From owner-svn-src-head@FreeBSD.ORG  Sat Jul  9 15:36:30 2011
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3B769106566C;
	Sat,  9 Jul 2011 15:36:30 +0000 (UTC) (envelope-from ed@hoeg.nl)
Received: from mx0.hoeg.nl (mx0.hoeg.nl [IPv6:2a01:4f8:101:5343::aa])
	by mx1.freebsd.org (Postfix) with ESMTP id CEB2D8FC0A;
	Sat,  9 Jul 2011 15:36:29 +0000 (UTC)
Received: by mx0.hoeg.nl (Postfix, from userid 1000)
	id C2D5D2A28CC5; Sat,  9 Jul 2011 17:36:28 +0200 (CEST)
Date: Sat, 9 Jul 2011 17:36:28 +0200
From: Ed Schouten <ed@80386.nl>
To: Konstantin Belousov <kib@FreeBSD.org>
Message-ID: <20110709153628.GJ16219@hoeg.nl>
References: <201107091429.p69ETNNu003910@svn.freebsd.org>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="P6YfpwaDcfcOCJkJ"
Content-Disposition: inline
In-Reply-To: <201107091429.p69ETNNu003910@svn.freebsd.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
	src-committers@freebsd.org
Subject: Re: svn commit: r223884 - head/sys/sys
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 09 Jul 2011 15:36:30 -0000


--P6YfpwaDcfcOCJkJ
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi Kostik,

* Konstantin Belousov <kib@FreeBSD.org>, 20110709 16:29:
> +static __inline uint16_t
> +bitcount16(uint32_t x)

Shouldn't we use uint16_t for the argument here?

When I saw the code, I thought by myself, this could be done more
efficiently:

| static __inline uint16_t
| bitcount16(uint16_t x)
| {
|
| 	x =3D (x & 0x5555) + ((x >> 1) & 0x5555);
| 	x =3D (x & 0x3333) + ((x >> 2) & 0x3333);
| 	x *=3D 0x1111;
| 	return (x >> 12);
| }

But some testing revealed it works for all inputs, except 65536. d'oh!

--=20
 Ed Schouten <ed@80386.nl>
 WWW: http://80386.nl/

--P6YfpwaDcfcOCJkJ
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (FreeBSD)
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=03JA
-----END PGP SIGNATURE-----

--P6YfpwaDcfcOCJkJ--