1 /*
2 * Copyright (c) 2023 Nordic Semiconductor ASA
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #ifndef NSI_COMMON_SRC_NSI_INTERNAL_H
8 #define NSI_COMMON_SRC_NSI_INTERNAL_H
9
10 #include <stdint.h>
11
12 #ifdef __cplusplus
13 extern "C" {
14 #endif
15
16 /**
17 * @brief find least significant bit set in a 32-bit word
18 *
19 * This routine finds the first bit set starting from the least significant bit
20 * in the argument passed in and returns the index of that bit. Bits are
21 * numbered starting at 1 from the least significant bit. A return value of
22 * zero indicates that the value passed is zero.
23 *
24 * @return least significant bit set, 0 if @a op is 0
25 */
26
nsi_find_lsb_set(uint32_t op)27 static inline unsigned int nsi_find_lsb_set(uint32_t op)
28 {
29 return __builtin_ffs(op);
30 }
31
32 /**
33 * @brief find least significant bit set in a 64-bit word
34 *
35 * This routine finds the first bit set starting from the least significant bit
36 * in the argument passed in and returns the index of that bit. Bits are
37 * numbered starting at 1 from the least significant bit. A return value of
38 * zero indicates that the value passed is zero.
39 *
40 * @return least significant bit set, 0 if @a op is 0
41 */
42
nsi_find_lsb_set64(uint64_t op)43 static inline unsigned int nsi_find_lsb_set64(uint64_t op)
44 {
45 return __builtin_ffsll(op);
46 }
47
48 #ifdef __cplusplus
49 }
50 #endif
51
52 #endif /* NSI_COMMON_SRC_NSI_INTERNAL_H */
53
