From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id D83E046073 for ; Sat, 30 Sep 2023 17:46:04 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 89E7468CC1E; Sat, 30 Sep 2023 20:46:01 +0300 (EEST) Received: from ursule.remlab.net (vps-a2bccee9.vps.ovh.net [51.75.19.47]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 760A268CC0D for ; Sat, 30 Sep 2023 20:45:55 +0300 (EEST) Received: from basile.remlab.net (localhost [IPv6:::1]) by ursule.remlab.net (Postfix) with ESMTP id 7A292C006C for ; Sat, 30 Sep 2023 20:45:54 +0300 (EEST) From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= To: ffmpeg-devel@ffmpeg.org Date: Sat, 30 Sep 2023 20:45:54 +0300 Message-ID: <20230930174554.8650-1-remi@remlab.net> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH] lavu/float_dsp: avoid reg-stride in R-V V reverse_fmul X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: This revectors the inner loop to reverse vectors element in vectors, thus eliminating the negative register stride. Note that RVV does not have a vector reverse instruction, so this uses a gather. --- libavutil/riscv/float_dsp_rvv.S | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/libavutil/riscv/float_dsp_rvv.S b/libavutil/riscv/float_dsp_rvv.S index 7cfc890bc2..7e9e84d526 100644 --- a/libavutil/riscv/float_dsp_rvv.S +++ b/libavutil/riscv/float_dsp_rvv.S @@ -125,20 +125,25 @@ func ff_vector_fmul_add_rvv, zve32f ret endfunc +// TODO factor vrsub, separate last iteration? // (a0) = (a1) * reverse(a2) [0..a3-1] func ff_vector_fmul_reverse_rvv, zve32f + vsetvli t0, zero, e16, m4, ta, ma sh2add a2, a3, a2 - li t2, -4 // byte stride - addi a2, a2, -4 + vid.v v0 + vadd.vi v0, v0, 1 1: - vsetvli t0, a3, e32, m8, ta, ma + vsetvli t0, a3, e16, m4, ta, ma slli t1, t0, 2 - vle32.v v16, (a1) + vrsub.vx v4, v0, t0 // v4[i] = [VL-1, VL-2... 1, 0] + sub a2, a2, t1 + vsetvli zero, zero, e32, m8, ta, ma + vle32.v v8, (a2) sub a3, a3, t0 - vlse32.v v24, (a2), t2 + vle32.v v16, (a1) add a1, a1, t1 + vrgatherei16.vv v24, v8, v4 // v24 = reverse(v8) vfmul.vv v16, v16, v24 - sub a2, a2, t1 vse32.v v16, (a0) add a0, a0, t1 bnez a3, 1b -- 2.42.0 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".