Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763989AbXFRRIf (ORCPT ); Mon, 18 Jun 2007 13:08:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759643AbXFRRI2 (ORCPT ); Mon, 18 Jun 2007 13:08:28 -0400 Received: from gw.goop.org ([64.81.55.164]:37485 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752752AbXFRRI1 (ORCPT ); Mon, 18 Jun 2007 13:08:27 -0400 Message-ID: <4676BBC9.3060707@goop.org> Date: Mon, 18 Jun 2007 10:07:21 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Denis Cheng CC: trivial@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization References: <467658db.0f98600a.5a55.ffffdd79@mx.google.com> In-Reply-To: <467658db.0f98600a.5a55.ffffdd79@mx.google.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 841 Lines: 21 Denis Cheng wrote: > From: Denis Cheng > > the explicit memset call could be optimized out by data initialization, > thus all the fill working can be done by the compiler implicitly. > How does the generated code change? Does gcc do something stupid like statically allocate a prototype structure full of zeros, and then memcpy it in? Or does it generate a series of explicit assignments for each member? Or does it generate a memset anyway? Seems to me that this gives gcc the opportunity to be more stupid, and the only right answer is what we're doing anyway. J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/