From patchwork Mon Oct 19 14:24:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 23084 Return-Path: X-Original-To: patchwork@ffaux-bg.ffmpeg.org Delivered-To: patchwork@ffaux-bg.ffmpeg.org Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by ffaux.localdomain (Postfix) with ESMTP id 8461C448C78 for ; Mon, 19 Oct 2020 17:26:12 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 6A23068B787; Mon, 19 Oct 2020 17:26:12 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe01-2.mx.upcmail.net (vie01a-dmta-pe01-2.mx.upcmail.net [62.179.121.155]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id E071068B649 for ; Mon, 19 Oct 2020 17:26:02 +0300 (EEST) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe01.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1kUW6s-0003ez-0E for ffmpeg-devel@ffmpeg.org; Mon, 19 Oct 2020 16:26:02 +0200 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id UW5uk1aP5Ir7GUW5ukaaWw; Mon, 19 Oct 2020 16:25:02 +0200 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.68.29 X-CNFS-Analysis: v=2.3 cv=QN4WuTDL c=1 sm=1 tr=0 a=2hcxjKEKjp0CzLx6oWAm4g==:117 a=2hcxjKEKjp0CzLx6oWAm4g==:17 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=ytUGk9Q8pmp7zyxsyWoA:9 a=pHzHmUro8NiASowvMSCR:22 a=xoEH_sTeL_Rfw54TyV31:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Mon, 19 Oct 2020 16:24:57 +0200 Message-Id: <20201019142501.6867-3-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201019142501.6867-1-michael@niedermayer.cc> References: <20201019142501.6867-1-michael@niedermayer.cc> X-CMAE-Envelope: MS4wfOIzGc5/0l8vZYqiZZq80nytvTiXn7B7giNMuD+rOEc5ySFWGMfI8GW6jrAh2IwDYbkEjlYuse8QfWpZ7Z8RzMiEi4r+U9PU/HnxuQnUO0LM2PoQc2+N nHR58aoB5TXmFQkTRvuFx7agUwNdPJInvaipxuLoF2/Ge1X/y4h9gy3w Subject: [FFmpeg-devel] [PATCH 3/7] avutil/common: Implement av_sat_add64_c() with fewer branches X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 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 MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" No benchmark because this is not used in any speed relevant pathes nor is it used where __builtin_add_overflow is available. So I do not know how to realistically benchmark it. Signed-off-by: Michael Niedermayer --- libavutil/common.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/libavutil/common.h b/libavutil/common.h index 92b721a59c..a48c0648f8 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -303,11 +303,10 @@ static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) { int64_t tmp; return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN); #else - if (b >= 0 && a >= INT64_MAX - b) - return INT64_MAX; - if (b <= 0 && a <= INT64_MIN - b) - return INT64_MIN; - return a + b; + int64_t s = a+(uint64_t)b; + if ((int64_t)(a^b | ~s^b) >= 0) + return b < 0 ? INT64_MIN : INT64_MAX; + return s; #endif }