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Annotation of Gnu-Mach/linux/src/include/asm-i386/atomic.h, revision 1.1

1.1     ! root        1: #ifndef __ARCH_I386_ATOMIC__
        !             2: #define __ARCH_I386_ATOMIC__
        !             3: 
        !             4: /*
        !             5:  * Atomic operations that C can't guarantee us.  Useful for
        !             6:  * resource counting etc..
        !             7:  */
        !             8: 
        !             9: #ifdef __SMP__
        !            10: #define LOCK "lock ; "
        !            11: #else
        !            12: #define LOCK ""
        !            13: #endif
        !            14: 
        !            15: /*
        !            16:  * Make sure gcc doesn't try to be clever and move things around
        !            17:  * on us. We need to use _exactly_ the address the user gave us,
        !            18:  * not some alias that contains the same information.
        !            19:  */
        !            20: #define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
        !            21: 
        !            22: typedef int atomic_t;
        !            23: 
        !            24: static __inline__ void atomic_add(atomic_t i, atomic_t *v)
        !            25: {
        !            26:        __asm__ __volatile__(
        !            27:                LOCK "addl %1,%0"
        !            28:                :"=m" (__atomic_fool_gcc(v))
        !            29:                :"ir" (i), "m" (__atomic_fool_gcc(v)));
        !            30: }
        !            31: 
        !            32: static __inline__ void atomic_sub(atomic_t i, atomic_t *v)
        !            33: {
        !            34:        __asm__ __volatile__(
        !            35:                LOCK "subl %1,%0"
        !            36:                :"=m" (__atomic_fool_gcc(v))
        !            37:                :"ir" (i), "m" (__atomic_fool_gcc(v)));
        !            38: }
        !            39: 
        !            40: static __inline__ void atomic_inc(atomic_t *v)
        !            41: {
        !            42:        __asm__ __volatile__(
        !            43:                LOCK "incl %0"
        !            44:                :"=m" (__atomic_fool_gcc(v))
        !            45:                :"m" (__atomic_fool_gcc(v)));
        !            46: }
        !            47: 
        !            48: static __inline__ void atomic_dec(atomic_t *v)
        !            49: {
        !            50:        __asm__ __volatile__(
        !            51:                LOCK "decl %0"
        !            52:                :"=m" (__atomic_fool_gcc(v))
        !            53:                :"m" (__atomic_fool_gcc(v)));
        !            54: }
        !            55: 
        !            56: static __inline__ int atomic_dec_and_test(atomic_t *v)
        !            57: {
        !            58:        unsigned char c;
        !            59: 
        !            60:        __asm__ __volatile__(
        !            61:                LOCK "decl %0; sete %1"
        !            62:                :"=m" (__atomic_fool_gcc(v)), "=qm" (c)
        !            63:                :"m" (__atomic_fool_gcc(v)));
        !            64:        return c != 0;
        !            65: }
        !            66: 
        !            67: #endif

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