From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by sourceware.org (Postfix) with ESMTPS id C564A3858402 for ; Thu, 11 Nov 2021 17:35:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C564A3858402 Received: by mail-pl1-x62a.google.com with SMTP id y7so6436764plp.0 for ; Thu, 11 Nov 2021 09:35:29 -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 :content-transfer-encoding; bh=nZmmYustPkbme1oVhbbASgjOfTuXd3WlhO3nMY7sBVc=; b=WZeWNKz2atVFFeKQEey3o2/NUSldhsAq1dHdSlQYROKaPWccXTyUefQtMfpNrsFAAd EaPgkpOjWMw1gp5Nl4021GMP/pS1VKofZ9XDBrZKaVT6EuR0wFNJa7fh5Q95anEb6X7v vE43FUmMFIMRcwDtlBHfXEYZ72jlOccNxK850FtdLaLOpL/m8pKVrRxpBtVpZ+TpfCtL rxR/EfyrfATcYri5ME5BhowsFbDsG9Vdb+1aND5Cg8LxFBEnwA8GDFv98Wr3WLsUcH6L B7C+aSycW5uVqgzdsjG42bT1Jw9TFVvgs1/sqEuFybxj0AeiRYkdVnsJt4PjIHBgHQiH nebg== X-Gm-Message-State: AOAM531iM7Sl/zTj+MrPlPYH3yWa6fr16zPZjWlxPiXTOTrqDR9+h+JK tAauHqHxH0xngupldJqi67k= X-Google-Smtp-Source: ABdhPJzspGup1PAUhsiwYPDYKh7vMv1op7QB027LMn1kOZKvXO/a2r3PjaX5T/Hy4/se/VAP0+bQ9w== X-Received: by 2002:a17:902:7001:b0:13d:d5b7:d06e with SMTP id y1-20020a170902700100b0013dd5b7d06emr592976plk.61.1636652128848; Thu, 11 Nov 2021 09:35:28 -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 d6sm3532604pfh.190.2021.11.11.09.35.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Nov 2021 09:35:26 -0800 (PST) Message-ID: Date: Thu, 11 Nov 2021 10:35:24 -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] Remove loop crossing restriction from the backward threader. Content-Language: en-US To: Aldy Hernandez , GCC patches References: <20211111172432.893034-1-aldyh@redhat.com> From: Jeff Law In-Reply-To: <20211111172432.893034-1-aldyh@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-4.5 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=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org 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, 11 Nov 2021 17:35:31 -0000 On 11/11/2021 10:24 AM, Aldy Hernandez wrote: > We have much more thorough restrictions, that are shared between both > threader implementations, in the registry. I've been meaning to > remove the backward threader one, since it's only purpose was reducing > the search space. Previously there was a small time penalty for its > removal, but with the various patches in the past month, it looks like > the removal is a wash performance wise. > > This catches 8 more jump threads in the backward threader in my suite. > Presumably, because we disallowed all loop crossing, whereas the > registry restrictions allow some crossing (if we exit the loop, etc). > > OK pending tests on x86-64 Linux? > > gcc/ChangeLog: > > * tree-ssa-threadbackward.c > (back_threader_profitability::profitable_path_p): Remove loop > crossing restriction. OK jeff