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 002B0C369BA for ; Wed, 16 Apr 2025 19:04:05 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u582x-0007sp-Mo; Wed, 16 Apr 2025 15:03:43 -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 1u582w-0007sb-DN for qemu-devel@nongnu.org; Wed, 16 Apr 2025 15:03:42 -0400 Received: from mail-pl1-x635.google.com ([2607:f8b0:4864:20::635]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1u582u-0003z9-BP for qemu-devel@nongnu.org; Wed, 16 Apr 2025 15:03:42 -0400 Received: by mail-pl1-x635.google.com with SMTP id d9443c01a7336-223fb0f619dso419955ad.1 for ; Wed, 16 Apr 2025 12:03:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1744830219; x=1745435019; 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=GWaw/85VgbqmnW5jtSyMcsIX/+EzF1RIDX7Z6BsLX2Y=; b=QtKyJamgyi8bN/F9a99w6Do3fENsO8lc/nEc31dZ1Mv7Yibp9GAJdKS4Iww29IACaH 3IOnlsiltrrgUHzZgvJz7JHsn62+54Jv26j1g3bkTLkugJscHLNapcAnpbqACIV+vC0O dt1qbRVprIhggIO45Q0tKP56FmKz70hzfLiZp832awmb9ltJD1Od0TXPxYZsp7UEM54z LySaS3Q7NKDLLgXw2caTUP8atTQBp8rHlzG3bN0pKJGMZnUEYs4VcXfqTwfNbtDZKMoG dQRX2/PLwiahu8L78Bs+1yCVVttVUvzYlaKBoX8WwFfOWEFESDnUTqo4+KZuvKjdOKEY gMPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744830219; x=1745435019; 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=GWaw/85VgbqmnW5jtSyMcsIX/+EzF1RIDX7Z6BsLX2Y=; b=PjLWPeOMBlIK0W3J+ZEACzkGzChIAf5tuSOE02iEqeV74VJ++P1bW0QGjOAgzsyAGF hSoN9RfWJOShLJ7od+WL4SxAtRR25R03cX17klhrI4lvRtTTfqqEGppZRZGkCsW+gza/ 6LSUsiCRIQ+VN/wjEz9upY/Jvl2rA6i/EqaonU/WgL5zQDCgEUjuky2QHXObr1TEkoSJ eOLC24yFJvFWGrZEcaaW66PB9GLIXz0sXB9pWiNKrg1hb5gl+HlyQIle3E/bj/G/bwIR oAXBo+PDLjQrJM4exUqeDx7GbRI44AGj8fQnyLooPQ6wNLD45i02saludSNk5pJ0yrNh kutw== X-Forwarded-Encrypted: i=1; AJvYcCXzGQCOJ3uKy/+8xl7OEn8SiHvrT5/3SDNQUSeLa/4621xNHVfudLiWST7oNdKdI/a+eQd6i4kbjHiL@nongnu.org X-Gm-Message-State: AOJu0Ywmrvdc4iX/YmR7KC9x914COXJKKSg8G/Qac6fbVWBTJg0P+0g2 mXVvPIxiuHbiqLqXitGQoMdj3aHm38euOQXZvBKhyvhHk5eZp62EG52HkgvERJw= X-Gm-Gg: ASbGncsshoylB4nyCsB9+yhT6mBLTaqZx1CKzeLBlOkaKOEKmLVfaTSDqLRjp/HWnTl Weas9rMHhHij+fdv/0RW17gRl55Rl6cxxsHQ2FqWMshMoVhZJcwBFORt2KVanYAtdsm50neFCfO BCPuXyV+InMw438PwWCwuKRtheYJO4+1vTgmC7ltoWnuY5EYE3u2zyf1Y9NonmHSDpJ9+E5YAez 8AUY0xZt8FVv/Uw0A+mou1UfDRRrDr5aRDF7Trd9nZn7bSCGbRPBIl7NcEzu7+01u9TvIm8Z/Rb Ti4hKMBWX2KIsJ+5GoGW32PxoXedXrJwk/M7bM9YNwW4xGXnxf+IO0a2I/T7RSbN X-Google-Smtp-Source: AGHT+IFpf/uGef+ar0V7z3v/9LICm2pkwQFqegrq1bOnoGt1KVUpRZctzSLG2aTVolgLzBQ4S7IMAA== X-Received: by 2002:a17:903:247:b0:216:410d:4c53 with SMTP id d9443c01a7336-22c3597eeb9mr50370385ad.41.1744830218768; Wed, 16 Apr 2025 12:03:38 -0700 (PDT) Received: from [192.168.1.87] ([38.41.223.211]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-22c33ef1190sm18038275ad.9.2025.04.16.12.03.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 16 Apr 2025 12:03:38 -0700 (PDT) Message-ID: <2e8510ab-459e-4a37-a37a-b8b74a74146c@linaro.org> Date: Wed, 16 Apr 2025 12:03:37 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 116/163] tcg/optimize: With two const operands, prefer 0 in arg1 Content-Language: en-US To: Richard Henderson , qemu-devel@nongnu.org References: <20250415192515.232910-1-richard.henderson@linaro.org> <20250415192515.232910-117-richard.henderson@linaro.org> From: Pierrick Bouvier In-Reply-To: <20250415192515.232910-117-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::635; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pl1-x635.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: > For most binary operands, two const operands fold. > However, the add/sub carry opcodes have a third input. > Prefer "reg, zero, const" since many risc hosts have a > zero register that can fit a "reg, reg, const" insn format. > > Signed-off-by: Richard Henderson > --- > tcg/optimize.c | 18 ++++++++++++------ > 1 file changed, 12 insertions(+), 6 deletions(-) > > diff --git a/tcg/optimize.c b/tcg/optimize.c > index 1b3d0b5b5d..442f5b75e6 100644 > --- a/tcg/optimize.c > +++ b/tcg/optimize.c > @@ -725,12 +725,18 @@ static int do_constant_folding_cond(TCGType type, TCGArg x, > > #define NO_DEST temp_arg(NULL) > > +static int pref_commutative(TempOptInfo *ti) > +{ > + /* Slight preference for non-zero constants second. */ > + return !ti_is_const(ti) ? 0 : ti_const_val(ti) ? 3 : 2; > +} > + > static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2) > { > TCGArg a1 = *p1, a2 = *p2; > int sum = 0; > - sum += arg_is_const(a1); > - sum -= arg_is_const(a2); > + sum += pref_commutative(arg_info(a1)); > + sum -= pref_commutative(arg_info(a2)); > > /* Prefer the constant in second argument, and then the form > op a, a, b, which is better handled on non-RISC hosts. */ > @@ -745,10 +751,10 @@ static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2) > static bool swap_commutative2(TCGArg *p1, TCGArg *p2) > { > int sum = 0; > - sum += arg_is_const(p1[0]); > - sum += arg_is_const(p1[1]); > - sum -= arg_is_const(p2[0]); > - sum -= arg_is_const(p2[1]); > + sum += pref_commutative(arg_info(p1[0])); > + sum += pref_commutative(arg_info(p1[1])); > + sum -= pref_commutative(arg_info(p2[0])); > + sum -= pref_commutative(arg_info(p2[1])); > if (sum > 0) { > TCGArg t; > t = p1[0], p1[0] = p2[0], p2[0] = t; Reviewed-by: Pierrick Bouvier