fix powerpc atomic compare-and-swap function

previous version did not compare at all; it was just a fancy atomic
write. untested. further atomic fixes may be needed.
This commit is contained in:
Rich Felker 2012-11-14 14:24:22 -05:00
parent 574d01a696
commit e7257d3e63

View File

@ -25,12 +25,13 @@ static inline int a_ctz_64(uint64_t x)
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;
}