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Merge branch 'sh/pm-runtime' into sh-latest
[mirror_ubuntu-bionic-kernel.git] / lib / hweight.c
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3b9ed1a5 1#include <linux/module.h>
1977f032 2#include <linux/bitops.h>
3b9ed1a5
AM
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
d61931d8 12unsigned int __sw_hweight32(unsigned int w)
3b9ed1a5 13{
39d997b5
AM
14#ifdef ARCH_HAS_FAST_MULTIPLIER
15 w -= (w >> 1) & 0x55555555;
16 w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
17 w = (w + (w >> 4)) & 0x0f0f0f0f;
18 return (w * 0x01010101) >> 24;
19#else
f9b41929 20 unsigned int res = w - ((w >> 1) & 0x55555555);
3b9ed1a5 21 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
f9b41929
AM
22 res = (res + (res >> 4)) & 0x0F0F0F0F;
23 res = res + (res >> 8);
24 return (res + (res >> 16)) & 0x000000FF;
39d997b5 25#endif
3b9ed1a5 26}
d61931d8 27EXPORT_SYMBOL(__sw_hweight32);
3b9ed1a5 28
d61931d8 29unsigned int __sw_hweight16(unsigned int w)
3b9ed1a5 30{
f9b41929 31 unsigned int res = w - ((w >> 1) & 0x5555);
3b9ed1a5 32 res = (res & 0x3333) + ((res >> 2) & 0x3333);
f9b41929
AM
33 res = (res + (res >> 4)) & 0x0F0F;
34 return (res + (res >> 8)) & 0x00FF;
3b9ed1a5 35}
d61931d8 36EXPORT_SYMBOL(__sw_hweight16);
3b9ed1a5 37
d61931d8 38unsigned int __sw_hweight8(unsigned int w)
3b9ed1a5 39{
f9b41929 40 unsigned int res = w - ((w >> 1) & 0x55);
3b9ed1a5 41 res = (res & 0x33) + ((res >> 2) & 0x33);
f9b41929 42 return (res + (res >> 4)) & 0x0F;
3b9ed1a5 43}
d61931d8 44EXPORT_SYMBOL(__sw_hweight8);
3b9ed1a5 45
d61931d8 46unsigned long __sw_hweight64(__u64 w)
3b9ed1a5
AM
47{
48#if BITS_PER_LONG == 32
d61931d8
BP
49 return __sw_hweight32((unsigned int)(w >> 32)) +
50 __sw_hweight32((unsigned int)w);
3b9ed1a5 51#elif BITS_PER_LONG == 64
0136611c
AK
52#ifdef ARCH_HAS_FAST_MULTIPLIER
53 w -= (w >> 1) & 0x5555555555555555ul;
54 w = (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
55 w = (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
56 return (w * 0x0101010101010101ul) >> 56;
57#else
f9b41929 58 __u64 res = w - ((w >> 1) & 0x5555555555555555ul);
3b9ed1a5 59 res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
f9b41929
AM
60 res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
61 res = res + (res >> 8);
62 res = res + (res >> 16);
63 return (res + (res >> 32)) & 0x00000000000000FFul;
0136611c 64#endif
3b9ed1a5
AM
65#endif
66}
d61931d8 67EXPORT_SYMBOL(__sw_hweight64);