Date: Sat, 5 Apr 2003 08:16:17 +0300 From: Ruslan Ermilov <ru@FreeBSD.org> To: "M. Warner Losh" <imp@bsdimp.com> Cc: mike@FreeBSD.org Subject: Re: cvs commit: src/sys/sys endian.h src/share/man/man9 byteorder.9 Message-ID: <20030405051617.GB38538@sunbay.com> In-Reply-To: <20030404.160823.91026001.imp@bsdimp.com> References: <Pine.BSF.4.21.0304031545540.15187-100000@root.org> <20030403184229.D18209@espresso.bsdmike.org> <20030404085200.GA1765@sunbay.com> <20030404.160823.91026001.imp@bsdimp.com>
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--8w3uRX/HFJGApMzv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 04, 2003 at 04:08:23PM -0700, M. Warner Losh wrote: > In message: <20030404085200.GA1765@sunbay.com> > Ruslan Ermilov <ru@FreeBSD.org> writes: > : +#define BSWAP64(x) (uint64_t) \ > : + (((x) >> 56) | (((x) >> 40) & 0xff00) | (((x) >> 24) & 0xff0000) | \ > : + (((x) >> 8) & 0xff000000) | (((x) << 8) & ((uint64_t)0xff << 32)) | \ > : + (((x) << 24) & ((uint64_t)0xff << 40)) | \ > : + (((x) << 40) & ((uint64_t)0xff << 48)) | (((x) << 56))) >=20 > 0xffull or 0xffULL might be better than the casts here. This does > assume that 0ull =3D=3D (uint64_t)0, which does hold for all our > architectures... >=20 Why make assumptions where uint64_t gives us precisely what we need? Note that these are evaluated at compile time, so it cannot affect the run-time performance. Cheers, --=20 Ruslan Ermilov Sysadmin and DBA, ru@sunbay.com Sunbay Software AG, ru@FreeBSD.org FreeBSD committer, +380.652.512.251 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age --8w3uRX/HFJGApMzv Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (FreeBSD) iD8DBQE+jmahUkv4P6juNwoRAuJ3AJ9Rc8UbtMvJo6/88fmsuxWuC+Sj2ACfccgo Dlr3EVZdp3l5jgC6R2c9LXU= =vfBQ -----END PGP SIGNATURE----- --8w3uRX/HFJGApMzv--
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