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 A80A4C433EF for ; Mon, 9 May 2022 20:44:03 +0000 (UTC) Received: from localhost ([::1]:46614 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1noAEc-00036y-Cy for qemu-devel@archiver.kernel.org; Mon, 09 May 2022 16:44:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1noADV-0002Dj-1q for qemu-devel@nongnu.org; Mon, 09 May 2022 16:42:53 -0400 Received: from mail-pg1-x536.google.com ([2607:f8b0:4864:20::536]:33505) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1noADT-0002xa-B7 for qemu-devel@nongnu.org; Mon, 09 May 2022 16:42:52 -0400 Received: by mail-pg1-x536.google.com with SMTP id k14so13022222pga.0 for ; Mon, 09 May 2022 13:42:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=JUQ504MnQHGnlG80Ce1nCg0VwTC5aoJxM7f014+HvOw=; b=Ag7ev+ctd2hEGpmSHt5miOeUD05G3j8vmXWOXfvjlWv9tsHThea6RB5PJCgOnhITf7 MUwzz7co/MeuMV27yLTRRJA5pplPW9hjJYUG79djXniW9hC/g8ykk3RsRIHyV0NztvpY DQdWmrv+QZTwwndszbtdNoWtdV2300xAbp+zRixPL8zwdSbmBBk34lT6zsZOz9oLX0lu 73pe4IVIk8/sh+D0g9RktuYBnG3mopJ/b8cZoCdF5gWl3GoYXhJNJJWNsA0GKZaTtMi3 qmfR9yxOvYQjRgj4zUw+uSw9S215j07GgRYkwp64QWH+dfy58drrXieOZM7R6tX2YRLZ iv2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=JUQ504MnQHGnlG80Ce1nCg0VwTC5aoJxM7f014+HvOw=; b=Y4fhq9/T8Fngxr42M/Ae7M3uvJCVDKloeMvI/5NDWmrD/3jH3d+gUy7OgVbfbfG1Uc Qlr55258m2SjxaGDs7PyaKeAYeD4p8GTDyrAE77kTtx2Vabfjxa+HUXdgkxINbA9fvwc whU5k2GV5KxQfB8fU9m79ShjsSnBQnF/LJ2VzdOT7LAVkHlXBcbJFIAVM103j/hhE08A qk7wAR8Oe9qoCUiCMlcguPbus7ct7mOY1HxjW1MCnD+XNJB8cbHxLwnx+ZRDGaeUtmo+ NZq+N0sNHk+NKsBbuj8nWzKZzgY164QRjOajbTMKfNjqf7GenTD2xxd2Ck0nipWeLgzf EU+A== X-Gm-Message-State: AOAM532S8LMP+X+4v4uXy1lhPQ8r7nYo4HdMVoS4INaseWxsphZLjU2g SWndGLG9aEwvr3e34P2tCsEtlw== X-Google-Smtp-Source: ABdhPJwdLIyWsPA4U9Cd2PLnARBREmDjBjot7jglxwmEWIpbdiKbhYvd5tjqDfk15vAP9KhKTziz0Q== X-Received: by 2002:a05:6a00:21c2:b0:4fe:81f:46c7 with SMTP id t2-20020a056a0021c200b004fe081f46c7mr17332545pfj.5.1652128969850; Mon, 09 May 2022 13:42:49 -0700 (PDT) Received: from [192.168.1.6] ([71.212.142.129]) by smtp.gmail.com with ESMTPSA id z29-20020aa79f9d000000b0050dc7628170sm9099010pfr.74.2022.05.09.13.42.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 May 2022 13:42:49 -0700 (PDT) Message-ID: <517b84ca-a27d-c79b-b649-b8358ff60857@linaro.org> Date: Mon, 9 May 2022 13:42:47 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH] target/arm: Drop unsupported_encoding() macro Content-Language: en-US To: Peter Maydell , qemu-arm@nongnu.org, qemu-devel@nongnu.org References: <20220509160443.3561604-1-peter.maydell@linaro.org> From: Richard Henderson In-Reply-To: <20220509160443.3561604-1-peter.maydell@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::536; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x536.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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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" On 5/9/22 11:04, Peter Maydell wrote: > The unsupported_encoding() macro logs a LOG_UNIMP message and then > generates code to raise the usual exception for an unallocated > encoding. Back when we were still implementing the A64 decoder this > was helpful for flagging up when guest code was using something we > hadn't yet implemented. Now we completely cover the A64 instruction > set it is barely used. The only remaining uses are for five > instructions whose semantics are "UNDEF, unless being run under > external halting debug": > * HLT (when not being used for semihosting) > * DCPSR1, DCPS2, DCPS3 > * DRPS > > QEMU doesn't implement external halting debug, so for us the UNDEF is > the architecturally correct behaviour (because it's not possible to > execute these instructions with halting debug enabled). The > LOG_UNIMP doesn't serve a useful purpose; replace these uses of > unsupported_encoding() with unallocated_encoding(), and delete the > macro. > > Signed-off-by: Peter Maydell > --- > target/arm/translate-a64.h | 9 --------- > target/arm/translate-a64.c | 8 ++++---- > 2 files changed, 4 insertions(+), 13 deletions(-) Reviewed-by: Richard Henderson r~