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
|
#ifndef BITMAP_H_
#define BITMAP_H_
#include <stdint.h>
#include <string.h>
typedef uint8_t bm_base_type_t;
/* Define a large bit map. */
#define DEFINE_BITMAP(name, nr_bits) bm_base_type_t name[(nr_bits) / 8]
/* Efficiently convert a bit number to the corresponding bit map.
* Resolves at compile-time, if bitnr is a compile-time constant.
* Uses an efficient table lookup otherwise.
*/
extern const uint8_t _bit_to_mask8[8];
#define BITMASK8(bitnr) ( \
(uint8_t)(__builtin_constant_p(bitnr) ? \
(1u << (bitnr)) : \
_bit_to_mask8[(bitnr)]) \
)
/* Get a bit from a large bit map.
* Return: The return value is either 0 or non-zero depending on whether
* the bit is 0 or 1.
*/
static inline uint8_t bm_get_bit(const bm_base_type_t *bm, uint8_t bit_number)
{
uint8_t byte_number = bit_number >> 3;
bit_number = bit_number & 7u;
return (uint8_t)(bm[byte_number] & BITMASK8(bit_number));
}
/* Get a bit from a large bit map.
* Return: The return value is either 0 or 1 depending on whether
* the bit is 0 or 1.
*/
static inline uint8_t bm_get_bool(const bm_base_type_t *bm, uint8_t bit_number)
{
return !!bm_get_bit(bm, bit_number);
}
/* Set a bit in a large bit map. */
static inline void bm_set_bit(bm_base_type_t *bm, uint8_t bit_number)
{
uint8_t byte_number = bit_number >> 3;
bit_number = bit_number & 7u;
bm[byte_number] = (bm_base_type_t)(bm[byte_number] | BITMASK8(bit_number));
}
/* Clear a bit in a large bit map. */
static inline void bm_clear_bit(bm_base_type_t *bm, uint8_t bit_number)
{
uint8_t byte_number = bit_number >> 3;
bit_number = bit_number & 7u;
bm[byte_number] = (bm_base_type_t)(bm[byte_number] & ~BITMASK8(bit_number));
}
/* Write a bit in a large bit map. */
static inline void bm_write_bit(bm_base_type_t *bm,
uint8_t bit_number, uint8_t bit_value)
{
if (bit_value)
bm_set_bit(bm, bit_number);
else
bm_clear_bit(bm, bit_number);
}
/* Initialize all bits in the bit map. */
#define bm_init(bm, all_set) _bm_init(bm, sizeof(bm), all_set)
static inline void _bm_init(bm_base_type_t *bm, uint8_t bm_size,
uint8_t all_set)
{
memset(bm, all_set ? 0xFF : 0, bm_size);
}
#endif /* BITMAP_H_ */
|
