From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x136.google.com (mail-il1-x136.google.com [IPv6:2607:f8b0:4864:20::136]) by sourceware.org (Postfix) with ESMTPS id 5D11F3858D37 for ; Sat, 11 Nov 2023 17:46:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5D11F3858D37 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 5D11F3858D37 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::136 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699724811; cv=none; b=GT+nZYnbGEKVELDoNKPSi+iuGFJ7q1nopDr2Crz2yp6NjI1IqXSfMorVqgEGoDAYLjgdOEU2vXc5KsTp5fnbaay5cmlyHWfHCcUnyYyGCnUJJBkN4UkNv+7Uc3XM21UAI2uiSmsKoRsZOXbevKW0MHSgfmuakLvOsblFODepqJk= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699724811; c=relaxed/simple; bh=JALZkDrAy8oVa/TtUO0/GGKw9r+ZycT55fv867n9umA=; h=DKIM-Signature:Message-ID:Date:MIME-Version:Subject:To:From; b=R+S/xeUFet3+VNwJPBRhTiYHDzZDv+Dv7XBqk5ICkxPCo4p+KdbwGI6Q//qH5vtV5nR0YAMLkZPnkQXQ/adKkbWZUetYzI0ngXf1QGRxR4sw8/ngWQWsFH+zufFPj5QeL9G8VrZP/BD6zQ7pPpCdgTFzRAJu77hsr+rEqv3H0yM= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-il1-x136.google.com with SMTP id e9e14a558f8ab-357ccaf982eso11257895ab.0 for ; Sat, 11 Nov 2023 09:46:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699724807; x=1700329607; darn=gcc.gnu.org; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=v4Z/a/pj2bAeo4Bs9Xr7FTs1RXZNe8u26l4+amcFK/0=; b=OxvSeL4Q5XQCEG9iN9Ud9Azi+bwVlv9Vn51RFjDwMcMjuqiQrmxLAaAZRUgyZOCpP0 M32MW1JBzjAEF3y3GQx3+Eqt5Ttfpc5giSqk5wNeO2ZUUVuZxJpvBz0VxND82IHCzPND rZYD2SO/kOQw+a9bOda/FG28n07j7fxwp7lZ4nNfYXcHCqSuznuLPq3eZOI8P2ERnP4D jcig1L1clsJjYAPla47K2W7VtSZAjLnKwc7gpQnQAOxes10LMw1iIB8Ts638VzT7oJ9G cdydpFzlgDT8ZAtBUPHcK5T4usjoC24SJ292SXCnRApkzVJHbxdWHSi9hI6JoS0jaEoJ dONg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699724807; x=1700329607; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=v4Z/a/pj2bAeo4Bs9Xr7FTs1RXZNe8u26l4+amcFK/0=; b=HrxOgpN34IJntFlEI5moORt+/8up22tSLYrPiiNSFl/ItcBLly9ha31S+YKgb98Fgv i8no2a4ikTu0XEtDXwZ8KnC4lL93/pIJ4aAp2Q7QuXKpOJ05UjcHFe9qj9KzCFRrkYlu CROic5Y+8x+pBCM5V+FXXqNuZ8mkb8VsrlyvZbnseWJqQxx/5ls3wIAXHmRB51ClwG+J KQbC0cFzGXHbEbU9lZncRpjwJ2stfNWBvO2aIYbV6jVmth9XYltFGOvMNA3KKxgub2Xg Uo8CKJbqih1GWhR28Wh8ODhxqf5DpOuTmZ1Kko/tjwyA/3hHW0oc3W3r+2Msept7e6kL /n3A== X-Gm-Message-State: AOJu0YwqtMo7Rv90liPv7jp1RU8HtEamT5sqrNPN5rHvrNiDeE4m5867 LQBy1ciD9JfGGevsSY0Tgek= X-Google-Smtp-Source: AGHT+IE5HV1/AA7gzRDX2fOw96+KWCzN5AZKY7CfXgdCEA2q0mAPnJvPlfMdG9RMW4bZYoHBv48VhA== X-Received: by 2002:a05:6e02:1e05:b0:359:30b1:425d with SMTP id g5-20020a056e021e0500b0035930b1425dmr4356067ila.10.1699724807356; Sat, 11 Nov 2023 09:46:47 -0800 (PST) Received: from [172.31.0.109] ([136.36.130.248]) by smtp.gmail.com with ESMTPSA id j14-20020a056e020eee00b003593297c253sm550499ilk.75.2023.11.11.09.46.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 11 Nov 2023 09:46:46 -0800 (PST) Message-ID: <4891f44d-9e33-4fc9-adc4-76a38550c8ad@gmail.com> Date: Sat, 11 Nov 2023 10:46:45 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/7] ira/lra: Support subreg coalesce Content-Language: en-US To: Lehua Ding , gcc-patches@gcc.gnu.org, vmakarov@redhat.com, juzhe.zhong@rivai.ai, richard.sandiford@arm.com References: <20231108034740.834590-1-lehua.ding@rivai.ai> <3d6ec0ee-6542-4b6a-a2cd-7fd54c136af9@gmail.com> From: Jeff Law In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 11/11/23 08:33, Richard Sandiford wrote: >> Joern's code is a bit of a mess, but Jivan and I are slowly untangling >> it from a correctness standpoint. It'll also need the usual cleanups. > > Ah, nice! How configurable are the bit ranges? We might be able to use > something similar to track lanes in a vector operation, to detect the > dead code in: > > ins v0.b[4], w0 > ... > ins v0.b[4], w1 > > It sounds like the bit ranges you have now would do that for some > common/useful cases, even if it doesn't handle the general case. It could probably be extended to handle more cases. Right now the regions tracked are static. Bits 0..7, 8..16, 16..31 and 32..64. I don't think extending it to additional regions would be terribly hard. > > Maybe dead lanes are better tracked at the gimple level though, not sure. > (But AArch64 might need to lower lane operations more than it does now if > we want gimple to handle it.) I'd think the best place depends on what you want to do with the dead lane information. THe more complex the transformation you want to make the more likely gimple is the right spot. If you're looking to do something simplistic like Joern's code does when it finds dead chunks RTL seems like the natural choice. jeff