From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 67050 invoked by alias); 3 May 2016 08:39:17 -0000 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 Received: (qmail 67036 invoked by uid 89); 3 May 2016 08:39:16 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.5 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE autolearn=no version=3.3.2 spammy=HX-Envelope-From:sk:ebotcaz, H*F:U*ebotcazou, HContent-Transfer-Encoding:7Bit, Hx-languages-length:1051 X-HELO: smtp.eu.adacore.com Received: from mel.act-europe.fr (HELO smtp.eu.adacore.com) (194.98.77.210) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Tue, 03 May 2016 08:39:15 +0000 Received: from localhost (localhost [127.0.0.1]) by filtered-smtp.eu.adacore.com (Postfix) with ESMTP id 3FBE9812E8; Tue, 3 May 2016 10:39:11 +0200 (CEST) Received: from smtp.eu.adacore.com ([127.0.0.1]) by localhost (smtp.eu.adacore.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id snC7GXW00LnX; Tue, 3 May 2016 10:39:11 +0200 (CEST) Received: from polaris.localnet (bon31-6-88-161-99-133.fbx.proxad.net [88.161.99.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.eu.adacore.com (Postfix) with ESMTPSA id 1D64F812E7; Tue, 3 May 2016 10:39:10 +0200 (CEST) From: Eric Botcazou To: Richard Biener Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH][GCC7] Remove scaling of COMPONENT_REF/ARRAY_REF ops 2/3 Date: Tue, 03 May 2016 08:39:00 -0000 Message-ID: <1734703.hJZHvL7VIE@polaris> User-Agent: KMail/4.14.10 (Linux/3.16.7-35-desktop; KDE/4.14.9; x86_64; ; ) In-Reply-To: References: <3564626.L9kKSTKFH1@polaris> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-SW-Source: 2016-05/txt/msg00160.txt.bz2 > It seems to me that the issue in the end is that where we compute > alignment from is the pieces gathered by get_inner_reference > instead of computing it alongside of that information in > get_inner_reference, taking advantage of DECL_OFFSET_ALIGN > and the array element type alignment there. This would be > another opportunity to merge get_inner_reference and > get_object_alignment_2 (or have a common worker). Yes, the problem is the way we extract the alignment information in the RTL expander by means of get_inner_reference. > Do I understand you correctly that without using -fno-tree-ccp there > are currently no regressions? What about -O0 then? The code > generated by -O0 on x86_64 currently is quite horrible of course, > so maybe we don't care too much... I think -Og disables CCPs > bit-tracking though. There are no regressions at -O, at least in simple cases. Of course -O0 is also pessimized because CCP bit-tracking isn't enabled at -O0. -- Eric Botcazou