mirror of
git://git.musl-libc.org/musl
synced 2024-12-24 23:52:48 +00:00
fd224a800b
at present this is done only for consistency, since this file defines
its own a_cas_p rather than using the new generic one from atomic.h
added in commit 225f6a6b5b. these
definitions may however be useful if we ever need to add other
pointer-sized atomic operations.
76 lines
1.3 KiB
C
76 lines
1.3 KiB
C
#define a_ll a_ll
|
|
static inline int a_ll(volatile int *p)
|
|
{
|
|
int v;
|
|
__asm__ __volatile__ ("ldaxr %w0,%1" : "=r"(v) : "Q"(*p));
|
|
return v;
|
|
}
|
|
|
|
#define a_sc a_sc
|
|
static inline int a_sc(volatile int *p, int v)
|
|
{
|
|
int r;
|
|
__asm__ __volatile__ ("stlxr %w0,%w2,%1" : "=&r"(r), "=Q"(*p) : "r"(v) : "memory");
|
|
return !r;
|
|
}
|
|
|
|
#define a_barrier a_barrier
|
|
static inline void a_barrier()
|
|
{
|
|
__asm__ __volatile__ ("dmb ish" : : : "memory");
|
|
}
|
|
|
|
#define a_cas a_cas
|
|
static inline int a_cas(volatile int *p, int t, int s)
|
|
{
|
|
int old;
|
|
do {
|
|
old = a_ll(p);
|
|
if (old != t) {
|
|
a_barrier();
|
|
break;
|
|
}
|
|
} while (!a_sc(p, s));
|
|
return old;
|
|
}
|
|
|
|
#define a_ll_p a_ll_p
|
|
static inline void *a_ll_p(volatile void *p)
|
|
{
|
|
void *v;
|
|
__asm__ __volatile__ ("ldaxr %0, %1" : "=r"(v) : "Q"(*(void *volatile *)p));
|
|
return v;
|
|
}
|
|
|
|
#define a_sc_p a_sc_p
|
|
static inline int a_sc_p(volatile int *p, void *v)
|
|
{
|
|
int r;
|
|
__asm__ __volatile__ ("stlxr %w0,%2,%1" : "=&r"(r), "=Q"(*(void *volatile *)p) : "r"(v) : "memory");
|
|
return !r;
|
|
}
|
|
|
|
#define a_cas_p a_cas_p
|
|
static inline void *a_cas_p(volatile void *p, void *t, void *s)
|
|
{
|
|
void *old;
|
|
do {
|
|
old = a_ll_p(p);
|
|
if (old != t) {
|
|
a_barrier();
|
|
break;
|
|
}
|
|
} while (!a_sc_p(p, s));
|
|
return old;
|
|
}
|
|
|
|
#define a_ctz_64 a_ctz_64
|
|
static inline int a_ctz_64(uint64_t x)
|
|
{
|
|
__asm__(
|
|
" rbit %0, %1\n"
|
|
" clz %0, %0\n"
|
|
: "=r"(x) : "r"(x));
|
|
return x;
|
|
}
|