From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18691 invoked by alias); 6 Feb 2020 13:57:01 -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 18673 invoked by uid 89); 6 Feb 2020 13:57:01 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=H*i:sk:10930ad, H*MI:sk:10930ad, H*f:sk:10930ad, H*f:sk:mptr1z9 X-HELO: gate.crashing.org Received: from gate.crashing.org (HELO gate.crashing.org) (63.228.1.57) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 06 Feb 2020 13:57:00 +0000 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 016DuoB1010600; Thu, 6 Feb 2020 07:56:50 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 016Dun3e010598; Thu, 6 Feb 2020 07:56:49 -0600 Date: Thu, 06 Feb 2020 13:57:00 -0000 From: Segher Boessenkool To: Jeff Law Cc: Richard Sandiford , gcc-patches List Subject: Re: [RFA] [PR rtl-optimization/90275] Handle nop reg->reg copies in cse Message-ID: <20200206135649.GZ22482@gate.crashing.org> References: <10930ad518483e1d3d4fea149045802313cac45e.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <10930ad518483e1d3d4fea149045802313cac45e.camel@redhat.com> User-Agent: Mutt/1.4.2.3i X-IsSubscribed: yes X-SW-Source: 2020-02/txt/msg00363.txt.bz2 On Wed, Feb 05, 2020 at 11:48:23AM -0700, Jeff Law wrote: > Yea, it's closely related. In your case you need to effectively ignore > the nop insn to get the optimization you want. In mine that nop insn > causes an ICE. > > I think we could take your cse bits + adding a !CALL_P separately from > the simplify-rtx stuff which Segher objected to. THat'd likely solve > the ARM ICEs and take you a tiny step forward on optimizing that SVE > case. Thoughts? CSE should consistently keep track of what insns are no-op moves (in its definition, all passes have a slightly different definition of this), and use that everywhere consistently. (Or we should rewrite CSE). Segher