Commit | Line | Data |
---|---|---|
8bc3bcc9 | 1 | #include <linux/export.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 | ||
fd5df2a4 | 12 | #ifndef __HAVE_ARCH_SW_HWEIGHT |
d61931d8 | 13 | unsigned int __sw_hweight32(unsigned int w) |
3b9ed1a5 | 14 | { |
72d93104 | 15 | #ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER |
39d997b5 AM |
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 | |
f9b41929 | 21 | unsigned int res = w - ((w >> 1) & 0x55555555); |
3b9ed1a5 | 22 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
f9b41929 AM |
23 | res = (res + (res >> 4)) & 0x0F0F0F0F; |
24 | res = res + (res >> 8); | |
25 | return (res + (res >> 16)) & 0x000000FF; | |
39d997b5 | 26 | #endif |
3b9ed1a5 | 27 | } |
d61931d8 | 28 | EXPORT_SYMBOL(__sw_hweight32); |
fd5df2a4 | 29 | #endif |
3b9ed1a5 | 30 | |
d61931d8 | 31 | unsigned int __sw_hweight16(unsigned int w) |
3b9ed1a5 | 32 | { |
f9b41929 | 33 | unsigned int res = w - ((w >> 1) & 0x5555); |
3b9ed1a5 | 34 | res = (res & 0x3333) + ((res >> 2) & 0x3333); |
f9b41929 AM |
35 | res = (res + (res >> 4)) & 0x0F0F; |
36 | return (res + (res >> 8)) & 0x00FF; | |
3b9ed1a5 | 37 | } |
d61931d8 | 38 | EXPORT_SYMBOL(__sw_hweight16); |
3b9ed1a5 | 39 | |
d61931d8 | 40 | unsigned int __sw_hweight8(unsigned int w) |
3b9ed1a5 | 41 | { |
f9b41929 | 42 | unsigned int res = w - ((w >> 1) & 0x55); |
3b9ed1a5 | 43 | res = (res & 0x33) + ((res >> 2) & 0x33); |
f9b41929 | 44 | return (res + (res >> 4)) & 0x0F; |
3b9ed1a5 | 45 | } |
d61931d8 | 46 | EXPORT_SYMBOL(__sw_hweight8); |
3b9ed1a5 | 47 | |
fd5df2a4 | 48 | #ifndef __HAVE_ARCH_SW_HWEIGHT |
d61931d8 | 49 | unsigned long __sw_hweight64(__u64 w) |
3b9ed1a5 AM |
50 | { |
51 | #if BITS_PER_LONG == 32 | |
d61931d8 BP |
52 | return __sw_hweight32((unsigned int)(w >> 32)) + |
53 | __sw_hweight32((unsigned int)w); | |
3b9ed1a5 | 54 | #elif BITS_PER_LONG == 64 |
72d93104 | 55 | #ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER |
0136611c AK |
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 | |
f9b41929 | 61 | __u64 res = w - ((w >> 1) & 0x5555555555555555ul); |
3b9ed1a5 | 62 | res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); |
f9b41929 AM |
63 | res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful; |
64 | res = res + (res >> 8); | |
65 | res = res + (res >> 16); | |
66 | return (res + (res >> 32)) & 0x00000000000000FFul; | |
0136611c | 67 | #endif |
3b9ed1a5 AM |
68 | #endif |
69 | } | |
d61931d8 | 70 | EXPORT_SYMBOL(__sw_hweight64); |
fd5df2a4 | 71 | #endif |