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Date: Wed, 30 Apr 2003 13:55:12 -0700
From: Andrew Morton <akpm@digeo.com>
To: dphillips@sistina.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] Faster generic_fls
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Daniel Phillips <dphillips@sistina.com> wrote:
>
> +static inline unsigned fls8(unsigned n)
> +{
> +	return n & 0xf0?
> +	    n & 0xc0? (n >> 7) + 7: (n >> 5) + 5:
> +	    n & 0x0c? (n >> 3) + 3: n - ((n + 1) >> 2);
> +}

	return fls_table[n];


That'll be faster in benchmarks, possibly slower in real world.  As usual.