From patchwork Sat Nov 11 15:27:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?R=C3=A9mi_Denis-Courmont?= X-Patchwork-Id: 44614 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a05:6a20:92a5:b0:181:818d:5e7f with SMTP id q37csp353257pzg; Sat, 11 Nov 2023 07:27:34 -0800 (PST) X-Google-Smtp-Source: AGHT+IHzMn/dXZ23cGYnDYbipFHa54ZzZufVwCopymD/twloT0h39tSg5eWR2cmozSAgw55IhCKB X-Received: by 2002:a17:906:26cb:b0:9df:4232:5276 with SMTP id u11-20020a17090626cb00b009df42325276mr1426741ejc.76.1699716454119; Sat, 11 Nov 2023 07:27:34 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1699716454; cv=none; d=google.com; s=arc-20160816; b=ennpynU1GPBFhgusZ6nE3bXjlftcJmO9jgzlapoKfCDGCSSNiKy3JKcNt2yDum4gnv KDowfDTSWAmJG7sKHglk/SVHGpmZ8p3NZZGzjPsFC4Q23tCX/I5ERV6lw1VQSjL0aT7d HApRQKt7/p5W6yMpUIjLtWnwDMwUbp9hASJohWuiB/Y+qP3s8L1cgFaY3r2aQ2SNjUU/ d8/3US8gUtLswhrQg9sIpZnpm9w1iInY84OkDb4QnTRYNWGWT+o4CbL0aOgqP2agVjPC GmHs1F/SCcoCwahN7H5dYORow96UaRLNbAv+MXeol65xI1cZbzBcSVclczj0L8uGs3So Ir3g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:reply-to:list-subscribe :list-help:list-post:list-archive:list-unsubscribe:list-id :precedence:subject:mime-version:message-id:date:to:from :delivered-to; bh=dBn7Tzi4mD3Xu1s1B/Ox49fvOb48gIrcw4R9c9m2WlQ=; fh=YOA8vD9MJZuwZ71F/05pj6KdCjf6jQRmzLS+CATXUQk=; b=mp25EFyXn0MJyXSy0dFzwRC9nN03FmZcm3BTFw/cxq49GPBEo5xvoUhFW3NnR8MvXR sjG/YAANwZGXz/4C+DFUXNUumCoI3qghG2LvT9+u79EPCkVDvK/LdhUprAnj7zbFsZOk c2yHlAfOCfmG7TwU0KFmk2IZrKDt74LZTPLBh6qGRt5Bc2tHFIl3sHAnMt+yDu1EFcTj XTIWe9OMnVYmWN0YQNtd9pwt3qoI4a4ZILUlAx9147Is9tovq0AmRHj/2+oVedUZZEx1 zhT7DsIxlGIoMvGiFkPnU6UVUZDwYyJ1YPRmCdAdUWAJ2R/43H9Rp0WtnuLPzj1lu+wA PFbg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id mb18-20020a170906eb1200b00991f9e2a81asi835799ejb.238.2023.11.11.07.27.33; Sat, 11 Nov 2023 07:27:34 -0800 (PST) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 1EC8A68CCA3; Sat, 11 Nov 2023 17:27:31 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from ursule.remlab.net (vps-a2bccee9.vps.ovh.net [51.75.19.47]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 40A1A68C944 for ; Sat, 11 Nov 2023 17:27:24 +0200 (EET) Received: from basile.remlab.net (localhost [IPv6:::1]) by ursule.remlab.net (Postfix) with ESMTP id C0AF5C006B for ; Sat, 11 Nov 2023 17:27:23 +0200 (EET) From: =?utf-8?q?R=C3=A9mi_Denis-Courmont?= To: ffmpeg-devel@ffmpeg.org Date: Sat, 11 Nov 2023 17:27:23 +0200 Message-ID: <20231111152723.41888-1-remi@remlab.net> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH] lavc/exrdsp: unroll predictor 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 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: qtCTl2Dx62kq With explicit unrolling, we can skip half of the sign bit flips, and the compiler is then better able to optimise the scalar loop: predictor_c: 31376.0 (before) predictor_c: 23703.0 (after) --- libavcodec/exrdsp.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/libavcodec/exrdsp.c b/libavcodec/exrdsp.c index 752e1eb553..248cb93c5a 100644 --- a/libavcodec/exrdsp.c +++ b/libavcodec/exrdsp.c @@ -40,10 +40,20 @@ static void reorder_pixels_scalar(uint8_t *dst, const uint8_t *src, ptrdiff_t si static void predictor_scalar(uint8_t *src, ptrdiff_t size) { - ptrdiff_t i; + /* Unrolled: `src[i + 1] += src[i] - 128;` */ + if ((size & 1) == 0) { + src[1] += src[0] ^ 0x80; + src++; + size--; + } + + for (ptrdiff_t i = 1; i < size; i += 2) { + uint8_t a = src[i] + src[i - 1]; - for (i = 1; i < size; i++) - src[i] += src[i-1] - 128; + src[i] = a; + src[i + 1] += a; + src[i] ^= 0x80; + } } av_cold void ff_exrdsp_init(ExrDSPContext *c)