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 1B760C4829A for ; Tue, 6 Feb 2024 23:11:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXUaH-0003gW-Ho; Tue, 06 Feb 2024 18:10:33 -0500 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 1rXUaG-0003gO-65 for qemu-devel@nongnu.org; Tue, 06 Feb 2024 18:10:32 -0500 Received: from mail-pg1-x534.google.com ([2607:f8b0:4864:20::534]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rXUZy-00042F-3Y for qemu-devel@nongnu.org; Tue, 06 Feb 2024 18:10:31 -0500 Received: by mail-pg1-x534.google.com with SMTP id 41be03b00d2f7-53fa455cd94so4606914a12.2 for ; Tue, 06 Feb 2024 15:10:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1707261011; x=1707865811; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=Nb6Wza40c6L36QhzW3uecpEsAvY+79c4j5Br1ngTz4E=; b=ZeGVvS1keiN8HuXV6kXz4RtsRSV78yhyoBsBGyP2Vab1X7dk2kKmcPrG5JbtVemOZ+ 7b1jSEV+xrfcsBjBwWo/Y/1tLEJvYnYd0j+bbBxB62IfMW67yUTy5OnnaNSLz6Dgl50Z pZBGjcr8EwuXo/UCFklrFjJmTtz5nixSNV4kMoDFvLu2O4O1gyM2HqcPjLUYsibvoZde xbaRTHoQI3mqNNq19fOk46d8khqFDzMs/uJ5xUReq9+olXA2nrHqTZcHFu7Uhcba+Tcf jCfDYmWsy0QbDSpmTzNqxJN0GztmTLUDu7nh4OvPOZpj4Pg+beB9BXQbmbec84PKX1EY Mb4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707261011; x=1707865811; h=content-transfer-encoding:in-reply-to:from:references:cc: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=Nb6Wza40c6L36QhzW3uecpEsAvY+79c4j5Br1ngTz4E=; b=HXdIDbLB3X/tfQQJJ/L1Ho+XjpFug9ZQdvQV0kmtC6Hm+psBufVHffBehWXQQ6TYlM MXbp9DhTH2czd5MEiAJaq1TL98ZFOE6/7rSwKWueyR+tg7YCyPL/nwA9EMDYn1t35OIT 0tZnxjFc1BPyCLru2lbyAh0fa8uftXJb6J9ubcbo1xE3AwWisx4bTWNeZTXS/mDxLC3E foh05yAvfkSA2weukXwCafU8apUEIMaiswJtVbUe5F2f1eaCXcRdoRTdrAbuCHJRoNjJ OdvZl3Foy1k07wV8Mfz+7OkcruZyA3vnJ739dXhfgj/Dot2ORbdj4O8avrSSORXql8Hf GRdg== X-Gm-Message-State: AOJu0Yz4/lyyxg/+mk/C2kOaIHHKvIH65p4Zxuw3UZOmWNduu5aZj9KZ FKiFtBHHvOHt6DrC6/FR7il32XAzTA99i9p8x85AxwDYqH9ymUZaRTr8xOF2c2k= X-Google-Smtp-Source: AGHT+IHAtoQilVeAzoC0cCdT7fDQZqKuMGNMZLOkaYRLNPzU96FV8HYDzFBl9tWAu+DnPVcfxGyLBw== X-Received: by 2002:a17:90a:34ca:b0:296:1e9:2c91 with SMTP id m10-20020a17090a34ca00b0029601e92c91mr1106496pjf.31.1707261010643; Tue, 06 Feb 2024 15:10:10 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCVpCbhnY7THJmic/xHgAtgBuAs61Aiv3C02c6MHjhe+jnmZLOnjeeQeDc3Slm6zIamODegwZadv7eJ8Zpj8RVxKsOIlDFVPPvDazJVe8Vf5bcTHeU7WsS6Qncs= Received: from [192.168.0.100] ([43.252.112.155]) by smtp.gmail.com with ESMTPSA id i12-20020a17090332cc00b001d6f7875f57sm56263plr.162.2024.02.06.15.10.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 06 Feb 2024 15:10:10 -0800 (PST) Message-ID: <478af5cc-2eee-4d7d-9417-8e6af372f7c5@linaro.org> Date: Wed, 7 Feb 2024 09:10:03 +1000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 5/6] util/bufferiszero: optimize SSE2 and AVX2 variants Content-Language: en-US To: Alexander Monakov , qemu-devel@nongnu.org Cc: Mikhail Romanov , Paolo Bonzini References: <20240206204809.9859-1-amonakov@ispras.ru> <20240206204809.9859-6-amonakov@ispras.ru> From: Richard Henderson In-Reply-To: <20240206204809.9859-6-amonakov@ispras.ru> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::534; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x534.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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 2/7/24 06:48, Alexander Monakov wrote: > Increase unroll factor in SIMD loops from 4x to 8x in order to move > their bottlenecks from ALU port contention to load issue rate (two loads > per cycle on popular x86 implementations). Ah, that answers my question re 128 vs 256 byte minimum. So as far as this patch goes, Reviewed-by: Richard Henderson r~