[fio.git] / lib / hweight.c

#include "hweight.h"

unsigned int hweight8(uint8_t w)
{
	unsigned int res = w - ((w >> 1) & 0x55);

	res = (res & 0x33) + ((res >> 2) & 0x33);
	return (res + (res >> 4)) & 0x0F;
}

unsigned int hweight32(uint32_t 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;
}
Commit	Line	Data
51aa2da8 JA	1	#include "hweight.h"
	2
	3	unsigned 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
	11	unsigned 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	}