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
 
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
30unsigned int __sw_hweight16(unsigned int w)
31{
32	unsigned int res = w - ((w >> 1) & 0x5555);
33	res = (res & 0x3333) + ((res >> 2) & 0x3333);
34	res = (res + (res >> 4)) & 0x0F0F;
35	return (res + (res >> 8)) & 0x00FF;
36}
37EXPORT_SYMBOL(__sw_hweight16);
38
39unsigned int __sw_hweight8(unsigned int w)
40{
41	unsigned int res = w - ((w >> 1) & 0x55);
42	res = (res & 0x33) + ((res >> 2) & 0x33);
43	return (res + (res >> 4)) & 0x0F;
44}
45EXPORT_SYMBOL(__sw_hweight8);
46
 
47unsigned long __sw_hweight64(__u64 w)
48{
49#if BITS_PER_LONG == 32
50	return __sw_hweight32((unsigned int)(w >> 32)) +
51	       __sw_hweight32((unsigned int)w);
52#elif BITS_PER_LONG == 64
53#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
54	w -= (w >> 1) & 0x5555555555555555ul;
55	w =  (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
56	w =  (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
57	return (w * 0x0101010101010101ul) >> 56;
58#else
59	__u64 res = w - ((w >> 1) & 0x5555555555555555ul);
60	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
61	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
62	res = res + (res >> 8);
63	res = res + (res >> 16);
64	return (res + (res >> 32)) & 0x00000000000000FFul;
65#endif
66#endif
67}
68EXPORT_SYMBOL(__sw_hweight64);

 
 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