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| | #define a_barrier a_barrier
static inline void a_barrier()
{
__asm__ __volatile__ ("fence rw,rw" : : : "memory");
}
#ifdef __riscv_zacas
#define a_cas a_cas
static inline int a_cas(volatile int *p, int t, int s)
{
int old = t;
__asm__ __volatile__ (
"amocas.w.aqrl %0, %2, %1"
: "+r"(old), "+A"(*(volatile int *)p)
: "r"(s)
: "memory");
return old;
}
#else /* Fallback to lr/sc when Zacas is not available */
#define a_cas a_cas
static inline int a_cas(volatile int *p, int t, int s)
{
int old, tmp;
__asm__ __volatile__ (
"\n1: lr.w.aqrl %0, (%2)\n"
" bne %0, %3, 1f\n"
" sc.w.aqrl %1, %4, (%2)\n"
" bnez %1, 1b\n"
"1:"
: "=&r"(old), "=&r"(tmp)
: "r"(p), "r"((long)t), "r"((long)s)
: "memory");
return old;
}
#endif /* __riscv_zacas */
|