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/*
* Copyright (c) 2015 Janne Grunau <janne-libav@jannau.net>
*
* 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_AARCH64_TIMER_H
#define AVUTIL_AARCH64_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(
"isb \t\n"
#if defined(__ANDROID__) || defined(__APPLE__)
// cntvct_el0 has lower resolution than pmccntr_el0, but is usually
// accessible from user space by default.
"mrs %0, cntvct_el0 "
#else
// pmccntr_el0 has higher resolution, but is usually not accessible
// from user space by default (but access can be enabled with a custom
// kernel module).
"mrs %0, pmccntr_el0 "
#endif
: "=r"(cycle_counter) :: "memory" );
return cycle_counter;
}
#endif /* HAVE_INLINE_ASM */
#endif /* AVUTIL_AARCH64_TIMER_H */
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