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 D2B70FC6160 for ; Fri, 13 Sep 2024 16:28:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sp98v-0003FU-IV; Fri, 13 Sep 2024 12:27:33 -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 1sp98s-00035W-Qv for qemu-devel@nongnu.org; Fri, 13 Sep 2024 12:27:30 -0400 Received: from mail-pf1-x430.google.com ([2607:f8b0:4864:20::430]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sp98p-00086W-Rj for qemu-devel@nongnu.org; Fri, 13 Sep 2024 12:27:29 -0400 Received: by mail-pf1-x430.google.com with SMTP id d2e1a72fcca58-71798a15ce5so2444569b3a.0 for ; Fri, 13 Sep 2024 09:27:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1726244845; x=1726849645; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=YoSm0Etri+zSW70lkI72O4NbskD5YrQTqqRlYI+Rcqg=; b=kRB/IlYBmJz5VvYtLh2K6Rfl1mDQVlTqS27LUstEY33d7GUCWmBOJYkhBr4pCf9Qrk 2nBMHQG3h1SCVRcDbbC8gY9VhTpzU4aQzTBKaFR1CdQICyci1ewxEMPTRJPv+MnX7KkP PDLd75/U+7QOOBBkNoGwRfg8cjSBmFtKqJsVwyhCaTjo4Rq7o022d87Mpxpejs1k+w4l RQxGF96bdhAjJNchykb0BRcBWnuvj3VCvJrGNVx4zWBXw10e8vJYmKmc8crGbxxi+3WX WlZguhvdXZUg5OJxHt/rpQiksw9FYBfb5PjWMNlxH7ZQ7FGoKgo4FiUt9G3P9hvhFxa5 HoHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726244845; x=1726849645; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YoSm0Etri+zSW70lkI72O4NbskD5YrQTqqRlYI+Rcqg=; b=LFd85FMph0MAvRwHRcsyhXX+gZxS7I+QyKK0REgrq3hdfonahiVCMpr651Ly1hbktY xCX24REq/K8OO4wQQsB8rclEuA7YsFuG8Wnq0bQxTbtNd74nS6V+CZKjPb6a7hSrEuDv 86HkSBI5IJV/XinmZ6DBdhEbRiOG1Mo9BBpedf58hZFPKvnvZT76wGSxnFlXoH3hflgF CM+IDk6hEbVtSN7cvN9H9Km4WIZQ98YNCo2RhXDouj2H2zmMDFTiM34f/yqPXjcVfiy0 tWLPQfrgpw6EiWmSmgOpyvEh4l5CXXlst/rr0e+Lk+c5mtMQeyV8bcJs+PGGug4DeeQh zMiw== X-Gm-Message-State: AOJu0Yz/zCESxoH3PjDaXZreSGv3VF1YL4zSdkyFD1cXbXtuLCtTyE+A +CE8zsMVjvLAS+kITzvdre1ESkn99nBOR7b9++eI/BQeI//CKosYBNCLp6fEuUM= X-Google-Smtp-Source: AGHT+IHRJ5ZSHOoLhafVpdV3281jkzWnwqwICaTRflPfgUMeHqyfY3+UsfuI7pdKAjImiMn5pBsR5Q== X-Received: by 2002:a05:6a00:3e27:b0:714:228d:e9f2 with SMTP id d2e1a72fcca58-719263a954amr10827891b3a.3.1726244844486; Fri, 13 Sep 2024 09:27:24 -0700 (PDT) Received: from [192.168.0.4] (174-21-81-121.tukw.qwest.net. [174.21.81.121]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-719090af3cbsm6293953b3a.168.2024.09.13.09.27.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 13 Sep 2024 09:27:23 -0700 (PDT) Message-ID: <69ebf16e-dd3d-4dfb-be81-5034e8fe781f@linaro.org> Date: Fri, 13 Sep 2024 09:27:21 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] tcg: Fix branch/label link during plugin expansion To: =?UTF-8?Q?Alex_Benn=C3=A9e?= Cc: qemu-devel@nongnu.org, pierrick.bouvier@linaro.org References: <20240910212351.977753-1-richard.henderson@linaro.org> <87jzffrgw0.fsf@draig.linaro.org> Content-Language: en-US From: Richard Henderson In-Reply-To: <87jzffrgw0.fsf@draig.linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::430; envelope-from=richard.henderson@linaro.org; helo=mail-pf1-x430.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 9/13/24 03:23, Alex Bennée wrote: >> Note that the branch is X < 0 (unsigned), which is always false, and >> thus the branch is optimized away. > > I'm obviously missing something reading this. How can TCG know the state > of the scoreboard variables and optimise away the branch? 0 < 0 is of course false. r~