2 * Sherlock Library -- Binary Logarithm
4 * (c) 1997 Martin Mares, <mj@atrey.karlin.mff.cuni.cz>
20 if (x & 0xffff0000) l += 16;
21 if (x & 0xff00ff00) l += 8;
22 if (x & 0xf0f0f0f0) l += 4;
23 if (x & 0xcccccccc) l += 2;
24 if (x & 0xaaaaaaaa) l++;