From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd2a.google.com (mail-io1-xd2a.google.com [IPv6:2607:f8b0:4864:20::d2a]) by sourceware.org (Postfix) with ESMTPS id 242A13858D1E for ; Tue, 7 Nov 2023 01:01:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 242A13858D1E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 242A13858D1E Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::d2a ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699318914; cv=none; b=KcFXbBjNcRoIOUFtvG4q8vre3c+IjNj+3pJmNIdI0Ah5607LQsedlYtuhBln/Rjtv2xm1D/w3xAR3BgvELIkuzg4lzTgo1VsOYHUsnfL8bmcPTlg6l+wHZ0JIAjfuGfRyCpgOiZhVNt7QVaG92RvHK73KqQLSWhtPxsrtK0JqMw= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699318914; c=relaxed/simple; bh=xaHkgowGzdPN+MKB7FvejT+sl7+GZ7ovBPogsMlJYf4=; h=DKIM-Signature:Message-ID:Date:MIME-Version:Subject:To:From; b=KUlo0V6gUf3dXUiNB/XGhlW/NnWAZIryRq3UP9KfoqD8N1qtgKAyeKUmTrAF+opyT5Bdh2nSKK8p7lWcXHu89XsO0qVQ/N5QcB7xlnnuii05yQ9CndUJUpHfk70oBw+QJTTXVYcJPJsrHGCgc7LMYClZjaIFPmb3yUV546Zwqf0= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-io1-xd2a.google.com with SMTP id ca18e2360f4ac-7a66aa8ebb7so211739939f.3 for ; Mon, 06 Nov 2023 17:01:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699318912; x=1699923712; darn=gcc.gnu.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=NTcSDpiDafqoqQHZ2Xjyt9XsS5wQ/+vggv5VAkE8L/Q=; b=R2NcJ/IooSbjk2KRaqOiAKb/9veK30B8yRkYd8B3rgiZ3G2k2+DUDeGCGXlzDmuzgd TAv6twYsXcWebVcyQvrcPSy4blJCDrDCF7h9KQokpkZwWvoGxoddawDVTa0jv+vPEKEa 98x5bM+IUA4/l9FyLQFIGOqXGy1mvkGt7MiRk6M6P/KYG0rKLpUcA8FKer5Vq5O6nWsj duO/pm7TfYsR8NPXTRE450QK4WgyiqsNJnXWbt/Ao4XALirq9uUfO5NI+TrCZ16qNLvo M+UBBbfwNtIMtWJOIXj7jGqORRSAWxk+xjgQRuFR+YnwpujaRY7MkBSUWl3L+JEchcw0 7ivA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699318912; x=1699923712; 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=NTcSDpiDafqoqQHZ2Xjyt9XsS5wQ/+vggv5VAkE8L/Q=; b=vX4h/Bq6Ei2hZJtuyi0L7H5G6yiGFQvW/ge3eV3+qZj7V9gHo3WxqYGTyuzyrBa0/o tXTJbU4IyjzwdXrcwQurw1ZMd+Fgwy1SMdGJjCqyM1Pv2p6Kx7plCvR1B0sOpT8oerUN msCON756jCnQM9w9nuMHL4W7+FxIfmcta0/9tqj9oGl/YpxXdwqoCi9yBq2ccWM3K6FY daRx16h0Wyc5hEnitfOX4BeAIY2X+bT77n04Ute7vbXtVgr7X064o6TmsVu8e48+iQJU 0YhT10ntN4f6VafBwzjUuAVl1IgABLhgBW7MpG8exnsyk6zOc9qFtIKBSwICMs8v2O4R 1OUg== X-Gm-Message-State: AOJu0Yx6c/H7Kb+Q/xn5ei7+U8Gkejv8JP8rmv8VVvoHMKOObjm99wFe mV5Rrv1KEwR8b3VELqV8jBaOUO06xCgyTg== X-Google-Smtp-Source: AGHT+IGPLqnLWqvyBrqO5wDfowIGOOU+RzOJBJDEgPahGMm8sAosBxAierldgUurhpi+vwWmTXorJw== X-Received: by 2002:a05:6602:2f05:b0:7a9:5a98:2f63 with SMTP id q5-20020a0566022f0500b007a95a982f63mr38188518iow.11.1699318911768; Mon, 06 Nov 2023 17:01:51 -0800 (PST) Received: from [172.31.0.109] ([136.36.130.248]) by smtp.gmail.com with ESMTPSA id m4-20020a5e8d04000000b00785cfdd968bsm2674306ioj.5.2023.11.06.17.01.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 06 Nov 2023 17:01:51 -0800 (PST) Message-ID: <9e575af0-4469-4076-8631-2363c85035a5@gmail.com> Date: Mon, 6 Nov 2023 18:01:50 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 06/12] mode-switching: Tweak entry/exit handling Content-Language: en-US To: gcc-patches@gcc.gnu.org, jlaw@ventanamicro.com, richard.sandiford@arm.com References: From: Jeff Law In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.3 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,T_SCC_BODY_TEXT_LINE 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 11/5/23 11:48, Richard Sandiford wrote: > An entity isn't transparent in a block that requires a specific mode. > optimize_mode_switching took that into account for normal insns, > but didn't for the exit block. Later patches misbehaved because > of this. > > In contrast, an entity was correctly marked as non-transparent > in the entry block, but the reasoning seemed a bit convoluted. > It also referred to a function that no longer exists. > Since KILL = ~TRANSP, the entity is by definition not transparent > in a block that defines the entity, so I think we can make it so > without comment. > > Finally, the exit handling was nested in the entry handling, > but that doesn't seem necessary. A target could say that an > entity is undefined on entry but must be defined on return, > on a "be liberal in what you accept, be conservative in what > you do" principle. > > gcc/ > * mode-switching.cc (optimize_mode_switching): Mark the exit > block as nontransparent if it requires a specific mode. > Handle the entry and exit mode as sibling rather than nested > concepts. Remove outdated comment. OK jeff