https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115857
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
unsigned hammWeight(unsigned char a)
{
a = ((a & 0xAA) >> 1) + (a & 0x55);
a = ((a & 0xCC) >> 2) + (a & 0x33);
a = ((a & 0xF0) >> 4) + (a & 0x0F);
return a;
}
Could be optimized to just POPCOUNT(a) if you have popcountqi2 optab. Maybe
even just popcount((unsigned int)a) if you have a popcountsi2 optab. And then
could optimize:
popcount(a&0xff) + popcount((a>>8)&0xff)
into popcount (a&0xffff)
etc.
