Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753052AbbGARnr (ORCPT ); Wed, 1 Jul 2015 13:43:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60373 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751985AbbGARnk (ORCPT ); Wed, 1 Jul 2015 13:43:40 -0400 Date: Wed, 1 Jul 2015 19:43:33 +0200 From: Jakub Jelinek To: Vladimir Makarov Cc: Andy Lutomirski , gcc@gcc.gnu.org, "linux-kernel@vger.kernel.org" , Linus Torvalds , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner Subject: Re: gcc feature request / RFC: extra clobbered regs Message-ID: <20150701174333.GA10247@tucnak.redhat.com> Reply-To: Jakub Jelinek References: <20150630213736.GQ10247@tucnak.redhat.com> <559405E5.7000405@redhat.com> <20150701153133.GY10247@tucnak.redhat.com> <559424D4.6010908@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <559424D4.6010908@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 21 On Wed, Jul 01, 2015 at 01:35:16PM -0400, Vladimir Makarov wrote: > Actually it raise a question for me. If we describe that a function > clobbers more than calling convention and then use it as a value (assigning > a variable or passing as an argument) and loosing a track of it and than > call it. How can RA know what the call clobbers actually. So for the > function with the attributes we should prohibit use it as a value or make > the attributes as a part of the function type, or at least say it is unsafe. > So now I see this as a *bigger problem* with this extension. Although I > guess it already exists as we have description of different ABI as an > extension. Unfortunately target attribute is function decl attribute rather than function type. And having more attributes affect switchable targets will be non-fun. Jakub -- 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/