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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C53C6C98302 for ; Tue, 22 Sep 2026 13:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/R6fYs03tP4ZFtc0PyuIU1iu3fhJBLn/4XXMTcOieW0=; b=kuvpDEGdUuUpHF kPEdi77Fg9/MPUL6SGTApdfnVV+JhUW3RSE59kwLXPP4crWOcVuFCFrvUyhaawcGZmmotifHwLCO6 uoTzhgkTZyk3fxmjMJOf0GIlcvbVCkD2ZbwtaaCiZqC9+hlv218NkgPnM5a8DGCnimW1AfFc+U5In 2VaWhylUqQe15ENipz2NWxYkghU2o2D5S52IkXx9vr+RYYnN361n6ofTnQjM3YZ+Vj6qSlOPVM9ZV q9IGnJiUyXv2MNuXaaBlMPZ1Wj+WGm6mLfxDUxqUFMj4Yt+OuY1vAr82ZViffvAMVFH9JroYgJTc/ HZ5Hqc27LuZDVjNZWxjg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x90tB-00000005bFL-1GHS; Tue, 22 Sep 2026 13:50:29 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x90t9-00000005bED-0ETj for linux-riscv@lists.infradead.org; Tue, 22 Sep 2026 13:50:28 +0000 From: Nam Cao DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1790085024; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LD4Dt1VUowZxVym8KcVqrFzWA9GmmHGYh/uLDgQnS14=; b=NY/Z972E8io5RKYuLLWT4laqvmc7zfb/pkzogbdqmbPBDLTuyagus4/xOri9jYXR81fT1g nLBtkj2zwmiEXI/9FQ5wVrFQrEDs2ZUf7187TMD7llJrIe3ynavsL9uH7gR1rt8ZjZCHVd VXDEQYmQXKdVVn9jQDZclayKxdSZehAg+146YApOF5dOF+T2UTDHuT1pyqYTe2DeLgUcRG 41yup6LLbyBbaykYqQ+3sNmXmhHmFByPWxlTWbbN4KLIBYZRpeqOYBz7MQ2LdhwUHrY0ft 8AfyRiwgI3csBtQftyvJl2DK3ofb6UdWfmLWYVfQSnxO5d1b2MAkNwUO0y0ERQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1790085024; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LD4Dt1VUowZxVym8KcVqrFzWA9GmmHGYh/uLDgQnS14=; b=Qk23kcZip5Cfoen/tLRwu5rBgruubDgq/l4i8elkpnVTnRsPlPy1F8wJHJXQ3tb5E0g082 xz5TpahA4l3mONCQ== To: Jisheng Zhang , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/3] riscv: word-at-a-time: improve find_zero() without Zbb In-Reply-To: <20260908235312.8440-3-jszhang@kernel.org> References: <20260908235312.8440-1-jszhang@kernel.org> <20260908235312.8440-3-jszhang@kernel.org> Date: Tue, 22 Sep 2026 15:50:24 +0200 Message-ID: <87pky5e6ov.fsf@yellow.woof> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260922_065027_255783_270CCC8B X-CRM114-Status: UNSURE ( 6.55 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Jisheng Zhang writes: > Previous commit improved the find_zero() performance for !RISCV_ISA_ZBB. > What about RISCV_ISA_ZBB=y but the HW doesn't support Zbb? We have the > same heavy generic fls64() issue. This patch separation makes sense in your first version. Now it makes more sense to squash this part to the first patch. ... > To remove non-necessary zero bits couting on RV32, we also replace the > 'fls64(mask) >> 3' with '!mask ? 0 : ((__fls(mask) + 1) >> 3);' This should be its own patch. Nam _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv