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#include <stdbool.h>
#include <stdint.h>
#include "test.h"
typedef uint32_t uint32;
typedef struct {
volatile uint32_t value;
} pg_atomic_uint32;
static inline bool
pg_atomic_compare_exchange_u32_impl(volatile pg_atomic_uint32 *ptr,
uint32 *expected, uint32 newval)
{
char ret;
/*
* Perform cmpxchg and use the zero flag which it implicitly sets when
* equal to measure the success.
*/
__asm__ __volatile__(
" lock \n"
" cmpxchgl %4,%5 \n"
" setz %2 \n"
: "=a" (*expected), "=m"(ptr->value), "=q" (ret)
: "a" (*expected), "r" (newval), "m"(ptr->value)
: "memory", "cc");
ASSERT(1, ret);
return (bool) ret;
}
int main() {
pg_atomic_uint32 atomic_var = {0};
uint32_t expected = 0;
uint32_t newval = 1;
if (pg_atomic_compare_exchange_u32_impl(&atomic_var, &expected, newval)) {
printf("Exchange succeeded\n");
} else {
printf("Exchange failed\n");
}
return 0;
}
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