From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31845 invoked by alias); 18 Feb 2011 08:10:57 -0000 Received: (qmail 31819 invoked by uid 22791); 18 Feb 2011 08:10:53 -0000 X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from vpn.id2.novell.com (HELO vpn.id2.novell.com) (195.33.99.129) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 18 Feb 2011 08:10:45 +0000 Received: from EMEA1-MTA by vpn.id2.novell.com with Novell_GroupWise; Fri, 18 Feb 2011 08:10:42 +0000 Message-Id: <4D5E37C702000078000329DE@vpn.id2.novell.com> Date: Fri, 18 Feb 2011 08:10:00 -0000 From: "Jan Beulich" To: "H.J. Lu" Cc: "GCC Development" ,, "Jakub Jelinek" , "Binutils" , "GNU C Library" , "Jan Hubicka" , "H. Peter Anvin" Subject: Re: x32 psABI draft version 0.2 References: <4D5C2DD2.10608@zytor.com> <4D5CEBDE02000078000325A2@vpn.id2.novell.com> <20110217142916.GI13037@sunsite.ms.mff.cuni.cz> <20110217152233.GB11346@atrey.karlin.mff.cuni.cz> <20110217154452.GA18799@kam.mff.cuni.cz> <4D5D56B70200007800032747@vpn.id2.novell.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-IsSubscribed: yes Mailing-List: contact binutils-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sourceware.org X-SW-Source: 2011-02/txt/msg00239.txt.bz2 >>> On 17.02.11 at 18:59, "H.J. Lu" wrote: > On Thu, Feb 17, 2011 at 8:11 AM, Jan Beulich wrote: >>>>> On 17.02.11 at 16:49, "H.J. Lu" wrote: >>> On Thu, Feb 17, 2011 at 7:44 AM, Jan Hubicka wrote: >>>>> > According to Mozilla folks however REL+RELA scheme used by EABI lea= ds >>>>> > to significandly smaller libxul.so size >>>>> > >>>>> > According to http://glandium.org/blog/?p=3D1177 the difference is a= bout 4-5MB >>>>> > (out of approximately 20-30MB shared lib) >>>>> >>>>> This is orthogonal to x32 psABI. >>>> >>>> Understood. I am just pointing out that x86-64 Mozilla suffers from s= tartup >>>> problems (extra 5MB of disk read needed) compared to both x86 and ARM = EABI >>>> because x86-64 ABI is RELA only. If x86-64 ABI was REL+RELA like EABI = is, we >>>> would not have this problem here. >>>> >>> >>> If people want to see REL+RELA in x32, they have to contribute codes. >> >> That's exactly the wrong way round: First the specification has to allow >> for (but not require) it, and only then does it make sense to write code. >> >=20 > No, it has to be supported at least by static linker and dynamic > linker. Otherwise, no one can use it. I'm afraid I have to disagree: ELF (and the psABI) is not specific to a particular OS, and hence it allowing something doesn't mean the OS ABI may not restrict it. Hence the psABI first has to at least not forbid something (as it currently does for REL on x86-64), in order for an implementation of that something to make sense. Jan