1 /* ANDROID_CHANGE_BEGIN */ 2 #if 0 3 #include <linux/bitops.h> 4 #else 5 #include "include/linux/bitops.h" 6 #endif 7 /* ANDROID_CHANGE_END */ 8 9 /** 10 * hweightN - returns the hamming weight of a N-bit word 11 * @x: the word to weigh 12 * 13 * The Hamming Weight of a number is the total number of bits set in it. 14 */ 15 16 unsigned int hweight32(unsigned int w) 17 { 18 unsigned int res = w - ((w >> 1) & 0x55555555); 19 res = (res & 0x33333333) + ((res >> 2) & 0x33333333); 20 res = (res + (res >> 4)) & 0x0F0F0F0F; 21 res = res + (res >> 8); 22 return (res + (res >> 16)) & 0x000000FF; 23 } 24 25 unsigned long hweight64(__u64 w) 26 { 27 #if BITS_PER_LONG == 32 28 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); 29 #elif BITS_PER_LONG == 64 30 __u64 res = w - ((w >> 1) & 0x5555555555555555ul); 31 res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); 32 res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful; 33 res = res + (res >> 8); 34 res = res + (res >> 16); 35 return (res + (res >> 32)) & 0x00000000000000FFul; 36 #endif 37 } 38
