From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32007 invoked by alias); 16 Jul 2010 19:35:52 -0000 Received: (qmail 31998 invoked by uid 22791); 16 Jul 2010 19:35:52 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from one.firstfloor.org (HELO one.firstfloor.org) (213.235.205.2) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 16 Jul 2010 19:35:48 +0000 Received: from basil.firstfloor.org (p5B3C96F4.dip0.t-ipconnect.de [91.60.150.244]) by one.firstfloor.org (Postfix) with ESMTP id 4E73322C8069; Fri, 16 Jul 2010 21:35:46 +0200 (CEST) Received: by basil.firstfloor.org (Postfix, from userid 1000) id A3A5FB157F; Fri, 16 Jul 2010 21:35:45 +0200 (CEST) From: Andi Kleen To: "H.J. Lu" Cc: GCC Patches , Uros Bizjak Subject: Re: Turn on -fomit-frame-pointer by default for 32bit x86? References: Date: Fri, 16 Jul 2010 19:35:00 -0000 In-Reply-To: (H. J. Lu's message of "Tue, 13 Jul 2010 11:15:29 -0700") Message-ID: <87sk3jkyni.fsf@basil.nowhere.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2010-07/txt/msg01380.txt.bz2 "H.J. Lu" writes: > [hjl@gnu-6 tmp]$ /usr/gcc-4.5/bin/gcc -m32 -S x.c -O3 > [hjl@gnu-6 tmp]$ cat x.s > .file "x.c" > .text > .globl foo > .type foo, @function > foo: > pushl %ebp > movl %esp, %ebp > popl %ebp > ret > > Can we turn on -fomit-frame-pointer by default for 32bit? I think it's a good idea, but in general one side effect one should be aware of is that it breaks many profilers with calltrace per sample support. Those tend to not be able to read unwind tables. -Andi -- ak@linux.intel.com -- Speaking for myself only.