#include <linux/module.h>#include <asm/types.h> /** * hweightN - returns the hamming weight of a N-bit word * @x: the word to weigh * * The Hamming Weight of a number is the total number of bits set in it. */ unsigned int hweight32(unsigned int w){	unsigned int res = w - ((w >> 1) & 0x55555555);	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);	res = (res + (res >> 4)) & 0x0F0F0F0F;	res = res + (res >> 8);	return (res + (res >> 16)) & 0x000000FF;}EXPORT_SYMBOL(hweight32); unsigned int hweight16(unsigned int w){	unsigned int res = w - ((w >> 1) & 0x5555);	res = (res & 0x3333) + ((res >> 2) & 0x3333);	res = (res + (res >> 4)) & 0x0F0F;	return (res + (res >> 8)) & 0x00FF;}EXPORT_SYMBOL(hweight16); unsigned int hweight8(unsigned int w){	unsigned int res = w - ((w >> 1) & 0x55);	res = (res & 0x33) + ((res >> 2) & 0x33);	return (res + (res >> 4)) & 0x0F;}EXPORT_SYMBOL(hweight8); unsigned long hweight64(__u64 w){#if BITS_PER_LONG == 32	return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);#elif BITS_PER_LONG == 64	__u64 res = w - ((w >> 1) & 0x5555555555555555ul);	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;	res = res + (res >> 8);	res = res + (res >> 16);	return (res + (res >> 32)) & 0x00000000000000FFul;#else#error BITS_PER_LONG not defined#endif}EXPORT_SYMBOL(hweight64);