From owner-freebsd-arch@FreeBSD.ORG Tue Oct 9 02:53:58 2007 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3D21916A419 for ; Tue, 9 Oct 2007 02:53:58 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.geekcn.org (tarsier.geekcn.org [210.51.165.229]) by mx1.freebsd.org (Postfix) with ESMTP id 21A7213C467 for ; Tue, 9 Oct 2007 02:53:56 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from localhost (tarsier.geekcn.org [210.51.165.229]) by tarsier.geekcn.org (Postfix) with ESMTP id EFCA7EB90FA; Tue, 9 Oct 2007 10:53:55 +0800 (CST) X-Virus-Scanned: amavisd-new at geekcn.org Received: from tarsier.geekcn.org ([210.51.165.229]) by localhost (mail.geekcn.org [210.51.165.229]) (amavisd-new, port 10024) with ESMTP id r+zxMessgE+D; Tue, 9 Oct 2007 10:53:44 +0800 (CST) Received: from LI-Xins-MacBook.local (c-67-161-39-180.hsd1.ca.comcast.net [67.161.39.180]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tarsier.geekcn.org (Postfix) with ESMTP id 8D681EB569B; Tue, 9 Oct 2007 10:53:43 +0800 (CST) DomainKey-Signature: a=rsa-sha1; s=default; d=delphij.net; c=nofws; q=dns; h=message-id:date:from:reply-to:organization:user-agent: mime-version:to:cc:subject:references:in-reply-to: x-enigmail-version:openpgp:content-type; b=Z3/AL8IrkP3nrOaLg44LA5XLztQrldEbd5MKSZOYuhzxdFFRuw5xdUCBjnUle3pmR cMESdYVzwg5zBybS7wRoQ== Message-ID: <470AED31.60201@delphij.net> Date: Mon, 08 Oct 2007 19:53:37 -0700 From: LI Xin Organization: The FreeBSD Project User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: Bruce Evans References: <470ACEA1.3030309@delphij.net> <20071009122751.X54949@besplex.bde.org> In-Reply-To: <20071009122751.X54949@besplex.bde.org> X-Enigmail-Version: 0.95.3 OpenPGP: url=http://www.delphij.net/delphij.asc Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="------------enig21800BF69FE11B6A0A24B616" Cc: d@delphij.net, freebsd-arch@freebsd.org Subject: Re: Why we optimize by time by default for < -O2 case? X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: d@delphij.net List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Oct 2007 02:53:58 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig21800BF69FE11B6A0A24B616 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Bruce Evans wrote: > On Mon, 8 Oct 2007, LI Xin wrote: >=20 >> I wonder why we want to optimize by time by default and not by space b= y >> default for the system compiler, does the reasoning still hold true? >=20 > -O means optimize for time if possible. >=20 >> The commit log said: >> >> Modified files: >> contrib/gcc toplev.c >> Log: >> Clarify revision 1.14: >> Gcc 3.1's -O0 and -O1 actually optimized alignment for space, but we >> feel >> it should optimize alignment for time like Gcc 2.95 used to.=20 >> Optimization >> for space should give 1-byte alignment on i386's, but doesn't quite. >> >> Revision Changes Path >> 1.15 +0 -0 src/contrib/gcc/toplev.c >=20 > Without this change, -O pessimizes for time. Does this affect all platforms or is it i386 only, on the latest GCC version? Cheers, --=20 Xin LI http://www.delphij.net/ FreeBSD - The Power to Serve! --------------enig21800BF69FE11B6A0A24B616 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHCu0yOfuToMruuMARCqq6AJ9kgt+/seMxXRUvLOos4Q/N2aRIXQCeI0A7 DvXzq5qtLgwhZQx1iG5Bnl0= =IXVY -----END PGP SIGNATURE----- --------------enig21800BF69FE11B6A0A24B616--