From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x433.google.com (mail-pf1-x433.google.com [IPv6:2607:f8b0:4864:20::433]) by sourceware.org (Postfix) with ESMTPS id 720533857410 for ; Tue, 15 Jun 2021 04:03:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 720533857410 Received: by mail-pf1-x433.google.com with SMTP id x73so12246861pfc.8 for ; Mon, 14 Jun 2021 21:03:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=phELZjxVyWnKi+F45bgWVimIk1Nidih4aXCnEU5dvMw=; b=PaJ8mPF8Ieg+UjasTSFC1Kc+L7sLKgUf0fAyx0jKEnTMjSXv4s83+SFuuk0x2Tyj7m bmM9Z4D88CApvwXWxzBLRIcVTyVs9/T4lea6BDxzztp5sikt8J6NIQSkP6Ke/ZKksiku fG5b/7mCrs6EMix42TcY0FP6GJDv3YKujtflGAF8yoPRyJdLkUFRwrDSGfe+f0d3MTKJ gjflMUPd48eZ599mg32JeObzN3mihWi8P1afI8UbEkfk4PuCQpLY3taffbN3NO0MmNu7 w7u5MW08MQRUGJqcmKAGz8wXMKvmsGYLmxCfY8lL+GDkEf0IWM+BgM8IZezZoIf5p3E8 pJrw== X-Gm-Message-State: AOAM532rDMGmmhbMHTmkROwPH/iEr3nUCNf4/nQYusNHTg3TSvRTwAaU aIt9ysFAcHFVyvXTxwNlBikjJVG+PGI2qw== X-Google-Smtp-Source: ABdhPJxzdwwpXj5VONWcpCh/YudfVCjzGZZO2W4QW2+UU1P/5PIMcNqfu/aG9zm/tFBdfPNOqHUxqQ== X-Received: by 2002:a65:66cf:: with SMTP id c15mr15184806pgw.121.1623729821160; Mon, 14 Jun 2021 21:03:41 -0700 (PDT) Received: from [172.31.0.175] (c-98-202-48-222.hsd1.ut.comcast.net. [98.202.48.222]) by smtp.gmail.com with ESMTPSA id a23sm13544627pff.43.2021.06.14.21.03.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Jun 2021 21:03:40 -0700 (PDT) Subject: Re: replacing the backwards threader and more To: Richard Biener Cc: Aldy Hernandez , GCC Mailing List References: <07775b9d-b8eb-48cb-57ef-9cc278d38967@redhat.com> From: Jeff Law Message-ID: Date: Mon, 14 Jun 2021 22:03:37 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Jun 2021 04:03:44 -0000 On 6/14/2021 12:40 AM, Richard Biener wrote: > >> I bet it's going to be tougher to remove DOM's threader. It knows how >> to do thinks like resolve memory references using temporary equivalences >> and such. But I bet it's enough to drop the VRP based threaders. > Yes. In fact I am wondering if adding threading to the not iterating FRE > would make it possible to drop DOM, replacing it with instances of FRE. I'd think so.  I'd approach as: 1. Remove the VRP threader instances. 2. Drop cprop and redundancy elimination from DOM using FRE instead 3. What's left of DOM is just forward jump threading.  Revamp & simplify.  Then either make it a distinct pass or as a sub-pass of FRE. But one could just as easily look at adding threading to FRE and just killing DOM and its jump threading. Jeff