From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by sourceware.org (Postfix) with ESMTPS id A7AEC385841A for ; Thu, 2 Dec 2021 18:24:05 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A7AEC385841A Received: by mail-pg1-x534.google.com with SMTP id f125so633395pgc.0 for ; Thu, 02 Dec 2021 10:24:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to; bh=6rkp7cS9T6QxslaJUi5mCsB/ajA7HCORLJePaJevX6Q=; b=mGjDQJp35T5ak5qolJuEgYgOthm9OZ0J8Zrz202LQxH7ZOme6jLg8//qhDrS5paIi/ OKdsYiilzP3Ni4OPvWEw3uODHr7sIKAKt+ocqpwm6M/NZNG0ZMh7KbN9It0ovbxFGVmG NAuAz/xACJG6DZ05cZSYpzI0BtET75UEtLPCUt/aDjwY/w3q3VXWMfgfn46zJCDNJhE7 OrN45sGLiqvsA9eH81/Px5vuPIIE3aIpn35QaFL/+eP26NlyZD5jG/PKuYDd/m7ppCZ/ NsX9jaQ2tjpPHBupVXVH2H6xACloJmfjdAwI75NUya1e8f0xrVNKdCO1JGH3sQDnds9A cjfg== X-Gm-Message-State: AOAM531YVXkvsOobBlHaTPx3+hsG6sS2pMvaE3JmzsCFyOLlmxQlmekX sboyZm2KvLOeUhs1hlx0wAw= X-Google-Smtp-Source: ABdhPJxAd+fjwTEYmPkDvNJ6iVdXeRYfQXhesUaDLwyE8gpPoiO09AIOErY0cBodTKJ+9OUNhDqrww== X-Received: by 2002:a05:6a00:2af:b0:4a2:a6f0:8eec with SMTP id q15-20020a056a0002af00b004a2a6f08eecmr13783406pfs.23.1638469444537; Thu, 02 Dec 2021 10:24:04 -0800 (PST) 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 a6sm219468pjd.40.2021.12.02.10.24.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Dec 2021 10:24:04 -0800 (PST) Message-ID: <5cd26688-13a7-c1cc-f4ef-abaf1b806b23@gmail.com> Date: Thu, 2 Dec 2021 11:24:03 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCH] regrename: Skip renaming if instruction is noop move. Content-Language: en-US To: Jojo R , Richard Biener Cc: GCC Patches , Kito Cheng References: <20211116114422.16071-1-rjiejie@linux.alibaba.com> <93c447dc-350d-4f76-93bf-82c648aa82df@Spark> <94b16de8-b32b-460e-aebf-0f4f38e4496a@Spark> From: Jeff Law In-Reply-To: <94b16de8-b32b-460e-aebf-0f4f38e4496a@Spark> X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00, BODY_8BITS, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, HTML_MESSAGE, KAM_SHORT, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Dec 2021 18:24:07 -0000 On 11/18/2021 11:23 PM, Jojo R wrote: > > — Jojo > 在 2021年11月19日 +0800 AM12:13，Jeff Law ，写道： > > > > On 11/16/2021 7:20 PM, Jojo R via Gcc-patches wrote: > > — Jojo > 在 2021年11月16日 +0800 PM8:12，Richard Biener > ，写道： > > On Tue, Nov 16, 2021 at 12:45 PM Jojo R via Gcc-patches > wrote: > > Skip renaming if instruction is noop move, and it will > been removed for performance. > > Is there any (target specific) testcase you can add? Such > commits are > problematic > when later bisected to since the intent isn't clear. > > I made a issue in bugzilla, please check it, thanks. > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103296 > > So what Richi is asking is can you construct a testcase for the > testsuite?  Having a BZ is helpful because we can reference it in the > commit message, but a test, even if it's target specific, is even > better > from a long term maintenance standpoint. > > I found this issue from the ISA extension vector of risc-v target, and > It has not been upstream by now, normal test case without vector isa > Is difficult to construct for this patch, but I think it’s simple and > useful for > other ISAs or targets, or recommit this patch after our risc-v Vector ISA > Is ready on master branch ? > > Any suggestions ? So I tried to trigger this on x86, but wasn't able with relatively light testing. My recommendation would be to add a little comment like this before the change: /* If this insn is a noop move, then do not rename in this chain as doing so     would inhibit removal of the noop move.  */ OK with that change. Thanks for your patience. jeff