github.com/afumu/libc@v0.0.6/musl/arch/or1k/atomic_arch.h (about)

     1  #define a_cas a_cas
     2  static inline int a_cas(volatile int *p, int t, int s)
     3  {
     4  	__asm__("1:	l.lwa %0, %1\n"
     5  		"	l.sfeq %0, %2\n"
     6  		"	l.bnf 1f\n"
     7  		"	 l.nop\n"
     8  		"	l.swa %1, %3\n"
     9  		"	l.bnf 1b\n"
    10  		"	 l.nop\n"
    11  		"1:	\n"
    12  		: "=&r"(t), "+m"(*p) : "r"(t), "r"(s) : "cc", "memory" );
    13          return t;
    14  }