mirror of https://github.com/FFmpeg/FFmpeg.git
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.pull/172/head
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/*
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* Copyright (c) 2015 Janne Grunau <janne-libav@jannau.net> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVUTIL_AARCH64_TIMER_H |
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#define AVUTIL_AARCH64_TIMER_H |
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#include <stdint.h> |
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#include "config.h" |
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#if HAVE_INLINE_ASM |
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#define AV_READ_TIME read_time |
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static inline uint64_t read_time(void) |
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{ |
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uint64_t cycle_counter; |
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__asm__ volatile( |
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"isb \t\n" |
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"mrs %0, pmccntr_el0 " |
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: "=r"(cycle_counter) :: "memory" ); |
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return cycle_counter; |
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} |
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#endif /* HAVE_INLINE_ASM */ |
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#endif /* AVUTIL_AARCH64_TIMER_H */ |
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