mirror of
git://git.musl-libc.org/musl
synced 2024-12-23 23:23:12 +00:00
e7257d3e63
previous version did not compare at all; it was just a fancy atomic write. untested. further atomic fixes may be needed.
118 lines
2.0 KiB
C
118 lines
2.0 KiB
C
#ifndef _INTERNAL_ATOMIC_H
|
|
#define _INTERNAL_ATOMIC_H
|
|
|
|
#include <stdint.h>
|
|
#include <endian.h>
|
|
|
|
static inline int a_ctz_l(unsigned long x)
|
|
{
|
|
static const char debruijn32[32] = {
|
|
0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
|
|
31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
|
|
};
|
|
return debruijn32[(x&-x)*0x076be629 >> 27];
|
|
}
|
|
|
|
static inline int a_ctz_64(uint64_t x)
|
|
{
|
|
uint32_t y = x;
|
|
if (!y) {
|
|
y = x>>32;
|
|
return 32 + a_ctz_l(y);
|
|
}
|
|
return a_ctz_l(y);
|
|
}
|
|
|
|
static inline int a_cas(volatile int *p, int t, int s)
|
|
{
|
|
__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;
|
|
}
|
|
|
|
static inline void *a_cas_p(volatile void *p, void *t, void *s)
|
|
{
|
|
return (void *)a_cas(p, (int)t, (int)s);
|
|
}
|
|
|
|
static inline long a_cas_l(volatile void *p, long t, long s)
|
|
{
|
|
return a_cas(p, t, s);
|
|
}
|
|
|
|
|
|
static inline int a_swap(volatile int *x, int v)
|
|
{
|
|
int old;
|
|
do old = *x;
|
|
while (a_cas(x, old, v) != old);
|
|
return old;
|
|
}
|
|
|
|
static inline int a_fetch_add(volatile int *x, int v)
|
|
{
|
|
int old;
|
|
do old = *x;
|
|
while (a_cas(x, old, old+v) != old);
|
|
return old;
|
|
}
|
|
|
|
static inline void a_inc(volatile int *x)
|
|
{
|
|
a_fetch_add(x, 1);
|
|
}
|
|
|
|
static inline void a_dec(volatile int *x)
|
|
{
|
|
a_fetch_add(x, -1);
|
|
}
|
|
|
|
static inline void a_store(volatile int *p, int x)
|
|
{
|
|
*p=x;
|
|
}
|
|
|
|
static inline void a_spin()
|
|
{
|
|
}
|
|
|
|
static inline void a_crash()
|
|
{
|
|
*(volatile char *)0=0;
|
|
}
|
|
|
|
static inline void a_and(volatile int *p, int v)
|
|
{
|
|
int old;
|
|
do old = *p;
|
|
while (a_cas(p, old, old&v) != old);
|
|
}
|
|
|
|
static inline void a_or(volatile int *p, int v)
|
|
{
|
|
int old;
|
|
do old = *p;
|
|
while (a_cas(p, old, old|v) != old);
|
|
}
|
|
|
|
static inline void a_and_64(volatile uint64_t *p, uint64_t v)
|
|
{
|
|
union { uint64_t v; uint32_t r[2]; } u = { v };
|
|
a_and((int *)p, u.r[0]);
|
|
a_and((int *)p+1, u.r[1]);
|
|
}
|
|
|
|
static inline void a_or_64(volatile uint64_t *p, uint64_t v)
|
|
{
|
|
union { uint64_t v; uint32_t r[2]; } u = { v };
|
|
a_or((int *)p, u.r[0]);
|
|
a_or((int *)p+1, u.r[1]);
|
|
}
|
|
|
|
#endif
|