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/*
* Copyright (C) 2016, Emilio G. Cota <cota@braap.org>
*
* License: GNU GPL, version 2.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_PROCESSOR_H
#define QEMU_PROCESSOR_H
#include "qemu/atomic.h"
#if defined(__i386__) || defined(__x86_64__)
# define cpu_relax() asm volatile("rep; nop" ::: "memory")
#elif defined(__ia64__)
# define cpu_relax() asm volatile("hint @pause" ::: "memory")
#elif defined(__aarch64__)
# define cpu_relax() asm volatile("yield" ::: "memory")
#elif defined(__powerpc64__)
/* set Hardware Multi-Threading (HMT) priority to low; then back to medium */
# define cpu_relax() asm volatile("or 1, 1, 1;" \
"or 2, 2, 2;" ::: "memory")
#else
# define cpu_relax() barrier()
#endif
#endif /* QEMU_PROCESSOR_H */
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