previous version did not compare at all; it was just a fancy atomic
write. untested. further atomic fixes may be needed.
static inline int a_cas(volatile int *p, int t, int s)
{
-
- __asm__( "1: lwarx 10, 0, %1\n"
- " stwcx. %3, 0, %1\n"
- " bne- 1b\n"
- " mr %0, 10\n"
- : "=r"(t) : "r"(p), "r"(t), "r"(s) : "memory" );
+ __asm__("1: lwarx %0, 0, %1\n"
+ " cmpw %0, %2\n"
+ " bne 1f\n"
+ " stwcx. %3, 0, %1\n"
+ " bne- 1b\n"
+ "1: \n"
+ : "=&r"(t) : "r"(p), "r"(t), "r"(s) : "cc", "memory" );
return t;
}