From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-x22b.google.com (mail-oi1-x22b.google.com [IPv6:2607:f8b0:4864:20::22b]) by sourceware.org (Postfix) with ESMTPS id 866903858D38 for ; Fri, 11 Nov 2022 19:49:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 866903858D38 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-oi1-x22b.google.com with SMTP id m204so5827492oib.6 for ; Fri, 11 Nov 2022 11:49:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=42FK5jumxh6Nlt/LzjuotqlSsLudKcg1X1RvEUKov6g=; b=Rdv3v135yLoKProZddwf/kGqnN4srjxGYt2Nr9jx7QITtr2lvbjw8DllkVhyIACANe Xe7kon73wZ6furltYvjGPRZ9/5/Rm+TpT4Oa0tyAXPfFkWjS86GlEf0vvXBiooT96Ktg bdZI57cvV/g005qi5YyjePU8yKShFgizqNRKmfeFl96pgHGhypZbT293zvXEeITryk1e ZkYpFKP42/J3WZE2nCy1gMlLTNGR1bvQvxZfR70d1WyCAx150hB4VCHXJ8x6NVdyV3Sx wi0+Ph5xSzOuvge5s5OlxABCbXVrxzGiY9jPGv2Fr4IBBLZAUMM8v1hOifU0Pw6adOp6 UI2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=42FK5jumxh6Nlt/LzjuotqlSsLudKcg1X1RvEUKov6g=; b=N3LsHDNtWdCr6MmcNFqwTiT6oE772UhqiXgpgpgwGnCfpCX/e86TsCVeFefYMuTkjd 3rG2VvELDQb4tHKvP2ZDoV36HZNkS9rtFI7pTKpE6HMukiiZV5/Ga6ASSd75laAvKy+E BSCItdREkxGAj3RPuPkaAam9f/x7V6kY6CW/wMmRgdfF37IRR1k19SOD+2junCsBw6rP MBAV8KkzDFLAQvOr/mrQOeinGyp0p/sDLIJZ8JfJvT3CZlqLvuNHww9/HLTUoJ8MwWu0 jQLlL5iYv7ujf96tyrf7AcMjOxogm8kQi2mDiMew7DpmyjuVHo1qNMzT6vD+IExBtaNa GGMA== X-Gm-Message-State: ANoB5pn2xAaZOke6i2JMQizgBJlplxg9jrNN4gckfu7I8hbsH2K5OKGT jfSGFQ355/9NAEqEMuYGLtTgNa417cIfJgwDQeo= X-Google-Smtp-Source: AA0mqf4cDiZxyyJgovI6QG9Ayk5mNgJBqOEslm2E1XRMK64ssI65a0ax4qJ3f5YmDuM73n5Q1gS8DWfOAUdT1ioYNt4= X-Received: by 2002:a05:6808:bc7:b0:359:d97b:3f6f with SMTP id o7-20020a0568080bc700b00359d97b3f6fmr1603152oik.298.1668196147854; Fri, 11 Nov 2022 11:49:07 -0800 (PST) MIME-Version: 1.0 References: <21665493-a9f9-3429-c9ae-ea69bc7751e2@suse.com> <2a971dfe-00b6-856b-5f3b-8a1cd7dc78c6@suse.com> <3d6d6d28-d4ed-5871-e20b-62aaa89ca6d4@suse.com> In-Reply-To: <3d6d6d28-d4ed-5871-e20b-62aaa89ca6d4@suse.com> From: "H.J. Lu" Date: Fri, 11 Nov 2022 11:48:31 -0800 Message-ID: Subject: Re: [PATCH] x86: fold special-operand insn attributes into a single enum To: Jan Beulich , Kong Lingling , "Jiang, Haochen" , Lili Cui Cc: Binutils Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3017.3 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 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 Fri, Nov 11, 2022 at 12:22 AM Jan Beulich wrote: > > On 11.11.2022 09:00, Jan Beulich via Binutils wrote: > > On 10.11.2022 18:38, H.J. Lu wrote: > >> On Thu, Nov 10, 2022 at 5:45 AM Jan Beulich wrote: > >>> > >>> Attributes which aren't used together in any single insn template can be > >>> converted from individual booleans to a single enum, as was done for a few > >>> other attributes before. This is more space efficient. Collect together > >>> all attributes which express special operand constraints (and which fit > >>> the criteria for folding). > >> > >> These assumptions may not be all true for future new instructions. > > > > It seems pretty unlikely to me that any of these assumptions would break. > > If one does, converting back to an individual bit is an easy option. I > > think this minor risk is far outweighed by the benefits of the change. We > > really have still some ways to go to reach reasonable data representation > > within the generated opcode table (and of course also in the source table, > > but that's an orthogonal direction of work, where I also have further > > changes pending). > > I should probably expand: For most of these I don't expect new uses to appear > at all. Note also that I left alone e.g. ImmExt, for having a bigger risk of > a new conflicting use appearing. > > If you have concerns for a specific attribute, please voice it that way. I'm > certainly willing to re-consider for individual attributes (albeit as said > in the earlier reply, the way back for any individual one is easy); I'm not > going to accept a blanket "no". > > Jan Lingling, Lili, Haochen, do you have any comments? Thanks. -- H.J.