From owner-freebsd-current@FreeBSD.ORG  Tue May 27 03:10:26 2003
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id D919637B404; Tue, 27 May 2003 03:10:26 -0700 (PDT)
Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 4044B43F75; Tue, 27 May 2003 03:10:25 -0700 (PDT)
	(envelope-from bde@zeta.org.au)
Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246])
	by mailman.zeta.org.au (8.9.3p2/8.8.7) with ESMTP id UAA14762;
	Tue, 27 May 2003 20:10:02 +1000
Date: Tue, 27 May 2003 20:10:01 +1000 (EST)
From: Bruce Evans <bde@zeta.org.au>
X-X-Sender: bde@gamplex.bde.org
To: Doug Rabson <dfr@nlsystems.com>
In-Reply-To: <200305270942.42945.dfr@nlsystems.com>
Message-ID: <20030527200208.L1802@gamplex.bde.org>
References: <200305201025.30296.jlido@goof.com>
	<20030522093623.30915ed0.fearow@attbi.com>
	<200305270942.42945.dfr@nlsystems.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: freebsd-current@freebsd.org
Subject: Re: gcc/libm floating-point bug?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 27 May 2003 10:10:27 -0000

On Tue, 27 May 2003, Doug Rabson wrote:

> On Thursday 22 May 2003 6:32 pm, David O'Brien wrote:
> > On Thu, May 22, 2003 at 09:36:23AM -0500, Anti wrote:
> > > p4 should expand to "-march=pentium4 -mno-sse2"
> >
> > If we are going to make any change, it should be one we know will
> > deal with the issue once and for all.  I also considered submitting a
> > patch like that, but it is too late in the game to figure out if
> > "-march=pentium4 -mno-sse2" would be sufficient in all cases.
>
> Even for special cases, it is hard to use -msse (or -msse2) with
> gcc-3.2.x since it doesn't always manage to 16-byte align the stack
> pointer. This makes it hard to declare local vector float variables
> safely. All of this appears to be fixed in gcc-3.3-prerelease at least.

Isn't this "fixed" in gcc-3.any (gcc-3.2 on i386's at least) except
for signal stacks which are partly the kernel's responsibility?  gcc-3.2
still pessimizes stack alignment and invites bugs by doing it in
functions that don't need it and depending on callers doing it.

Bruce