xref: /haiku/src/system/libroot/posix/musl/internal/atomic.h (revision e1c4049fed1047bdb957b0529e1921e97ef94770)
1 #ifndef _ATOMIC_H
2 #define _ATOMIC_H
3 
4 #include <stdint.h>
5 
6 #include "atomic_arch.h"
7 
8 #ifndef a_crash
9 #define a_crash a_crash
10 static inline void a_crash()
11 {
12 	*(volatile char *)0=0;
13 }
14 #endif
15 
16 #ifndef a_ctz_32
17 #define a_ctz_32 a_ctz_32
18 static inline int a_ctz_32(uint32_t x)
19 {
20 #ifdef a_clz_32
21 	return 31-a_clz_32(x&-x);
22 #else
23 	static const char debruijn32[32] = {
24 		0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
25 		31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
26 	};
27 	return debruijn32[(x&-x)*0x076be629 >> 27];
28 #endif
29 }
30 #endif
31 
32 #ifndef a_ctz_64
33 #define a_ctz_64 a_ctz_64
34 static inline int a_ctz_64(uint64_t x)
35 {
36 	static const char debruijn64[64] = {
37 		0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
38 		62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
39 		63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
40 		51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
41 	};
42 	if (sizeof(long) < 8) {
43 		uint32_t y = x;
44 		if (!y) {
45 			y = x>>32;
46 			return 32 + a_ctz_32(y);
47 		}
48 		return a_ctz_32(y);
49 	}
50 	return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58];
51 }
52 #endif
53 
54 static inline int a_ctz_l(unsigned long x)
55 {
56 	return (sizeof(long) < 8) ? a_ctz_32(x) : a_ctz_64(x);
57 }
58 
59 #ifndef a_clz_64
60 #define a_clz_64 a_clz_64
61 static inline int a_clz_64(uint64_t x)
62 {
63 #ifdef a_clz_32
64 	if (x>>32)
65 		return a_clz_32(x>>32);
66 	return a_clz_32(x) + 32;
67 #else
68 	uint32_t y;
69 	int r;
70 	if (x>>32) y=x>>32, r=0; else y=x, r=32;
71 	if (y>>16) y>>=16; else r |= 16;
72 	if (y>>8) y>>=8; else r |= 8;
73 	if (y>>4) y>>=4; else r |= 4;
74 	if (y>>2) y>>=2; else r |= 2;
75 	return r | !(y>>1);
76 #endif
77 }
78 #endif
79 
80 #ifndef a_clz_32
81 #define a_clz_32 a_clz_32
82 static inline int a_clz_32(uint32_t x)
83 {
84 	x >>= 1;
85 	x |= x >> 1;
86 	x |= x >> 2;
87 	x |= x >> 4;
88 	x |= x >> 8;
89 	x |= x >> 16;
90 	x++;
91 	return 31-a_ctz_32(x);
92 }
93 #endif
94 
95 #endif
96