1#include <linux/export.h>
 2#include <linux/bitops.h>
 3#include <asm/types.h>
 4
 5/**
 6 * hweightN - returns the hamming weight of a N-bit word
 7 * @x: the word to weigh
 8 *
 9 * The Hamming Weight of a number is the total number of bits set in it.
10 */
11
12#ifndef __HAVE_ARCH_SW_HWEIGHT
13unsigned int __sw_hweight32(unsigned int w)
14{
15#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
16	w -= (w >> 1) & 0x55555555;
17	w =  (w & 0x33333333) + ((w >> 2) & 0x33333333);
18	w =  (w + (w >> 4)) & 0x0f0f0f0f;
19	return (w * 0x01010101) >> 24;
20#else
21	unsigned int res = w - ((w >> 1) & 0x55555555);
22	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
23	res = (res + (res >> 4)) & 0x0F0F0F0F;
24	res = res + (res >> 8);
25	return (res + (res >> 16)) & 0x000000FF;
26#endif
27}
28EXPORT_SYMBOL(__sw_hweight32);
29#endif
30
31unsigned int __sw_hweight16(unsigned int w)
32{
33	unsigned int res = w - ((w >> 1) & 0x5555);
34	res = (res & 0x3333) + ((res >> 2) & 0x3333);
35	res = (res + (res >> 4)) & 0x0F0F;
36	return (res + (res >> 8)) & 0x00FF;
37}
38EXPORT_SYMBOL(__sw_hweight16);
39
40unsigned int __sw_hweight8(unsigned int w)
41{
42	unsigned int res = w - ((w >> 1) & 0x55);
43	res = (res & 0x33) + ((res >> 2) & 0x33);
44	return (res + (res >> 4)) & 0x0F;
45}
46EXPORT_SYMBOL(__sw_hweight8);
47
48#ifndef __HAVE_ARCH_SW_HWEIGHT
49unsigned long __sw_hweight64(__u64 w)
50{
51#if BITS_PER_LONG == 32
52	return __sw_hweight32((unsigned int)(w >> 32)) +
53	       __sw_hweight32((unsigned int)w);
54#elif BITS_PER_LONG == 64
55#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
56	w -= (w >> 1) & 0x5555555555555555ul;
57	w =  (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
58	w =  (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
59	return (w * 0x0101010101010101ul) >> 56;
60#else
61	__u64 res = w - ((w >> 1) & 0x5555555555555555ul);
62	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
63	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
64	res = res + (res >> 8);
65	res = res + (res >> 16);
66	return (res + (res >> 32)) & 0x00000000000000FFul;
67#endif
68#endif
69}
70EXPORT_SYMBOL(__sw_hweight64);
71#endif

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/export.h>
 3#include <linux/bitops.h>
 4#include <asm/types.h>
 5
 6/**
 7 * hweightN - returns the hamming weight of a N-bit word
 8 * @x: the word to weigh
 9 *
10 * The Hamming Weight of a number is the total number of bits set in it.
11 */
12
13#ifndef __HAVE_ARCH_SW_HWEIGHT
14unsigned int __sw_hweight32(unsigned int w)
15{
16#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
17	w -= (w >> 1) & 0x55555555;
18	w =  (w & 0x33333333) + ((w >> 2) & 0x33333333);
19	w =  (w + (w >> 4)) & 0x0f0f0f0f;
20	return (w * 0x01010101) >> 24;
21#else
22	unsigned int res = w - ((w >> 1) & 0x55555555);
23	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
24	res = (res + (res >> 4)) & 0x0F0F0F0F;
25	res = res + (res >> 8);
26	return (res + (res >> 16)) & 0x000000FF;
27#endif
28}
29EXPORT_SYMBOL(__sw_hweight32);
30#endif
31
32unsigned int __sw_hweight16(unsigned int w)
33{
34	unsigned int res = w - ((w >> 1) & 0x5555);
35	res = (res & 0x3333) + ((res >> 2) & 0x3333);
36	res = (res + (res >> 4)) & 0x0F0F;
37	return (res + (res >> 8)) & 0x00FF;
38}
39EXPORT_SYMBOL(__sw_hweight16);
40
41unsigned int __sw_hweight8(unsigned int w)
42{
43	unsigned int res = w - ((w >> 1) & 0x55);
44	res = (res & 0x33) + ((res >> 2) & 0x33);
45	return (res + (res >> 4)) & 0x0F;
46}
47EXPORT_SYMBOL(__sw_hweight8);
48
49#ifndef __HAVE_ARCH_SW_HWEIGHT
50unsigned long __sw_hweight64(__u64 w)
51{
52#if BITS_PER_LONG == 32
53	return __sw_hweight32((unsigned int)(w >> 32)) +
54	       __sw_hweight32((unsigned int)w);
55#elif BITS_PER_LONG == 64
56#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
57	w -= (w >> 1) & 0x5555555555555555ul;
58	w =  (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
59	w =  (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
60	return (w * 0x0101010101010101ul) >> 56;
61#else
62	__u64 res = w - ((w >> 1) & 0x5555555555555555ul);
63	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
64	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
65	res = res + (res >> 8);
66	res = res + (res >> 16);
67	return (res + (res >> 32)) & 0x00000000000000FFul;
68#endif
69#endif
70}
71EXPORT_SYMBOL(__sw_hweight64);
72#endif