak <santoshprasadnayak@...il.com>
> 
> Sparse is giving the following warning:
> "warning: dubious: x | !y"
> 
> "enic_are_pp_different" is static and expected to return true or false.
> Logical or is indended here. With logical or, in best case, execution will be
> faster because if leftmost operand is true then no need to check other operands.
> 
> Signed-off-by: Santosh Nayak <santoshprasadnayak@...il.com>

As others have explained, this code is intentional.  It's faster because
the resulting code has less branches and therefore less potential
branch mispredictions.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html