hweight.c revision 51aa2da8cf422a06ddfa1ce673f3bfc03f96b86e
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} 20