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From: Frederik Deweerdt <deweerdt@free.fr>
To: kernel-janitors@vger.kernel.org
Subject: Re: [KJ] another cleanup TO DO:  is_power_of_2() check
Date: Mon, 08 Jan 2007 23:09:26 +0000	[thread overview]
Message-ID: <20070108230925.GF15292@slug> (raw)
In-Reply-To: <Pine.LNX.4.64.0701081732070.25196@localhost.localdomain>

On Mon, Jan 08, 2007 at 05:37:16PM -0500, Robert P. J. Day wrote:
> 
>   there are *numerous* places in the code that check if some value is
> a power of 2 using the basic test "((x & (x - 1)) = 0)":
> 
>   $ grep -Er "(.*) ?\& ?\(\1 ?- ?1\)" .
> 
> as you can see, that test is all over the place.
> 
>   occasionally, someone decides to do the right thing and define a
> macro:
> 
>   $ grep -r "#define is_power_of_2" .
Some of which really are is_power_of_2_but_not_0 :). That corner case
set aside, but it is handled differently throughout the source, it seems
fine to me.

Regards,
Frederik
> 
> i'm thinking it might be cleaner to define that macro in kernel.h and
> clean up the source to use that macro, rather than constantly
> rewriting that expression.
> 
>   thoughts?
> 
> rday
> _______________________________________________
> Kernel-janitors mailing list
> Kernel-janitors@lists.osdl.org
> https://lists.osdl.org/mailman/listinfo/kernel-janitors
> 
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  reply	other threads:[~2007-01-08 23:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-08 22:37 [KJ] another cleanup TO DO: is_power_of_2() check Robert P. J. Day
2007-01-08 23:09 ` Frederik Deweerdt [this message]
2007-01-08 23:15 ` Robert P. J. Day
2007-01-09  0:06 ` Frederik Deweerdt

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