Date: Wed, 7 Mar 2001 02:44:56 -0800 From: Kris Kennaway <kris@obsecurity.org> To: Jordan Hubbard <jkh@osd.bsdi.com> Cc: kris@obsecurity.org, ohartman@klima.physik.uni-mainz.de, antony@abacus.co.uk, freebsd-stable@FreeBSD.ORG Subject: Re: ARCH flag in new make.conf Message-ID: <20010307024456.A37349@mollari.cthul.hu> In-Reply-To: <20010307020500X.jkh@osd.bsdi.com>; from jkh@osd.bsdi.com on Wed, Mar 07, 2001 at 02:05:00AM -0800 References: <20010307012454.A14664@mollari.cthul.hu> <20010307014323M.jkh@osd.bsdi.com> <20010307015036.A36721@mollari.cthul.hu> <20010307020500X.jkh@osd.bsdi.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--opJtzjQTFsWo+cga
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Wed, Mar 07, 2001 at 02:05:00AM -0800, Jordan Hubbard wrote:
> From: Kris Kennaway <kris@obsecurity.org>
> Subject: Re: ARCH flag in new make.conf
> Date: Wed, 7 Mar 2001 01:50:37 -0800
>=20
> > I can be confident it is not a dangerous option, having never seen
> > code failure caused by it desipite extensive use for a long time.
>=20
> Well, first off you're not even setting it to the same value he
> was. :)
Yes I am:
While picking a specific CPU TYPE will schedule things
appropriately for that particular chip, the compiler will not
generate any code that does not run on the i386 without the
`-march=3DCPU TYPE' option being used. `i586' is equivalent to
`pentium' and `i686' is equivalent to `pentiumpro'. `k6' is the
AMD chip as opposed to the Intel ones.
i686 =3D=3D pentiumpro
> > This is not the case with optimizations generally accepted to be
> > dangerous (like -O2) from which I have seen many failures from on my
>=20
> Grrr. Please stop raising -O2 - it's a total red herring and I've
> never implied any kind of causual link between the overall
> optimization level and the architecture specific optimizations. :( I
> don't know why everybody keeps bringing it up like it was garlic for
> warding off vampires or something.
I was trying to justify to myself why you thought this was such a bad
thing, I thought perhaps you were thinking of a similarity with -O2.
> > own systems. Given the number of people who use -march with no ill
> > effects the 50/50 estimate is not very accurate.
>=20
> Ahem, do we actually know that number? I can't help but feel like
> we're both swinging in the dark here, the only difference being that
> I'm arguing about avoiding a serious failure and you're arguing about
> avoiding a serious warning. :)
This whole thing came totally out of the blue for me, I would have
appreciated a bit of discussion before unilaterally declaring the
project I've been working on "bad for users".
Kris
--opJtzjQTFsWo+cga
Content-Type: application/pgp-signature
Content-Disposition: inline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.4 (FreeBSD)
Comment: For info see http://www.gnupg.org
iD8DBQE6phEnWry0BWjoQKURAixeAKCSL/Fh74EI+faXeJVRK5cYTPISmgCfWRgx
CUcPjOL08CluWGMxjZGsFAw=
=O040
-----END PGP SIGNATURE-----
--opJtzjQTFsWo+cga--
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010307024456.A37349>