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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C132FC388F7 for ; Tue, 20 Oct 2020 15:14:35 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0B02E2222D for ; Tue, 20 Oct 2020 15:14:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="mVUDyWw/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B02E2222D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45882 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kUtLO-0007mv-31 for qemu-devel@archiver.kernel.org; Tue, 20 Oct 2020 11:14:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54622) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kUtID-0003fV-34 for qemu-devel@nongnu.org; Tue, 20 Oct 2020 11:11:17 -0400 Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]:34428) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kUtIB-0006UR-CV for qemu-devel@nongnu.org; Tue, 20 Oct 2020 11:11:16 -0400 Received: by mail-pg1-x541.google.com with SMTP id t14so1266559pgg.1 for ; Tue, 20 Oct 2020 08:11:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=How1s8vldAjAq1q7OzxOvlrtGvGHNZfb8tzuyxAXLng=; b=mVUDyWw/I0khaxb18+0WuCH1i6ACW/eNgY7DZLNjHXoB1qTcvNTjLcbjtMmwWsWIl/ IPKH+XrJWwVetWCe0tXEuZKci1EuHHkTb1OWqFcj1iyOje3MTNo4J2ghLo0JFrj6em6i Xd3jDkdIDw6atCZXIS66B1KcjJ4u027lrg17a43u5uysS/euknx7dHR/Ir2LLMlojK/r gr7AQc4JnpgL+OpDRQPvSo7FMSG6aPKZNWJjobPzLJSPSHy8zojKiiD42vT3nKo3u/ns z9YYAy1dNNEM9nlxCduLuTVOYe3FLTCg7aauAsvsSjuFCvnCBbdBvNpeSglQf1DcY6cR kJYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=How1s8vldAjAq1q7OzxOvlrtGvGHNZfb8tzuyxAXLng=; b=tKIAuvr0bRfyjrxg9pvN4WBiNVvn/GUmxtd9lfMSaiisKNsx3sRvTFoZJ6ej3yOkqL tfAAPlX0mtzDW8IEBrPABpJ7QEPq8yPEndtNstQ5CeNRoGuj/P5Fu3bDBI+ciJH+QVe5 VOo7ed+diUCM7a4jzA3NC/B6vGU/wmFxDu6HQd4i7DYK2x9/8PgiotLMJFw6P9s47uD9 BAYlhe8jH137w8f2rNPtSeKS7XRVd7QS1Qma7QzCJsSR3BaMEuilU55FPCYb2o+anuSh 6jRzcqtOTPoDgLjSlheYTJ081MF6DbONrkrXKdPVxyQHAd8IPONQtp1Githx2NZ8D8Yj BBiA== X-Gm-Message-State: AOAM533PmpPhv3p/Qo9GJCZu+wExHAEjbMmQZ/4aBLhNptASR8A82uMc cSnSrEw2eUnX/RwvPAA7+zY1sBU5qfs6XQ== X-Google-Smtp-Source: ABdhPJy4wNscz7gGaFd3ZEKl+L+XYnlxQTz2y3M1yzG73oc5L1DC9RSa/n1wLuKQDXDztetd7ELA8A== X-Received: by 2002:a62:32c5:0:b029:158:7361:58d3 with SMTP id y188-20020a6232c50000b0290158736158d3mr1591111pfy.75.1603206671024; Tue, 20 Oct 2020 08:11:11 -0700 (PDT) Received: from [192.168.1.11] ([71.212.141.89]) by smtp.gmail.com with ESMTPSA id g85sm2613447pfb.4.2020.10.20.08.11.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 20 Oct 2020 08:11:09 -0700 (PDT) Subject: Re: [PATCH 4/4] target/s390x: Improve SUB LOGICAL WITH BORROW To: David Hildenbrand , qemu-devel@nongnu.org References: <20201017022901.78425-1-richard.henderson@linaro.org> <20201017022901.78425-5-richard.henderson@linaro.org> From: Richard Henderson Message-ID: <3d014021-bf0c-c2d8-fcc1-a6a66a843353@linaro.org> Date: Tue, 20 Oct 2020 08:11:07 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::541; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x541.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. 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 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 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 10/20/20 7:17 AM, David Hildenbrand wrote: >> + case CC_OP_ADDU: > > Can you give me a hint how we're converting the carry into a borrow? > > Can we apply something similar to compute_carry()? > >> + tcg_gen_subi_i64(cc_src, cc_src, 1); Right here: subtract one. carry = {1,0} -> borrow = {0,-1} I'll add some more comments for v2. r~