From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23348 invoked by alias); 2 May 2012 22:14:36 -0000 Received: (qmail 23130 invoked by uid 22791); 2 May 2012 22:14:33 -0000 X-SWARE-Spam-Status: No, hits=-4.9 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,KHOP_RCVD_TRUST,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE X-Spam-Check-By: sourceware.org Received: from mail-qa0-f48.google.com (HELO mail-qa0-f48.google.com) (209.85.216.48) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 02 May 2012 22:14:19 +0000 Received: by qady23 with SMTP id y23so1045630qad.14 for ; Wed, 02 May 2012 15:14:19 -0700 (PDT) MIME-Version: 1.0 Received: by 10.224.183.76 with SMTP id cf12mr607307qab.74.1335996858991; Wed, 02 May 2012 15:14:18 -0700 (PDT) Received: by 10.229.169.130 with HTTP; Wed, 2 May 2012 15:14:18 -0700 (PDT) In-Reply-To: <201205022143.q42Lhd3G018067@glazunov.sibelius.xs4all.nl> References: <20120410202953.GA23862@intel.com> <201204171143.q3HBh9LV021759@glazunov.sibelius.xs4all.nl> <201205022143.q42Lhd3G018067@glazunov.sibelius.xs4all.nl> Date: Wed, 02 May 2012 22:14:00 -0000 Message-ID: Subject: Re: PATCH: Also check for `movl %esp, %ebp' for x32 From: "H.J. Lu" To: Mark Kettenis Cc: gdb-patches@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes 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: 2012-05/txt/msg00041.txt.bz2 On Wed, May 2, 2012 at 2:43 PM, Mark Kettenis wro= te: >> Date: Sun, 29 Apr 2012 11:37:49 -0700 >> From: "H.J. Lu" >> >> On Tue, Apr 24, 2012 at 9:27 AM, H.J. Lu wrote: >> > On Tue, Apr 17, 2012 at 7:30 AM, H.J. Lu wrote: >> >> On Tue, Apr 17, 2012 at 4:43 AM, Mark Kettenis wrote: >> >>>> Date: Tue, 10 Apr 2012 13:29:53 -0700 >> >>>> From: "H.J. Lu" >> >>>> >> >>>> Hi, >> >>>> >> >>>> X32 may use `movl %esp, %ebp' in prologue. =A0This patch checks it = for >> >>>> x32. =A0Tested on Linux/x86-64. =A0OK for trunk? >> >>> >> >>> Sorry, but I'm not sure it is a good idea to mix ABIs in the code li= ke >> >>> that. =A0Up until now, I've made a conscious attempt to keep the i386 >> >>> and amd64 ABIs seperated out as much as possible. =A0Can you post a >> >>> complete diff of the -tdep.c related changes to support x32 in GDB, >> >>> such that I can judge where this is heading? >> >> >> >> Here is the complete x32 GDB patch: >> >> >> >> http://sourceware.org/ml/gdb-patches/2012-04/msg00476.html >> >> >> > >> > Hi Mark, >> > >> > Have you looked at my change? >> > >> > Thanks. >> >> Ping. > > Sorry; been travelling too much lately... > > I did have a look at it, but still have some questions. > >> Hi, >> >> X32 may use `movl %esp, %ebp' in prologue. =A0This patch checks it for >> x32. =A0Tested on Linux/x86-64. =A0OK for trunk? > > But the prologues generated by various compilers are expected to be > otherwise the same for both the x32 ABI and the normal 64-bit ABI? =A0I > guess x32 has to use "pushq %rbp" as "pushl %ebp" isn't available. > And I guess you want to keep the stack 16-byte aligned anyway. =A0I > suppose that "movq %rsp, %rbp" is still ok for x32, but "movl %esp, > %ebp" can be encoded in less bytes, so it might be a bit more > efficient for x32. That is correct. > But what about the stack align code that we check for in > amd64_analyze_stack_align()? =A0Wouldn't that be different for x32 as > well? That is true. I will submit a separate patch for it. Thanks. --=20 H.J.