Message ID | 1420885981-136302-1-git-send-email-waterman@cs.berkeley.edu |
---|---|
State | New |
Headers | show |
diff --git a/libatomic/fop_n.c b/libatomic/fop_n.c index 307184d..c2556eb 100644 --- a/libatomic/fop_n.c +++ b/libatomic/fop_n.c @@ -112,9 +112,9 @@ SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel) pre_barrier (smodel); - wptr = (UWORD *)mptr; - shift = 0; - mask = -1; + wptr = (UWORD *)((uintptr_t)mptr & -WORDSIZE); + shift = (((uintptr_t)mptr % WORDSIZE) * CHAR_BIT) ^ SIZE(INVERT_MASK); + mask = SIZE(MASK) << shift; wopval = (UWORD)opval << shift; woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED);