From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4482 invoked by alias); 30 Dec 2010 08:00:26 -0000 Received: (qmail 4474 invoked by uid 22791); 30 Dec 2010 08:00:25 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from rock.gnat.com (HELO rock.gnat.com) (205.232.38.15) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 30 Dec 2010 08:00:19 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id F0D9F2BAC2C; Thu, 30 Dec 2010 03:00:17 -0500 (EST) Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id YhzAo0PTDNYR; Thu, 30 Dec 2010 03:00:17 -0500 (EST) Received: from joel.gnat.com (localhost.localdomain [127.0.0.1]) by rock.gnat.com (Postfix) with ESMTP id 775F22BAC29; Thu, 30 Dec 2010 03:00:17 -0500 (EST) Received: by joel.gnat.com (Postfix, from userid 1000) id 0645B145870; Thu, 30 Dec 2010 12:00:09 +0400 (RET) Date: Thu, 30 Dec 2010 20:40:00 -0000 From: Joel Brobecker To: Eli Zaretskii Cc: gdb-patches@sourceware.org Subject: Re: [RFA] unexpected multiple location for breakpoint Message-ID: <20101230080009.GJ2396@adacore.com> References: <1290474625-1582-1-git-send-email-brobecker@adacore.com> <20101126172942.GK2634@adacore.com> <20101127183532.GA10136@caradoc.them.org> <20101210122337.GC2596@adacore.com> <20101228112546.GB2436@adacore.com> <83tyhxbthv.fsf@gnu.org> <20101229054841.GF2396@adacore.com> <83oc84bgv3.fsf@gnu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83oc84bgv3.fsf@gnu.org> User-Agent: Mutt/1.5.20 (2009-06-14) 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: 2010-12/txt/msg00558.txt.bz2 > > I worry about the effect at -O0. It is common to see the same source > > line being split across the code. For instance, with conditional > > loops, the condition evaluation is often placed at the end of the > > loop, and its code is associated to the initial line. > > Are you saying that GCC does that under -O0? I'd be surprised. But I > realize that it does that for higher optimization levels. Still, my > question is how would it be worse to have the inferior stop several > times through the loop than not stop at all? Actually, it does, even at -O0. I don't think it's unreasonable. I don't think we are worse, but the reason why I bring it up is because it's a definite departure from what we've been trying to do so far (minimize the number of breakpoint locations). In fact, the patch that triggered this discussion was trying to go one step further. So, I'm just wondering if there might be some issues that I am not taking into consideration. I'm willing to make that change, but this is going to require general consent among the maintainers (and I'm not looking forward to all the mods in the testsuite to adjust it :-/). -- Joel