PR #22417 opened by Deng-zewen URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/22417 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/22417.patch
libavutil/riscv: Add timer support using rdtime This adds a RISC-V-specific high-resolution timer implementation in libavutil/riscv/timer.h, using the 'rdtime' instruction for real-time tick counting. This is analogous to architecture-specific timers on ARM, x86, and others, providing better performance and lower overhead than the generic clock_gettime(CLOCK_MONOTONIC) fallback. Signed-off-by: deng.zewen [email protected] >From bd56555669c75bf37b5396121f4e6740b6410e09 Mon Sep 17 00:00:00 2001 From: "deng.zewen" <[email protected]> Date: Fri, 6 Mar 2026 15:56:59 +0800 Subject: [PATCH] libavutil/riscv: Add timer support using rdtime --- libavutil/riscv/timer.h | 38 ++++++++++++++++++++++++++++++++++++++ libavutil/timer.h | 2 ++ 2 files changed, 40 insertions(+) create mode 100644 libavutil/riscv/timer.h diff --git a/libavutil/riscv/timer.h b/libavutil/riscv/timer.h new file mode 100644 index 0000000000..796d23d366 --- /dev/null +++ b/libavutil/riscv/timer.h @@ -0,0 +1,38 @@ +/* + * Copyright (c) 2026 Deng Zewen <[email protected]> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_RISCV_TIMER_H +#define AVUTIL_RISCV_TIMER_H + +#include <stdint.h> +#include "config.h" + +#if HAVE_INLINE_ASM + +#define AV_READ_TIME read_time +static inline uint64_t read_time(void) +{ + uint64_t cycle_counter; + __asm__ volatile("rdtime %0" : "=r" (cycle_counter) : : "memory"); + return cycle_counter; +} +#endif /* HAVE_INLINE_ASM */ + +#endif /* AVUTIL_RISCV_TIMER_H */ \ No newline at end of file diff --git a/libavutil/timer.h b/libavutil/timer.h index 03706b0d10..d61ffe7da2 100644 --- a/libavutil/timer.h +++ b/libavutil/timer.h @@ -65,6 +65,8 @@ # include "x86/timer.h" #elif ARCH_LOONGARCH # include "loongarch/timer.h" +#elif ARCH_RISCV +# include "riscv/timer.h" #endif #if !defined(AV_READ_TIME) -- 2.52.0 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
