From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 98630C369BA for ; Wed, 16 Apr 2025 18:59:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u57yt-0004WG-DR; Wed, 16 Apr 2025 14:59:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u57yn-0004Ut-RB for qemu-devel@nongnu.org; Wed, 16 Apr 2025 14:59:25 -0400 Received: from mail-pf1-x42b.google.com ([2607:f8b0:4864:20::42b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1u57yl-0003Mh-Jf for qemu-devel@nongnu.org; Wed, 16 Apr 2025 14:59:25 -0400 Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-739b3fe7ce8so6271289b3a.0 for ; Wed, 16 Apr 2025 11:59:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1744829961; x=1745434761; darn=nongnu.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=r/E7EIaqziZydBDXn99AOa+bVBf7gDyVJ4nzRyJ5umw=; b=YT3y5KMe7mE9jbMS1FC0h4s4te4zHE8OURKTSYdeUsumt2NyYwRYfa1oBa5A2oUxXg opWvoWCQlId1sbRA4Im2U5Em8oGAFhkiEf4aspYcekTXCMQivSFx+dScfQkPFImnKLLr /zTQUnYoKoYAl2jHPMkhS/EySZVkt+HuG1DGPmSvLIwngdP7UlhlbAwEHuCy8ZpGcXc8 bMo8UDPu1FgSgtIz4Ak7Qvg59Ox5venXB6VAUeNtquOm9dQICjDiamc9v4a0RBiCdiDS s2aaZw6BlyuhUB5is78SM8LB6Jrg0z0tknev2R5+YfOT1Ya3tziQwbs7STXaibTyoatF 2d1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744829961; x=1745434761; 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=r/E7EIaqziZydBDXn99AOa+bVBf7gDyVJ4nzRyJ5umw=; b=Vo0QHgtup5SxAU1emY5XUycYKQ6FU/VMlFVqQ0+O7gDIMIbALYLpJz1hxl2BNYbe4J MvqARTl3f23zvWXB4JDg3PEfxzPtUe1bCA3yVeUhJY7jV9WA06cdDbsfMdMgnYy6QG/8 mr6Yo6kQHQor151kWtVZVC0XOSOPdcOeJ6ARlY6xkJYvTsiSuox3FEk+gDUo9PdnEz7k RST2t1yL7uEyISZwoIW5mIuQtK9hozUmoXVgAHFZLYketcOJ5DtXvzPm54EksUCr4fEL wFhqvFje7rvzT57NmpsLVBQwRL7Mfu32guCJdO8ZVVCpGy/l/XycaRHDSlG/MZCJTW7b tsSw== X-Forwarded-Encrypted: i=1; AJvYcCWD2OZ1hevFvoak5jhk9tpexa8t7f/wE8Z3VloRGHtb/8uD78gj53WWIOGbrxhSxaECl6qipb2heLYj@nongnu.org X-Gm-Message-State: AOJu0YxUScdIHSqG3tjgovz3fNp5zH/v68zZ5xzPShAg58Vo5Gx21qXg qj4mxnFaSWkJ47+pQl7YlY1NKzYcyGjxXZQz93LMhXjdUasKEJBk2PJ/lZ9OwdE= X-Gm-Gg: ASbGncvM5Fema8lL2ygZaeQsI0Gq8GM7F6Eugzj0unQMOY21bEjazmUgnP5x/kjHN1c kAh47rNR+huN8gRnZ1WZ/vMxjUyh7gGVOTkSgFghO9QOXbQLp9WEqxRF9VUBkG0cagU+JQgaR41 FtDRRTGrZR7/HQ0S+ZdOKTEqikGu42CpCnqyUsrKqgS+nsAd9GddijE9e+RzJKHWgPFxWdVuCvB 0nZmeHxFhm+NVZQQVkMmnvdwwH6onfuuBBc2Gon81WbSbZJLuYoUmKFXCj9f7JMecrL4Mmi4b5R Sjp6GRNYnYrhtc88V6XsExrmHmFtOl/oXm7PmYFCwpDtTKNoNMYFuw== X-Google-Smtp-Source: AGHT+IGx4Jhjppj9iYgkqrcrbz26KITWqrep9G+R090hL+nxQzEW42NsCvnJsq9UkMonHKGTQAyOYA== X-Received: by 2002:a05:6a20:1443:b0:1f5:5ca4:2744 with SMTP id adf61e73a8af0-203b3eb22a0mr4324475637.17.1744829961523; Wed, 16 Apr 2025 11:59:21 -0700 (PDT) Received: from [192.168.1.87] ([38.41.223.211]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b0b220fc366sm1633996a12.42.2025.04.16.11.59.