Number of bits set

From Teknologisk videncenter
Revision as of 07:00, 24 February 2012 by Heth (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

C programming

The following function returns number of bits set i

int NumberOfSetBits32(int i)
{
    i = i - ((i >> 1) & 0x55555555);
    i = (i & 0x33333333) + ((i >> 2) & 0x33333333);
    return (((i + (i >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
}