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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_CUTILS_ATOMIC_X86_H
#define ANDROID_CUTILS_ATOMIC_X86_H
#include <stdint.h>
#ifndef ANDROID_ATOMIC_INLINE
#define ANDROID_ATOMIC_INLINE inline __attribute__((always_inline))
#endif
extern ANDROID_ATOMIC_INLINE void android_compiler_barrier(void)
{
__asm__ __volatile__ ("" : : : "memory");
}
#if ANDROID_SMP == 0
extern ANDROID_ATOMIC_INLINE void android_memory_barrier(void)
{
android_compiler_barrier();
}
#else
extern ANDROID_ATOMIC_INLINE void android_memory_barrier(void)
{
__asm__ __volatile__ ("mfence" : : : "memory");
}
#endif
extern ANDROID_ATOMIC_INLINE int32_t
android_atomic_acquire_load(volatile const int32_t *ptr)
{
int32_t value = *ptr;
android_compiler_barrier();
return value;
}
extern ANDROID_ATOMIC_INLINE int32_t
android_atomic_release_load(volatile const int32_t *ptr)
{
android_memory_barrier();
return *ptr;
}
extern ANDROID_ATOMIC_INLINE void
android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
{
*ptr = value;
android_memory_barrier();
}
extern ANDROID_ATOMIC_INLINE void
android_atomic_release_store(int32_t value, volatile int32_t *ptr)
{
android_compiler_barrier();
*ptr = value;
}
extern ANDROID_ATOMIC_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 ANDROID_ATOMIC_INLINE int
android_atomic_acquire_cas(int32_t old_value,
int32_t new_value,
volatile int32_t *ptr)
{
/* Loads are not reordered with other loads. */
return android_atomic_cas(old_value, new_value, ptr);
}
extern ANDROID_ATOMIC_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 ANDROID_ATOMIC_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 ANDROID_ATOMIC_INLINE int32_t
android_atomic_inc(volatile int32_t *addr)
{
return android_atomic_add(1, addr);
}
extern ANDROID_ATOMIC_INLINE int32_t
android_atomic_dec(volatile int32_t *addr)
{
return android_atomic_add(-1, addr);
}
extern ANDROID_ATOMIC_INLINE int32_t
android_atomic_and(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;
}
extern ANDROID_ATOMIC_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;
}
#endif /* ANDROID_CUTILS_ATOMIC_X86_H */