From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20512 invoked by alias); 21 Oct 2007 18:08:06 -0000 Received: (qmail 20501 invoked by uid 22791); 21 Oct 2007 18:08:05 -0000 X-Spam-Check-By: sourceware.org Received: from mtagate6.de.ibm.com (HELO mtagate6.de.ibm.com) (195.212.29.155) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 21 Oct 2007 18:08:01 +0000 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate6.de.ibm.com (8.13.8/8.13.8) with ESMTP id l9LI7vE1392528 for ; Sun, 21 Oct 2007 18:07:57 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l9LI7vxO2015326 for ; Sun, 21 Oct 2007 20:07:57 +0200 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l9LI7v0H011129 for ; Sun, 21 Oct 2007 20:07:57 +0200 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.12.11) with SMTP id l9LI7vCL011126; Sun, 21 Oct 2007 20:07:57 +0200 Message-Id: <200710211807.l9LI7vCL011126@d12av02.megacenter.de.ibm.com> Received: by tuxmaker.boeblingen.de.ibm.com (sSMTP sendmail emulation); Sun, 21 Oct 2007 20:07:57 +0200 Subject: Re: [commit] Use -mabi=altivec for AltiVec tests To: drow@false.org (Daniel Jacobowitz) Date: Sun, 21 Oct 2007 19:37:00 -0000 From: "Ulrich Weigand" Cc: gdb-patches@sourceware.org In-Reply-To: <20071021130504.GA10828@caradoc.them.org> from "Daniel Jacobowitz" at Oct 21, 2007 09:05:04 AM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2007-10/txt/msg00474.txt.bz2 Daniel Jacobowitz wrote: > I don't think this is a good idea. -mabi=altivec is an ABI-changing > option; you're supposed to match the ABI of your system libraries. > It will work out OK in practice though since the stack alignment is > already large enough on powerpc-linux. Sorry, I didn't consider this controversial, or I would have posted an RFC first ... I understand it to be general practice to use -mabi=altivec with applications on Linux, and that should be OK as long as no system library interface using vector arguments is used. Is this a problem in other environments? However, if you prefer, I certainly have no objections to reverting the patch (or maybe restricting it to Linux only) ... > I committed a GCC HEAD patch several weeks ago to mark the vector ABI of > PowerPC object files. I also posted a linker patch to propogate this > into linked objects and I have the matching patch to GDB to > auto-detect the correct ABI and support both in GDB. That also > fixes this test. Supporting both ABIs in GDB is certainly a good thing. However, the point of this test case is to verify that GDB implements the AltiVec ABI correctly, so IMO we really want to exercise that code path, not bypass it. In fact, if we support both ABIs in GDB, we probably want to run the test twice, once compiled with -mabi=altivec and once with -mabi=no-altivec ... > Unfortunately the linker patch is hung up right now because it notices > this same dubious action (linking -mabi=altivec and -mabi=no-altivec > code) and warns about it. That causes a bunch of GCC testcase > failures. The GCC testcases in question use, but do not actually > need, -mabi=altivec; they just need a nasty bug in -maltivec > -mabi=no-altivec fixed and my patch for that didn't get any comments > :-( Can you point me to the patch in question? Maybe I can ping David ... Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE Ulrich.Weigand@de.ibm.com