882     "

   883 !

   884 

   885 bitCount

   886     "return the number of 1-bits in the receiver"

   887 

   888 %{  /* NOCONTEXT */

   889     int _cnt = 0;

   890     int _self = __intVal(self);

   891     //                  0  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15

   892     int _counts[16] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };

   893 

   894     _cnt = _counts[_self & 0xF]; _self = _self>>4;         // ______xx

   895     _cnt += _counts[_self & 0xF]; _self = _self>>4;

   896     if (_self != 0) {

   897         _cnt += _counts[_self & 0xF]; _self = _self>>4;     // xxxxxx__ 

   898         _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   899         _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   900         _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   901         _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   902         _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   903 # if __POINTER_SIZE__ == 8

   904         if (_self != 0) {

   905             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   906             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   907             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   908             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   909             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   910             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   911             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   912             _cnt += _counts[_self & 0xF]; _self = _self>>4;      

   913         }

   914 # endif

   915     }

   916 

   917     RETURN ( __MKSMALLINT(_cnt));

   918 %}

   919 

   920     "

   921      1 to:10000 do:[:n |

   922         self assert:(n bitCount = ((n printStringRadix:2) occurrencesOf:$1))

   923      ]