Atomic-x86.h

#ifndef ANDROID_CUTILS_ATOMIC_X86_H
#define ANDROID_CUTILS_ATOMIC_X86_H

#include <stdint.h>


#ifdef __cplusplus
extern "C" {
#endif


extern inline int32_t android_atomic_add(int32_t increment,
		volatile int32_t *ptr)
{
	__asm__ __volatile__ ("lock; xaddl %0, %1"
			: "+r" (increment), "+m" (*ptr)
			: : "memory");
	/* increment now holds the old value of *ptr */
	return increment;
}

extern inline int android_atomic_cas(int32_t old_value, int32_t new_value,
		volatile int32_t *ptr)
{
	int32_t prev;
	__asm__ __volatile__ ("lock; cmpxchgl %1, %2"
			: "=a" (prev)
			: "q" (new_value), "m" (*ptr), "0" (old_value)
			: "memory");
	return prev != old_value;
}

extern inline int32_t android_atomic_inc(volatile int32_t *addr)
{
	return android_atomic_add(1, addr);
}

extern inline int32_t android_atomic_dec(volatile int32_t *addr)
{
	return android_atomic_add(-1, addr);
}

extern inline int android_atomic_release_cas(int32_t old_value,
		int32_t new_value,
		volatile int32_t *ptr)
{
	/* Stores are not reordered with other stores. */
	return android_atomic_cas(old_value, new_value, ptr);
}

extern inline int32_t android_atomic_or(int32_t value, volatile int32_t *ptr)
{
	int32_t prev, status;
	do {
		prev = *ptr;
		status = android_atomic_cas(prev, prev | value, ptr);
	} while (__builtin_expect(status != 0, 0));
	return prev;
}

#define android_atomic_cmpxchg android_atomic_release_cas

#ifdef __cplusplus
} // extern "C"
#endif

#endif