1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
3#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
4
5/*
6 * Compile time versions of __arch_hweightN()
7 */
8#define __const_hweight8(w) \
9 ((unsigned int) \
10 ((!!((w) & (1ULL << 0))) + \
11 (!!((w) & (1ULL << 1))) + \
12 (!!((w) & (1ULL << 2))) + \
13 (!!((w) & (1ULL << 3))) + \
14 (!!((w) & (1ULL << 4))) + \
15 (!!((w) & (1ULL << 5))) + \
16 (!!((w) & (1ULL << 6))) + \
17 (!!((w) & (1ULL << 7)))))
18
19#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 ))
20#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
21#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32))
22
23/*
24 * Generic interface.
25 */
26#define hweight8(w) (__builtin_constant_p(w) ? __const_hweight8(w) : __arch_hweight8(w))
27#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w))
28#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w))
29#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
30
31/*
32 * Interface for known constant arguments
33 */
34#define HWEIGHT8(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w))
35#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w))
36#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w))
37#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w))
38
39/*
40 * Type invariant interface to the compile time constant hweight functions.
41 */
42#define HWEIGHT(w) HWEIGHT64((u64)w)
43
44#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */
45