From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 51939 invoked by alias); 12 Aug 2015 09:02:17 -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 51924 invoked by uid 89); 12 Aug 2015 09:02:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.2 required=5.0 tests=AWL,BAYES_05,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: foss.arm.com Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 12 Aug 2015 09:02:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3692675; Wed, 12 Aug 2015 02:02:12 -0700 (PDT) Received: from e105689-lin.cambridge.arm.com (e105689-lin.cambridge.arm.com [10.2.207.32]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0DAE43F21A; Wed, 12 Aug 2015 02:02:13 -0700 (PDT) Message-ID: <55CB0B93.5010104@foss.arm.com> Date: Wed, 12 Aug 2015 09:02:00 -0000 From: Richard Earnshaw User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Richard Henderson , "gcc-patches@gcc.gnu.org" CC: David Edelsohn , Marcus Shawcroft Subject: Re: [PATCH ppc64,aarch64,alpha 00/15] Improve backend constant generation References: <1439341904-9345-1-git-send-email-rth@redhat.com> <55CB0487.1020505@foss.arm.com> <55CB0731.30905@foss.arm.com> In-Reply-To: <55CB0731.30905@foss.arm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-08/txt/msg00575.txt.bz2 On 12/08/15 09:43, Richard Earnshaw wrote: > On 12/08/15 09:32, Richard Earnshaw wrote: >> On 12/08/15 02:11, Richard Henderson wrote: >>> I'm somewhat surprised that the operands to the logicals aren't >>> visible at rtl generation time, given all the work done in gimple. >>> And failing that, combine has enough REG_EQUAL notes that it ought >>> to be able to put things back together and see the simpler pattern. >>> >> >> We've tried it in the past. Exposing the individual steps prevents the >> higher-level rtl-based optimizations since they can no-longer deal with >> the complete sub-expression. > > Eg. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63724 > > R. > And https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65768 R.