From 64034849dad8410bedbe1def4c533490fb85cc4a Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Thu, 3 Dec 2015 00:12:39 +0100 Subject: arm64: add cycle counter support The ISB (instruction synchronization barrier) might be too heavy for START/STOPTIMER use but should be more accurate in checkasm where the timing overhead is subtracted. --- libavutil/aarch64/timer.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ libavutil/timer.h | 4 +++- 2 files changed, 47 insertions(+), 1 deletion(-) create mode 100644 libavutil/aarch64/timer.h (limited to 'libavutil') diff --git a/libavutil/aarch64/timer.h b/libavutil/aarch64/timer.h new file mode 100644 index 0000000000..382cfd959c --- /dev/null +++ b/libavutil/aarch64/timer.h @@ -0,0 +1,44 @@ +/* + * Copyright (c) 2015 Janne Grunau + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_AARCH64_TIMER_H +#define AVUTIL_AARCH64_TIMER_H + +#include +#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( + "isb \t\n" + "mrs %0, pmccntr_el0 " + : "=r"(cycle_counter) :: "memory" ); + + return cycle_counter; +} + +#endif /* HAVE_INLINE_ASM */ + +#endif /* AVUTIL_AARCH64_TIMER_H */ diff --git a/libavutil/timer.h b/libavutil/timer.h index 0d93d7c0ef..cc4c5a5901 100644 --- a/libavutil/timer.h +++ b/libavutil/timer.h @@ -38,7 +38,9 @@ #include "log.h" -#if ARCH_ARM +#if ARCH_AARCH64 +# include "aarch64/timer.h" +#elif ARCH_ARM # include "arm/timer.h" #elif ARCH_BFIN # include "bfin/timer.h" -- cgit v1.2.3