log: remember to free output buffer when done
[fio.git] / lib / hweight.c
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51aa2da8
JA
1#include "hweight.h"
2
3unsigned int hweight8(uint8_t w)
4{
5 unsigned int res = w - ((w >> 1) & 0x55);
6
7 res = (res & 0x33) + ((res >> 2) & 0x33);
8 return (res + (res >> 4)) & 0x0F;
9}
10
11unsigned int hweight32(uint32_t w)
12{
13 unsigned int res = w - ((w >> 1) & 0x55555555);
14
15 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
16 res = (res + (res >> 4)) & 0x0F0F0F0F;
17 res = res + (res >> 8);
18 return (res + (res >> 16)) & 0x000000FF;
19}
def823d4
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20
21unsigned int hweight64(uint64_t w)
22{
23#if BITS_PER_LONG == 32
24 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
25#else
a240e441
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26 uint64_t res = w - ((w >> 1) & 0x5555555555555555ULL);
27 res = (res & 0x3333333333333333ULL) + ((res >> 2) & 0x3333333333333333ULL);
28 res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
def823d4
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29 res = res + (res >> 8);
30 res = res + (res >> 16);
a240e441 31 return (res + (res >> 32)) & 0x00000000000000FFULL;
def823d4
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32#endif
33}