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#ifdef __GNUC__
/*
* These atomic operations copied from the linux kernel and altered
* only slightly. I need to get official permission to distribute
* under the Artistic License.
*/
/* We really need to integrate the atomic typedef with the typedef
* used by sv_refcnt of an SV. It's possible that for CPUs like alpha
* where we'd need to up sv_refcnt from 32 to 64 bits, we may be better
* off sticking with EMULATE_ATOMIC_REFCOUNTS instead.
*/
typedef U32 atomic_t; /* kludge */
#ifdef i386
# ifdef NO_SMP
# define LOCK ""
# else
# define LOCK "lock ; "
# endif
# define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
static __inline__ void atomic_inc(atomic_t *v)
{
__asm__ __volatile__(
LOCK "incl %0"
:"=m" (__atomic_fool_gcc(v))
:"m" (__atomic_fool_gcc(v)));
}
static __inline__ int atomic_dec_and_test(atomic_t *v)
{
unsigned char c;
__asm__ __volatile__(
LOCK "decl %0; sete %1"
:"=m" (__atomic_fool_gcc(v)), "=qm" (c)
:"m" (__atomic_fool_gcc(v)));
return c != 0;
}
# else
/* XXX What symbol does gcc define for sparc64? */
# ifdef sparc64
# define __atomic_fool_gcc(x) ((struct { int a[100]; } *)x)
typedef U32 atomic_t;
extern __inline__ void atomic_add(int i, atomic_t *v)
{
__asm__ __volatile__("
1: lduw [%1], %%g5
add %%g5, %0, %%g7
cas [%1], %%g5, %%g7
sub %%g5, %%g7, %%g5
brnz,pn %%g5, 1b
nop"
: /* No outputs */
: "HIr" (i), "r" (__atomic_fool_gcc(v))
: "g5", "g7", "memory");
}
extern __inline__ int atomic_sub_return(int i, atomic_t *v)
{
unsigned long oldval;
__asm__ __volatile__("
1: lduw [%2], %%g5
sub %%g5, %1, %%g7
cas [%2], %%g5, %%g7
sub %%g5, %%g7, %%g5
brnz,pn %%g5, 1b
sub %%g7, %1, %0"
: "=&r" (oldval)
: "HIr" (i), "r" (__atomic_fool_gcc(v))
: "g5", "g7", "memory");
return (int)oldval;
}
#define atomic_inc(v) atomic_add(1,(v))
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
/* Add further gcc architectures here */
# else
# define EMULATE_ATOMIC_REFCOUNTS
# endif /* sparc64 */
#endif /* i386 */
#else
/* Add non-gcc native atomic operations here */
# define EMULATE_ATOMIC_REFCOUNTS
#endif
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