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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57084 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kUtPl-00044L-Lc for qemu-devel@archiver.kernel.org; Tue, 20 Oct 2020 11:19:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54958) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kUtJK-0004wq-9B for qemu-devel@nongnu.org; Tue, 20 Oct 2020 11:12:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:44974) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kUtJG-0006aH-EQ for qemu-devel@nongnu.org; Tue, 20 Oct 2020 11:12:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603206740; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Dj+TOnvvZZ5vmfM8lwC0G0qMF8jX4le6TVB5sIfrB5s=; b=bowTzD6zU+UjDsvnTGmcjsctBjnlULc8ZA4/270isPmhmbMfJCcHbPGFgumrpaSlv4ZXow xlF3O1ZuEb7Sg3J2xuSlVkEwUoKsAApND+0VUu439u/SY/e71yUtBx3s2qzIj+vJk2D68E /4GzauQVPOFduBg+rZx9wliLtzuSxh0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-162-CNpotVffPPW4WIMx97vDbQ-1; Tue, 20 Oct 2020 11:12:17 -0400 X-MC-Unique: CNpotVffPPW4WIMx97vDbQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 455161084C85; Tue, 20 Oct 2020 15:12:16 +0000 (UTC) Received: from [10.36.114.141] (ovpn-114-141.ams2.redhat.com [10.36.114.141]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D5471002C0E; Tue, 20 Oct 2020 15:12:15 +0000 (UTC) Subject: Re: [PATCH 4/4] target/s390x: Improve SUB LOGICAL WITH BORROW To: Richard Henderson , qemu-devel@nongnu.org References: <20201017022901.78425-1-richard.henderson@linaro.org> <20201017022901.78425-5-richard.henderson@linaro.org> <3d014021-bf0c-c2d8-fcc1-a6a66a843353@linaro.org> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <2a48d29a-6fa5-6557-e929-9434f0f1723e@redhat.com> Date: Tue, 20 Oct 2020 17:12:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <3d014021-bf0c-c2d8-fcc1-a6a66a843353@linaro.org> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/20 01:15:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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, DKIMWL_WL_HIGH=-0.001, 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, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, 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 20.10.20 17:11, Richard Henderson wrote: > 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} Ok, so it's really that simple :) Thanks! -- Thanks, David / dhildenb