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 16 Apr 2025 11:59:21 -0700 (PDT) Message-ID: <81a73738-11e6-4cd4-a98c-b1da07cac51d@linaro.org> Date: Wed, 16 Apr 2025 11:59:20 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 122/163] tcg/i386: Special case addci r, 0, 0 Content-Language: en-US To: Richard Henderson , qemu-devel@nongnu.org References: <20250415192515.232910-1-richard.henderson@linaro.org> <20250415192515.232910-123-richard.henderson@linaro.org> From: Pierrick Bouvier In-Reply-To: <20250415192515.232910-123-richard.henderson@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::42b; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pf1-x42b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 4/15/25 12:24, Richard Henderson wrote: > Using addci with two zeros as input in order to capture the value > of the carry-in bit is common. Special case this with sbb+neg so > that we do not have to load 0 into a register first. > > Signed-off-by: Richard Henderson > --- > tcg/i386/tcg-target-con-set.h | 1 + > tcg/i386/tcg-target.c.inc | 46 ++++++++++++++++++++++++++++++++--- > 2 files changed, 44 insertions(+), 3 deletions(-) > > diff --git a/tcg/i386/tcg-target-con-set.h b/tcg/i386/tcg-target-con-set.h > index 85c93836bb..458d69c3c0 100644 > --- a/tcg/i386/tcg-target-con-set.h > +++ b/tcg/i386/tcg-target-con-set.h > @@ -45,6 +45,7 @@ C_O1_I2(r, L, L) > C_O1_I2(r, r, r) > C_O1_I2(r, r, re) > C_O1_I2(r, r, ri) > +C_O1_I2(r, rO, re) > C_O1_I2(x, x, x) > C_N1_I2(r, r, r) > C_N1_I2(r, r, rW) > diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc > index 44f9afc0d6..da05f13b21 100644 > --- a/tcg/i386/tcg-target.c.inc > +++ b/tcg/i386/tcg-target.c.inc > @@ -2670,10 +2670,50 @@ static const TCGOutOpBinary outop_addcio = { > .out_rri = tgen_addcio_imm, > }; > > +static void tgen_addci_rrr(TCGContext *s, TCGType type, > + TCGReg a0, TCGReg a1, TCGReg a2) > +{ > + /* Because "0O" is not a valid constraint, we must match ourselves. */ > + if (a0 == a2) { > + tgen_addcio(s, type, a0, a0, a1); > + } else { > + tcg_out_mov(s, type, a0, a1); > + tgen_addcio(s, type, a0, a0, a2); > + } > +} > + > +static void tgen_addci_rri(TCGContext *s, TCGType type, > + TCGReg a0, TCGReg a1, tcg_target_long a2) > +{ > + tcg_out_mov(s, type, a0, a1); > + tgen_addcio_imm(s, type, a0, a0, a2); > +} > + > +static void tgen_addci_rir(TCGContext *s, TCGType type, > + TCGReg a0, tcg_target_long a1, TCGReg a2) > +{ > + tgen_addci_rri(s, type, a0, a2, a1); > +} > + > +static void tgen_addci_rii(TCGContext *s, TCGType type, TCGReg a0, > + tcg_target_long a1, tcg_target_long a2) > +{ > + if (a2 == 0) { > + /* Implement 0 + 0 + C with -(x - x - c). */ > + tgen_arithr(s, ARITH_SBB, a0, a0); > + tcg_out_modrm(s, OPC_GRP3_Ev, EXT3_NEG, a0); > + } else { > + tcg_out_movi(s, type, a0, a2); > + tgen_addcio_imm(s, type, a0, a0, a1); > + } > +} > + > static const TCGOutOpAddSubCarry outop_addci = { > - .base.static_constraint = C_O1_I2(r, 0, re), > - .out_rrr = tgen_addcio, > - .out_rri = tgen_addcio_imm, > + .base.static_constraint = C_O1_I2(r, rO, re), > + .out_rrr = tgen_addci_rrr, > + .out_rri = tgen_addci_rri, > + .out_rir = tgen_addci_rir, > + .out_rii = tgen_addci_rii, > }; > > static void tcg_out_set_carry(TCGContext *s) Reviewed-by: Pierrick Bouvier