1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
static inline int
atomic·ll(volatile int *p)
{
int v;
__asm__ __volatile__ ("ldaxr %w0,%1" : "=r"(v) : "Q"(*p));
return v;
}
static inline int
atomic·sc(volatile int *p, int v)
{
int r;
__asm__ __volatile__ ("stlxr %w0,%w2,%1" : "=&r"(r), "=Q"(*p) : "r"(v) : "memory");
return !r;
}
static inline void
atomic·barrier()
{
__asm__ __volatile__ ("dmb ish" : : : "memory");
}
static inline int
atomic·cas(volatile int *p, int t, int s)
{
int old;
do{
old = atomic·ll(p);
if(old != t){
atomic·barrier();
break;
}
}while(!atomic·sc(p, s));
return old;
}
static inline void
*atomic·llp(volatile void *p)
{
void *v;
__asm__ __volatile__ ("ldaxr %0, %1" : "=r"(v) : "Q"(*(void *volatile *)p));
return v;
}
static inline int
atomic·scp(volatile int *p, void *v)
{
int r;
__asm__ __volatile__ ("stlxr %w0,%2,%1" : "=&r"(r), "=Q"(*(void *volatile *)p) : "r"(v) : "memory");
return !r;
}
static inline void
*atomic·casp(volatile void *p, void *t, void *s)
{
void *old;
do{
old = atomic·llp(p);
if(old != t){
atomic·barrier();
break;
}
}while(!atomic·scp(p, s));
return old;
}
static inline int
atomic·ctz64(uint64 x)
{
__asm__(
" rbit %0, %1\n"
" clz %0, %0\n"
: "=r"(x) : "r"(x));
return x;
}
static inline int
atomic·clz64(uint64 x)
{
__asm__("clz %0, %1" : "=r"(x) : "r"(x));
return x;
}
|
