From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29325 invoked by alias); 5 Sep 2011 07:33:06 -0000 Received: (qmail 29305 invoked by uid 22791); 5 Sep 2011 07:33:04 -0000 X-SWARE-Spam-Status: No, hits=-3.5 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from cantor2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 05 Sep 2011 07:32:48 +0000 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.221.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id 68AB48B013; Mon, 5 Sep 2011 09:32:47 +0200 (CEST) Date: Mon, 05 Sep 2011 07:33:00 -0000 From: Richard Guenther To: Eric Botcazou Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Remove bogus TYPE_IS_SIZETYPE special-casing in extract_muldiv_1 In-Reply-To: <201109031124.37807.ebotcazou@adacore.com> Message-ID: References: <201109021525.56458.ebotcazou@adacore.com> <201109031124.37807.ebotcazou@adacore.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) 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: 2011-09/txt/msg00264.txt.bz2 On Sat, 3 Sep 2011, Eric Botcazou wrote: > > Well, even when sign-extended there is a constant you can't negate > > without overflow. I would start digging for a testcase with > > such case - but as said, testcases involving TYPE_IS_SIZETYPE are > > very hard to generate for me. > > We run thousands of Ada tests every night on many platforms and never detected > a problem here, so finding a testcase with the unpatched compiler is probably > very hard - if there is really something to be found, which I doubt. > > > Well, but I'd expect you can have a set of Ada types, a function that > > returns just its size and some scan-tree-dumps that check those sizes > > are folded to a constant. Or to just N statements. > > We probably should, but we don't have them (yet). Like for the vast majority > of the transformations made by the folder I guess, so... > > > If you insist I can revert the patch and apply it together with the > > sign-extension change. > > Yes, IMHO it should be part of the final patch. Reverted now. Richard.