From nobody Wed Feb 11 13:42:09 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9C1DC77B7C for ; Wed, 10 May 2023 03:53:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235772AbjEJDxZ (ORCPT ); Tue, 9 May 2023 23:53:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235642AbjEJDxQ (ORCPT ); Tue, 9 May 2023 23:53:16 -0400 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AF98E10D for ; Tue, 9 May 2023 20:53:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=iEiFU y1jQsRM6aIe5Ug6C6I5S7K8RRjm4135kykYFHY=; b=kauZQLk2XXLBOu4xJE3XR 4fl5u+T5bRybY2yydZfvCRtnVIU1brx6hI4krs+8NYWr8KCZr8RnRUx6IM2ToyCw WGvfxfyHK3trkzUq+mZJdVrTOxikBJMNxLlvGci0/xdttQF3TOjh6bXljEFv+712 3TdLFvcSz+cZzw1PaQipCQ= Received: from zhangf-virtual-machine.localdomain (unknown [180.111.102.183]) by zwqz-smtp-mta-g3-4 (Coremail) with SMTP id _____wBHlVQOFVtk+zPWBQ--.60792S4; Wed, 10 May 2023 11:52:56 +0800 (CST) From: zhangfei To: ajones@ventanamicro.com Cc: aou@eecs.berkeley.edu, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, palmer@dabbelt.com, paul.walmsley@sifive.com, zhang_fei_0403@163.com, zhangfei@nj.iscas.ac.cn Subject: [PATCH 2/2] riscv: Optimize memset Date: Wed, 10 May 2023 11:52:42 +0800 Message-Id: <20230510035243.8586-3-zhang_fei_0403@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230510035243.8586-1-zhang_fei_0403@163.com> References: <20230509-b0dc346928ddc8d2b5690f67@orel> <20230510035243.8586-1-zhang_fei_0403@163.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wBHlVQOFVtk+zPWBQ--.60792S4 X-Coremail-Antispam: 1Uf129KBjvdXoW7GryxZw13AFWrKrWxtrW8JFb_yoWkAFc_Gr WxCa97JFyDJFZ3Xa9rtw13Kry8uFZ8KrykG3WDtw1UG3WFkwnxtrWYqry5AF18XwsrGay3 G3ZrJr4rXr1UGjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IUUWlkPUUUUU== X-Originating-IP: [180.111.102.183] X-CM-SenderInfo: x2kd0w5bihxsiquqjqqrwthudrp/xtbCfAlrl2DcJd-5aAAAse Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: zhangfei This patch has been optimized for memset data sizes less than 16 bytes. Compared to byte by byte storage, significant performance improvement has b= een achieved. It allows storage instructions to be executed in parallel and reduces the n= umber of jumps. Signed-off-by: Fei Zhang --- arch/riscv/lib/memset.S | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S index e613c5c27998..6113a2696e79 100644 --- a/arch/riscv/lib/memset.S +++ b/arch/riscv/lib/memset.S @@ -106,9 +106,36 @@ WEAK(memset) beqz a2, 6f add a3, t0, a2 5: - sb a1, 0(t0) - addi t0, t0, 1 - bltu t0, a3, 5b + sb a1, 0(t0) + sb a1, -1(a3) + li a4, 2 + bgeu a4, a2, 6f + + sb a1, 1(t0) + sb a1, 2(t0) + sb a1, -2(a3) + sb a1, -3(a3) + li a4, 6 + bgeu a4, a2, 6f + + sb a1, 3(t0) + sb a1, -4(a3) + li a4, 8 + bgeu a4, a2, 6f + + sb a1, 4(t0) + sb a1, -5(a3) + li a4, 10 + bgeu a4, a2, 6f + + sb a1, 5(t0) + sb a1, 6(t0) + sb a1, -6(a3) + sb a1, -7(a3) + li a4, 14 + bgeu a4, a2, 6f + + sb a1, 7(t0) 6: ret END(__memset) --=20 2.33.0