#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 */